Apparatus and system for writing data to electromechanical display elements
First Claim
Patent Images
1. An apparatus for displaying images, comprising:
- an electromechanical display element comprising at least a portion of an array of electromechanical display elements;
a column driver configured to assert a voltage on one or more columns of the array; and
a row driver configured to pulse one or more rows of the array with a voltage,wherein the column driver and row driver are configured to apply a plurality of potential differences across the electromechanical display element during a display write process, the column driver and row driver being configured to write display data to the electromechanical display element with a first potential difference of a first polarity during a first portion of the display write process, re-write the display data to the electromechanical display element with a second potential difference having a polarity opposite the first polarity during a second portion of the display write process, apply a third potential difference having the first polarity to the electromechanical display element during a third portion of the display write process, and apply a fourth potential difference having the opposite polarity to the electromechanical display element during a fourth portion of the display write process,wherein a state of the electromechanical display element does not change during or between the third and fourth portions of the display write process,wherein a transition time between applying the third and fourth potential differences is less than or equal to τ
iMoD+τ
RC, wherein τ
iMoD includes a constant of said electromechanical display element determined with reference to physical characteristics of said electromechanical display element, and wherein τ
RC includes a constant related to electrical characteristics of said electromechanical display element.
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Accused Products
Abstract
Charge balanced display data writing systems, apparatuses, and methods use write and hold cycles of opposite polarity during selected frame update periods. A release cycle may be provided to reduce the chance that a given display element will become stuck in an actuated state.
97 Citations
24 Claims
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1. An apparatus for displaying images, comprising:
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an electromechanical display element comprising at least a portion of an array of electromechanical display elements; a column driver configured to assert a voltage on one or more columns of the array; and a row driver configured to pulse one or more rows of the array with a voltage, wherein the column driver and row driver are configured to apply a plurality of potential differences across the electromechanical display element during a display write process, the column driver and row driver being configured to write display data to the electromechanical display element with a first potential difference of a first polarity during a first portion of the display write process, re-write the display data to the electromechanical display element with a second potential difference having a polarity opposite the first polarity during a second portion of the display write process, apply a third potential difference having the first polarity to the electromechanical display element during a third portion of the display write process, and apply a fourth potential difference having the opposite polarity to the electromechanical display element during a fourth portion of the display write process, wherein a state of the electromechanical display element does not change during or between the third and fourth portions of the display write process, wherein a transition time between applying the third and fourth potential differences is less than or equal to τ
iMoD+τ
RC, wherein τ
iMoD includes a constant of said electromechanical display element determined with reference to physical characteristics of said electromechanical display element, and wherein τ
RC includes a constant related to electrical characteristics of said electromechanical display element. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for actuating an electromechanical display element, said electromechanical display element comprising a portion of an array of electromechanical display elements, said apparatus comprising:
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means for writing display data to said electromechanical display element with a potential difference of a first polarity during a first portion of a display write process; means for re-writing said display data to said electromechanical display element with a potential difference having a polarity opposite said first polarity during a second portion of said display write process; means for applying a first bias potential having said first polarity to said electromechanical display element during a third portion of said display write process; and means for applying a second bias potential having said opposite polarity to said electromechanical display element during a fourth portion of said display write process, wherein a state of said electromechanical display element does not change during or between said third and fourth portions, wherein a transition time between applying the first and second bias potentials is less than or equal to τ
iMoD+τ
RC, wherein τ
iMoD includes a constant of said electromechanical display element determined with reference to physical characteristics of said electromechanical display element, and wherein τ
RC includes a constant related to electrical characteristics of said electromechanical display element. - View Dependent Claims (10, 11)
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12. A system for writing frames of display data, comprising:
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an array of electromechanical display elements; and an array controller comprising a column driver and a row driver, the column driver configured to assert a potential on one or more columns of the array, the row driver configured to pulse one or more rows of the array with a potential, wherein the array controller is configured to write display data to the electromechanical display elements, the writing requiring less than a defined frame update period, and wherein the array controller is further configured to apply a series of bias potentials of alternating polarity to the electromechanical display elements for the remainder of said frame update period, and wherein a state of the electromechanical display elements does not change during the remainder, wherein a transition time between a pair of consecutive bias potentials is less than or equal to τ
iMoD+τ
RC wherein τ
iMoD includes a constant of said electromechanical display elements determined with reference to physical characteristics of said electromechanical display elements, and wherein τ
RC includes a constant related to electrical characteristics of said electromechanical display elements. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. An apparatus for writing frames of display data to an array of electromechanical display elements at a rate of one frame per defined frame update period, said apparatus comprising:
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means for writing display data to said electromechanical display elements, wherein said writing takes less than said frame update period; and means for applying a series of bias potentials of alternating polarity to said electromechanical display elements for the remainder of said frame update period, wherein a state of said electromechanical display elements does not change during said remainder, wherein a transition time between a pair of consecutive bias potentials is less than or equal to τ
iMoD+τ
RC, wherein τ
iMoD includes a constant of said electromechanical display elements determined with reference to physical characteristics of said electromechanical display elements, and wherein τ
RC includes a constant related to electrical characteristics of said electromechanical display elements. - View Dependent Claims (21)
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22. A device for driving display elements, comprising:
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a display comprising a plurality of pixels; and a display controller configured to periodically release substantially all pixels of said display, the display controller being configured to periodically release each pixel such that there is no perceptible effect on visual appearance of the display to a normal observer, wherein each pixel is released at a rate of less than once per frame. - View Dependent Claims (23, 24)
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Specification