System and method to heat LCDs using UV LEDs

Patent metadata

Field	Value
Publication number	US-11181765-B2
Application number	US-202117215470-A
Country	US
Kind code	B2
Filing date	Mar 29, 2021
Priority date	Mar 27, 2020
Publication date	Nov 23, 2021
Grant date	Nov 23, 2021

Abstract

An inexpensive system for maintaining an LCD display above an operative temperature includes ultraviolet (UV) light-emitting diodes (LEDs) incorporated into a backlight structure. The UV LEDs operate in a frequency range sufficiently removed from the visible band to not interfere with the user. A temperature sensor continuously or periodically monitors the temperature of the LCD and activates the UV LEDs to maintain the LCD in a predetermined temperature range for a desired response time.

First claim

What is claimed is:

1. An liquid-crystal display (LCD) device comprising:
an LCD layer; and
a backlight layer comprising a plurality of light-emitting diodes (LEDs),
wherein the plurality of LEDS comprises:
a set of visible light LEDs; and
a set of ultraviolet (UV) LEDs disposed on the backlight layer to substantially uniformly heat the LCD layer.

2. The LCD device of claim 1 ; wherein the UV LEDs are configured to operate within a wavelength range between 375 nm and 425 nm.

3. The LCD device of claim 1 ; wherein the UV LEDs are disposed among the visible light LEDs at a density of no more than one UV LEDs per six square centimeters of backlight layer.

4. The LCD device of claim 1 ; further comprising at least one processor in data communication with a memory storing processor executable code for configuring the at least one processor to periodically activate the UV LEDs for a period of time.

5. The LCD device of claim 4 ; further comprising a temperature sensor in data communication with the at least one processor, where in the at least one processor is further configured to:
receive a temperature value form the temperature sensor; and
activate the UV LEDs when the temperature value is below a defined threshold.

6. The LCD device of claim 4 ; further comprising a temperature sensor in data communication with the at least one processor, where in the at least one processor is further configured to:
continuously receive temperature values from the temperature sensor; and
activate the UV LEDs based on a relation of a current temperature to a rate of temperature change and a known heating coefficient of the UV LEDs.

7. The LCD device of claim 4 ; further comprising a temperature sensor in data communication with the at least one processor, where in the at least one processor is further configured to:
receive a temperature value from the temperature sensor; and
deactivate the UV LEDs when the temperature value is above a defined threshold.

8. An avionics display system comprising:
an liquid-crystal display (LCD) device comprising:
an LCD layer; and
a backlight layer comprising a plurality of light-emitting diodes (LEDs),

wherein the plurality of LEDS comprises:
a set of visible light LEDs; and
a set of ultraviolet (UV) LEDs disposed on the backlight layer to substantially uniformly heat the LCD layer.

9. The avionics display system of claim 8 ; wherein the UV LEDs are configured to operate within a wavelength range between 375 nm and 425 nm.

10. The avionics display system of claim 8 ; wherein the UV LEDs are disposed among the visible light LEDs at a density of no more than one UV LEDs per six square centimeters of backlight layer.

11. The avionics display system of claim 8 ; further comprising at least one processor in data communication with a memory storing processor executable code for configuring the at least one processor to periodically activate the UV LEDs for a period of time.

12. The avionics display system of claim 11 ; where in the at least one processor is further configured to:
determine that the avionics display system is in a startup sequence; and
activate the UV LEDs until the startup sequence is concluded.

13. The avionics display system of claim 11 ; further comprising a temperature sensor in data communication with the at least one processor, where in the at least one processor is further configured to:
receive a temperature value form the temperature sensor; and
activate the UV LEDs when the temperature value is below a defined threshold.

14. The avionics display system of claim 11 ; further comprising a temperature sensor in data communication with the at least one processor, where in the at least one processor is further configured to:
continuously receive temperature values from the temperature sensor; and
activate the UV LEDs based on a relation of a current temperature to a rate of temperature change and a known heating coefficient of the UV LEDs.

15. The avionics display system of claim 11 ; further comprising a temperature sensor in data communication with the at least one processor, where in the at least one processor is further configured to:
receive a temperature value from the temperature sensor; and
deactivate the UV LEDs when the temperature value is above a defined threshold.

Assignees

• Rockwell Collins Inc

Inventors

• Johnson Ricky J
• Covington Blake P

Classifications

• H05B3/0038

  for industrial applications · CPC title

• G02F2201/086

  UV absorbing · CPC title

• G02F1/133382 Primary

  Heating or cooling of liquid crystal cells other than for activation, e.g. circuits or arrangements for temperature control, stabilisation or uniform distribution over the cell · CPC title

• H05K7/20954 Primary

  for display panels · CPC title

• H05B6/00

  Heating by electric, magnetic or electromagnetic fields · CPC title