Method for driving an electro-optic display

Abstract

A method of driving an electro-optic display having a plurality of display pixels is described. The method includes updating the electro-optic display with a first image including image data from a first portion of scrollable content. The method also includes receiving user input having one or more parameters and generating a second image based on at least one parameter of the user input. The second image includes a portion of image data from the first portion of the scrollable content and image data from a second portion of the scrollable content. The method also includes updating the electro-optic display with the second image.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Application No. 63 / 419,330, filed October 25, 2022, the entire contents of which are incorporated herein by reference. Additionally, the entire contents of any patents, published applications, or other published works referenced herein are incorporated by reference in their entirety.

[0002] FIELD OF THE INVENTION The present invention relates to a method of driving an electro-optic display, in particular a bistable electro-optic display, and to an apparatus for use in such a method. More particularly, the invention relates to a driving method which allows reduced "afterglow" and edge effects and reduced flashing in such displays. [Background technology]

[0003] Electro-optic displays typically have a backplane provided with a plurality of pixel electrodes, each of which defines one pixel of the display. Conventionally, a single common electrode spanning multiple pixels, usually the entire display, is provided on the opposite side of the electro-optic medium. Individual pixel electrodes can be driven directly (i.e., a separate conductor can be provided for each pixel electrode), or the pixel electrodes can be driven in an active matrix manner, which will be familiar to those skilled in the art of backplane technology. Because adjacent pixel electrodes will often be at different voltages, they must be separated by an inter-pixel gap of finite width to avoid electrical shorts between the electrodes. At first glance, it might seem that the electro-optic medium overlying these gaps would not switch when a drive voltage is applied to the pixel electrodes (indeed, this is often the case with some non-bistable electro-optic media, such as liquid crystals, and a black mask is typically provided to hide these non-switching gaps), but in the case of many bistable electro-optic media, the medium overlying the gaps will switch due to an edge artifact phenomenon known as "blooming".

[0004] Blooming refers to the tendency of application of a drive voltage to a pixel electrode to cause a change in the optical state of an electro-optic medium over an area larger than the physical size of the pixel electrode. While excessive blooming should be avoided (e.g., in high-resolution active-matrix displays, it is undesirable for application of a drive voltage to a single pixel to cause switching over an area covering several adjacent pixels, as this would reduce the effective resolution of the display), a controlled amount of blooming is often useful. For example, consider a black-on-white electro-optic display that displays numbers using a conventional seven-segment array of seven directly driven pixel electrodes for each digit. When a zero is displayed, for example, six segments are turned black. In the absence of blooming, the gaps between the six pixels would be visible. However, by providing a controlled amount of blooming, the gaps between pixels can be turned black, resulting in more visually appealing numbers, as described, for example, in U.S. Pat. No. 7,602,374 (incorporated herein in its entirety). However, blooming can lead to a problem referred to as "edge persistence."

[0005] Areas of blooming are not uniformly white or black, but are typically transition zones where the color of the medium transitions from white to black through various shades of gray as one moves across the area of ​​blooming. Thus, although edge afterimages will typically be areas of various shades of gray rather than uniform gray areas, they can still be visible and objectionable, particularly since the human eye has the ability to detect gray areas within monochromatic images where each pixel is assumed to be pure black or pure white. In some cases, asymmetric blooming can contribute to edge afterimages. "Asymmetric blooming" refers to the phenomenon that blooming is "asymmetric" in the sense that in some electro-optic media (e.g., the copper chromite / titania encapsulated electrophoretic media described in U.S. Pat. No. 7,002,728), there is greater blooming during a transition from one extreme optical state of a pixel to the other extreme optical state than during a transition in the opposite direction; in the media described in this patent, there is typically greater blooming during a transition from black to white than during a transition from white to black.

[0006] Therefore, a driving method that reduces the afterimage or blooming effect is needed. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] U.S. Patent No. 7,002,728 Summary of the Invention [Means for solving the problem]

[0008] The present invention provides a method of driving an electro-optic display, the method comprising: updating a first portion of the display using a drive scheme configured to display white text on a black background; implementing a time delay following updating the first portion of the display; and updating a second portion of the display using the drive scheme to create a swipe motion across the display. In some embodiments, the drive method further comprises removing edge artifacts from the display pixels.

[0009] In one aspect, the invention features a method of driving an electro-optic display having a plurality of display pixels. The method includes updating the electro-optic display with a first image including image data from a first portion of scrollable content. The method also includes receiving user input having one or more parameters and generating a second image based on at least one parameter of the user input. The second image includes a portion of image data from the first portion of the scrollable content and image data from a second portion of the scrollable content. The method also includes updating the electro-optic display with the second image.

[0010] In some embodiments of the method, updating the electro-optic display with the second image includes updating a first portion of the electro-optic display with a first segment of the second image, and implementing a time delay following the first portion of the electro-optic display, wherein the updating of the electro-optic display is suspended during the time delay, and updating a second portion of the electro-optic display with a second segment of the second image following the time delay.

[0011] In some embodiments, the method further includes applying the edge blanking waveform to a display pixel of the electro-optic display during the time delay. In some embodiments, the method further includes identifying a display pixel with an edge artifact using an algorithm configured to flag the display pixel having the edge artifact based on the next optical state of the display pixel and the optical state of at least one of a primary neighborhood of the display pixel, and applying the edge blanking waveform to the display pixel flagged by the algorithm during the time delay.

[0012] In some embodiments, the user input includes a swipe gesture on the electro-optic display. In some embodiments, the user input includes a first parameter indicating a direction of the swipe gesture and a second parameter indicating a magnitude of one or more of a velocity of the swipe gesture, a linear distance of the swipe gesture, and a pressure of the swipe gesture.

[0013] In some embodiments, the position of the first portion of the electro-optic display is based on an initial contact point of the swipe gesture and a direction of the swipe gesture. In some embodiments, the position of the second portion of the electro-optic display is adjacent to the position of the first portion of the electro-optic display. In some embodiments, the proportion of the portion of image data from the first portion of the scrollable content relative to the image data from the second portion of the scrollable content varies depending on the magnitude of the speed of the swipe gesture. In some embodiments, the portion of image data from the first portion of the scrollable content and the image data from the second portion of the scrollable content are contiguous within the scrollable content.

[0014] In another aspect, the invention features a method of driving an electro-optic display having a plurality of display pixels. The method includes updating the electro-optic display with a first image comprising image data and receiving user input comprising one or more parameters. The method also includes generating a second image based on at least one parameter of the user input, the second image comprising a portion of the image data of the first image but scaled to have dimensions equal to the first image. The method also includes updating the electro-optic display with the second image.

[0015] In some embodiments of the method, updating the electro-optic display with the second image includes updating a first portion of the electro-optic display with a first segment of the second image, and implementing a time delay following the first portion of the electro-optic display, wherein the updating of the electro-optic display is suspended during the time delay, and updating a second portion of the electro-optic display with a second segment of the second image following the time delay.

[0016] In some embodiments, the method further includes applying an edge blanking waveform to a display pixel of the electro-optic display during the time delay. In some embodiments, the method further includes identifying a display pixel with an edge artifact using an algorithm configured to flag the display pixel having the edge artifact based on the next optical state of the display pixel and the optical state of at least one of a primary neighborhood of the display pixel, and applying an edge blanking waveform to the display pixel flagged by the algorithm during the time delay.

[0017] In some embodiments, the user input comprises a pinch-out zoom gesture on an electro-optic display. In some embodiments, the user input comprises a parameter indicating a magnitude of the linear distance of the pinch-out zoom gesture.

[0018] In some embodiments, the amount that a portion of the image data of the first image is magnified in the second image is proportional to the magnitude of the linear distance of the pinch-out zoom gesture.

