System and method for enhancing visual acuity of head wearable displays
A head wearable display system comprising a target object detection module receiving multiple image pixels of a first portion and a second portion of a target object, and the corresponding depths; a first light emitter emitting multiple first-eye light signals to display a first-eye virtual image of the first portion and the second portion of the target object for a viewer; a first light direction modifier for respectively varying a light direction of each of the multiple first-eye light signals emitted from the first light emitter; a first collimator; a first combiner, for redirecting and converging the multiple first-eye light signals towards a first eye of the viewer. The first-eye virtual image of the first portion of the target object in a first field of view has a greater number of the multiple first-eye light signals per degree than that of the first-eye virtual image of the second portion of the target object in a second field of view.
1. A head wearable display system comprising:
a target object detection module receiving multiple image pixels of a first portion and a second portion of a target object, and the corresponding depths;
a first light emitter emitting multiple first-eye light signals to display a first-eye virtual image of the first portion and the second portion of the target object for a viewer;
a first light direction modifier for respectively varying a light direction of each of the multiple first-eye light signals emitted from the first light emitter;
a first collimator, disposed between the first light emitter and the first light direction modifier, to adjust a beam waist location of each of the multiple first-eye light signals so that the multiple first-eye light signals are separable from each other;
a first combiner, for redirecting and converging the multiple first-eye light signals towards a first eye of the viewer; and
wherein the first-eye virtual image of the first portion of the target object in a first field of view has a greater number of the multiple first-eye light signals per degree than that of the first-eye virtual image of the second portion of the target object in a second field of view,
wherein the multiple first-eye light signals are separable from each other if a spatial distance between centers of any two adjacent first-eye light signals on a cross-sectional plane of light path is larger than half of a greatest diameter of the two adjacent first-eye light signals.
2. The head wearable display system of claim 1 , wherein the number of the multiple first-eye light signals per degree for the first-eye virtual image of the target object is adjusted based on the corresponding depth of the target object.
3. The head wearable display system of claim 1 , wherein the number of the multiple first-eye light signals per degree for the first-eye virtual image of the first portion of the target object in the first field of view exceeds 120.
4. The head wearable display system of claim 1 , wherein a projection duration of the first light emitter for each of the multiple first-eye light signals is varied to modify a spot size of the multiple first-eye light signals for the first-eye virtual image of the first portion of the target object.
5. The head wearable display system of claim 1 , wherein a projection frequency of the first-eye light emitter is varied to modify the number of the multiple first-eye light signals per degree for the first-eye virtual image of the first portion of the target object.
6. The head wearable display system of claim 1 , wherein a swing frequency of the first light direction modifier is varied to modify the number of the multiple first-eye light signals per degree for the first-eye virtual image of the first portion of the target object.
7. The head wearable display system of claim 6 , wherein a light direction of the multiple first-eye light signals is varied at the swing frequency with respect to time for displaying the first-eye virtual image of the target object and the swing frequency is non-constant.
8. The head wearable display system of claim 7 , wherein the light direction comprises a first coordinate component and a second coordinate component; the first coordinate component and the second coordinate component of the light direction of first-eye light signals are respectively varied at a first swing frequency and a second swing frequency with respect to time for displaying the first-eye virtual image of the target object; and the first swing frequency or the second swing frequency is non-constant.
9. The head wearable display system of claim 7 , wherein each of the multiple first-eye light signals forms a pixel in the first-eye virtual image of the target object and a pixel density in the first-eye virtual image is not uniform.
10. The head wearable display system of claim 9 , wherein the first portion of the target object is a central portion, the second portion of the target object is a peripheral portion, and the first-eye virtual image of the first portion of the target object has a pixel density higher than the first-eye virtual image of the second portion of the target object.
11. The head wearable display system of claim 1 , wherein a spot area of each of two adjacent first-eye light signals on a cross-sectional plane of light path approximately adjoins each other.
12. The head wearable display system of claim 1 , wherein the first light emitter comprises a red laser diode, a green laser diode, and a blue laser diode.
13. The head wearable display system of claim 1 , wherein a first distance between the first light direction modifier and the first collimator is varied to modify a spot size of the multiple first-eye light signals for the first-eye virtual image of the first portion of the target object.
