Method and apparatus for amplitude band enabled addressing arrayed elements

• US 5,977,961 A
• Filed: 06/19/1996
• Issued: 11/02/1999
• Est. Priority Date: 06/19/1996
• Status: Expired due to Term

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Rindal, Abraham E.
• Primary Examiner(s): Luu, Matthew
• Assistant Examiner(s): PIZIALI, JEFFREY J
• Application Number:
  US08/665,763
• Time in Patent Office: 1,231 Days
• Field of Search: 345/173, 345/87, 345/100, 345/98, 345/60, 345/61, 345/62, 345/55, 345/74
• US Class Current: 345/208
• 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 3/2085 Special arrangements for addressing the individual elements of the matrix, other than by driving respective rows and columns in combination

Abstract

Arrayed display pixels are coupled such that all row pixels are coupled together by a row conductive element and all column pixels are coupled together by a column conductive element. The row-coupled pixels are driven by first and second row drivers and the column-coupled pixels are driven by first and second column drivers, a total of four drivers in all. The drivers each output time-varying signals of different frequencies. The vertical scan rate is determined by the frequency differential in the signals output by the two row drivers, and the horizontal scan rate frequency is determined by the frequency differential in the signals output by the two column drivers. The absolute frequencies of the four signals are set proportional to the propagation delay of the medium through which the driver signals travel. The invention implements a pixel enabling signal using the beat-frequency difference between two driver source signals that propagate through a pixel string from opposite ends of the string. The driver difference signal dwells sufficiently long on each pixel location to deliver sufficient energy to turn the pixel on or off. Video information to be displayed is used to modulate at least one of the row drivers and one of the column drivers.

Claims

1. A method for addressing a display comprising pixels arrayed in M rows and N columns, the method comprising:

(a) electromagnetically coupling together all pixels in each of said M rows;

(b) electromagnetically coupling together all pixels in each of said N columns;

(c) driving the row-coupled pixels coupled together in step (a) with first and second row drivers, coupled to drive respective first and second ends of said coupled together row-coupled pixels, and outputting respective row drive signals f1(t) and f2(t);

(d) driving the column-coupled pixels coupled together in step (b) with first and second column drivers, coupled to drive respective first and second ends of said coupled together column-coupled pixels, and outputting respective column drive signals f3(t) and f4(t);

wherein at least one condition is met selected from a group consisting of (i) frequency of f1(t)≠

frequency of f2(t), and frequency of f3(t)≠

frequency of f4(t); and

wherein said pixels in said display are enabled or disabled according to a beat frequency time-varying non-zero voltage magnitude determined by amplitude and frequency of said signals f1(t), f2(t), f3(3), f4(t) and by propagation time needed for said signals to reach a said pixel.

2. The method of claim 1, wherein at least one of steps (a) and (b) is carried out by providing a conductive element that couples together said pixels.

3. The method of claim 1, wherein at least one of steps (a) and (b) is carried out by providing a conductive plane that couples together said pixels.

4. The method of claim 2, wherein the first and second drivers are coupled to opposite ends of said conductive element.

5. The method of claim 3, wherein the first and second drivers are coupled to diametrically opposite ends of said conductive plane.

6. The method of claim 1, wherein peak amplitude of any one of said signals f1(t), f2(t), f3(t) and f4(t) is less than a minimum magnitude required to enable a said pixel, and wherein at least one of said f1(t), f2(t), f3(t) and f4(t) has a characteristic selected from the group consisting of (i) said signal is a digital pulse train, and (ii) said signal is sinusoidal.

7. The method of claim 1, wherein vertical scan rate for said display is determined by a differential between frequency of said f1(t) and frequency of said f2(t).

8. The method of claim 7, wherein absolute frequency of said f1(t) and absolute frequency of said f2(t) are set proportional to propagation delay encountered by said f1(t) and by said f2(t).

9. The method of claim 1, wherein horizontal scan rate of said display is determined by a differential between frequency of f3(t) and frequency of said f4(t).

10. The method of claim 9, wherein absolute frequency of said f3(t) and absolute frequency of said f4(t) are set proportional to propagation delay encountered by said f3(t) and by said f4(t).

