PASSIVE CIRCUITS FOR DE-MULTIPLEXING DISPLAY INPUTS

• US 20100321352A1
• Filed: 08/12/2010
• Published: 12/23/2010
• Est. Priority Date: 06/29/2006
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Chui, Clarence, Lewis, Alan, Mignard, Marc M.
• Granted Patent: US 8,040,338 B2
• Time in Patent Office: Days
• US Class Current: 345/204
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G09G 2310/0218 with collection of electrodes in groups for n-dimensional addressing
• 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 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/3466 based on interferometric effect

Abstract

A display array which can reduce the row connections between the display and the driver circuit and methods of manufacturing and operating the same are disclosed. In one embodiment, a display device comprises an array of MEMS display elements and a plurality of voltage dividers coupled to the array and configured to provide row output voltages to drive the array, wherein each row is connected to at least two inputs joined by a voltage divider.

Claims

1. A method of making a display device, the method comprising:

forming an array of microelectromechanical system (MEMS) display elements comprising a plurality of columns and rows of display elements; and

forming a demultiplexer comprising a plurality of passive impedance network circuits coupled to said array and configured to provide row output signals to drive said array, each passive impedance network comprising;

a row driving input line to which one of a plurality of row driving signals is applied,

at least one control input line; and

two or more row output lines, wherein each row output line is connected to a row of said array for providing a row output signal,

wherein the plurality of passive impedance network circuits have more outputs than inputs and provides a single row output signal for each row of said array, wherein each passive impedance network circuit comprises a voltage divider, wherein each passive impedance network is connected to a different one of the plurality of row driving signals.

2. The method of claim 1, wherein each voltage divider comprises:

a first terminal to which one of the row driving signals is applied;

a second terminal to which a control voltage signal is applied;

a third terminal coupled to a row of said array and configured to provide said row output signal to drive said row;

a first resistor between the first terminal and the third terminal, and

a second resistor between the second terminal and the third terminal,

wherein the first resistor and the second resistor are connected in series.

3. The device of claim 2, wherein the control voltage signal is a voltage of a constant value.

4. The method of claim 1, wherein each passive impedance network circuit comprises a resistor network.

5. The method of claim 1, wherein all voltage dividers are divided into groups of N voltage dividers and one input of all voltage dividers of each group is connected to the same row driving signal, wherein N is an integer larger than 1.

6. The method of claim 5, wherein there are totally at least N control voltage signals and each control voltage signal is applied to one and only one voltage divider within each of substantially all groups.

7. The method of claim 1, wherein said voltage dividers are fabricated in parallel with the process used to fabricate said array.

8. The method of claim 1, wherein said voltage dividers are formed on the periphery of said array.

9. The method of claim 1, wherein the steps of forming said array and forming said plurality of passive impedance network circuits are performed using the same material.

10. A method of making a display device, the method comprising:

forming an array of microelectromechanical system (MEMS) display elements on a substrate as a set of intersecting rows and columns; and

forming a plurality of passive impedance network circuits on the same or a different substrate, the passive impedance network circuits being configured to provide row output signals to drive the array based on a plurality of row driving signals and a plurality of control voltage signals, the number of the row output signals is larger than the sum of the number of the row driving signals and the number of control voltage signals, each passive impedance network comprising;

a first input lead to which one of the row driving signals is applied,

a second input lead to which one of the control voltage signals is applied, and

an output lead connected to a row of said array and configured to provide a row output signal to drive the row,

wherein each row driving signals are applied to at least two passive impedance network circuits, wherein each passive impedance network circuit is connected to a different row of said array, wherein no passive impedance network circuit shares the same row driving signal and the control voltage signal with another passive impedance network circuit.

11. The method of claim 10, wherein each control voltage signal is applied to at least two passive impedance network circuits.

12. The method of claim 10, wherein each passive impedance network circuit comprises a resistor network.

13. The method of claim 10, wherein each passive impedance network circuit comprises a voltage divider.

14. The method of claim 10, wherein each passive impedance network circuit further comprises:

a first resistor between the first input and the output lead, and

a second resistor between the second input and the output lead,

wherein the first resistor and the second resistor are connected in series.

15. The method of claim 10, wherein the steps of forming said array and forming said plurality of passive impedance network circuits comprise performing at least some common processing steps.

16. The method of claim 10, wherein the steps of forming said array and forming said plurality of passive impedance network circuits are performed in parallel.

17. The method of claim 10, wherein the steps of forming said array and forming said plurality of passive impedance network circuits are performed using the same material.

18. The method of claim 10, wherein said array and said passive impedance network circuits are formed on a common substrate.

19. The method of claim 10, wherein said passive impedance network circuits are formed on the periphery of said array.

20. A method of demultiplexing a row driving signal in a row by row addressing scheme of a display device, said method comprising:

applying said row driving signal to a plurality of rows through a set of series impedances;

applying a first control voltage to a first one of said plurality of rows through a first series impedance; and

applying a second control voltage to a second one of said plurality of rows through a second series impedance.