Backlit LCD monitor

• US 6,825,828 B2
• Filed: 02/21/2002
• Issued: 11/30/2004
• Est. Priority Date: 02/23/2001
• Status: Expired due to Fees

• Current Assignee: General Digital Corporation
• Original Assignee: General Digital Corporation
• Inventors: Burke, Thomas J., Elco, Gary, Gudrian, Bryan
• Primary Examiner(s): Chow, Dennis-Doon
• Assistant Examiner(s): Ward, Aaron S.
• Application Number:
  US10/080,983
• Publication Number:
  US 20020167637A1
• Time in Patent Office: 1,013 Days
• Field of Search: 345/102, 345/87, 345/77, 345/589-605, 345/101
• US Class Current: 345/101
• CPC Class Codes: G02F 1/133385 with cooling means, e.g. fans
• CPC Class Codes: G02F 1/133604 with lamps
• CPC Class Codes: G02F 1/133628 with cooling means
• CPC Class Codes: G02F 2201/58 Arrangements comprising a monitoring photodetector
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2320/048 using evaluation of the usage time
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336

Abstract

An exemplary embodiment of the invention is a backlit liquid crystal display (LCD) monitor comprising a backlight assembly, a cooling assembly, a rear cover assembly and a controller. The controller monitors temperature and controls cooling accordingly. The controller also monitors bulb luminance and adjusts bulb current accordingly. Faults are monitored and logged so that predictive repair before failure analysis may be performed.

Claims

1. A backlit liquid crystal display monitor comprising:

a backlight assembly having opposing top and bottom surfaces, said bottom surface including a plurality of fluorescent bulbs having parallel bulb axes, and two or more inverters to drive said bulbs;

a cooling assembly having opposing top and bottom surfaces, the top surface of said cooling assembly mounted on the bottom surface of said backlight assembly to form a backlight chamber defining air space around said bulbs, said cooling assembly including;

a light sensor on the top surface of said cooling assembly, said light sensor having a sensor axis that is perpendicular to the bulb axes of said fluorescent bulbs;

a temperature sensor;

a heat sink on the bottom surface of said cooling assembly; and

an air inlet and an air outlet in fluid communication with said closed air space and positioned for causing air to flow across said bulbs;

a rear cover assembly placed over the bottom surface of said cooling assembly to define an electronics chamber between said rear cover assembly and the bottom surface of said cooling assembly, the electronics chamber being separate from said backlight chamber, said rear cover assembly including;

an exhaust fan in fluid communication with said air outlet generating a first airflow through said backlight chamber;

a cover inlet in fluid communication with said air inlet;

a filter placed over said cover inlet; and

a fan positioned to draw air towards said heat sink in said electronics chamber generating a second airflow separate from said first airflow; and

a controller in communication with said sensors, said inverters, and said fans.

2. The monitor of claim 1 wherein said filter is a HEPA filter.

5. The monitor of claim 1 further comprising:

a fan status indicator light in communication with said controller;

a temperature status indicator light in communication with said controller; and

a power status indicator light in communication with said controller.

6. The monitor of claim 1 further comprising an I/O device that is in communication with said controller.

7. The monitor of claim 6 wherein said I/O device is a serial port.

8. The monitor of claim 6 wherein said I/O device is an infrared data association port.

9. The monitor of claim 6 wherein said I/O device is connected to a network.

10. The monitor of claim 9 wherein said network is the Internet.

11. The monitor of claim 9 wherein said network is an intranet.

12. The monitor of claim 1 wherein each said inverter drives a different portion of said bulbs.

13. The monitor of claim 1 wherein said light sensor generates real-time diagnostic data and wherein said light sensor is dynamically reconfigured in response to said diagnostic data.

3. A backlit liquid crystal display monitor comprising:

a backlight assembly having opposing top and bottom surfaces, said bottom surface including a plurality of fluorescent bulbs having parallel bulb axes, and two or more inverters to drive said bulbs;

a cooling assembly having opposing top and bottom surfaces, the top surface of said cooling assembly mounted on the bottom surface of said backlight assembly to form a closed air space around said bulbs, said cooling assembly including;

a light sensor on the top surface of said cooling assembly, said light sensor having a sensor axis that is perpendicular to the bulb axes of said fluorescent bulbs;

a temperature sensor;

a heat sink on the bottom surface of said cooling assembly; and

an air inlet and an air outlet in fluid communication with said closed air space and positioned for causing air to flow across said bulbs;

a rear cover assembly placed over the bottom surface of said cooling assembly, said rear cover assembly including;

an exhaust fan in fluid communication with said air outlet;

a cover inlet in fluid communication with said air inlet;

a filter placed over said cover inlet; and

a fan positioned to draw air towards said heat sink; and

a controller in communication with said sensors, said inverters, and said fans;

a brightness control device in communication with said controller; and

a remote brightness control device in communication with said controller, said remote brightness control device overriding said brightness control device.

4. The monitor of claim 3 wherein:

said remote brightness control device includes a switch for designating a brightness range and a potentiometer for specifying a brightness within a designated range.