# US 8,542,172 B2 · Driving of electro-optic displays > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,542,172 B2 - Document ID: US8542172B2 - Status: Granted - Kind: B2 - Application number: 12/515,114 - Filed: 2007-11-15 - Published: 2010-02-25 - Granted: 2013-09-24 - Earliest claimed: 2006-11-16 - Assignees: Liquavista B.V. - Applicants: Robert Gerardus Hendrik Boom; Roy Van Dijk; Henricus Petronella Maria Derckx - Inventors: Robert Gerardus Hendrik Boom; Roy Van Dijk; Henricus Petronella Maria Derckx - Web page: https://patentgrep.com/patent/US8542172B2 ## CPC - G02B 26/004: {based on a displacement or a deformation of a fluid} - G09G 3/16: by control of light from an independent source - G09G 3/34: by control of light from an independent source - G09G 3/3433: {using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices (using liquid crystal devices G09G3/36; using electrochromic devices G09G3/38)} - G09G 3/344: {based on particles moving in a fluid or in a gas, e.g. electrophoretic devices (electrophoretic devices per se G02F1/167)} - G09G 3/348: {based on the deformation of a fluid drop, e.g. electrowetting} - G09G 2310/0256: with the purpose of reversing the voltage across a light emitting or modulating element within a pixel - G09G 2310/061: for resetting or blanking - G09G 2330/021: Power management, e.g. power saving - G09G 2330/028: Generation of voltages supplied to electrode drivers in a matrix display other than LCD - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) ## Abstract A method of operating an electro-optic display apparatus, wherein the display apparatus includes a display device having image regions and a display driving system having a data input for selecting image regions. The data input is connected to the input of a distributor for providing signals for driving the image regions. Each image region has an active display state in which the image region is driven with an active voltage signal. The active voltage signal includes a first signal level which sets an image region to the active display state and a second signal level different from said first signal level and which is applied for a shorter duration than said first signal level. The method comprises the following three steps: (1) applying the first signal level to one of said image regions in response to receiving data on said data input indicating that said image region is to be set to the active display state, (2) applying the second signal level to said image region after said first signal level has been applied; and (3) reapplying said first signal level before receipt of further data for said image region on said data input. ## Claims ### Claim 1 A method of operating an electro-optic display apparatus, the display apparatus including a display device having image regions and a display driving system, the driving system having a distributor for providing signals for driving the image regions, and a data input for selecting image regions connected to the input of the distributor, each image region having an active display state in which the image region is driven with an active voltage signal, wherein the active voltage signal includes a first signal level which sets an image region to the active display state and a second signal level different from said first signal level and which is applied for a shorter duration than said first signal level, the method comprising: applying said first signal level to one of said image regions in response to receiving data on said data input indicating that said image region is to be set to the active display state, applying the second signal level to said image region after said first signal level has been applied; and reapplying said first signal level before receipt of further data for said image region on said data input, wherein said display driving system includes an output latch for latching data received via said data input, and wherein said second signal level is applied to a given image region without varying data held in said output latch for said image region. ### Claim 2 (depends on 1) A method according to claim 1, wherein said first signal level is substantially different to zero, and wherein said second signal level is substantially equal to zero. ### Claim 3 (depends on 1) A method according to claim 1, comprising applying a different voltage signal to a different image region, said different voltage signal being maintained at a substantially constant level whilst said active voltage signal is varied between said first signal level and said second signal level. ### Claim 4 (depends on 1) A method according to claim 1, wherein a plurality of image regions have a common signal line, the method comprising changing the voltage on the common signal line, thereby changing the active voltage signal of the image region from the first signal level to the second signal level and back to the first signal level. ### Claim 5 (depends on 1) A method according to claim 1, wherein the display driving system includes a driver stage for each image region and one or more driver stages have a power supply input, the method including changing a voltage of a power applied to the power supply input in response to a reset signal, thereby changing the active voltage signal of the one or more driver stages from the first signal level to the second signal level and back to the first signal level. ### Claim 6 (depends on 5) A method according to claim 5, wherein one or more driver stages and the latch have a common power supply input, the method comprising reducing the voltage of the power to a minimum voltage for operation of the latch in response to the reset signal. ### Claim 7 (depends on 1) A method according to claim 1, comprising receiving a separate signal from an input separate from said data input, said separate signal defining one or more characteristics relating to the application of the second signal level. ### Claim 8 (depends on 7) A method according to claim 7, wherein said separate signal has a signal waveform which corresponds with a waveform with which said second signal is applied. ### Claim 9 (depends on 7) A method according to claim 7, wherein said separate signal is in the form of data which defines one or more characteristics of a waveform with which said second signal is applied. ### Claim 10 (depends on 9) A method according to claim 9, comprising receiving a separate signal from an input separate from said data input, said separate signal being in the form of data which defines one or more characteristics of a waveform with which said second signal is applied, wherein said waveform generator is responsive to said separate signal. ### Claim 11 (depends on 1) A method according to claim 1, wherein said display driving system includes a waveform generator, and the method comprises generating a waveform with which said second signal is applied using said waveform generator. ### Claim 12 (depends on 11) A method according to claim 11, wherein said display driving system includes a data register, and wherein said waveform generator is responsive to said data register. ### Claim 13 (depends on 1) A method according to claim 1, wherein said display driving system includes a plurality of driver