[0019] In some embodiments, the position of the first portion of the electro-optic display is based on an initial contact point of a pinch-out zoom gesture. In some embodiments, the position of the second portion of the electro-optic display is adjacent to the position of the first portion of the electro-optic display. In some embodiments, the second portion of the electro-optic display surrounds the first portion of the electro-optic display. In some embodiments, the second segment of the second image surrounds the first segment of the second image. In some embodiments, the second segment of the second image includes content of the first segment of the second image. [Brief explanation of the drawings]

[0020] Additional details of one or more embodiments of the subject matter described herein are set forth in the accompanying drawings and description below. Other features, aspects, and advantages of the subject matter will become apparent from the description contained herein and the accompanying drawings. The drawings are not necessarily to scale, and elements of similar structure are generally annotated with like reference numerals throughout the drawings for illustrative purposes. However, the specific nature and function of elements in different embodiments may not be the same. Furthermore, the drawings are intended only to facilitate explanation of the subject matter. The drawings do not depict every aspect of the described embodiments and do not limit the scope of the disclosure or claims.

[0021] [Figure 1] FIG. 1 is a circuit diagram illustrating an electrophoretic display.

[0022] [Figure 2] FIG. 2 shows a circuit model of the electro-optic imaging layer.

[0023] [Figure 3]FIG. 3 illustrates a segmented swipe action under dark mode.

[0024] [Figure 4] FIG. 4 illustrates a dark mode swipe action with edge erasure.

[0025] [Figure 5] Figure 5 shows waveforms for implementing the dark mode swipe action.

[0026] [Figure 6] FIG. 6 illustrates the optical kickback of the white and black rails due to post-drive discharge.

[0027] [Figure 7] FIG. 7 illustrates the benefits of two stages of updating a drive scheme in accordance with the subject matter disclosed herein.

[0028] [Figure 8] FIG. 8 illustrates the black optical kickback with two stages of updating the drive scheme.

[0029] [Figure 9] FIG. 9 illustrates steps of a method for presenting content in a continuous scrolling mode.

[0030] [Figure 10] FIG. 10 illustrates an exemplary display device according to embodiments described herein.

[0031] [Figure 11] FIG. 11 is an exemplary diagram illustrating the operation of a method for presenting content in a continuous scroll mode according to embodiments described herein.

[0032] [Figure 12] FIG. 12 is an exemplary diagram illustrating the operation of a method for presenting content in a continuous scroll mode according to embodiments described herein.

[0033] [Figure 13] FIG. 13 is a diagram illustrating a continuous scrolling action on a portion of an image.

[0034] [Figure 14] FIG. 14 is an exemplary diagram illustrating an image processed according to the described embodiment.

[0035] [Figure 15] FIG. 15 is an exemplary diagram illustrating the operation of a method for presenting content in zoom mode according to embodiments described herein.

[0036] [Figure 16] FIG. 16 is an exemplary diagram illustrating the operation of a method for presenting content in zoom mode according to embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0037] The present invention relates to a method of driving an electro-optic display, in particular a bistable electro-optic display, and to an apparatus for use in such a method. More particularly, the present invention relates to a driving method that may enable reduced "afterglow" and edge effects, and reduced flashing in such displays. The present invention is particularly, but not exclusively, intended for use with particle-based electrophoretic displays, in which one or more types of charged particles are present in a fluid and are caused to move through the fluid under the influence of an electric field to change the appearance of the display.

[0038] The term "electro-optic" as applied to a material or display is used in its conventional sense in the imaging arts and is used herein to refer to a material having first and second display states that differ in at least one optical property, the material being changed from its first to its second display state by application of an electric field to the material. The optical property is typically color perceptible to the human eye, but may be another optical property such as optical transmittance, reflectance, luminescence, or, in the case of displays intended for machine-reading, pseudocolor in the sense of a change in reflectance of electromagnetic wavelengths outside the visible range.

[0039] The term "gray state" is used herein in its conventional sense in the imaging arts to refer to a state intermediate between two extreme pixel optical states, and does not necessarily imply a black-to-white transition between the two extreme states of black and white. For example, several E INK patents and published applications referenced below describe electrophoretic displays in which the extreme states are white and dark blue, whereby the intermediate "gray state" is actually light blue. In fact, as already noted, a change in optical state may not be a change in color at all. The terms "black" and "white" may be used hereinafter to refer to the two extreme optical states of a display and should generally be understood to include extreme optical states that are not strictly black and white, such as the aforementioned white and dark blue states. The term "monochrome" may be used hereinafter to refer to a drive scheme that drives pixels to only those two extreme optical states, with no intervening gray states.

[0040] Although some electro-optic materials are solid in the sense that the material has a solid exterior surface, the material may often have an interior liquid- or gas-filled space. Such displays using solid electro-optic materials may hereinafter be referred to for convenience as "solid electro-optic displays." Thus, the term "solid electro-optic display" includes rotating dichroic member displays, encapsulated electrophoretic displays, microcell electrophoretic displays, and encapsulated liquid crystal displays.

[0041] The terms "bistable" and "bistable" are used herein in their conventional sense in the art to refer to displays comprising display elements having first and second display states that differ in at least one optical property, whereby any given element, after being driven with an address pulse of finite duration to exhibit either the first or second display state, persists after the address pulse terminates for at least several times, e.g., at least four times, the minimum duration of the address pulse required to change the state of the display element. U.S. Pat. No. 7,170,670 shows that some grayscale-capable particle-based electrophoretic displays are stable not only in their extreme black and white states but also in their intermediate gray states, and the same is true for several other types of electro-optic displays. Displays of this type are properly referred to as "multistable" rather than bistable, although for convenience the term "bistable" may be used herein to encompass both bistable and multistable displays.

[0042] The term "impulse" is used herein in its conventional sense of the integral of voltage with respect to time. However, some bistable electro-optic media act as charge transducers, and for such media, an alternative definition of impulse may be used: the integral of current over time (equal to the total charge applied). The appropriate definition of impulse should be used depending on whether the medium acts as a voltage-time impulse transducer or a charge impulse transducer.

[0043] Much of the discussion below will focus on methods for driving one or more pixels of an electro-optic display through a transition from an initial gray level to a final gray level (which may or may not differ from the initial gray level). The term "waveform" will be used to refer to the overall voltage versus time curve used to effect a transition from a specific initial gray level to a specific final gray level. Typically, such a waveform will comprise multiple waveform elements. That is, if these elements are essentially rectangular (i.e., if a given element comprises the application of a constant voltage over a period of time), the element may be referred to as a "pulse" or "drive pulse." The term "drive scheme" refers to a set of waveforms sufficient to effect all possible transitions between gray levels for a specific display. A display may utilize more than one drive scheme. For example, U.S. Pat. No. 7,012,600, incorporated herein in its entirety, teaches that a drive scheme may need to be modified depending on parameters such as the temperature of the display or the time it has been in operation during its lifetime, and thus a display may be provided with multiple different drive schemes to be used at different temperatures, etc. A set of drive schemes used in this manner may be referred to as a "set of related drive schemes." Also, as described in some of the aforementioned MEDEOD applications, two or more drive schemes may be used simultaneously in different areas of the same display, and a set of drive schemes used in this way may be referred to as a "set of simultaneous drive schemes."

[0044] Several types of electro-optic displays are known. One type of electro-optic display is the rotating dichroic member type, as described in, for example, U.S. Patent Nos. 5,808,783, 5,777,782, 5,760,761, 6,054,071, 6,055,091, 6,097,531, 6,128,124, 6,137,467, and 6,147,791. (This type of display is often referred to as a "rotating dichroic ball" display, but in some of the patents mentioned above, the term "rotating dichroic member" is preferred as it is more accurate because the rotating member is not spherical.) Such displays use a number of small bodies (typically spherical or cylindrical) that have two or more portions with different optical properties and an internal dipole. These bodies are suspended within liquid-filled vacuoles in a matrix, and the vacuoles are filled with liquid so that the bodies are free to rotate. The appearance of the display is changed by applying an electric field thereto, thus rotating the bodies to various positions and varying the position of the portion of the body that is seen through the viewing surface. This type of electro-optic medium is typically bistable.

[0045] Another type of electro-optic display uses an electrochromic medium, for example, in the form of a nanochromic film, which comprises electrodes formed at least in part from a semiconducting metal oxide and a plurality of dye molecules attached to the electrodes, capable of reversible color change. See, for example, O'Regan, B., et al., Nature 1991, 353, 737, and Wood, D., Information Display, 18(3), 24 (March 2002). See also Bach, U., et al., Adv. Mater., 2002, 14(11), 845. Nanochromic films of this type are also described, for example, in U.S. Patent Nos. 6,301,038, 6,870,657, and 6,950,220. This type of medium is also typically bistable.

