Apparatus and method for use of large liquid crystal display with small driver

• US 20060232528A1
• Filed: 04/15/2005
• Published: 10/19/2006
• Est. Priority Date: 04/15/2005
• Status: Abandoned Application

• Current Assignee: Agamatrix Incorporated (AgaMatrix Holdings LLC d/b/a WaveForm Diabetes)
• Original Assignee: Agamatrix Incorporated (AgaMatrix Holdings LLC d/b/a WaveForm Diabetes)
• Inventors: Harding, Ian, Vu, Sonny, Tsai, Gary, Diamond, Steven, Wei, Baoguo, Forest, Martin
• Application Number:
  US10/907,802
• Publication Number:
  US 20060232528A1
• Time in Patent Office: Days
• US Class Current: 345/87
• CPC Class Codes: G09G 2310/0297 Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns
• CPC Class Codes: G09G 3/3644 with the matrix divided into sections
• CPC Class Codes: G09G 3/3681 suitable for passive matrices only
• CPC Class Codes: G09G 3/3692 suitable for passive matrices only

Abstract

A liquid crystal display driver has N common drive lines and M segment drive lines. A liquid crystal display has M segment driver leads and N times P common drive leads, P being at least two. P multiplexers are provided, each external to the liquid crystal display driver. Each of the M segment driver lines is connected with a respective one of the M segment drive leads. Each multiplexer comprising N switches, each switch defining a normally-open contact, a normally-closed contact, and a common contact. Each of the switches is connected by its common contact with a respective one of the common drive leads of the liquid crystal display. Each of the switches is connected by its normally-closed contact with a cancel signal. The N switches of each multiplexer are each connected with a respective one of the N common drive lines of the liquid crystal display driver.

Claims

1. Apparatus comprising:

a liquid crystal display driver having N common drive lines and M segment drive lines, the liquid crystal display driver comprising an integrated circuit;

a liquid crystal display having M segment driver leads and N times P common drive leads, wherein P is at least two; and

P multiplexers, each external to the integrated circuit;

each of the M segment driver lines connected with a respective one of the M segment drive leads;

each multiplexer comprising N switches, each switch defining a normally-open contact, a normally-closed contact, and a common contact;

each of the switches connected by its common contact with a respective one of the common drive leads of the liquid crystal display;

each of the switches connected by its normally-closed contact with a cancel signal;

the N switches of each multiplexer each connected with a respective one of the N common drive lines of the liquid crystal display driver.

2. The apparatus of claim 1 wherein P is 2.

3. The apparatus of claim 2 wherein N is four and M is thirty-two.

4. The apparatus of claim 1 further comprising means driving each of the P multiplexers quickly in turn.

5. Apparatus comprising:

a liquid crystal display driver having N common drive lines and M segment drive lines, the liquid crystal display driver comprising an integrated circuit;

a liquid crystal display having M times R segment driver leads and N times P common drive leads, wherein P is at least two and R is at least two;

P common drive lead multiplexers, each external to the integrated circuit; and

R segment drive lead multiplexers, each external to the integrated circuit;

each segment drive lead multiplexers comprising M switches, each switch defining a normally-open contact, a normally-closed contact, and a common contact;

each of the switches of the segment drive lead multiplexer connected by its common contact with a respective one of the segment drive leads of the liquid crystal display;

each of the switches of the segment drive lead multiplexer connected by its normally-closed contact with a cancel signal;

the M switches of each segment driver lead multiplexer each connected with a respective one of the M segment drive leads of the liquid crystal display driver;

each common drive lead multiplexer comprising N switches, each switch defining a normally-open contact, a normally-closed contact, and a common contact;

each of the switches of the common lead multiplexer connected by its common contact with a respective one of the common drive leads of the liquid crystal display;

each of the switches of the common lead multiplexer connected by its normally-closed contact with a cancel signal;

the N switches of each common lead multiplexer each connected with a respective one of the N common drive lines of the liquid crystal display driver.

6. The apparatus of claim 5 wherein P is 2.

7. The apparatus of claim 6 wherein R is two.

8. The apparatus of claim 5 further comprising means driving each of the P multiplexers quickly in turn.

9. A method for use with a liquid crystal display and a display driver and a multiplexer external to the display driver, the display having common leads and segment leads, the display having segments each controlled by a respective common lead and a respective segment lead, the driver having common drive lines and segment drive lines, the method comprising the steps of:

employing the multiplexer to connect drive lines selectively to leads of the display.

10. The method of claim 9 wherein the connected drive lines are common drive lines and the connected leads are common leads.

11. The method of claim 9 wherein the connected drive lines are segment drive lines and the connected leads are segment leads.

12. The method of claim 9 wherein the selective connection of drive lines to leads is carried out quickly in turn.