BI-STABLE DISPLAY FAIL SAFES AND DEVICES INCORPORATING THE SAME

• US 20100323431A1
• Filed: 06/18/2009
• Published: 12/23/2010
• Est. Priority Date: 06/18/2009
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Kurtock, James R., Rutkowski, Paul S., Davies, Robert G., Blackburn, Michael J., Cadio, Michel A., Gardner, Randy J.
• Granted Patent: US 8,436,844 B2
• Time in Patent Office: Days
• US Class Current: 435/286.1
• CPC Class Codes: G01N 33/48785 Electrical and electronic details of measuring devices for physical analysis of liquid biological material not specific to a particular test method, e.g. user interface or power supply
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2330/10 Dealing with defective pixels
• CPC Class Codes: G09G 2330/12 Test circuits or failure detection circuits included in a display system, as permanent part thereof
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• CPC Class Codes: G09G 3/16 by control of light from an independent source

Abstract

A control circuit and method for controlling a bi-stable display having bi-stable segments each capable of transitioning between an on state and an off state via application of a voltage are disclosed. The voltage is provided to a display driver from a charge pump, and supplied to individual ones of the bi-stable segments via outputs from the display driver in accordance with display instructions provided by a system controller. Both a bi-stable segment voltage level of at least one of the outputs of the display driver and a charge pump voltage level of the voltage are detected and compared to a valid bi-stable segment voltage level and a valid charge pump voltage level, respectively. A malfunction signal may be provided to the system controller if either of the detected voltage levels is not valid. The control circuit is useful in an electronic device such as, for example, a blood glucose measuring device.

Claims

1. A control circuit for controlling a bi-stable display comprising:

a system controller, a display driver, a bi-stable segment monitoring module, and a charge pump, wherein;

the charge pump is configured to generate one or more charge pump voltages;

the bi-stable display comprises a plurality of bi-stable segments capable of transitioning between an on state and an off state with an application of the charge pump voltages;

the display driver comprises a plurality of outputs that correspond to the plurality of bi-stable segments, and is operable to control individual ones of the plurality of bi-stable segments by applying the charge pump voltages to the plurality of bi-stable segments via the plurality of outputs in accordance with display instructions provided by the system controller; and

the bi-stable segment monitoring module is operable to detect a bi-stable segment voltage level of at least one output of the display driver and compare the detected bi-stable segment voltage level of the output with a valid bi-stable segment voltage level of the output.

2. A control circuit as claimed in claim 1 further comprising a charge pump monitoring module operable to monitor a charge pump voltage level of the charge pump and compare the monitored charge pump voltage level with a valid charge pump voltage level.

3. A control circuit as claimed in claim 1 wherein the bi-stable segment monitoring module is operable to provide a bi-stable segment malfunction signal to the system controller if the detected bi-stable segment voltage level of the output does not equal the valid bi-stable segment voltage level.

4. A control circuit as claimed in claim 3 wherein the system controller is operable to provide an alarm upon receipt of the bi-stable segment malfunction signal.

5. A control circuit as claimed in claim 1 wherein:

each bi-stable segment of the bi-stable display comprises a top electrode and a bottom electrode;

the top electrode and the bottom electrode are electrically coupled to an output of the display driver;

the bi-stable segment monitoring module is operable to measure a voltage level at the top electrode and the bottom electrode;

the bi-stable segment monitoring module is operable to detect a differential voltage between the voltage level at the top electrode and the voltage level at the bottom electrode; and

the bi-stable segment monitoring module is operable to provide a bi-stable segment malfunction signal to the system controller if the detected differential voltage between the voltage level at the top electrode and the voltage level at the bottom electrode does not equal a valid differential voltage.

6. A control circuit as claimed in claim 1 wherein:

the display driver is operable to provide a write operation completed signal to the system controller upon successful completion of the display instructions;

the bi-stable segment monitoring module is operable to suppress the write operation completed signal if a detected bi-stable segment voltage level of an output does not equal the valid bi- stable segment voltage level; and

the system controller is operable to provide an alarm if the write operation completed signal is not received within a period of time after providing the display instructions to the display driver.