[0046] Another type of electro-optic display is the electrowetting display developed by Philips and described in Hayes, RA, et al., "Video-Speed ​​Electronic Paper Based on Electrowetting," Nature, 425, 383-385 (2003). U.S. Patent No. 7,420,549 indicates that such electrowetting displays can be made bistable.

[0047] One type of electro-optic display that has been the subject of intensive research and development interest for many years is particle-based electrophoretic displays, in which a plurality of charged particles move through a fluid under the influence of an electric field. For example, the particles that make up electrophoretic displays tend to settle, resulting in a poor usable lifespan of these displays.

[0048] As noted above, electrophoretic media require the presence of a fluid. In most prior art electrophoretic media, this fluid is liquid, but electrophoretic media can also be produced using gaseous fluids (see, e.g., Kitamura, T., et al., “Electrical toner movement for electronic paper-like display” (IDW Japan, 2001, Paper HCS1-1) and Yamaguchi, Y., et al., “Toner display using insulative particles charged triboelectrically” (IDW Japan, 2001, Paper AMD4-4)). See also U.S. Patent Nos. 7,321,459 and 7,236,291. Such gas-based electrophoretic media are believed to be susceptible to the same types of problems as liquid-based electrophoretic media due to particle settling when used in an orientation that allows such settling, such as in a sign where the media is positioned in a vertical plane. In fact, particle settling is believed to be a more serious problem in gas-based electrophoretic media than in liquid-based electrophoretic media because the lower viscosity of the gaseous suspending fluid, compared to the viscosity of a liquid, allows for faster settling of the electrophoretic particles.

[0049] Numerous patents and applications assigned to or in the name of the Massachusetts Institute of Technology (MIT) and E Ink Corporation describe various techniques used in encapsulated electrophoretic and other electro-optic media. Such encapsulated media include a multiplicity of small capsules, each of which itself includes an internal phase containing electrophoretically movable particles in a fluid medium, and a capsule wall surrounding the internal phase. Typically, the capsules are themselves held within a polymeric binder to form a coherent layer positioned between two electrodes. Techniques described in these patents and applications include the following:

[0050] (a) electrophoretic particles, fluids, and fluid additives (see, e.g., U.S. Patent Nos. 7,002,728 and 7,679,814);

[0051] (b) capsules, binders, and encapsulation processes (see, e.g., U.S. Patent Nos. 6,922,276 and 7,411,719);

[0052] (c) microcell structures, wall materials, and methods of forming the microcells (see, e.g., U.S. Patent Nos. 7,072,095 and 9,279,906);

[0053] (d) methods of filling and sealing microcells (see, e.g., U.S. Patent Nos. 7,144,942 and 7,715,088);

[0054] (e) films and subassemblies containing electro-optical materials (see, e.g., U.S. Patent Nos. 6,982,178 and 7,839,564);

[0055] (f) backplanes, adhesive layers, and other auxiliary layers and methods used in displays (see, e.g., U.S. Patent Nos. 7,116,318 and 7,535,624);

[0056] (g) color formation and color control (see, e.g., U.S. Patent Nos. 7,075,502 and 7,839,564);

[0057] (h) display applications (see, e.g., U.S. Patent Nos. 7,312,784 and 8,009,348);

[0058] (i) non-electrophoretic displays, such as those described in U.S. Patent No. 6,241,921 and U.S. Patent Application Publication No. 2015 / 0277160, and non-display applications of encapsulation and microcell technology (see, e.g., U.S. Patent Application Publication Nos. 2015 / 0,005,720 and 2016 / 0,012,710);

[0059] (j) Methods of driving displays (e.g., U.S. Patent Nos. 5,930,026, 6,445,489, 6,504,524, 6,512,354, 6,531,997, 6,753,999, 6,825,970, 6,900,851, 6,995,550, 7,012,600, 7,023,420, 7,034,783, 7,061,166, 7,061,662, 7,116,466, 7,119,772, 7,177,066, 7,193,625, 7,202,84 No. 7, No. 7,242,514, No. 7,259,744, No. 7,304,787, No. 7,312,794, No. 7,327,511 , No. 7,408,699, No. 7,453,445, No. 7,492,339, No. 7,528,822, No. 7,545,358, No. 7 , No. 583,251, No. 7,602,374, No. 7,612,760, No. 7,679,599, No. 7,679,813, No. 7,6 No. 83,606, No. 7,688,297, No. 7,729,039, No. 7,733,311, No. 7,733,335, No. 7,787, No. 169, No. 7,859,742, No. 7,952,557, No. 7,956,841, No. 7,982,479, No. 7,999,78 No. 7, No. 8,077,141, No. 8,125,501, No. 8,139,050, No. 8,174,490, No. 8,243,013, No. 8,274,472, No. 8,289,250, No. 8,300,006, No. 8,305,341, No. 8,314,784, No. 8 ,373,649, No.8,384,658, No.8,456,414, No.8,462,102, No.8,537,105, No.8,55 No. 8,783, No. 8,558,785, No. 8,558,786, No. 8,558,855, No. 8,576,164, No. 8,576, No. 259, No. 8,593,396, No. 8,605,032, No. 8,643,595, No. 8,665,206, No. 8,681,191 No. 8,730,153, No. 8,810,525, No. 8,928,562, No. 8,928,641, No. 8,976,444, No. 9,013,394, No. 9,019,197, No. 9,019,198, No. 9,019,318, No. 9,082,352, No. 9,Nos. 171,508, 9,218,773, 9,224,338, 9,224,342, 9,224,344, 9,230,492, 9,251,736, 9,262,973, 9,269,311, 9,299,294, 9,373,289, 9,390,066, 9,390,661, 9,412,314, and 9,672,766, and U.S. Patent Application Publication Nos. 2003 / 0102858, 2004 / 0246562, 2005 / 0253777, 2007 / 0070032, 2007 / 0076289, 2007 / 0091418, 2007 / 0103427, 2007 / 0176912, 2007 / 0296452, 2008 / 0024429, 2008 / 0024482, 2008 / 0136774, 2008 / 0169821, and 2008 / 0218471 , No. 2008 / 0291129, No. 2008 / 0303780, No. 2009 / 0174651, No. 2009 / 0322721, No. 2010 / 0194733, No. 2010 / 0194789, No. 2010 / 0220121, No. 2010 / 0 No. 265561, No. 2010 / 0283804, No. 2011 / 0063314, No. 2011 / 0175875, No. 2011 / 0193840, No. 2011 / 0193841, No. 2011 / 0199671, No. 2011 / 0221740, No. 2012 / 0001957, 2012 / 0098740, 2013 / 0063333, 2013 / 0194250, 2013 / 0249782, 2013 / 0321278, 2014 / 0009817, 2014 / 008 No. 5355, No. 2014 / 0204012, No. 2014 / 0218277, No. 2014 / 0240210, No. 2014 / 0240373, No. 2014 / 0253425, No. 2014 / 0292830, No. 2014 / 0293398, No. 20 (See Nos. 14 / 0333685, 2014 / 0340734, 2015 / 0070744, 2015 / 0097877, 2015 / 0109283, 2015 / 0213749, 2015 / 0213765, 2015 / 0221257, 2015 / 0262255, 2016 / 0071465, 2016 / 0078820, 2016 / 0093253, 2016 / 0140910, 2016 / 0180777, and 2021 / 0389637).

[0060] Many of the aforementioned patents and applications recognize that the walls surrounding the separate microcapsules in an encapsulated electrophoretic medium may be replaced with a continuous phase, thus producing so-called polymer-dispersed electrophoretic displays, in which the electrophoretic medium comprises a plurality of separate droplets of electrophoretic fluid and a continuous phase of polymeric material, and that the separate droplets of electrophoretic fluid in such polymer-dispersed electrophoretic displays may be considered capsules or microcapsules even though a separate capsule membrane is not associated with each individual droplet. See, e.g., the aforementioned 2002 / 0,131,147. Therefore, for purposes of this application, such polymer-dispersed electrophoretic media are considered a subspecies of encapsulated electrophoretic media.

