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US 5,444,457 AGranted
DC integrating display driver employing pixel status memories
AssigneeRobert Hotto
InventorRobert Hotto
Life of this patent
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Abstract
This invention relates to an improved drive and control means for matrix addressable electro-optic displays, such as passive matrix LCDs and active matrix LCDs. The present invention achieves improved drive and control of displays through the use of real time computation and memory circuits to simulate the electro-optic condition and the accumulated DC bias of individual display elements. This eliminates the burden of frequent and symmetrical reversals of the drive polarity, and allows the implementation of flexible DC drive methodologies.
Claims65
In combination,
- display means formed from a plurality of elements each constructed to provide for the display of an image in accordance with the introduction of signals to such element,
- the elements being arranged in rows and columns,
- first means for selecting the elements in a plurality of rows for simultaneous processing,
- second means for providing signals to obtain the display of the images in the elements in the selected rows, and
- third means for processing the signals provided for the elements in the selected rows in a priority dependent upon the characteristics of such signals.
2 more elements
In combination,
- display means formed from a plurality of elements each constructed to provide for the display of an image in accordance with the introduction of signals to such elements,
- first means for providing a plurality of signals each representing the image to be displayed on an individual one of the elements, and
- second means for applying direct voltages to the elements in accordance with the signals provided for the elements to obtain a display on the display means,
- the first means being operative to provide the images for the elements in the plurality in a sequence of successive frames, and
- the second means being operative to apply the direct voltages to the elements in the plurality, in successive ones of the successive frames in the sequence, in accordance with the signals provided for such elements in such successive frames to obtain the display of the images for such elements in such successive frames on the display means.
2 more elements
In combination for use with display means formed from a plurality of elements each constructed to provide for the display of an image in accordance with the introduction of signals to such element,
- first means for providing signals representing the images to be demanded from individual elements in the display means,
- second means for storing signals representing the images provided from the .individual elements in the display means,
- third means for providing, for the individual elements in the display means, signals representing the difference between the signals from the second and first means for such elements, and
- fourth means for changing the images from the individual elements in the display means in accordance with the signals from the third means for such elements,
- the fourth means being operative to introduce direct voltages to the individual elements in the display means in accordance with the signals from the third means for such individual elements to change the images from such individual elements,
- fifth means for reversing the polarity of the direct voltages applied to the individual elements in the display means when the cumulative values of the direct voltages introduced to such individual elements approach a maximum bias voltage tolerance, and
- sixth means for establishing a priority in the changes provided in the individual elements in the display means in accordance with the characteristics of the signals from the third means for such individual elements,
- the sixth means being operative to establish the same priority in the changes provided by the fourth means for different ones of the individual elements in response to the same characteristics of the signals from the third means for such different ones of the individual elements.
5 more elements
In combination for use with display means formed from a plurality of elements each constructed to provide for the display of an image at such element in accordance with the introduction of signals to such element,
- first means for providing signals representing the images to be provided from individual elements in the display means,
- second means for providing for the processing simultaneously of the signals representing the images from a plurality of the individual elements in the display means, and
- third means for providing for the processing by the second means of the signals representing the images from the different ones of the individual elements in the display means in a priority dependent upon the characteristics of such signals.
In a combination as set forth in clam 13,
- fifth means for determining the temperatures of the elements in the plurality, and
- sixth means for modifying the operation of the fourth means in accordance with the temperature determinations from the fifth means.
In combination for use with display means formed from a plurality of elements each constructed to provide for the display of an image in accordance with the introduction of signals to such elements,
- first means for providing successive sequences of signals each representing the image to be provided from an individual one of the elements in the display means, each successive sequence of signals representing the image to be provided by all of the elements in the display means,
- second means for processing the signals in each successive sequence on an asynchronous basis relative to the provisions of the signals in each such successive sequence by the first means, and
- third means for providing for the display of the images on the elements in the display means in each successive sequence in accordance with the processing of the signals by the second means on the asynchronous basis relative to the provisions of the signals in each such successive sequence by the first means,
- the second means processing the signals for the individual elements in the display means in each successive sequence on a basis dependent upon the difference in the image from each element in the display means in such successive sequence and the previous one of such successive sequence,
- the second means processing the signals simultaneously for a plurality of the individual elements in each successive sequence on a priority basis dependent upon the characteristics of the signals representing the images from such individual elements in such successive sequence.
2 more elements
In combination for use with display means formed from a plurality of elements each constructed to provide for the display of an image in accordance with the introduction of signals to such element,
- first means for providing successive sequences of signals each representing the image to be provided from an individual one of the elements in the display means, each successive sequence of signals representing the images to be provided by all of the elements in the display means,
- second means for processing the signals in each successive sequence to determine the difference between the signals for each individual one of the elements in such successive sequence and the previous sequence, and
- third means for displaying the image from each individual one of the elements in the display means in each successive sequence in accordance with the difference signal from the second means for that element in that sequence and the previous sequence.
In combination for use with display means formed from a plurality of elements each constructed to provide for the display of an image in accordance with the introduction of signals to such element, the elements being constructed to become charged and discharged to provide a display in accordance with the net charge on such elements,
- first means for providing successive sequences of signals each representing the image to be provided from an individual one of the elements in the display means, each successive sequence of signals representing the images to be provided by all of the elements in the display means,
- second means for processing the signals from the different elements in the display means in the successive sequences to determine the changes to be made in the display means from the different elements in the display means in such successive sequences, and
- third means for providing for changes in the charges in the different elements in the display means in each successive sequence in accordance with the changes determined for such elements by the second means in that successive sequence.