7. A control circuit as claimed in claim 1 wherein:

the display driver is configured to provide the display instructions at a serial data output port; and

the bi-stable segment monitoring module is operable to receive the display instructions from the serial data output port, compare the display instructions received at the serial data output port with the display instructions from the system controller, and provide a bi-stable segment malfunction signal to the system controller if the display instructions received at the serial data output port does not equal the display instructions provided by the system controller.

8. A control circuit as claimed in claim 2 wherein the charge pump monitoring module is operable to provide a charge pump malfunction signal to the system controller if the monitored charge pump voltage level is not within a tolerance range of the valid charge pump voltage level.

9. A control circuit as claimed in claim 8 wherein the system controller is operable to provide an alarm upon receipt of the charge pump malfunction signal.

10. A control circuit as claimed in claim 8 wherein the charge pump monitoring module comprises a comparator configured to provide the charge pump malfunction signal to the system controller if the monitored charge pump voltage level is not within a tolerance range of the valid charge pump voltage level.

11. A control circuit as claimed in claim 8 wherein the charge pump monitoring module comprises an analog to digital converter to measure the charge pump voltage level.

12. A control circuit as claimed in claim 2 further comprising a secondary controller, wherein:

the bi-stable segment monitoring module is operable to provide a bi-stable segment malfunction signal to the secondary controller if the detected bi- stable segment voltage level of the output does not equal the valid bi-stable segment voltage level;

the charge pump monitoring module is operable to provide a charge pump malfunction signal to the secondary controller if the monitored charge pump voltage level is not within a tolerance range of the valid charge pump voltage level; and

the secondary controller is configured to provide the bi-stable segment malfunction signal and the charge pump malfunction signal to the system controller.

13. A control circuit as claimed in claim 1 wherein:

the control circuit further comprises a primary power source, a secondary controller, and a power source monitoring module;

the primary power source is operable to supply power to the control circuit;

the power source monitoring module is operable to monitor a power level of the primary power source and compare the monitored power level with a valid power source power level; and

the power source monitoring module is further operable to provide a power source alarm signal to the secondary controller if the monitored power level is not within a tolerance range of the valid power source power level.

14. A control circuit as claimed in claim 13 wherein:

the control circuit further comprises a secondary power source;

the secondary controller is operable to secure power from the secondary power source and provide error display data to the display driver upon receipt of the power source alarm signal; and

the display driver is operable to control individual ones of the plurality of bi-stable segments of the bi-stable display in accordance with the error display data.

15. A blood glucose measuring device for measuring a blood glucose level of a blood sample provided on a disposable measurement strip comprising a system controller, a bi-stable display, a bi-stable display control circuit, wherein:

the bi-stable display comprises a plurality of bi-stable segments capable of transitioning between an on state and an off state with an application of charge pump voltages;

the bi-stable display control circuit comprises;

a charge pump configured to generate one or more charge pump voltages;

a display driver comprising a plurality of outputs that correspond to the plurality of bi-stable segments, and is configured to control individual ones of the plurality of bi-stable segments by applying the charge pump voltages to the plurality of bi-stable segments via the plurality of outputs in accordance with display instructions provided by the system controller;

a bi-stable segment monitoring module configured to detect a bi-stable segment voltage level of at least one output of the display driver and compare the detected bi-stable segment voltage level of the output with a valid bi-stable segment voltage level of the output; and

a charge pump monitoring module configured to monitor a charge pump voltage level of the charge pump and compare the monitored charge pump voltage level with a valid charge pump voltage level; and

the system controller is configured to measure the blood glucose level of the blood sample and provide the display instructions to the display driver corresponding at least in part to the blood glucose measurement.

16. A blood glucose measuring device as claimed in claim 15 wherein:

each bi-stable segment of the bi-stable display comprises a top electrode and a bottom electrode;

the top electrode and the bottom electrode are electrically coupled to an output of the display driver;

the bi-stable segment monitoring module is configured to measure a voltage level at the top electrode and the bottom electrode;

the bi-stable segment monitoring module is configured to detect a differential voltage between the voltage level at the top electrode and the voltage level at the bottom electrode; and

the bi-stable segment monitoring module is configured to provide a bi-stable segment malfunction signal to the system controller if the detected differential voltage between the voltage level at the top electrode and the voltage level at the bottom electrode does not equal a valid differential voltage.

