Post-objective scanning beam systems
View Patent ↗Scanning beam systems, apparatus and techniques in optical post-objective designs with two beam scanners for display and other applications.
1. A scanning beam display system, comprising:
a light source that produces a beam of light;
a first beam scanner located in a plane to scan the beam of light along a first direction;
a second beam scanner located in the plane to scan the beam of light received from the first beam scanner along a second direction different from the first direction;
a screen having a display surface that is substantially perpendicular to and is located entirely on one side of the plane in which the first and second beam scanners are located, the screen being positioned to have one edge closer to the second beam scanner which scans the beam of light in beam directions that are not directed to the screen than to the first beam scanner; and
an optical reflector located on the side of the plane where the screen is located and has one end positioned away from the screen, the optical reflector oriented to reflect the beam of light from the second beam scanner onto the screen along a folded optical path to scan the beam of light along the first and the second directions on the screen.
2. The system as in claim 1 , comprising:
a scan lens placed in an optical path of the beam of light between the first and the second beam scanners to direct the beam of light from the first beam scanner along a line on the second beam scanner and to focus the beam of light via the folded optical path onto the screen.
3. The system as in claim 1 , wherein:
the first beam scanner is a polygon scanner comprising a plurality of different reflective facets, and
the second beam scanner is a 1-dimensional beam scanner.
4. The system as in claim 3 , comprising:
a beam focusing servo control module to dynamically control focus of the beam onto the screen to maintain a constant beam spot size of the beam of light on the screen at different locations.
5. The system as in claim 3 , comprising:
an optical distortion correcting module placed downstream from the second beam scanner to transmit the beam from the second beam scanner and configured to correct optical distortions in the beam.
6. The system as in claim 1 , comprising:
a beam focusing element placed in an optical path of the beam of light to adjust a focus of the beam of light on the screen; and
an actuator coupled to the beam focusing element to adjust a position of the beam focusing element, in response to a control signal, to adjust the focus in synchronization with scanning of the second beam scanner to maintain a constant beam spot size of the beam of light on the screen at different locations.
7. The system as in claim 6 , wherein:
the beam focusing element comprises a first lens and a second lens that are spaced from each other in an optical path of the beam of light, and
the actuator is engaged to at least one of the first and second lenses to adjust a spacing between the first and second lenses.
8. The system as in claim 1 , wherein:
the display surface of the screen is made of a material that absorbs light of the beam of light to emit light which presents images carried in the beam of light to a viewer.
9. The system as in claim 8 , wherein:
the surface comprises phosphor materials.
10. The system as in claim 8 , wherein:
the surface comprises parallel stripes of phosphor materials.
11. The system as in claim 1 , wherein:
the light source comprises lasers that produce laser beams to constitute the beam of light.