In combination for use with display means formed from a plurality of elements constructed to provide for the display of an image in accordance with the introduction of signals to such elements, the elements being disposed in rows and columns in the display means,
- first means for providing successive sequences of signals each representing the image to be provided from an individual one of the elements in the display means, each successive sequence of signals representing the image to be provided by all of the elements in such sequence,
- second means for processing the signals for the different elements in the display means in the successive sequences to determine the relative characteristics of the images in such different elements in such successive sequences,
- third means for processing the signals from the second means in each successive sequence to determine, from the relative characteristics of the images in the elements in such successive sequence, whether the rows or columns of the elements in the display means should be scanned in such successive sequence,
- fourth means for scanning the rows or columns in each successive sequence in accordance with the determinations provided by the third means in such successive sequence, and
- fifth means for changing the images provided from the different elements by the fourth means in each successive scan of the elements in the rows or columns in accordance with the relative characteristics determined by the second means for the different elements in such successive scan of the elements in the rows or columns.
2 more elements
In combination for use with display means formed from a plurality of elements each constructed to provide for the display of an image in accordance with the introduction of signals to such element,
- first means for providing signals representing the images to be provided from individual ones of the elements in the display means,
- second means responsive to the signals from the first means for the individual ones of the elements in the display means and to the images displayed in such individual ones of the elements in the display means for producing signals representing the changes to be provided in such images from such individual ones of the elements, and
- third means responsive to the signals from the second means for applying direct voltages to the individual ones of the elements in the display means to obtain the changes in the images in the individual ones of the elements in the display means.
In combination for use with display means formed from a plurality of elements each constructed to provide for the display of an image in accordance with the introduction of signals to such element,
- first means for providing signals representing the images to be provided from individual ones of the elements in the display means,
- second means for storing the signals representing the images provided from the individual ones of the elements in the display means,
- third means responsive to the signals from the first and second means from the individual ones of the elements in the display means for providing signals representing the differences between the signals from the first and second means for such individual ones of the elements in the display means, and
- fourth means responsive to the signals from the third means for providing for increases in the gray levels of the images in first elements in the display means in accordance with differences of one polarity as represented by the signals from the third means for such first elements and for providing for decreases in the gray levels of the images in second elements in the display means in accordance with differences of an opposite polarity as represented by the signals from the third means for such second elements.
1 more element
In combination for use with display means formed from a plurality of elements each constructed to provide for the display of an image in accordance with the introduction of signals to such element,
- first means for providing signals representing the gray levels of images to be provided from individual ones of the elements in the display means,
- second means for storing the signals representing the gray levels of the images provided from the individual ones of the elements in the display means, and
- third means for providing drive pulses on an incremental basis to the individual ones of the elements in the display means to minimize on the incremental basis the differences between the gray levels of the provided images from the second means and the gray levels of the to-be-provided images from the first means for such individual elements.
A drive system for a matrix addressable electro-optic display formed of a plurality of pixels, wherein the image is produced during successive display periods, said pixels being capable of being driven in either of two opposite polarity directions to produce the desired display,
- means for driving said pixels in a first polarity for a plurality of successive display periods,
- said pixels having a maximum bias violation tolerance,
- said drive system comprising means for reversing the first polarity of said drive signals to said pixels to prevent any of said pixels from exceeding said maximum bias violation tolerance, said pixels being overdriven in a reverse polarity direction for an initial display period to compensate for optical effects of polarity reversal on said display.
In combination,
- display means formed from a plurality of elements each constructed to provide for the display of an image in accordance with a charge on such element,
- first means for providing a plurality of signals representing the images to be provided on the different elements in the display,
- second means for selecting a number, more than one (1), of the elements on a priority basis for simultaneous processing in accordance with the characteristics of the signals representing the images for such elements, and
- third means for simultaneously producing voltage changes on the selected elements on an incremental basis in accordance with the characteristics of the signals representing the images for such elements.
1 more element
In combination,
- display means formed from a plurality of elements each constructed to provide for the display of an image in accordance with the introduction of signals to such element, the elements being disposed in a relationship defined by a plurality of rows and a plurality of columns,
- first means for providing the signals for each of the elements in each of a plurality of successive scans,
- second means for analyzing the signals for the elements in each scan to determine the priorities to be established in the rows or columns in such scan for acting upon the elements in such scan in producing the images for such elements, and
- third means for acting upon the elements in the rows and columns in each scan in accordance with the priorities determined for such rows or columns by the second means in such scan to produce the images on the elements in such scan.
1 more element
In combination,
- display means formed from a plurality of elements each constructed to provide for the display of an image in accordance with the introduction of signals to such element, the elements being disposed in a relationship defined by a plurality of rows and a plurality of columns,
- first means for providing the signals for each of the elements in each of a plurality of successive scans,
- second means for analyzing the signals for the elements in each scan to determine the priorities to be established initially in the rows or columns in such scan for acting upon the elements in such scan in producing the images for such elements,
- third means for applying voltage increments to the elements in such scan in accordance with the priorities initially established by the second means for the elements in such rows or columns in such scan,
- fourth means responsive to the voltage increments initially applied by the third means to the elements in such scan for obtaining a re-analysis by the second means of the priorities to be established subsequently in the rows or columns in such scan for acting upon the elements in such scan in producing the images for such elements, and
- fifth means responsive to the re-analysis by the second means for obtaining an operation of the third means in applying incremental changes in voltage to the elements in such scan in accordance with the priorities subsequently established by the second means for the elements in such rows or columns in such scan.
3 more elements
Dependencies are inferred from the claim text.