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US 7,878,657 B2Granted
Servo feedback control based on invisible scanning servo beam in scanning beam display systems with light-emitting screens
AssigneePrysm, Inc.
InventorRoger A. Hajjar
Life of this patent
Estimating the term…
Abstract
Scanning beam display systems that scan at least one invisible servo beam and an excitation beam onto a screen that emits visible light under excitation of the light of the excitation beam and control optical alignment of the excitation beam based on positioning of the servo beam on the screen via a feedback control.
Claims20
A scanning beam display system, comprising:
- an excitation light source to produce at least one excitation beam at an excitation wavelength;
- a servo light source to produce at least one servo beam at a servo beam wavelength that is different from the excitation wavelength;
- a beam scanning module to receive the excitation beam and the servo beam and to scan the excitation beam and the servo beam;
- a light-emitting screen positioned to receive the scanning excitation beam and the servo beam and comprising a light-emitting area which comprises (1) parallel light-emitting stripes which absorb light of the excitation beam to emit visible light, and (2) one or more stripe dividers parallel to and spatially interleaved with the light-emitting stripes with each stripe divider being located between two adjacent stripes, each stripe divider being optically reflective to at least the servo beam;
- an optical servo sensor positioned to receive light of the servo beam reflected by the stripe dividers and to produce a monitor signal indicative of positioning of the servo beam on the screen;
- and
- a control unit operable to, in response to the positioning of the servo beam on the screen in the monitor signal, adjust timing of optical pulses carried by the scanning excitation beam based on a relation between the servo beam and the excitation beam to control the spatial alignment of spatial positions of the optical pulses in the excitation beam on the screen.
4 more elements
A method for controlling a scanning beam display system, comprising:
- scanning at least one excitation beam of an excitation wavelength on a screen with parallel light-emitting stripes in a beam scanning direction perpendicular to the light-emitting stripes to excite the light-emitting stripes to emit visible light, wherein the screen comprises one or more stripe dividers parallel to and spatially interleaved with the light-emitting stripes with each stripe divider being located between two adjacent stripes and each stripe divider is optically reflective;
- scanning a servo beam of a servo beam wavelength different from the excitation wavelength on the screen;
- detecting light of the scanning servo beam reflected by the one or more stripe dividers to obtain a monitor signal indicative of positioning of the servo beam on the screen;
- and
- in response to the positioning of the servo beam on the screen, adjusting timing of optical pulses carried by the scanning excitation beam based on a relation between the servo beam and the excitation beam to control the spatial alignment of spatial positions of the optical pulses in the excitation beam on the screen.
2 more elements
A scanning beam display system, comprising:
- a light-emitting screen comprising a light-emitting area which comprises (1) parallel light-emitting stripes which absorb excitation light to emit visible light, and (2) one or more optically reflective stripe dividers parallel to and spatially interleaved with the light-emitting stripes with each stripe divider being located between two adjacent light-emitting stripes;
- a plurality of excitation lasers to produce excitation laser beams at an excitation wavelength;
- at least one servo light source fixed in position relative to the excitation lasers to produce at least one servo beam at a servo beam wavelength that is different from the excitation wavelength;
- a beam scanning module to receive the excitation laser beams and the servo beam and to scan the excitation laser beams and the servo beam on the screen;
- at least one first optical servo sensor positioned to receive light of the servo beam reflected from the screen to produce a first monitor signal indicative of positioning of the servo beam on the screen;
- at least one second optical servo sensor positioned to receive light of the excitation laser beams reflected from the screen to produce a second monitor signal indicative of positioning of each excitation laser beam on the screen;
- and
- a control unit operable to, in response to the first and the second monitor signals, adjust timing of optical pulses carried by each excitation laser beam based on a relation between the servo beam and each excitation laser beam to control the spatial alignment of spatial positions of the optical pulses in the excitation beam on the screen.
5 more elements
Dependencies are inferred from the claim text.