Energy sensing light emitting diode display

• US 8,963,817 B2
• Filed: 08/25/2011
• Issued: 02/24/2015
• Est. Priority Date: 12/31/2001
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Booth, Lawrence A. Jr., Seligson, Daniel
• Primary Examiner(s): Bost, Dwayne
• Assistant Examiner(s): KOHLMAN, CHRISTOPHER J
• Application Number:
  US13/218,277
• Publication Number:
  US 20110304592A1
• Time in Patent Office: 1,279 Days
• Field of Search: None
• US Class Current: 345/82
• CPC Class Codes: G06F 3/03542 Light pens for emitting or receiving light
• CPC Class Codes: G06F 3/0386 for light pen
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]

Abstract

A display that includes energy sensors within the display itself is disclosed. An Organic Light Emitting Diode (OLED) can be made to operate both as a light emitter and as an energy detector. When forward biased with an appropriate driving signal, the OLED emits light via electroluminescence, which can be used to make a portion of an image on the display. In another mode, the OLED can detect energy by converting incoming photons or energy into an electrical signal by the photoelectric effect. By operating OLEDs in the display in both emissive and sensing modes, energy that shines on the display, such as from an outside source can be detected at the same time an image is shown. Additionally, a display including OLEDs can detect light energy generated by the display itself.

Claims

1. A display device, comprising:

a plurality of light emitting diodes (LEDs) forming a display of the display device;

a driving circuit coupled to each of the LEDs, the driving circuit configured to drive each LED to emit light; and

a sensing circuit coupled to each of the LEDs, the sensing circuit configured to detect a shadow, wherein an LED in the shadow senses less light energy than an LED partially in or completely out of the shadow.

2. The display device of claim 1, wherein the shadow is from an operator'"'"'s finger.

3. The display device of claim 1, wherein the display is a touch screen.

4. The display device of claim 1, wherein the display device is associated with at least one of a portable device, a laptop computer, a telephone, and a personal digital assistant (PDA).

5. The display device of claim 1, wherein the sensing circuit is configured to receive an electrical signal from each LED when that LED is operated in a sense mode.

6. The display device of claim 1, wherein:

the shadow covers a portion of the display;

a first portion of the LEDs are located completely in the shadow and configured to sense a first level of light energy;

a second portion of the LEDs are located completely out of the shadow and configured to sense a second level of light energy; and

a third portion of the LEDs are located partially in the shadow and configured to sense a third level of light energy.

7. The display device of claim 6, wherein:

the sensing circuit is configured to receive data including the first, second, and third levels of light energy;

the driving circuit is configured to decrease current output to the LEDs that are completely or partially in the shadow based on the data so that the display appears to have one constant brightness across the entire display.

8. A display device, comprising:

a plurality of light emitting diodes (LEDs) forming a display of the display device;

a driving circuit coupled to each of the LEDs, the driving circuit configured to drive each LED to emit light; and

a sensing circuit coupled to each of the LEDs, the sensing circuit configured to detect a shadow, wherein the sensing circuit is configured to receive an electrical signal from each LED when that LED is operated in a sense mode, and wherein;

the plurality of LEDs includes first and second LEDs that are electrically connected to the driving circuit and the sensing circuit;

the sensing circuit is configured to sense first and second amounts of light incident on the first and second LEDs, respectively, wherein an LED in the shadow senses less light energy than an LED partially in or completely out of the shadow; and

the driving circuit is configured to individually control a brightness level of the first and second LEDs responsive to the first and second amounts of light, respectively, incident on the first and second LEDs as detected by the sensing circuit.

9. The display device of claim 8, wherein the driving circuit is configured to drive the first LED in response to an amount of light sensed by the second LED of the LEDs.

10. The display device of claim 8, wherein:

the driving circuit is configured to drive the first LED in response to an amount of light incident on the first LED sensed from an earlier point in time; and

the driving circuit is configured to drive the second LED in response to an amount of light incident on the second LED sensed from the earlier point in time.

11. A display device, comprising:

a plurality of light emitting diodes (LEDs) forming a display of the display device;

a driving circuit coupled to each of the LEDs, the driving circuit configured to drive each LED to emit light; and

a sensing circuit coupled to each of the LEDs, the sensing circuit configured to detect light energy, wherein the sensing circuit is configured to receive an electrical signal from each LED when that LED is operated in a sense mode, and wherein;

the plurality of LEDs includes first, second and third LEDs that are electrically connected to the driving circuit and the sensing circuit;

the sensing circuit is configured to sense first, second and third amounts of light incident on the first, second and third LEDs, respectively, based on whether each LED is in, partially in, or completely out of a shadow; and

the driving circuit is configured to individually control a brightness level of the first, second and third LEDs responsive to the first, second and third amounts of light, respectively, incident on the first, second and third LEDs as detected by the sensing circuit.

12. The display device of claim 11, wherein the driving circuit is configured to drive the first LED in response to an amount of light sensed by the second LED of the LEDs.

13. The display device of claim 11, wherein:

the driving circuit is configured to drive the first LED in response to an amount of light incident on the first LED sensed from an earlier point in time; and

the driving circuit is configured to drive the second LED in response to an amount of light incident on the second LED sensed from the earlier point in time.

14. The display device of claim 11, wherein the display device is associated with at least one of a portable device, a laptop computer, a telephone, and a personal digital assistant (PDA).

15. A method of operating a display having a plurality of light emitting diodes (LEDs), the method comprising:

driving each LED in an emit mode to display an image on the display;

switching at least one LED from the emit mode to a sense mode;

sensing an electrical signal from the at least one LED in the sense mode;

detecting a shadow on the display based on light energy sensed by the at least one LED, wherein an LED in the shadow senses less light energy than an LED that is partially in or completely out of the shadow; and

switching the at least one LED from the sense mode to the emit mode.

16. The method of claim 15, wherein detecting a shadow includes detecting the shadow from an operator'"'"'s finger.

17. The method of claim 15, wherein the display device is associated with at least one of a portable device, a laptop computer, a telephone, and a personal digital assistant (PDA).

18. The method of claim 16, wherein the switching of the at least one LED from the emit mode to the sense mode, the sensing of an electrical signal from the at least one LED, and the switching of the at least one LED from the sense mode to the emit mode occurs while the image is being displayed on the display.

19. A display system comprising:

a display panel capable of displaying an image wherein the display panel comprises a plurality of display elements wherein the display elements are capable of causing an image to be formed on the display panel and a plurality of sensing elements wherein the sensing elements are capable of sensing external light and wherein the display elements and the sensing elements are located in columns and rows,

driving circuitry capable of driving the display elements and causing an image to be formed on the display panel,

sensing circuitry capable of outputting information based on an amount of external light received by the sensing elements according to the column and row in which the sensing element is located, and

a data storage unit capable of storing output from the sensing circuitry according to the column and row in which the sensing element is located.

20. The display system of claim 19 wherein the sensing circuitry is capable of sending the data storage unit a value related to the brightness of the light sensed by a sensing element and the data storage unit is capable of storing the value.

21. The display system of claim 19 wherein the display panel is capable of forming an image while also sensing light.

22. The display system of claim 19 also including a position locator coupled to the data storage unit and including a comparator structured to compare data sensed by a sensing element in the sensing mode, the position locator structured to determine a position at which an external pointing device is pointing in response to compared data.

23. The display system of claim 19 wherein the display device is employed in a portable computing device.

24. The display system of claim 19 wherein the amount of external light received by each of the sensing elements is based on whether the sensing element is completely in, partially, in, or completely out of a shadow.