Display drive switch configuration

• US 8,310,421 B2
• Filed: 01/06/2010
• Issued: 11/13/2012
• Est. Priority Date: 01/06/2010
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Todorovich, Mark M.
• Primary Examiner(s): Nguyen, Chanh
• Assistant Examiner(s): JOHNSON, ALLISON WALTHALL
• Application Number:
  US12/683,333
• Publication Number:
  US 20110164014A1
• Time in Patent Office: 1,042 Days
• Field of Search: 345208-211, 345/85, 345/95, 345/108
• US Class Current: 345/85
• CPC Class Codes: G09G 2300/0473 Use of light emitting or modulating elements having two or more stable states when no power is applied
• CPC Class Codes: G09G 2300/06 Passive matrix structure, i.e. with direct application of both column and row voltages to the light emitting or modulating elements, other than LCD or OLED
• CPC Class Codes: G09G 2310/0205 Simultaneous scanning of several lines in flat panels
• CPC Class Codes: G09G 2310/0256 with the purpose of reversing the voltage across a light emitting or modulating element within a pixel
• CPC Class Codes: G09G 2310/0267 Details of drivers for scan electrodes, other than drivers for liquid crystal, plasma or OLED displays
• CPC Class Codes: G09G 2310/0275 Details of drivers for data electrodes, other than drivers for liquid crystal, plasma or OLED displays, not related to handling digital grey scale data or to communication of data to the pixels by means of a current
• CPC Class Codes: G09G 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3466 based on interferometric effect

Abstract

An apparatus and method for driving a display a display. Two switches for each common line are used to couple the common line to a respective first and second hold voltage supply lines. A third switch for each common line is used to couple the common line to a drive line. A waveform generator is used to generate the driving waveform on the drive line.

Claims

1. An apparatus for driving a display, the apparatus comprising:

a plurality of rows and columns of display elements, wherein each display element is configured to be placed in a plurality of discrete states;

a first hold voltage supply line configured to supply a first hold voltage;

a second hold voltage supply line configured to supply a second hold voltage;

one or more drive lines configured to supply a driving voltage waveform;

a waveform generator configured to generate the driving voltage waveform on the one or more drive lines, wherein the driving voltage waveform is configured to set each of the display elements in one of the discrete states;

a first switch configured to selectively couple a first one of the plurality of rows or columns to the first hold voltage supply line, wherein the first hold voltage is configured to maintain the discrete state of each of the display elements resulting from the driving voltage waveform;

a second switch configured to selectively couple the first one of the rows or columns to the second hold voltage supply line, wherein the second hold voltage is configured to maintain the discrete state of each of the display elements resulting from the driving voltage waveform; and

a third switch configured to selectively couple the first one of the rows or columns to a first drive line of the one or more drive lines.

2. The apparatus of claim 1, wherein the waveform generator comprises a processor configured to drive the first, second, and third switches.

3. The apparatus of claim 2, wherein the waveform generator comprises:

a plurality of voltage supply lines, wherein each of the plurality of voltage supply lines is configured to supply a particular voltage; and

a plurality of switches, wherein each of the plurality of switches is configured to selectively couple one of the plurality of voltage supply lines to one of the one or more drive lines, wherein the processor is configured to drive the plurality of switches to generate the driving voltage waveform.

4. The apparatus of claim 3, wherein the plurality of voltage supply lines comprises:

a positive address voltage supply line; and

a negative address voltage supply line.

5. The apparatus of claim 4, wherein the plurality of voltage supply lines further comprises a ground voltage supply line.

6. The apparatus of claim 4, wherein the positive address and negative address voltage supply lines are each associated with one of a set of colors.

7. The apparatus of claim 6, wherein the set of colors comprises red, green and blue.

8. The apparatus of claim 1, further comprising:

a third hold voltage supply line configured to supply a third hold voltage;

a fourth hold voltage supply line configured to supply a fourth hold voltage;

a fourth switch configured to selectively couple a second one of the rows or columns to the third hold voltage supply line;

a fifth switch configured to selectively couple the second one of the rows or columns to the fourth hold voltage supply line; and

a sixth switch configured to selectively couple the second one of the rows or columns to the first drive line.

9. The apparatus of claim 8:

wherein the first and second hold voltages are positive and negative hold voltages corresponding to a first color; and

wherein the third and fourth hold voltages are positive and negative hold voltages corresponding to a second color.

10. The apparatus of claim 1, further comprising a plurality of bi-stable display elements arranged in the plurality of rows or columns.

11. A method of displaying information on a display, the display comprising a plurality of rows and columns of display elements, wherein each display element is configured to be set in a plurality of discrete states with a driving voltage waveform, the method comprising:

activating a first switch to couple a first one of a plurality of rows or columns to a first hold voltage supply line configured to supply a first hold voltage, wherein the first hold voltage is configured to maintain the discrete state of each of the display elements resulting from the driving voltage waveform;

deactivating the first switch to uncouple the first one of the rows or columns from the first hold voltage supply line;

generating the driving voltage waveform on a first drive line;

activating a second switch to couple the first one of the rows or columns to the first drive line;

deactivating the second switch to uncouple the first one of the rows or columns from the first drive line; and

activating a third switch to couple the first one of the rows or columns to a second hold voltage supply line configured to supply a second hold voltage, wherein the second hold voltage is configured to maintain the discrete state of each of the display elements resulting from the driving voltage waveform.