14. The head wearable display system of claim 1 , further comprising:
a second light emitter emitting multiple second-eye light signals, corresponding to the multiple first-eye light signals, to display a second-eye virtual image of the first portion and the second portion of the target object for the viewer;
a second light direction modifier for respectively varying a light direction of each of the multiple second-eye light signals emitted from the second light emitter;
a second collimator, disposed between the second light emitter and the second light direction modifier, to adjust a beam waist location of each of the multiple second-eye light signals so that the multiple second-eye light signals are separable from each other;
wherein the first combiner receives and converges the multiple second-eye light signals towards a second eye of the viewer;
wherein the second-eye virtual image of the first portion of the target object in a third field of view has a greater number of the multiple second-eye light signals per degree than that of the second-eye virtual image of the second portion of the target object in a fourth field of view; and
wherein a first-eye light signal and a corresponding second-eye light signal are perceived by the viewer to display a virtual binocular pixel of a binocular virtual image of the target object with a depth that is related to an angle between the first-eye light signal and the corresponding second-eye light signal projected into the viewer's eyes.
15. The head wearable display system of claim 1 , further comprising:
a second light emitter emitting multiple second-eye light signals, corresponding to the multiple first-eye light signals, to display a second-eye virtual image of the first portion and the second portion of the target object for the viewer;
a second light direction modifier for respectively varying a light direction of each of the multiple second-eye light signals emitted from the second light emitter;
a second collimator, disposed between the second light emitter and the second light direction modifier, to adjust a beam waist location of each of the multiple second-eye light signals so that the multiple second-eye light signals are separable from each other;
a second combiner for redirecting and converging the multiple second-eye light signals towards a second eye of the viewer;
wherein the second-eye virtual image of the first portion of the target object in a third field of view has a greater number of the multiple second-eye light signals per degree than that of the second-eye virtual image of the second portion of the target object in a fourth field of view; and
wherein a first-eye light signal and a corresponding second-eye light signal are perceived by the viewer to display a virtual binocular pixel of a binocular virtual image of the target object with a depth that is related to an angle between the first-eye light signal and the corresponding second-eye light signal projected into the viewer's eyes.
16. The head wearable display system of claim 15 , further comprising an eye tracking device for respectively determining a visual axis of the viewer's first eye and the viewer's second eye to determine a location of fixation.
17. The head wearable display system of claim 16 , wherein a projection frequency of the first light emitter and a projection frequency of the second light emitter are varied according to the location of fixation to respectively modify the number of the multiple first-eye light signals per degree for the first-eye virtual image of the first portion of the target object and the number of the multiple second-eye light signals per degree for the second-eye virtual image of the first portion of the target object.
18. The head wearable display system of claim 16 , wherein a swing frequency of the first light direction modifier and the swing frequency of the second light direction modifier are varied according to the location of fixation to respectively modify the number of the multiple first-eye light signals per degree for the first-eye virtual image of the first portion of the target object and the number of the multiple second-eye light signals per degree for the second-eye virtual image of the first portion of the target object.
19. The head wearable display system of claim 16 , wherein a projection frequency of the first light emitter and a projection frequency of the second light emitter are varied according to the location of fixation to respectively modify the number of the multiple first-eye light signals per degree for the first-eye virtual image of the first portion of the target object and the number of the multiple second-eye light signals per degree for the second-eye virtual image of the first portion of the target object.
20. The head wearable display system of claim 16 , wherein a projection duration of the first light emitter for each of the multiple first-eye light signals and a projection duration of the second light emitter for each of the multiple second-eye light signals are varied according to the location of fixation to respectively modify a spot size of the multiple first-eye light signals for the first-eye virtual image of the first portion of the target object and a spot size of the multiple second-eye light signals for the second-eye virtual image of the first portion of the target object.
21. The head wearable display system of claim 16 , wherein a first distance between the first light direction modifier and the first collimator and a second distance between the second light direction modifier and the second collimator are varied according to the location of fixation to respectively modify a spot size of the multiple first-eye light signals for the first- eye virtual image of the first portion of the target object and a spot size of the multiple second- eye light signals for the second-eye virtual image of the first portion of the target object.
22. The head wearable display system of claim 15 , wherein the target object detection module determines a 3-dimensional coordinate for each of the multiple image pixels of the first portion and the second portion of the target object.
23. The head wearable display system of claim 15 , wherein the binocular virtual image of the target object is displayed to superimpose on the target object.
24. The head wearable display system of claim 15 , further comprising a shutter to substantially reduce environmental lights from entering the viewer's eyes.
25. The head wearable display system of claim 24 , wherein the shutter is activated by reducing transparency of the first combiner and the second combiner.