stages, each said driver stage being responsive to a first input signal defining said active voltage signal and a second input signal defining a signal which is used to apply a voltage at said second signal level. ### Claim 14 (depends on 1) A method according to claim 1, wherein said second signal level is applied in the form of a pulse waveform. ### Claim 15 (depends on 14) A method according to claim 14, wherein said pulse waveform has a duration of less than 10 milliseconds or less than or equal to 1 millisecond. ### Claim 16 (depends on 1) A method according to claim 1, wherein said display device is a segmented display in which each of said image regions corresponds with a different segment of the display, wherein said method comprises applying the active voltage signal to a segment during the interval between the first and the second consecutive data items corresponding to said segment. ### Claim 17 (depends on 1) A method according to claim 1, wherein said display device is an electrowetting display device. ### Claim 18 (depends on 17) A method according to claim 17, in which an image region comprises at least one first fluid and a second fluid immiscible with each other and at least one surface area, the method including applying voltages to the image region associated with a non-active display state and an active display state, in said non-active display state said first fluid tends to cover said at least one surface area, and in said active display state said second fluid tends to cover said at least one surface area. ### Claim 19 (depends on 1) A display driving system for an electro-optic display device having image regions, each image region having an active display state in which the image region is driven with an active voltage signal, adapted to perform the method of claim 1. ### Claim 20 (depends on 19) An electro-optic display apparatus including a display driving system according to claim 19 and a display device. ### Claim 21 A display driving system for an electro-optic display device having image regions, each image region having an active display state in which the image region is driven with an active voltage signal, including a data input for selecting image regions, comprising: a distributor having an input connected to the data input and having one or more distributor outputs; a driving assembly including one or more driver stages, each driver stage having an input connected to one of the distributor outputs and a driver stage output connected to one of said image regions for providing an active voltage signal, the active voltage signal including a first signal level for setting the image region to an active display state and a second signal level different from said first signal level and which is applied for shorter durations than said first signal level; a reset controller having an output providing a reset signal and connected to the driving assembly for providing in response to the reset signal at the one or more driver stage outputs the second signal level of the active voltage signal; and an output latch for latching data received via said data input, wherein the display driving system is configured such that said second signal level is applied to a given image region without varying data held in said output latch for said image region. ### Claim 22 (depends on 21) A display driving system according to claim 21, including a second distributor having an input connected to the output of the reset controller and one or more second distributor outputs, each driver stage having a second input connected to one of the second distributor outputs. ### Claim 23 (depends on 22) A display driving system according to claim 22, wherein each driver stage includes an AND gate connected to one of the distributor outputs and either one of the second distributor outputs or the output of the reset controller. ### Claim 24 (depends on 22) A display driving system according to claim 22, including a plurality of driver stages and each driver stage output comprising two terminals, wherein a plurality of driver stages have one of the terminals in common, the plurality of driver stages being arranged to change the voltage of the terminal in common in response to the reset signal, thereby changing the active voltage signal of each driver stage from the first signal level to the second signal level and back to the first signal level. ### Claim 25 (depends on 21) A display driving system according to claim 21, wherein each driver stage has a second input connected to the output of the reset controller. ### Claim 26 (depends on 21) A display driving system according to claim 21, wherein one or more driver stages have a power supply input and the driver stage is arranged to change a voltage of a power applied to the power supply input in response to the reset signal, thereby changing the active voltage signal of the one or more driver stages from the first signal level to the second signal level and back to the first signal level. ### Claim 27 (depends on 26) A display driving system according to claim 26, wherein the latch is connected to the outputs of the distributor for latching data received via said data input, wherein one or more driver stages and the latch have a common power supply input and the one or more driver stages are arranged to reduce in response to the reset signal the voltage of the power to a minimum voltage for operation of the latch. ### Claim 28 A display driving system for an electro-optic display device having image regions, each image region having an active display state in which the image region is driven with an active voltage signal, including a data input for selecting image regions, comprising: a distributor having an input connected to the data input and having one or more distributor outputs; a driving assembly including one or more driver stages, each driver stage having an input connected to one of the distributor outputs and a driver stage output connected to one of said image regions for providing an active voltage signal, the active voltage signal including a first signal level for setting the image region to an active display state and a second signal level different from said first signal level and which is applied for shorter durations than said first signal level; and a reset controller having an output providing a reset signal and connected to the driving assembly for providing in response to the reset signal at the one or more driver stage outputs the second signal level of the active voltage signal, wherein one or more driver stages have a power supply input and the driver stage is arranged to change a voltage of a power applied to the power supply input in response to the reset signal, thereby changing the active voltage signal of the one or more driver stages from the first signal level to the second signal level and back to the first signal level, and including a latch connected to the outputs of the distributor for latching data received via said data input, wherein one or more driver stages and the latch have a common power supply input and the one or more driver stages are arranged to reduce in response to the reset signal the voltage of the power to a minimum voltage for operation of the latch.