Addressing schemes for electronic displays

Abstract

An electronic display comprises an electro-optic material (preferably an electrophoretic medium) having a plurality of pixels, and separate first, second and third sets of addressing means for addressing these pixels. Each of the pixels is associated with one addressing means in each of the three sets, such that addressing of any specific pixel requires application of signals within predetermined ranges to each of the three addressing means associated with the specific pixel being addressed. The display may be in the form of a multi-page electronic book.

1 . A method of addressing a bistable electronic display having a plurality of pixels arranged in an array comprising a plurality of rows and plurality of columns, the method comprising selecting a plurality of rows or columns and applying a simultaneous and equivalent switching impulse to all selected rows and columns. 
   
   
       2 . An electronic display according to  claim 1  wherein the electronic display comprises an electrophoretic medium. 
   
   
       3 . An electronic display according to  claim 2  wherein said electrophoretic medium is an encapsulated electrophoretic medium. 
   
   
       4 . An electronic display according to  claim 1  wherein the electronic display comprises a rotating bichromal object material. 
   
   
       5 . An electronic display according to  claim 1  wherein the electronic display operates by principle of one of the following: rotating bichromal objects, electrochromics, or suspended particles. 
   
   
       6 . A method of addressing a bistable electronic display having a plurality of pixels arranged in a plurality of rows, the method comprising: (a) comparing a starting state of the display with a desired finishing state and determining for each pixel a change value representative of the change needed to change the starting state of that pixel to its desired finishing state; and (b) calculating from the pixel change values for each row, a switch direction value for that row, said switch direction value representing the value for which, if all pixels if that row were changed by the switch direction value, the row switch time required to switch the row to the desired finishing state would be minimized. 
   
   
       7 . A method according to  claim 6  further comprising any one or more of the following steps: (c) calculating the average switch direction value for all rows of the display; (d) identifying all rows with switch direction values less than the average switch direction value calculated in step (c); (e) calculating the average switch direction value of all rows identified in step (d); (f) applying to all rows identified in step (d) an impulse sufficient to cause a change in state equal to the average switch direction value calculated in step (e); (g) identifying all rows with switch direction values greater than the average switch direction value calculated in step (c); (h) calculating the average switch direction value of all rows identified in step (g); and (i) applying, to all rows identified in step (g), an impulse sufficient to cause a change in state equal to the average switch direction value calculated in step (g). 
   
   
       8 . An electronic display according to  claim 6  wherein the electronic display comprises an electrophoretic medium. 
   
   
       9 . An electronic display according to  claim 8  wherein said electrophoretic medium is an encapsulated electrophoretic medium. 
   
   
       10 . An electronic display according to  claim 6  wherein the electronic display comprises a rotating bichromal object material. 
   
   
       11 . An electronic display according to  claim 6  wherein the electronic display operates by principle of one of the following: rotating bichromal objects, electrochromics, or suspended particles. 
   
   
       12 . A method of addressing a bistable electronic display having a plurality of pixels, each of said pixels having a first display state, a second display state differing in at least one optical characteristic from the first display state, and a plurality of intermediate states having values of said optical characteristic intermediate those of said first and second display states, the method comprising: driving all the pixels of the display to the same one of said intermediate states; and thereafter addressing said pixels individually to drive them to their desired states. 
   
   
       13 . A method according to  claim 12  wherein the intermediate state to which all the pixels are driven is such that substantially the same size of impulse is necessary to drive any pixel from said intermediate state to said first and second display states. 
   
   
       14 . A method of addressing a bistable electronic display having a plurality of pixels arranged in a plurality of rows and columns, the method comprising: (a) comparing a starting state of the display with a desired finishing state and determining for each pixel a change value representative of the change needed to change the starting state of that pixel to its desired finishing state; (b) comparing the change values of pixels in differing rows but the same column and locating at least two of said pixels having the same change value; and (c) addressing said at least two pixels having the same value simultaneously by addressing the rows and the column on which said pixels are located. 
   
   
       15 . A method of addressing a bistable electronic display having a plurality of pixels, the method comprising: comparing a starting state of the display with a desired finishing state and determining which pixels differ between the two states; and addressing only those pixels which differ between the two states. 
   
   
       16 . A method of addressing a bistable electronic display having a plurality of pixels, which method comprises: providing an array of island capacitors associated with the pixels of the display; through passive matrix XY addressing, introducing electrical charge into the capacitors in a pattern matching the image desired on the display; and thereafter allowing the charges on the capacitors to complete the addressing of the pixels of the display. 
   
   
       17 . An electronic display comprising an electro-optic material having a plurality of separately addressable pixels wherein the number of driver outputs to the pixel array is less than the square root of the number of pixels. 
   
   
       18 . An electronic display comprising an electro-optic material having a plurality of pixels, and separate first, second and third sets of addressing means for addressing said pixels, each of said pixels being associated with one addressing means in each of said three sets, such that any specific pixel of the display can be addressed by application of signals within predetermined ranges to each of the three addressing means associated with said specific pixel. 
   
   
       19 . A method of addressing an electronic display, the method comprising: providing an electro-optic material having a plurality of pixels; providing first, second and third sets of addressing means for addressing said pixels, each of said pixels being associated with one addressing means in each of said three sets; and applying predetermined signals to the three addressing means associated with a specific pixel, thereby addressing said pixel.