[0061] A related type of electrophoretic display is the so-called "microcell electrophoretic display." In a microcell electrophoretic display, the charged particles and suspending fluid are not encapsulated in microcapsules, but instead are held within a plurality of cavities formed in a carrier medium, e.g., a polymer film. See, for example, International Application Publication No. WO 02 / 01,281 and Published U.S. Application No. 2002 / 0,075,556, both of which are assigned to Sipix Imaging, Inc.

[0062] Many of the aforementioned EINK and MIT patents and applications also contemplate microcell electrophoretic displays and polymer-dispersed electrophoretic displays. The term "encapsulated electrophoretic display" can refer to any such display type, which can be collectively described as "microcavity electrophoretic displays" to generalize across wall configurations.

[0063] Another type of electro-optic display is the electrowetting display developed by Philips and described in Hayes, R.A., et al., "Video-Speed ​​Electronic Paper Based on Electrowetting," Nature, 425, 383-385 (2003). Co-pending application Ser. No. 10 / 711,802, filed Oct. 6, 2004, shows that such electrowetting displays can be made bistable.

[0064] Other types of electro-optic materials may also be used, most notably bistable ferroelectric liquid crystal displays (FLCs), which are known in the art and exhibit remnant voltage behavior.

[0065] Although electrophoretic media can be opaque (e.g., because in many electrophoretic media the particles substantially block the transmission of visible light through the display) and operate in a reflective mode, some electrophoretic displays can be adapted to operate in a so-called "shield mode," in which one viewing state is substantially opaque and one viewing state is light-transmitting. See, e.g., U.S. Pat. Nos. 6,130,774 and 6,172,798, as well as U.S. Pat. Nos. 5,872,552, 6,144,361, 6,271,823, 6,225,971, and 6,184,856. Dielectrophoretic displays, which are similar to electrophoretic displays but rely on variations in electric field strength, can operate in a similar mode. See U.S. Pat. No. 4,418,346. Other types of electro-optic displays may also be capable of operating in a shield mode.

[0066] High-resolution displays may include individual pixels that are addressable without interference from neighboring pixels. One way to achieve such pixels is to provide an array of nonlinear elements, such as transistors or diodes, with at least one nonlinear element associated with each pixel, resulting in an "active matrix" display. The address or pixel electrode that addresses a pixel is connected to an appropriate voltage source through the associated nonlinear element. When the nonlinear element is a transistor, the pixel electrode may be connected to the drain of the transistor; although this arrangement will be assumed in the following description, it is essentially arbitrary; the pixel electrode may also be connected to the source of the transistor. In high-resolution arrays, pixels may be arranged in a two-dimensional array of rows and columns, such that any particular pixel is uniquely defined by the intersection of one defined row and one defined column. The sources of all transistors in each column may be connected to a single column electrode, while the gates of all transistors in each row may be connected to a single row electrode. Again, the assignment of sources to rows and gates to columns may be reversed, as desired.

[0067] The display can be written in a row-by-row manner. The row electrodes are connected to row drivers, which apply voltages to the selected row electrodes to ensure that all transistors in a selected row are conductive, while applying voltages to all other rows to ensure that all transistors in these unselected rows remain non-conductive. The column electrodes are connected to column drivers, which apply selected voltages to the various column electrodes to drive the pixels in a selected row to their desired optical states. (These voltages are relative to a common front electrode provided opposite the nonlinear array of electro-optic medium and which may span the entire display. As known in the art, voltages are relative and are the magnitude of the charge difference between two points. One voltage value is relative to another voltage value. For example, zero voltage (“0V”) refers to having no voltage difference relative to another voltage.) After a preselected interval known as the “line address time,” the selected row is deselected, another row is selected, and the voltages on the column drivers are changed so that the next line of the display is written.

[0068] However, in use, certain waveforms can create residual voltages on the pixels of an electro-optic display, and as is clear from the above discussion, this residual voltage creates several unwanted optical effects and is generally undesirable.

[0069] As presented herein, a "shift" in optical state associated with an address pulse refers to a situation in which the initial application of a particular address pulse to an electro-optic display results in a first optical state (e.g., a first shade of gray), and a subsequent application of the same address pulse to the electro-optic display results in a second optical state (e.g., a second shade of gray). A remnant voltage can cause a shift in optical state because the voltage applied to a pixel of an electro-optic display during application of an address pulse comprises the sum of the remnant voltage and the voltage of the address pulse.

[0070] "Drift" in the optical state of a display over time refers to the situation where the optical state of an electro-optic display changes while the display is stationary (e.g., during periods when no address pulses are applied to the display). Residual voltages can cause drift in the optical state because the optical state of a pixel depends on the remnant voltage of the pixel, and the remnant voltage of a pixel can decay over time.

[0071] As discussed above, "image persistence" refers to the situation where a trace of a previous image is still visible after an electro-optic display has been rewritten. Residual voltage can give rise to "edge image persistence," a type of image persistence in which the outline (edge) of part of the previous image remains visible.

[0072] (Example EPD)

[0073] 1 shows a schematic diagram of a pixel 100 of an electro-optic display in accordance with the subject matter presented herein. Pixel 100 may include an imaging film 110. In some embodiments, imaging film 110 may be bistable. In some embodiments, imaging film 110 may include, for example, but not limited to, an encapsulated electrophoretic imaging film, which may include charged pigment particles.

[0074] The imaging film 110 may be disposed between the front electrode 102 and the back electrode 104. The front electrode 102 may be formed between the imaging film and the front surface of the display. In some embodiments, the front electrode 102 may be transparent. In some embodiments, the front electrode 102 may be formed from any suitable transparent material, including, but not limited to, indium tin oxide (ITO). The back electrode 104 may be formed opposite the front electrode 102. In some embodiments, a parasitic capacitance (not shown) may be formed between the front electrode 102 and the back electrode 104.

[0075] Pixel 100 may be one of a plurality of pixels. The plurality of pixels may be arranged in a two-dimensional array of rows and columns to form a matrix, whereby any particular pixel may be uniquely defined by the intersection of a defined row and a defined column. In some embodiments, the matrix of pixels may be an “active matrix” in which each pixel is associated with at least one nonlinear circuit element 120. The nonlinear circuit element 120 may be coupled between the backplate electrode 104 and the address electrode 108. In some embodiments, the nonlinear element 120 may include a diode and / or a transistor, including, but not limited to, a MOSFET. The drain (or source) of the MOSFET may be coupled to the backplate electrode 104, the source (or drain) of the MOSFET may be coupled to the address electrode 108, and the gate of the MOSFET may be coupled to a driver electrode 106 configured to control activation and deactivation of the MOSFET. (For simplicity, the terminal of the MOSFET that is coupled to backplate electrode 104 will be referred to as the drain of the MOSFET, and the terminal of the MOSFET that is coupled to address electrode 108 will be referred to as the source of the MOSFET. However, those skilled in the art will recognize that in some embodiments, the source and drain of a MOSFET may be interchanged.)

[0076] In some active matrix embodiments, the address electrodes 108 of all pixels in each column may be connected to the same column electrode, and the driver electrodes 106 of all pixels in each row may be connected to the same row electrode. The row electrodes may be connected to a row driver, which may select one or more rows of pixels by applying to the selected row electrodes a voltage sufficient to actuate the nonlinear elements 120 of all pixels 100 in the selected row. The column electrodes may be connected to a column driver, which may apply appropriate voltages to the address electrodes 106 of the selected (actuated) pixels to drive the pixels to a desired optical state. The voltages applied to the address electrodes 108 may be relative to the voltages applied to the front plate electrodes 102 of the pixels (e.g., a voltage of about zero volts). In some embodiments, the front plate electrodes 102 of all pixels in the active matrix may be coupled to a common electrode.

[0077] In some embodiments, the active matrix pixels 100 can be written in a row-by-row manner. For example, a row of pixels can be selected by a row driver, and voltages corresponding to the desired optical state for the row of pixels can be applied to the pixels by a column driver. After a preselected interval known as a "line address time," the selected row can be deselected, another row can be selected, and the voltages on the column drivers can be changed, thereby writing another line of the display.