12. The method of claim 11, wherein generating the driving voltage waveform comprises selectively coupling the first drive line to one or more voltage supply lines of a plurality of voltage supply lines.

13. The method of claim 12, wherein coupling the first drive line to one or more voltage supply lines comprises activating a corresponding one or more switches of a plurality of switches.

14. The method of claim 12, wherein the plurality of voltage supply lines further comprises a ground voltage supply line.

15. The method of claim 12, wherein the plurality of voltage supply lines comprises:

a positive address voltage supply line; and

a negative address voltage supply line.

16. The method of claim 15, wherein the positive address and negative address voltage supply lines are each associated with one of a set of colors.

17. The method of claim 16, wherein the set of colors comprises red, green and blue.

18. The method of claim 11, further comprising:

activating a fourth switch to couple a second one of the rows or columns to a third hold voltage supply line configured to supply a third hold voltage;

deactivating the fourth switch to uncouple the second one of the rows or columns from the third hold voltage supply line;

activating a fifth switch to couple the second one of the rows or columns to the first drive line;

deactivating the fifth switch to uncouple the second one of the rows or columns from the first drive line; and

activating a sixth switch to couple the second one of the rows or columns to a fourth hold voltage supply line configured to supply a fourth hold voltage.

19. The method of claim 18:

wherein the first and second hold voltages are positive and negative hold voltages corresponding to a first color; and

wherein the third and fourth hold voltages are positive and negative hold voltages corresponding to a second color.

20. The method of claim 11, wherein the display comprises a plurality of bi-stable display elements arranged in the plurality of rows or columns.

21. The method of claim 11, further comprising:

obtaining information to be displayed; and

writing a portion of the information to be displayed to the first one of the rows or columns while the second switch is active.

22. An apparatus for driving a display, the apparatus comprising:

a plurality of rows and columns of means for displaying an image, wherein each displaying means is configured to be set in a plurality of discrete states;

means for supplying a first hold voltage;

means for supplying a second hold voltage;

one or more means for supplying a driving voltage waveform, wherein the driving voltage waveform is configured to set each of the displaying means in one of the discrete states;

means for generating the driving voltage waveform on the one or more means for supplying the driving voltage waveform;

means for selectively coupling a first one of a plurality of rows or columns to the means for supplying the first hold voltage, wherein the first hold voltage is configured to maintain the discrete state of each of the displaying means resulting from the driving voltage waveform;

means for selectively coupling the first one of the rows or columns to the means for supplying the second hold voltage, wherein the second hold voltage is configured to maintain the discrete state of each of the displaying means resulting from the driving voltage waveform; and

means for selectively coupling the first one of the rows or columns to a first one of the one or more means for supplying a driving voltage waveform.

23. The apparatus of claim 22, further comprising:

means for supplying a third hold voltage;

means for supplying a fourth hold voltage;

means for selectively coupling a second one of the rows or columns to the means for supplying the third hold voltage;

means for selectively coupling the second one of the rows or columns to the means for supplying the fourth hold voltage; and

means for selectively coupling the second one of the rows or columns to the means for generating the driving voltage waveform.

24. A non-transitory computer-readable medium having stored thereon, instructions that, if executed by a computing device, cause the computing device to perform a method of displaying information on a display, the display comprising a plurality of rows and columns of display elements, wherein each display element is configured to be set in a plurality of discrete states with a driving voltage waveform, the method comprising:

activating a first switch to couple a first one of a plurality of rows or columns to a first hold voltage supply line configured to supply a first hold voltage, wherein the first hold voltage is configured to maintain the discrete state of each of the display elements resulting from the driving voltage waveform;

deactivating the first switch to uncouple the first one of the rows or columns from the first hold voltage supply line;

generating the driving voltage waveform on a first drive line;

activating a second switch to couple the first one of the rows or columns to the first drive line;

deactivating the second switch to uncouple the first one of the rows or columns from the first drive line; and

activating a third switch to couple the first one of the rows or columns to a second hold voltage supply line configured to supply a second hold voltage, wherein the second hold voltage is configured to maintain the discrete state of each of the display elements resulting from the driving voltage waveform.

25. The non-transitory computer-readable medium of claim 24, wherein the method further comprises:

activating a fourth switch to couple a second one of the rows or columns to a third hold voltage supply line configured to supply a third hold voltage;

deactivating the fourth switch to uncouple the second one of the rows or columns from the third hold voltage supply line;

activating a fifth switch to couple the second one of the rows or columns to the first drive line;

deactivating the fifth switch to uncouple the second one of the rows or columns from the first drive line; and

activating a sixth switch to couple the second one of the rows or columns to a fourth hold voltage supply line configured to supply a fourth hold voltage.