Controlling electroluminescent panels in response to cumulative utilization
An electronic device includes a light source, which generates light in response to a signal, and a controller. Because the luminosity of the light source decays over time, the controller generates a utilization value based on a cumulative time that the light source is emitting light, and regulates the signal that is provided to the light source in response to the utilization value to at least partially compensate for decay in the luminosity of the light source.
1. An electronic device comprising:
an electroluminescent panel that generates light in response to a power signal; and
a controller that is configured to generate a utilization value based on a cumulative time that the electroluminescent panel has emitting light, to regulate the power signal provided to the electroluminescent panel in response to the utilization value to at least partially compensate for decay in luminosity of the electroluminescent panel over time, and to repetitively increase amplitude of the power signal provided to the electroluminescent panel by one or more defined incremental amounts in response to the utilization value indicating the cumulative time that the electroluminescent panel has emitting light exceeds a sequence of increasing threshold values.
2. The electronic device of claim 1 , wherein the controller is further configured to monitor amplitude of the power signal provided to the electroluminescent panel over periods of time, and to regulate the incremental amount by which it repetitively increases the amplitude of the power signal in response to the amplitude of the power signal provided to the electroluminescent panel.
3. The electronic device of claim 1 , further comprising an ambient light sensor that generates an ambient light signal, and wherein the controller is further configured to turn-off the light source and, correspondingly, stop increasing the utilization value when the ambient light signal exceeds a threshold value.
4. An electronic device comprising:
an electroluminescent panel that generates light in response to a power signal; and
a controller that is configured to generate a utilization value based on a cumulative time that the electroluminescent panel has emitting light, to regulate the power signal provided to the electroluminescent panel in response to the utilization value to at least partially compensate for decay in luminosity of the electroluminescent panel over time, and to vary frequency of the power signal provided to the electroluminescent panel to increase luminosity therefrom based on an increased utilization value indicating an increased cumulative time that the electroluminescent panel has emitting light.
5. An electronic device comprising:
a light source that generates light in response to a signal;
a controller that is configured to generate a utilization value based on a cumulative time that the light source has emitting light, and to regulate the signal provided to the light source in response to the utilization value to at least partially compensate for decay in luminosity of the light source over time; and
a temperature sensor that is configure to generate a temperature signal that is indicative of temperature of the light source, wherein the controller is further configured to generate the utilization time based on integration of the temperature signal over time, and to regulate the signal provided to the light source in response to the utilization value to at least partially compensate for decay in the luminosity of the light source due to effects of temperature over time.
6. The electronic device of claim 5 , wherein:
the light source comprises an electroluminescent panel that generates light in response to a power signal; and
the controller is further configured to regulate amplitude and/or frequency of the power signal provided to the light source in response to the utilization value to at least partially compensate for decay in the luminosity of the light source due to effects of temperature over time.
7. The electronic device of claim 5 , further comprising a liquid crystal display (LCD), and wherein:
the light source comprises an electroluminescent panel that generates light in response to a power signal, the electroluminescent panel being configured as a backlight to the LCD; and
the controller is configured to display indicia on the LCD, to generate the utilization value based on the cumulative time that the electroluminescent panel has backlit the LCD, and to regulate the power signal provided to the electroluminescent panel in response to the utilization value to at least partially compensate for decay in luminosity of the electroluminescent panel over time.
8. An electronic device comprising:
a light source that generates light in response to a signal;
a controller that is configured to generate a utilization value based on a cumulative time that the light source has emitting light, and to regulate the signal provided to the light source in response to the utilization value to at least partially compensate for decay in luminosity of the light source over time; and
a keypad, and wherein:
the light source comprises an electroluminescent panel that generates light in response to a power signal, the electroluminescent panel being configured as a backlight to the keypad; and
the controller is configured to initiate a cellular phone call and/or generate a data message in response to user actuation of the keypad, to generate the utilization value based on the cumulative time that the electroluminescent panel has backlit the keypad, and to regulate the power signal provided to the electroluminescent panel in response to the utilization value to at least partially compensate for decay in the luminosity of the electroluminescent panel over time.
9. A method comprising:
generating a utilization value based on a cumulative time that an electroluminescent panel has emitting light; and
regulating a power signal, which is provided to the electroluminescent panel to generate light, in response to the utilization value to at least partially compensate for decay in luminosity of the light source; and
repetitively increasing amplitude of the power signal provided to the electroluminescent panel by one or more defined incremental amounts in response to the utilization value indicating the cumulative time that the electroluminescent panel has emitting light exceeds a sequence of increasing threshold values.
10. The method of claim 9 , further comprising varying frequency of the power signal provided to the electroluminescent panel to increase luminosity therefrom based on an increased utilization value indicating an increased cumulative time that the electroluminescent panel has emitting light.
11. The method of claim 9 , further comprising:
monitoring amplitude of the power signal provided to the light source over periods of time; and
regulating the incremental amount by which it repetitively increases the amplitude of the power signal in response to the amplitude of the power signal provided to the light source.
12. The method of claim 9 further comprising:
monitoring amplitude of the signal provided to the light source; and
generating the utilization value in response to the cumulative time that the light source has emitted light and the associated amplitude of the signal.