17. A blood glucose measuring device as claimed in claim 16 wherein the system controller is configured to provide an alarm upon receipt of the bi-stable segment malfunction signal.

18. A blood glucose measuring device as claimed in claim 15 wherein the system controller is configured to instruct the display driver to sequentially turn on and off the bi-stable segments of the bi-stable display.

19. A blood glucose measuring device as claimed in claim 15 wherein the charge pump monitoring module is configured to provide a charge pump malfunction signal to the system controller if the monitored charge pump voltage level is not within a tolerance range of the valid charge pump voltage level.

20. A blood glucose measuring device as claimed in claim 19 wherein the system controller is configured to provide an alarm upon receipt of the charge pump malfunction signal.

21. A blood glucose measuring device as claimed in claim 15 wherein:

the bi-stable display control circuit further comprises a primary power source, a secondary controller, a secondary power source, and a power source monitoring module;

the primary power source is configured to supply power to the bi-stable display control circuit;

the power source monitoring module is configured to;

monitor a power level of the primary power source;

compare the monitored power level with a valid power source power level; and

provide a power source alarm signal to the secondary controller if the monitored power level is not within a tolerance range of the valid power source power level;

the secondary controller is configured to secure power from the secondary power source and provide error display data to the display driver upon receipt of the power source alarm signal; and

the display driver is configured to control individual ones of the plurality of bi-stable segments of the bi-stable display in accordance with the error display data.

22. An electronic device comprising:

a system controller;

a charge pump configured to generate one or more charge pump voltages;

a bi-stable display comprising one or more characters capable of displaying an intended character value, each character comprising one or more first bi-stable segments and one or more second bi-stable segments, each second bi-stable segment comprising a plurality of sub-segments, wherein the first bi-stable segments and the sub-segments are capable of transitioning between an on state and an off state with an application of the charge pump voltages; and

a display driver comprising a plurality of outputs that correspond to the first bi-stable segments and the sub-segments, and is operable apply the charge pump voltages to the first bi-stable segments and the sub-segments via the plurality of outputs in accordance with display instructions provided by the system controller.

23. An electronic device as claimed in claim 22 wherein a selected second bi-stable segment comprises a first sub-segment shaped as a word and a second sub-segment configured such that the word of the first sub-segment is not visible when the first sub-segment and the second sub-segment are both in an on state or both in an off state.

24. A method for controlling a bi-stable display having a plurality of bi-stable segments each capable of transitioning between an on state and an off state via application of a voltage, comprising:

providing the voltage from a charge pump to a display driver;

supplying the voltage to individual ones of the plurality of bi-stable segments via a plurality of outputs from the display driver in accordance with display instructions provided by a system controller;

detecting both a bi-stable segment voltage level of at least one of the plurality of outputs of the display driver and a charge pump voltage level of the voltage;

comparing both the detected bi-stable segment voltage level with a valid bi-stable segment voltage level and the detected charge pump voltage level with a valid charge pump voltage level; and

providing a malfunction signal to the system controller if either the detected bi-stable segment voltage level is not equal to the valid bi-stable segment voltage level, or the charge pump voltage level is not within a tolerance range of the valid charge pump voltage level.

25. A control circuit for controlling a bi-stable display comprising:

a system controller, a display driver, a charge pump, and a charge pump monitoring module, wherein;

the charge pump is configured to generate one or more charge pump voltages;

the bi-stable display comprises a plurality of bi-stable segments capable of transitioning between an on state and an off state with an application of the charge pump voltages;

the display driver comprises a plurality of outputs that correspond to the plurality of bi-stable segments, and is operable to control individual ones of the plurality of bi-stable segments by applying the charge pump voltages to the plurality of bi-stable segments via the plurality of outputs in accordance with display instructions provided by the system controller; and

the charge pump monitoring module is operable to monitor a charge pump voltage level of the charge pump, compare the monitored charge pump voltage level with a valid charge pump voltage level, and provide a charge pump malfunction signal to the system controller if the monitored charge pump voltage level is not within a tolerance range of the valid charge pump voltage level.