Beam scanning engine and display system with multiple beam scanners
A display system includes a display screen, a light source to generate a light beam to be modulated in accordance with image data, and a beam scanning module to receive the light beams and to direct the light beam onto an associated display region of the display screen. The beam scanning module includes a resonant scanning mirror configured to scan the light beam along a first scanning direction across the associated display region, and a polygon scanning mirror to scan the light beam along a second scanning direction across the associated display region.
1. A display system comprising:
a display screen;
a light source to generate a light beam to be modulated in accordance with image data; and
a beam scanning module to receive the light beams and to direct the light beam onto an associated display region of the display screen, the beam scanning module including
a resonant scanning mirror configured to scan the light beam along a first scanning direction across the associated display region, and
a polygon scanning mirror configured to scan the light beam along a second scanning direction across the associated display region, the polygon scanning mirror having a plurality of facets,
wherein the beam scanning module is configured to cause, for a first facet of the plurality of facets, the light beam to follow a path including a first plurality of scan lines extending primarily along the first direction and spaced apart along the second direction, and to cause, for a second facet of the plurality of facets, the light beam to follow a path that includes a second plurality of scan lines extending primarily along the first direction and spaced apart along the second direction, the first plurality of scan lines interlaced with the second plurality of scan lines.
2. The system of claim 1 , wherein the polygon scanning mirror comprises an N-sided polygon mirror.
3. The system of claim 2 , wherein the resonant scanning mirror causes the light beam to make n pluralities of interlaced scan lines extending primarily along the first direction across the display region and spaced apart along the second direction, and 1<n≤N.
4. The system of claim 3 , wherein 6≤n≤25.
5. The system of claim 4 , wherein 8≤n≤15.
6. The system of claim 3 , wherein n=N.
7. The system of claim 3 , wherein n<N, and the light beam is deactivated for (N-n) facets of the polygon mirror.
8. The system of claim 1 , wherein the rotating polygon scanning mirror is rotatable about an axis of rotation, and the plurality of facets have a same angle of inclination relative to the axis of rotation.
9. The system of claim 8 , wherein the plurality of facets are parallel to the axis of rotation.
10. The system of claim 1 , further comprising a controller configured to receive image data including pixel data representing intensity values of pixels, to split the pixel data into a plurality of fields including a first field corresponding to the first plurality of scan lines and a second field, and to modulate the light beam in accordance with the image data of the first field while the light beam impinges the first facet, and to modulate the light beam in accordance with the image data of the second field while the light beam impinges the second facet.
11. The system of claim 1 , wherein each of the first and second pluralities of scan lines comprises the same number of scan lines.
12. The system of claim 11 , wherein the number of scan lines is between 36 and 200, and wherein 24 to 96 of those scan lines fall within the display region.
13. The system of claim 11 , wherein between 60-80% of the number of scan lines fall within the display region.
14. The system of claim 1 , wherein the light beam is deactivated for scan lines positioned beyond opposite edges of the display region that are separated along the second direction.
15. The system of claim 1 , wherein a combination of oscillation of the resonant scanning mirror and rotation of polygon scanning mirror generates a sinuous path for the light beam to traverse.
16. The system of claim 15 , wherein the sinuous path comprises a sinusoidal path.
17. The system of claim 15 , wherein the light beam is deactivated for portions of the sinuous path that extend beyond opposite edges of the display region that are separated along the first direction.
18. The system of claim 1 , wherein a scanning speed of the light beam along the first scanning direction is greater than a scanning speed of the light beam along the second scanning direction.
19. The system of claim 1 , wherein the display screen comprises fluorescent material, and the light beam is an excitation beam to cause portions of the fluorescent material to fluoresce.
20. The system of claim 19 , wherein the fluorescent material comprises parallel stripes of extending along the second scanning direction.