Apparatus, systems, and methods for display devices including local dimming
An example device may include an electronic display configured to generate an augmented reality image element and an optical combiner configured to receive the augmented reality image element along with ambient light from outside the device. The optical combiner may be configured to provide an augmented reality image having the augmented reality image element located within a portion of an ambient image formed from the ambient light. The device may also include a dimmer element configured to selectively dim the portion of the ambient image in which the augmented reality image element is located.
1. A device, comprising:
an electronic display configured to generate an augmented reality image element;
an optical combiner configured to receive the augmented reality image element, to receive ambient light from outside the device, and to provide an augmented reality image having the augmented reality image element located within a portion of an ambient image, the ambient image formed from the ambient light;
a dimmer element configured to reduce an intensity of at least the portion of the ambient image to improve visibility of the augmented reality image element,
wherein the dimmer element comprises a photochromic layer, and
a UV shutter, wherein
the device is configured so that the photochromic layer is darkened by UV light passing through the UV shutter to selectively dim the portion of the ambient image in which the augmented reality image element is located,
the UV shutter includes UV shutter pixels, and
the photochromic layer is selectively darkened by UV light passing through UV shutter pixels that are in a UV transmissive state.
2. The device of claim 1 , wherein the device is an augmented reality headset configured to be worn by a user and the device is configured so that the augmented reality image element is projected towards an eye of the user after passing through the optical combiner.
3. The device of claim 1 , wherein the ambient light passes through the dimmer element before passing through the optical combiner.
4. The device of claim 1 , wherein the dimmer element further comprises a liquid crystal shutter, and the liquid crystal shutter is configured to selectively dim the portion of the ambient image in which the augmented reality image element is located.
5. The device of claim 4 , wherein the liquid crystal shutter comprises the photochromic layer.
6. The device of claim 5 , wherein the liquid crystal shutter includes a liquid crystal layer and the liquid crystal layer includes a photochromic material.
7. The device of claim 1 , wherein the photochromic layer is configured to partially absorb the ambient light when the ambient light includes UV light, the photochromic layer having a degree of optical absorption based on an intensity of the ambient light.
8. The device of claim 1 , wherein the UV shutter comprises a liquid crystal shutter.
9. The device of claim 1 , further comprising a control unit configured to:
generate or receive augmented reality information for display as the augmented reality image element;
activate the electronic display to provide the augmented reality image element; and
control the dimmer element to dim a selected portion of the ambient image to enhance visibility of the augmented reality image element.
10. The device of claim 1 , wherein:
the augmented reality image element includes a plurality of color channels,
the electronic display comprises a separate projector array for each color channel of the plurality of color channels, and
each projector array is coupled into the optical combiner.
11. The device of claim 10 , wherein each projector array comprises a microLED array.
12. The device of claim 10 , wherein each projector array comprises a microLED array having microLEDs spaced apart by less than 5 microns.
13. The device of claim 1 , further comprising an image sensor configured to determine an intensity of the ambient light as a function of direction,
wherein the dimmer element is selectively controlled based on one or more directions from which the intensity of the ambient light exceeds a threshold intensity.
14. The device of claim 1 , further comprising an eye tracking camera configured to determine a user gaze.
15. The device of claim 14 , wherein the dimmer element is selectively controlled based on the determined user gaze.
16. The device of claim 14 , wherein the dimmer element is selectively controlled based on one or more directions from which the intensity of the ambient light exceeds a threshold intensity, and not based on the determined user gaze.
17. A method, comprising:
combining an ambient image and an augmented reality image element to form an augmented reality image; and
dimming a selected portion of the ambient image to visually enhance the augmented reality image element,
wherein the selected portion of the ambient image includes the augmented reality image element,
wherein dimming the selected portion of the ambient image comprises using a dimmer element comprising a photochromic layer to dim the selected portion of the ambient image, and
wherein dimming the selected portion of the ambient image includes switching one or more pixels of a UV shutter into a UV transmissive state to allow UV light to reach the photochromic layer, the photochromic layer being darkened by the UV light.