Device and method for preventing ion build-up in liquid crystal displays

• US 20110044441A1
• Filed: 08/18/2009
• Published: 02/24/2011
• Est. Priority Date: 08/18/2009
• Status: Active Grant

• Current Assignee: Mitel Networks Corporation
• Original Assignee: Mitel Networks Corporation
• Inventors: Gancarcik, Edward Peter
• Granted Patent: US 8,526,584 B2
• Time in Patent Office: Days
• US Class Current: 379/93.05
• CPC Class Codes: G09G 2310/0278 Details of driving circuits arranged to drive both scan and data electrodes
• CPC Class Codes: G09G 2320/0204 Compensation of DC component across the pixels in flat panels
• CPC Class Codes: G09G 2320/0257 Reduction of after-image effects
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2330/022 in absence of operation, e.g. no data being entered during a predetermined time
• CPC Class Codes: G09G 2340/0435 Change or adaptation of the frame rate of the video stream
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3666 with the matrix divided into sections
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A desktop network protocol telephone set has a network interface for connecting the telephone set to a local area network. An audio interface provides audio signals to and from a handset of the telephone set. A processing circuit is responsive to communications from the network interface. A control circuit coupled to the processing circuit is used for changing a driving frequency of the LCD panel.

Claims

1. A desktop network protocol telephone set, comprising:

a network interface for connecting the telephone set to a local area network;

an audio interface for providing audio signals to and from a handset of the telephone set;

a processing circuit responsive to communications from the network interface; and

a control circuit for changing a driving frequency of the LCD panel driving an LCD panel.

2. The desktop network protocol telephone set of claim 1, wherein the control circuit has dynamic frequency control for changing the driving frequency of the LCD panel with an operating state of the telephone set.

3. The desktop network protocol telephone set of claim 1, wherein the control circuit drives the LCD panel at a first driving frequency during a full power operating mode of the telephone set and at a second driving frequency during a low power operating mode of the telephone set.

4. The desktop network protocol telephone set of claim 3, wherein the second frequency is greater than the first frequency.

5. The desktop network protocol telephone set of claim 3, wherein the low power operating mode is when a backlight of the LCD panel is operating at a user defined minimum intensity.

6. The desktop network protocol telephone set of claim 3, wherein the low power operating mode occurs when the telephone set is unattended for a predetermined period of time.

7. The desktop network protocol telephone set of claim 3, wherein the low power operating is user defined.

8. A method of operation of a desktop network protocol telephone set coupled to a local area network by a network interface, comprising:

first receiving first network transmissions from the local area network corresponding to received audio signals;

first converting the first network transmissions to a first audio signal provided to a handset of the telephone set;

second receiving a second audio signal from the handset;

second converting the second audio signal to second network transmissions and providing them to the network interface;

determining an operating state of the telephone set;

setting a frequency of an LCD panel of the telephone based on the operating state.

9. The method of claim 8, wherein determining an operating state of the telephone set further comprises determining a full power operating mode of the telephone set and a low power operating mode of the telephone set.

10. The method of claim 9, wherein the low power operating mode is when a backlight of the LCD panel is operating at a user defined minimum intensity.

11. The method of claim 9, wherein the full power operating mode is when a backlight of the LCD panel is operating at a user defined maximum intensity.

12. The method of claim 9, wherein setting a frequency further comprises setting the frequency of the LCD panel at a first driving frequency during the full power operating mode of the telephone set and at a second driving frequency during the low power operating mode of the telephone set.

13. The method of claim 12, wherein the second frequency is greater than the first frequency.

14. A desktop network protocol telephone set, comprising:

a network interface for connecting the telephone set to a local area network;

an audio interface for providing audio signals to and from a handset of the telephone set;

a processing circuit responsive to communications from the network interface; and

a control circuit for changing a driving frequency of a clock signal used to drive the LCD panel based on an operating state of the telephone set.

15. The desktop network protocol telephone set of claim 14, wherein the control circuit drives the LCD panel at a first driving frequency during a full power operating mode of the telephone set and at a second driving frequency during a low power operating mode of the telephone set.

16. The desktop network protocol telephone set of claim 15, wherein the second frequency is greater than the first frequency.

17. The desktop network protocol telephone set of claim 15, wherein the low power operating mode is when a backlight of the LCD panel is operating at a user defined minimum intensity.

18. The desktop network protocol telephone set of claim 15, wherein the low power operating mode occurs when the telephone set is unattended for a predetermined period of time.

19. The desktop network protocol telephone set of claim 15, wherein the low power operating is user defined.

20. The desktop network protocol telephone set of claim 14, wherein the control circuit drives the LCD panel at a first driving frequency during a full power operating mode of the telephone set and at a second driving frequency during a low power operating mode of the telephone set, wherein the second frequency is greater than the first frequency.