[0078] 2 shows a circuit model of an electro-optic imaging layer 110 disposed between a front electrode 102 and a back electrode 104 according to the subject matter presented herein. Resistor 202 and capacitor 204 may represent the resistance and capacitance of the electro-optic imaging layer 110, front electrode 102, and back electrode 104, including any adhesive layers. Resistor 212 and capacitor 214 may represent the resistance and capacitance of a lamination adhesive layer. Capacitor 216 may represent capacitance that may form at an interlayer interface contact area between the front electrode 102 and back electrode 104, e.g., the interface between the imaging layer and a lamination adhesive layer and / or the lamination adhesive layer and a backplane electrode. The voltage Vi across the imaging film 110 at a pixel may include the residual voltage of the pixel.

[0079] In some situations, it may be desirable for a single display to utilize multiple drive schemes. For example, a display capable of three or more gray levels may utilize a grayscale drive scheme ("GSDS") that can effect transitions between all possible gray levels and a monochrome drive scheme ("MDS") that effects transitions between only two gray levels, with the MDS providing faster display refresh than the GSDS. The MDS is used when all pixels being changed during a display refresh effect only the two gray levels used by the MDS. For example, the aforementioned U.S. Patent No. 7,119,772 describes a display in the form of an e-book or similar device that can display grayscale images and also display monochrome dialog boxes that allow the user to enter text related to the displayed image. When the user is entering text, a high-speed MDS is used for rapid updating of the dialog box, thus providing the user with rapid confirmation of the text being entered. On the other hand, when the entire grayscale image shown on the display is being changed, a slower GSDS is used.

[0080] Alternatively, a display may utilize a "direct update" drive scheme ("DUDS") in conjunction with a GSDS. While a DUDS may have two or more gray levels, typically fewer than a GSDS, the most important feature of a DUDS is that transitions are handled by simple unidirectional driving from an initial gray level to a final gray level, as opposed to the "indirect" transitions often used in GSDS (where, for at least some transitions, a pixel is driven from an initial gray level to one extreme optical state and then back to the final gray level). In some cases, a transition may be effected by driving from an initial gray level to one extreme optical state, then to the opposite extreme optical state, and finally to the final extreme optical state. See, for example, the drive scheme illustrated in Figures 11A and 11B of the aforementioned U.S. Pat. No. 7,012,600. Thus, the electrophoretic displays of the present application may have update times in grayscale mode that are about 2-3 times the saturation pulse length (where "saturation pulse length" is defined as the period at a particular voltage that is sufficient to drive a pixel of the display from one extreme optical state to the other), or about 700-900 ms, while DUDS have a maximum update time equal to the saturation pulse length, or about 200-300 ms.

[0081] However, variations in the drive schemes are not limited to differences in the number of gray levels used. For example, drive schemes can be divided into global drive schemes, in which a drive voltage is applied to every pixel in an area (which may be the entire display or some defined portion thereof) to which a global update drive scheme (more precisely referred to as a "global full" or "GC" drive scheme) is applied, and partial update drive schemes, in which a drive voltage is applied only to pixels undergoing a non-zero transition (i.e., a transition in which the initial and final gray levels are different from each other), but no drive voltage is applied during a zero transition (in which the initial and final gray levels are the same). An intermediate form of drive scheme (designated a "globally constrained" or "GL" drive scheme) is similar to the GC drive scheme, except that, with respect to the GL drive scheme, a drive voltage is applied only to pixels undergoing a non-zero transition (i.e., a transition in which the initial and final gray levels are different from each other), but no drive voltage is applied during a zero transition (in which the initial and final gray levels are the same). The GL drive scheme is characterized by not applying drive voltages to pixels undergoing a zero transition (e.g., white to white or black to black), meaning that these pixels undergo zero or no optical transactions. For example, in a display used as an e-book reader displaying black text on a white background, there will be many white pixels, particularly in the margins and between the lines of text, that remain unchanged from one page of text to the next. Thus, not rewriting these white pixels substantially reduces the apparent "flash effect" of display redraws. Similarly, for a display used as an e-book reader displaying white text on a black background (i.e., dark mode operation), there will be many black pixels, particularly in the margins and between the lines of text, that remain unchanged from one page of text to the next. Thus, not rewriting these black pixels substantially reduces the apparent "flash effect" of display redraws. Instead, only pixels undergoing active optical transactions are updated.

[0082] However, certain problems remain with this type of GL drive scheme. First, as discussed in detail in some of the aforementioned MEDEOD applications, bistable electro-optic media are typically not perfectly bistable, and pixels placed in one extreme optical state will gradually drift toward intermediate gray levels over a period of minutes to hours. In particular, pixels that are driven white will slowly drift toward a light gray color. Thus, in a GL drive scheme, if a white pixel is allowed to remain undriven through several page turns, during which other white pixels (e.g., pixels forming part of a text character) are driven, the newly updated white pixel will be slightly brighter than the undriven white pixel, and eventually the difference will be apparent even to an untrained user.

[0083] Second, when an undriven pixel is adjacent to a pixel being updated, the driving of the driven pixel causes a change in optical state over an area slightly larger than the area of ​​the driven pixel, and this area encroaches into the area of ​​the adjacent pixel, a phenomenon known as "blooming." Such blooming appears as an edge effect along the edge where the undriven pixel is adjacent to the driven pixel. Similar edge effects occur when using area updates (where only a specific area of ​​the display is updated, e.g., to show an image), except that in the case of area updates, the edge effect occurs at the boundary of the area being updated. Over time, such edge effects become visually distracting and must be eliminated. Until now, such edge effects (and the effect of color drift in undriven white pixels) have typically been eliminated by using a single GC update at intervals. Unfortunately, using such occasional GC updates can reintroduce the problem of "flash-like" updates; in fact, the flashing effect of the updates can be exacerbated by the fact that flash-like updates only occur at long intervals.

[0084] In light of the above, the GL mode can be further modified to include algorithms (e.g., Regal algorithms) configured to eliminate edge persistence or blooming artifacts, such as those described in U.S. Pat. Nos. 11,030,936 and 11,568,786 (incorporated herein in their entireties). These algorithms can be configured to apply corrective pulses to pixels experiencing blooming from neighboring pixels. This new drive mode (e.g., GLR, GLR16) can function to reduce flash caused by blooming while updating a white background with minimal text residue. Other drive schemes, such as those described in U.S. Pat. No. 11,520,202, use waveform selection to optimize differential blooming reduction depending on the display application.

[0085] For some applications, electro-optic displays such as those presented in FIGS. 1 and 2 may be driven with a GL driving scheme to reduce the apparent "flash effect" of display refresh operations. Furthermore, to improve the transition experience as an electro-optic display progresses from one page to the next, some methods pipeline display updates in segments, resulting in a short delay τ (e.g., 10 ms to 20 ms) from one segment to another. For example, the driving method presented herein first updates a first portion of the display (e.g., 304 in FIG. 3 ) using a driving scheme such as a GL driving scheme. The method then introduces or implements a time delay, followed by an update of a second portion of the display (e.g., 306 in FIG. 3 ), thus providing the illusion of a page refresh. FIG. 3 illustrates a possible segment-by-segment sequence for updating in dark mode. Updating the display in this manner would create the illusion of "swiping" through pages. The direction of this "swipe" may be left-to-right, right-to-left, top-to-bottom, or bottom-to-top and may be inferred by detecting the user's input action on the touch panel, giving the user the impression of control over the display action. As shown, updating the display from a completely black page 300 to an updated page 302 may occur through a series of segmented updates. Starting with the first segmented update 304, only a portion of the display is updated, with a portion of the text being displayed. Subsequently, after a short delay τ, the next segment 306 may be updated on the display. Subsequent segments 308-322 may be updated on the display in a similar manner, with short delays τ between them, until the display is fully updated. The display updates are paused or interrupted during the delay time τ. This method of updating creates the illusion of swiping a page and can provide less flash compared to a single, full display update.

