Dynamic illumination control for laser projection display
View Patent ↗A display apparatus ( 10 ) has at least one color channel providing a modulated light for each of a plurality of image frames ( 92 ). One or more laser sources that provide an illumination beam having a first polarization transmission axis. An imaging modulator ( 854, 85 g, 85 b ) in the path of the illumination beam is actuable to direct the modulated light toward a projection lens. A laser blanking apparatus in the path of the modulated light is disposed to block transient light between image frames and has at least one analyzer ( 66 ) having a second polarization transmission axis that is orthogonal to the first polarization transmission axis and at least one light polarization modulator that is synchronously timed to rotate polarization of transient light during an interval between frames.
1. A display apparatus comprising:
at least one color channel providing a modulated light for each of a plurality of image frames, wherein an image frame is a single image formed by the modulated light, each color channel including:
one or more laser sources that provide a polarized illumination beam; and
an imaging modulator in the path of the illumination beam actuable to modulate light in the illumination beam and direct the modulated light toward a projection lens; and
a laser blanking apparatus in the path of the modulated light from the imaging modulator and disposed to block stray light from optical components of the display system during time intervals between successive image frames, the laser blanking apparatus including:
a light polarization modulator that is synchronously timed to control the polarization of the modulated light to provide light having only a first polarization during all image frame time intervals and light having only a second polarization orthogonal to the first polarization during the time intervals between image frames; and
an analyzer having a polarization transmission axis that transmits light from the polarization modulator of the first polarization thereby transmitting the image frames and does not transmit light from the polarization modulator of the second polarization thereby blocking the stray light.
2. The display apparatus of claim 1 wherein the light polarization modulator is an electro-optical modulator.
3. The display apparatus of claim 1 wherein the laser blanking apparatus comprises an analyzer within each of a plurality of color channels.
4. The display apparatus of claim 1 wherein the laser blanking apparatus comprises an electro-optical modulator within each of a plurality of color channels.
5. The display apparatus of claim 1 wherein the imaging modulator is a linear light modulator taken from the group consisting of a grating electromechanical device, a piezoelectric based spatial light modulator, and a grating light valve.
6. The display apparatus of claim 1 wherein the imaging modulator is an area spatial light modulator taken from the group consisting of a digital micromirror device and a liquid crystal device.
7. The display apparatus of claim 1 wherein the display apparatus forms a three-dimensional or a dual-viewer image.
8. A display apparatus comprising:
a) at least one color channel providing successive lines of modulated light for each of a plurality of image frames, wherein an image frame is a single image formed by the modulated light, each color channel including:
one or more laser sources that provide a linear polarized illumination beam; and
a linear light imaging modulator in the path of the illumination beam and comprising an array of ribbons actuated to form the line of modulated light;
b) a scanning element and a projection lens for forming each image frame by scanning each modulated line of light from the at least one color channel toward a display surface; and
c) a laser blanking apparatus in the path of the modulated light from the imaging modulator and disposed to block stray light from optical components of the display system during time intervals between successive image frames, including:
a light polarization modulator that is synchronously timed to control the polarization of the modulated light to provide light having only a first polarization during all image frame time intervals and light having only a second polarization orthogonal to the first polarization during the time intervals between image frames; and
an analyzer having a polarization transmission axis that transmits light from the polarization modulator of the first polarization thereby transmitting the image frames and does not transmit light from the polarization modulator of the second polarization thereby blocking the stray light.
9. The display apparatus of claim 8 wherein the light polarization modulator is an electro-optical modulator.
10. The display apparatus of claim 8 wherein the laser blanking apparatus comprises an analyzer within each of a plurality of color channels.
11. The display apparatus of claim 8 wherein the laser blanking apparatus comprises an electro-optical modulator within each of a plurality of color channels.
12. The display apparatus of claim 8 wherein the imaging modulator is a linear light modulator taken from the group consisting of a grating electromechanical device, a piezoelectric based spatial light modulator, and a grating light valve.