11. The method of claim 1, wherein said display is fabricated using a technique selected from the group consisting of (i) monochrome liquid crystal display, (ii) color liquid crystal display, (iii) plasma display, (iv) cold cathode display, (v) electroluminescent display, (vi) light emitting diode display, and (vii) micro-mirror display.

12. The method of claim 1, further comprising:

(e) coupling a video signal to modulate at least one signal selected from said f1(t), f2(t), f3(t) and f4(t).

13. A method for addressing a display comprising pixels arrayed in M rows and N columns, the method comprising:

(a) electromagnetically coupling together all pixels in each of said M rows with a row conductive element having first and second ends;

(b) electromagnetically coupling together all pixels in each of said N columns using a column conductive element having first and second ends, wherein said first end of said column conductive element is coupled to said second end of said row conductive element;

(c) driving the row-coupled pixels coupled together in step (a) with a first row driver outputting a row driver signal f1(t);

(d) driving the column-coupled pixels coupled together in step (b) with a first column driver outputting a column driver signal f4(t), wherein frequency of f4(t)≠

frequency of f1(t);

wherein said pixels in said display are enabled or disabled according to a beat frequency time-varying non-zero voltage magnitude determined by amplitude and frequency of said signals f1(t) and f4(t) and by propagation time needed for said signals to reach a said pixel.

14. The method of claim 13, wherein peak amplitude of each of said f1(t) and f4(t) is less than a minimum magnitude required to enable a said pixel, and wherein at least one of said f1(t) and said f4(t) has a characteristic selected from the group consisting of (i) said signal is a digital pulse train, and (ii) said signal is sinusoidal.

15. The method of claim 13, wherein said display has at least one characteristic selected from the group consisting of (i) a scan rate determined by a differential between frequency of said f1(t) and frequency of said f4(t), and (ii) wherein absolute frequency of said f1(t) and absolute frequency of said f4(t) are set proportional to propagation delay encountered by said f1(t) and by said f4(t).

16. A display, driveable with less than five drivers, comprising:

pixels arrayed in M rows and N columns;

a row conductive element electromagnetically coupling together all pixels in said M rows, said row conductive element having a first end and a second end;

a column conductive element electromagnetically coupling together all pixels in each of said N columns, said column conductive element having a first end and a second end;

a first row driver coupled to said first end of said row conductive element and outputting a first row drive signal f1(t);

a second row driver coupled to said second end of said row conductive element and outputting a second row drive signal f2(t), wherein frequency of f1(t)≠

frequency of f2(t);

a first column driver coupled to said first end of said column conductive element and outputting a first column drive signal f3(t); and

a second column driver coupled to said second end of said column conductive element and outputting a second column drive signal f4(t), wherein f3(t)≠

f4(t);

wherein at least one condition is met selected from a group consisting of (i) frequency of f1(t)≠

frequency of f2(t), and frequency of f3(t)≠

frequency of f4(t), and wherein at least one of said f1(t), f2(3), f3(t), and f4(t) is modulatable with a video signal to be displayed on said display;

wherein said pixels in said display are enabled or disabled according to a beat frequency time-varying non-zero voltage magnitude determined by amplitude and frequency of said signals f1(t), f2(t), f3(3), f4(t) and by propagation time needed for said signals to reach a said pixel.

17. The display of claim 16, wherein at least one of said row conductive element and said column conductive element includes a conductive plane that couples together said pixels.

18. The display of claim 16, wherein peak amplitude of any one of said signals f1(t), f2(t), f3(t) and f4(t) is less than a minimum magnitude required to enable a said pixel, and wherein at least one of said f1(t), f2(t), f3(t) and f4(t) has a characteristic selected from the group consisting of (i) said signal is a digital pulse train, and (ii) said signal is sinusoidal.

19. The display of claim 16, wherein said display has at least one scan characteristic selected from the group consisting of (i) a vertical scan rate determined by a differential between frequency of said f1(t) and frequency of said f2(t), and (ii) a horizontal scan rate of said display determined by a differential between frequency of f3(t) and frequency of said f4(t).

20. The display of claim 16, wherein absolute frequency of each said row drive signal and each said column drive signal is, respectively, set proportional to propagation delay encountered by each said row drive signal and each said column drive signal.