[0086] As described above, when operating in dark mode and using a segmented and low-flash drive scheme, sometimes a drive or update cycle may include two stages. Referring to FIG. 4 , stage 1 402 may perform a swipe action without any post-drive discharge, and stage 2 404 may perform an edge-erasing action. In this configuration, stage 1 update 402 may use a low-flash globally constrained (GL) drive scheme, while the electro-optic display is updated through multiple segmented swipes, as illustrated in FIG. 3 . Alternatively, the electro-optic display may be updated with a single or one-segment swipe. Subsequently, when transitioning from the current image to the next image, an imaging algorithm may be used to identify and / or determine pixels that may be likely to exhibit blooming and / or edge artifacts. An example of such an algorithm is presented below. [Table 1] where: nextpixels(i,j) represents the next image pixel at location (i,j) currentpixels(i,j) represents the current pixel at location (i,j) Cardinal neighbors represent the pixels to the north, south, east, and west of a pixel edgeclearstate represents the special edge clear pixel state

[0087] In practice, the algorithm described above may identify and / or flag display pixels that exhibit edge artifacts and apply an edge blanking waveform to these pixels. For example, for a particular display pixel, if at least one of the display pixel's primary neighboring pixels has a current optical state that is not black and a next optical state that is black (i.e., the primary neighboring pixel is undergoing an active optical transition), then the particular display pixel is deemed to have a high likelihood of exhibiting edge artifacts and is therefore flagged. Thus, the particular display pixel will receive the edge blanking waveform in stage 2. Furthermore, if the particular pixel has a current optical state that is not black, a next optical state that is black, and has at least one primary neighboring pixel with a black current optical state and a black next optical state, then the particular display pixel is deemed to have a high likelihood of exhibiting edge artifacts and is therefore flagged.

[0088] It has also been observed that the swipe algorithm described herein can be used for displays presenting black text on a white background. For example, replacing "black" with "white" in the algorithm presented above would result in an algorithm suitable for non-dark mode operation.

[0089] In some embodiments, in stage 2 404, edge artifact cancellation may begin after the stage 1 402 update is complete, and a time delay τ may be inserted between the two stages. In practice, τ should be as short as possible for a seamless transition appearance and to avoid the user detecting undesired edge artifacts. To do this, practices may either: (1) perform a pipeline update of the edge map with a special edge cancellation DC imbalance waveform with post-drive discharge; or (2) justify the remainder of the standard transition by modifying the waveform lookup table to include the edge cancellation waveform and inserting a zero scan frame before the edge cancellation waveform, as shown in FIG. 5.

[0090] As shown in FIG. 5, implementing an update scheme as described herein provides the option of not using a post-drive discharge to discharge accumulated residual voltage that can result in high optical kickback. FIG. 6 illustrates a comparison of the resulting optical kickback when a post-drive discharge is applied. Blue line 604 shows increased optical kickback to the white rail due to a post-drive discharge (e.g., the potential applied across the ink to drive the display to the white state) compared to red line 602 when no post-drive discharge is applied. Similarly, blue line 608 shows increased optical kickback to the black rail due to a post-drive discharge (e.g., the potential applied across the ink to drive the display to the black state) compared to red line 606 when no post-drive discharge is applied.

[0091] In practice, application of the driving scheme described herein enables multi-segmented swipes to be performed in dark mode without edge artifacts. Furthermore, optical kickback can be reduced in typical usage scenarios, as shown in FIG. 7 . “Kickback” or “self-erase” is a phenomenon observed in some electro-optic displays (see, for example, Ota, I., et al., “Developments in Electrophoretic Displays” (Proceedings of the SID, 18, 243 (1977)), where self-erase was reported in an unencapsulated electrophoretic display), whereby, when the voltage applied across the display is switched off, the electro-optic medium may at least partially reverse its optical state, and in some cases, a reverse voltage, which may be greater than the operating voltage, may be observed to develop across the electrodes. Motivated by this usage scenario, a black background is always established by using a waveform that does not require edge erasure, thus eliminating the need for post-drive discharge. The edge erasure usage occurs only when a dark mode GL (i.e., sky black-to-black transition and / or white-to-white transition) is initiated in the next update sequence, during which the combined dwell and update time of the GL transition has passed.

[0092] In Figure 7, the red box 702 is the area where the detailed optical trace shown in Figure 8 was captured during the key transition of setting the black background, with the following transition: white → black → black. Figure 8 provides optical traces comparing the proposed strategy (red lines) 802, 806 with alternative strategies for dark mode implementation (blue lines) 804, 808. The proposed strategy (red lines) 802, 806 has a white → black (using a waveform without a drive after discharge to set the black background) and a black → black (using a low flash empty black / black waveform that ends with an edge erase with a drive after discharge).

[0093] Additionally, in some embodiments, the following may be implemented: white-to-black transition (using a specialized waveform with post-drive discharge to set the black background); black-to-black (using a low-flash empty black / black waveform with post-drive discharge and edge blanking). As shown in Figure 8, the proposed strategy (blue lines) 804, 808 maintains a darker black color better than the current commercial strategies (red lines) 802, 806. This is because the proposed strategy sets black using a specialized waveform without the need for a post-drive discharge; when a post-drive discharge is needed later in stage 2 for edge blanking of the low-flash waveform, black is already set in place for the time duration of T. T = dwell time + update time for low flash waveform + τ

[0094] T allows for natural decay of residual charge in the ink system and reduces optical kickback due to assertion of post-drive discharge on a black background. As shown in Figure 8, as T decreases, the black of the proposed strategy will be less black with more optical kickback in Stage 2 of the proposed low flash waveform.

[0095] In one embodiment of implementation, minimum T is preset to a value where optical kickback is acceptable, and then τ can be adjusted accordingly, i.e.: τ = max(0, T - dwell time - update time for low flash waveform)

[0096] In another embodiment, the update time for the low-flash waveform +τ is always set to an acceptable optical kickback level. In yet another embodiment, the first low-flash update after black is set should always have a large T to ensure that most of the black background remains black, and should employ over-dark driving in areas where optical kickback is expected in subsequent low-flash updates. The proposed approach can also be used in daytime modes (i.e., displaying black text on a white background). In its generalization, this strategy involves using Stage 1 (as a driving mechanism to reach the desired coarse optical state (in this case, displaying text on a black background, but with issues related to edge artifacts)) and Stage 2 (as a driving mechanism to refine the optical state (in this case, erasing edges)).

[0097] The techniques described above provide an improved user experience by reducing the apparent flashing effect of transitions between images. Additionally, the image update pattern presented in response to the user's swiping motion gives the user a perception of control over the action of the display, while the update pattern creates the compelling impression of turning the pages of a traditional printed book. For example, a user may be browsing some form of digital content (e.g., an e-book, a web page, etc.) where the entire content is too large to view on the display screen as a single image. Using the swiping techniques described above, the user can advance (or go back) through the digital content one image (e.g., page) at a time. Each subsequent image presented on the display includes the next adjacent portion of the digital content that will fit on the display, and none of the content of the previous image is displayed. As an example, a user reading page 10 of an e-book can swipe and advance to page 11. The techniques described above can be used to update the display with the content of page 11, and none of the content of page 10 remains on the display after the update.

[0098] In addition to presenting digital content in an image-by-image mode, emulating the page-by-page presentation of a traditional printed book, display devices are also generally capable of presenting digital content (e.g., e-books, web pages, etc.) in a continuous scrolling mode. For example, a traditional display device can be configured to fluidly and continuously scroll through digital content in response to touch input (e.g., swipes) from a user, as with a touch-enabled device.

[0099] Continuous scrolling operations can employ different drive schemes. Drive schemes using direct update waveforms, such as DUDS, have the advantage of shorter refresh times and less flashing, but only support transitions between black and white states. DUDS may therefore be insufficient to provide a display with smooth, animated updates during scrolling operations. GL and GLR drive schemes have the advantage of including waveforms that support transitions between all gray levels. Such drive schemes can be used for scrolling, but, as discussed above, can appear garish with longer transition times.

[0100] Thus, as discussed above, continuous scrolling can be a challenge for display devices incorporating electrophoretic displays due to the time required to refresh the display and the perceived flashing effect that results from the update waveform. The techniques described herein include features to address these shortcomings of conventional displays in displaying content in continuous scrolling mode. For example, the page swipe technique described above can be further enhanced to provide additional improvements to the user experience during continuous scrolling operations on electrophoretic displays.

[0101] 9 illustrates steps of a method 900 for presenting content in a continuous scroll mode. Method 900 includes updating (910) an electro-optic display with a first image. For example, the electro-optic display can be updated with a first image 1101 (FIG. 11) that includes image data from a first portion of scrollable content, such as scrollable content 1160, as shown in FIG. 11.

