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

• US 8,526,584 B2
• Filed: 08/18/2009
• Issued: 09/03/2013
• Est. Priority Date: 08/18/2009
• Status: Active Grant

• Current Assignee: Mitel Networks Corporation
• Original Assignee: Mitel Networks Corporation
• Inventors: Gancarcik, Edward Peter
• Primary Examiner(s): Sing, Simon
• Assistant Examiner(s): BEZUAYEHU, SOLOMON G
• Application Number:
  US12/583,343
• Publication Number:
  US 20110044441A1
• Time in Patent Office: 1,477 Days
• Field of Search: 379 8801- 8819, 345204-215
• 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 setting a clock signal driving an LCD panel at a first driving frequency during a full power operating mode of the telephone set and a second, higher driving frequency during a low power operating mode of the telephone set.

2. The desktop network protocol telephone set of claim 1, wherein the low power operating mode is when a backlight of the LCD panel is operating at a user defined minimum intensity.

3. The desktop network protocol telephone set of claim 1, wherein the low power operating mode occurs when the telephone set is unattended for a predetermined period of time.

4. The desktop network protocol telephone set of claim 1, wherein the low power operating is user defined.

5. 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 a clock signal driving an LCD panel of the telephone set at a first driving frequency during a full power operating mode of the telephone set and at a second, higher driving frequency during a low power operating mode of the telephone set.

6. The method of claim 5, wherein the low power operating mode is when a backlight of the LCD panel is operating at a user defined minimum intensity.

7. The method of claim 5, wherein the full power operating mode is when a backlight of the LCD panel is operating at a user defined maximum intensity.