Optical input diodes
Examples of the present disclosure relate to a device, method, and system for optical input diodes. A liquid crystal display (LCD) backlight device may include a processor and a color filter of a pixel including at least one of a red filter, a green filter, or a blue filter. The LCD backlight device may also include a diode to emit light through the color filter in response to being driven by the processor. The diode may generate a voltage in response to light passing through the color filter and arriving on the diode, where an image value may be calculated as a function of the voltage generated and a color filter value of the color filter.
1. A liquid crystal display (LCD) backlight device comprising:
a processor;
a color filter of a pixel comprising at least one of a red filter, a green filter, or a blue filter; and
a diode to emit light through the color filter in response to being driven by the processor, the diode to generate a voltage in response to light passing through the color filter and arriving on the diode, where an image value is calculated as a function of the voltage generated and a color filter value of the color filter.
2. The device of claim 1 , wherein the diode emitting light through the color filter is a first phase of operating the LCD backlight device, the diode not emitting light through the color filter is a second phase of operating the LCD backlight device, and the color filter blocks light passage for two of the red filter, the green filter, or the blue filter in response to the diode entering the second phase from the first phase.
3. The device of claim 2 , wherein:
the color filter blocks light passage for each two-filter combination of the red filter, the green filter, and the blue filter during the second phase; and
the processor records a voltage value for each two-filter blocked combination to correspond to the color filter that is not blocked corresponding to the light arrived on the diode during each two-filter blocked combination.
4. The device of claim 3 , wherein the processor generates a composite image value for the pixel from each of the color filter value's voltages and the respective voltages generated for each of the two-filter blocked combinations of the red filter, the green filter, and the blue filter.
5. The device of claim 2 , wherein the color filter value of the color filter for which light passage is not blocked as a result of entering the second phase, this color filter value is not changed in response to the diode entering the second phase from the first phase.
6. The device of claim 2 , wherein the color filter value of the color filter for which light passage is not blocked is changed to a value that maximizes light passage through itself in response to the diode entering the second phase from the first phase.
7. The device of claim 1 , comprising a voltage detector connected in an electrical signal path between the diode and the processor.
8. The device of claim 1 , comprising a plurality of diodes including the diode, wherein the voltages generated by the plurality of diodes is summed for the pixel through which light is passing and the image value is calculated as a function of the summed voltage generated and the color filter value of the color filter through which light is permitted to travel.
9. The device of claim 8 , wherein each diode in the plurality of diodes is assigned to a distinct bank of diodes where each distinct bank of diodes has a known position in a display and relative voltages measured in each distinct bank of diodes corresponds to a distance measure, and wherein the distance measure of each distinct bank of diodes can be used in combination with other distance measures to estimate a location of a light source.
10. The device of claim 1 , wherein the LCD backlight device comprises at least one edge backlight located along the edge of an LCD.
11. A method for identifying optical input from a diode comprising:
emitting light with a diode through a color filter;
generating a voltage with the diode in response to light passing through the color filter and arriving on the diode; and
calculating an image value as a function of the voltage generated and a color filter value of the color filter.
12. The method of claim 11 , wherein the diode emitting light through the color filter is a first phase, the diode not emitting light through the color filter is a second phase, and the color filter blocks light passage for two of a red filter, a green filter, or a blue filter in response to the diode entering a second phase from the first phase.
13. The method of claim 12 , comprising:
blocking, by the color filter, light passage for each two-filter combination of the red filter, the green filter, and the blue filter during the second phase; and
recording a voltage value for each two-filter blocked combination to correspond to the color filter that is not blocked corresponding to the light arrived on the diode during each two-filter blocked combination.
14. The method of claim 13 , comprising generating a composite image value for a pixel from each of the color filter value's voltages and the respective voltages generated for each of the two-filter blocked combinations of the red filter, green filter, and blue filter.
15. The method of claim 11 , comprising measuring the voltage generated by the diode with a voltage detector connected in an electrical signal path between the diode and a processor.
16. The method of claim 11 , wherein the diode is located in an edge backlight located along an edge of an LCD.
17. A system for identifying an image with diodes comprising:
a processor;
a liquid crystal display (LCD);
a light emitting diode backlight array;
a color filter of a pixel comprising at least one of a red filter, a green filter, or a blue filter; and
a diode in the light emitting diode backlight array to emit light through the color filter in response to being driven by the processor, the diode to generate a voltage in response to light passing through the color filter and arriving on the diode, where an image value is calculated as a function of the voltage generated and a color filter value of the color filter.
18. The system of claim 17 , wherein the diode emitting light through the color filter is a first phase of operating the system, the diode not emitting light through the color filter is a second phase of operating the system, and the color filter blocks light passage for two of the red filter, the green filter, or the blue filter in response to the diode entering the second phase from the first phase.
19. The system of claim 17 , comprising a voltage detector connected in an electrical signal path between the diode and the processor.
20. The system of claim 17 , wherein the diode voltage is generated in response to light passing through the color filter while red, green, and blue subpixels of one or more pixels are active at the same time so that a greyscale image value is calculated as a function of the voltage generated and color filter values of the color filter.