[0102] Next, method 900 may include receiving 920 a user input, including one or more parameters. For example, the user input may be a swipe gesture applied to a touch panel surface of an electro-optic display to indicate the user's desire to scroll displayed content. Referring to FIG. 10 , display device 1000 may detect a user's input 1020 action 1030 on a touch panel 1010. The input 1020 may be a gesture (e.g., a swipe, a drag, a flick, a pinch in, a pinch out, etc.) applied by a user's finger. In some embodiments, the input 1020 is applied by an active or passive input device, such as a stylus or a computer mouse.

[0103] The display device 1000 can detect certain characteristics or parameters of the input 1020. For example, the directionality of the input 1020 can be detected, as described above. In some embodiments, the display device 1000 can detect a parameter indicative of a desired scrolling speed. For example, the magnitude of the velocity at which the user applies the input 1020 to the touch panel 1010 can be used as a parameter indicative of the desired scrolling speed. In some embodiments, the desired scrolling speed is inferred based on the magnitude of the linear distance or stroke length of the input 1020 on the touch panel 1010. For example, a drag gesture spanning one inch on the touch panel 1010 may infer a slow desired scrolling speed, while a drag gesture spanning three to four inches on the touch panel 1010 may infer a desire for a faster scrolling speed. In some embodiments, the desired scrolling speed is inferred based on at least one of the rate at which the user applies the first input 1020 to the touch panel 1010 and the duration from the time when the user applies the first input 1020 to the touch panel 1010 to the time when the user applies the second input 1020 to the touch panel 1010. In some embodiments, the amount of pressure with which the user applies the input 1020 to the touch panel 1010 can be used as a parameter indicative of the desired scrolling speed.

[0104] Returning to FIG. 9 , after receiving the user input, the method 900 includes generating (930) a second image based on at least one parameter of the user input. This may be considered an image separation operation that determines the image data of the scrollable content 1160 that will be the next image presented on the display. The parameters of the detected input 1020 are used to define how the image separation operation functions to generate the second image. FIG. 11 provides an example of three images, image 1101, image 1102, and image 1103, resulting from the image separation operation based on the detection of an action 1130, in this case a request to scroll up the scrollable content 1160. The “scroll up” action 1130 is a user input received while the user is viewing the portion of the scrollable content 1160 represented by image 1101. In response to the parameters of the action 1130, the image separation operation identifies the portion of the scrollable content 1160 represented by image 1102 as the next image to be presented during the scrolling operation.

[0105] Unlike the page-by-page swipe mode described above, in which each subsequent image presented on the display does not include any of the content of the previous image, the image separation operation of the scroll mode is configured so that each subsequent image presented on the display includes at least a portion of the content of the previous image. For example, as shown in Figure 11, image 1101 (e.g., a first image) includes image data from a first portion of scrollable content 1160. Image 1102 (e.g., a second image) includes a portion 1140 of the image data from image 1101, while the remainder of the content of image 1102 is a second portion 1150 of scrollable content 1160 that includes content that was not presented in image 1101.

[0106] 9, upon completion of the image separation operation and generating the second image, method 900 includes updating (940) the electro-optic display with the second image. For example, the second image can be presented on the display using the "swipe update" technique described above. A segmentation and low-flash drive scheme such as described above in connection with FIGS. 1-8 can be used to transition from image 1101 to 1102, along with the aforementioned algorithms used to identify and / or flag display pixels that will exhibit edge artifacts and apply edge-cancelling waveforms to these pixels.

[0107] According to the swipe update technique, a first segment of the second image can be presented on a first portion of the electro-optic display. The location of the first segment can be based on an initial contact point of the swipe gesture and a direction of the swipe gesture. For example, if the initial contact point of the user's swipe gesture is near the bottom of the display and continues toward the top of the display, the first segment of the second image can be presented on a first portion of the electro-optic display at the bottom of the display.

[0108] After the display is updated with image 1102, method 900 reaches a decision point (950) where, if the scrolling operation should continue, it can return to step 930, perform another image separation operation, generate a subsequent image, and then continue updating the display with the subsequent image. For example, if the magnitude of the linear distance of the swipe gesture is large, the method can continue generating images and updating the display several more times. Alternatively, method 900 ends (960), leaving the most recently presented image on the display. In the example illustrated by FIG. 11 , method 900 performs subsequent image generation (930) and identifies the portion of scrollable content 1160 indicated by image 1103 (e.g., the third image) as the next image to be presented during the scrolling operation. Following image generation operation (930), an update step (940) is used to transition from presenting the content of image 1102 to presenting the content of image 1103.

[0109] Whether the scrolling action should continue can be based on parameters of the action 1130. The speed and / or length of the gesture applied to the touchscreen can be used to infer how far forward (or backward) from the current image the user wants to scroll. For example, a fast and / or long action 1130 can be used to infer that the user wants the scrolling action to advance several images from the current image. In some embodiments, the display is configured to advance a fixed number of images in response to a request to scroll content.

[0110] As described above, each subsequent image identified and generated by the image generation or separation operation (930) includes a portion of content from the previous image and a new portion that includes content not presented in the previous image. The parameters of the action 1130 can also be used to infer how much of the portion should be in the subsequent image and how much should be new. For example, a slower and / or shorter gesture applied to the touchscreen as action 1130 can be used to infer that the user wants to scroll slowly. Thus, in this case, the portion 1140 of the image identified by the image generation operation (930) will comprise a much larger percentage of the image than the new portion 1150. In other words, the proportion of the portion 1140 of image data from the first image (e.g., the first portion 1160 of the scrollable content) relative to the image data from the second portion 1150 of the scrollable content 1160 that is not found in the first image varies depending on the magnitude of the speed of the swipe gesture.

[0111] FIG. 12 provides another example illustrating the operation of method 900. (For ease of comparison, structures in FIG. 12 that are similar to FIG. 11 are generally annotated with like reference numerals.) It is noteworthy that the arrow symbol indicating action 1230 is larger than the arrow symbol indicating action 1130 in FIG. 11. This means that the magnitude of at least one of the parameters (e.g., speed, length, pressure, etc.) of action 1230 exceeds the same parameter of action 1130. For example, action 1230 may indicate a faster and / or longer gesture applied to the touchscreen. Thus, to create the illusion of a greater “jump” in scroll mode, some portion 1240 of the image identified by image generation operation 930 and new portion 1250 are approximately equal in size.

[0112] In some embodiments, parameters of the actions 1130 / 1230 are used to estimate a desired duration of the scrolling operation. For example, the speed and / or length of a gesture applied to the touchscreen can be an indication of the number of images that method 900 will present during the scrolling operation. In some embodiments, parameters of the actions 1130 / 1230 are used to estimate a desired perceived acceleration and deceleration rate of the scrolling operation. For example, a fast and / or long gesture applied to the touchscreen can cause method 900 to initially present a subsequent image in which the portion 1140 / 1240 is much smaller than the new portion 1150 / 1250 of the image, creating the illusion of accelerating or fast scrolling. Method 900 can then gradually change the proportion of the portion 1140 / 1240 to provide the illusion of deceleration, and finally, method 900 can terminate and stop the scrolling operation.

[0113] Figure 13 is a diagram illustrating a continuous scrolling operation on a portion of an image. In the illustration of Figure 13, designated "initial state," a display device 1300 presents an image on a touch screen 1310. The portion of the image displayed on the touch screen 1310 includes a sub-image 1301, which is an image displaying a portion of the content of digital content 1360. In this embodiment, the methods described herein can be used to detect a user's input 1320 action 1330 on the touch screen 1310, perform a scrolling operation, and scroll through the content of the digital content 1360. In this embodiment, the scrolling operation is performed only on the sub-image 1301 portion of the display screen. The other content of the displayed image does not change.

[0114] In the illustration of FIG. 13 , designated “final state,” display device 1300 now presents sub-image 1305, which includes the final content of digital content 1360. Thus, it can be inferred that method 900 identified and transitioned four sub-images (e.g., sub-images 1302-1305) in the course of a scrolling action applied to the content of digital content 1360 from the initial state to the final state. This embodiment avoids unnecessary distractions when scrolling through complex images and relies on swipe updates for scroll directionality. Scroll transitions can also be performed faster because only a portion of the overall image displayed changes during each update.

[0115] In another embodiment, the displayed image constitutes digital content, and the techniques described herein can be applied to display portions of the image in different formats. For example, the techniques described herein can be applied to enable a zoom function. FIG. 14 is an exemplary diagram illustrating images processed in accordance with the described embodiment. Image 1401 displays a passage of text from an electronic book. Image 1402 has the same dimensions as image 1401 but displays only a portion 1412 of the content of image 1401. Furthermore, the format of the content displayed in image 1402 has been modified, in this case, enlarged, as part of the zoom operation. Similarly, image 1403 has the same dimensions as image 1402 but displays only a portion 1413 of the content of image 1402. Furthermore, the format of the content displayed in image 1403 has been modified, in this case, enlarged, as part of the zoom operation.

[0116] FIG. 15 is an exemplary diagram illustrating the operation of a method for presenting content in a zoom mode according to embodiments described herein. The diagram illustrates a zoom transition from image 1401 (e.g., a first image) to 1402 (e.g., a second image). The method detects a request to zoom the content. For example, a display device can detect a user input indicating a zoom action (e.g., a touch with two fingers and a gesture in which they move away from each other, also referred to as a pinch-out gesture). The method starts with image 1401, which includes the same content as image 1401 shown in FIG. 14. The method begins the transition from image 1401 to image 1402 by first updating image 1401 with first portion 1570, which is a first part of the content of image 1402. Referring to FIG. 15, image 1401a shows a first segment or portion 1570 of image 1402 that is embedded within or overlaid on the content of image 1401.

[0117] The method then continues by updating image 1401a with a second segment or portion 1580, which is a second portion of the content of image 1402. Referring to FIG. 15, image 1401b shows second portion 1580 embedded within or overlaid on the content of image 1401a. The method continues updating in this manner until the entire content of image 1402 is displayed. As described above in connection with FIGS. 1-8, a segmentation and low-flash drive scheme can be used to transition from image 1401 to 1402, along with the aforementioned algorithms used to identify and / or flag display pixels that will exhibit edge artifacts and apply edge-cancelling waveforms to these pixels. In this case, the drive scheme performs regional updates to the display that do not begin at one of the edges of the display. For example, as shown in image 1401a of FIG. 15, an area in the center of the display is updated first with a first segment or portion 1570, giving the illusion of a zooming action as additional segments of image 1402 are presented on the display.

[0118] 16 , in some embodiments, second portion 1580 includes all of the content of first portion 1570, as represented by 1580a. In some embodiments, second portion 1580 does not include the content of first portion 1570, as represented by 1580b. This provides the advantage of faster updates during zoom operations, as fewer display pixels are required to be updated when transitioning from image 1401a to image 1401b (or when transitioning from image 1401b to a subsequent image until the entire content of image 1402 is displayed).

[0119] Thus, the inventive techniques described herein can be used to improve the user experience by providing the illusion of fluidity and directionality of separated images as they transition. The use of swipes not only provides directionality to scrolling, which is important, but also an animated way in which the swipe update progression reduces the perceived flash effect of the updates and provides the illusion of fluidity. Images are updated continuously using the "swipe update" technique, providing the illusion of movement in scrolling and zooming actions. Because the images are separated in such a way that the displayed image is actually changing, the desired effect of making the user perceive the content as moving is achieved in an animated way.

[0120] Additionally, the inventive techniques described herein can enable updating a display with an image having pixels set to any gray level using a waveform capable of displaying full gray levels (e.g., GLR or Regal waveform mode). Additionally, the inherent artifact cancellation of swipe updates reduces or eliminates any undesirable image artifacts during or after continuous scrolling operations. Advantageously, these techniques can be applied to black text on a white background, night or dark mode (white text on a black background), and CFA-based color displays.

[0121] It will be apparent to those skilled in the art that numerous changes and modifications can be made in the specific embodiments of the invention described above without departing from the scope of the invention. Accordingly, the whole of the foregoing description is to be interpreted in an illustrative sense, and not in a restrictive sense.

Claims

1. 1. A method of driving an electro-optic display having a plurality of display pixels, the method comprising: updating the electro-optic display with a first image comprising image data from a first portion of the scrollable content; receiving user input comprising one or more parameters; generating a second image based on at least one parameter of the user input, the second image comprising: a portion of the image data from the first portion of the scrollable content; image data from a second portion of the scrollable content; and and updating the electro-optic display with the second image; and A method comprising:

2. Updating the electro-optic display with the second image comprises: updating a first portion of the electro-optic display with a first segment of the second image; implementing a time delay following the first portion of the electro-optic display, wherein updating of the electro-optic display is suspended during the time delay; updating a second portion of the electro-optic display with a second segment of the second image following the time delay; and The method of claim 1 , comprising:

3. 3. The method of claim 2, further comprising applying an edge blanking waveform to the display pixels of the electro-optic display during the time delay.

4. identifying a display pixel with an edge artifact using an algorithm, the algorithm configured to flag a display pixel having an edge artifact based on a next optical state of the display pixel and the optical state of at least one of a major neighborhood of the display pixel; applying an edge blanking waveform to the display pixels flagged by the algorithm during the time delay; The method of claim 2 further comprising:

5. The method of claim 1 , wherein the user input comprises a swipe gesture on the electro-optic display.

6. 6. The method of claim 5, wherein the user input comprises a first parameter indicating a direction of the swipe gesture and a second parameter, the second parameter indicating a magnitude of one or more of a velocity of the swipe gesture, a linear distance of the swipe gesture, and a pressure of the swipe gesture.

7. The method of claim 6 , wherein the position of the first portion of the electro-optic display is based on an initial contact point of the swipe gesture and the direction of the swipe gesture.

8. The method of claim 7 , wherein the location of the second portion of the electro-optic display is adjacent to the location of the first portion of the electro-optic display.

9. 7. The method of claim 6, wherein a ratio of the portion of the image data from the first portion of the scrollable content to the image data from the second portion of the scrollable content varies depending on the magnitude of the velocity of the swipe gesture.

10. The method of claim 1 , wherein the portion of the image data from the first portion of the scrollable content and the image data from the second portion of the scrollable content are contiguous within the scrollable content.

11. 1. A method of driving an electro-optic display having a plurality of display pixels, the method comprising: updating the electro-optic display with a first image comprising image data; receiving user input comprising one or more parameters; generating a second image based on at least one parameter of the user input, the second image comprising a portion of the image data of the first image but enlarged to have dimensions equal to those of the first image; updating the electro-optic display with the second image; and A method comprising:

12. Updating the electro-optic display with the second image comprises: updating a first portion of the electro-optic display with a first segment of the second image; implementing a time delay following the first portion of the electro-optic display, wherein updating of the electro-optic display is suspended during the time delay; updating a second portion of the electro-optic display with a second segment of the second image following the time delay; and The method of claim 11 , comprising:

13. 13. The method of claim 12, further comprising applying an edge blanking waveform to the display pixels of the electro-optic display during the time delay.

14. identifying a display pixel with an edge artifact using an algorithm, the algorithm configured to flag a display pixel having an edge artifact based on a next optical state of the display pixel and the optical state of at least one of a major neighborhood of the display pixel; applying an edge blanking waveform to the display pixels flagged by the algorithm during the time delay; The method of claim 12 further comprising:

15. The method of claim 11 , wherein the user input comprises a pinch-out zoom gesture on the electro-optic display.

16. The method of claim 15 , wherein the user input comprises a parameter indicating a magnitude of a linear distance of the pinch-out zoom gesture.

17. The method of claim 16 , wherein the amount by which the portion of the image data of the first image is magnified in the second image is proportional to the magnitude of the linear distance of the pinch-out zoom gesture.

18. The method of claim 16 , wherein the position of the first portion of the electro-optic display is based on an initial contact point of the pinch-out zoom gesture.

19. 17. The method of claim 16, wherein the location of the second portion of the electro-optic display is adjacent to the location of the first portion of the electro-optic display.

20. 17. The method of claim 16, wherein the second portion of the electro-optic display surrounds the first portion of the electro-optic display.

21. The method of claim 16 , wherein the second segment of the second image surrounds the first segment of the second image.

22. The method of claim 16 , wherein the second segment of the second image includes content of the first segment of the second image.

Images