Efficient user-defined SDR-to-HDR conversion with model templates
Embodiments are disclosed for projection systems with rotatable anamorphic lenses. In an embodiment, an optical projection system comprises: a light source; an optical integrator configured to receive light from the light source and to distribute a uniform pattern of light; a relay lens system including two or more rotatable anamorphic lenses, the anamorphic lenses oriented about an optical axis to transform the uniform pattern of light into an image having a specified aspect ratio; at least one spatial light modulator configured to receive the image and direct a spatially modulated image along an optical path; and at least one projection lens configured to receive the spatially modulated image from the optical path and to project the spatially modulated image onto an image plane with the specified aspect ratio. In a DLP projection system, the relative angle of the two or more rotatable anamorphic lenses is less than 90 degrees to pre-distort the image, resulting in a more rectangular spatially modulated image having the specified aspect ratio.
1 . A digital light processing, DLP, projection system comprising:
a light source;
a rectangular integrator rod configured to receive light from the light source and to distribute a uniform pattern of light;
a relay lens system including two or more rotatable anamorphic lenses, the anamorphic lenses oriented about an optical axis to simultaneously transform the uniform pattern of light into an image having a specified aspect ratio and a relative angle of the anamorphic lenses with respect to each other being less than 90 degrees to pre-distort the image;
at least one spatial light modulator configured to receive the pre-distorted image and to direct a spatially modulated image along an optical path; and
at least one projection lens configured to receive the spatially modulated image from the optical path and to project the spatially modulated image onto an image plane with the specified aspect ratio.
2 . The system of claim 1 , wherein the light source is one or more lasers.
3 . The system of claim 1 , wherein the corrected image has a substantially rectangular shape.
4 . The system of claim 1 , wherein the optical integrator has an aspect ratio of about 2.08:1, the anamorphic lenses have a compression ratio of about 1.13:1, and the pre-distorted image received by the spatial light modulator has an aspect ratio of about 1.85:1 or about 2.35:1.
5 . The system of claim 1 , wherein the anamorphic lenses are configured to be rotated together to a first angular position to stretch the image vertically, and then rotated together to a second angular position to stretch the image horizontally.
6 . The system of claim 1 , wherein at least one of the anamorphic lenses has at least one convex surface arranged perpendicular to the optical axis.
7 . The system of claim 1 , wherein at least one of the anamorphic lenses is a cylindrical lens.
8 . The system of claim 7 , wherein the two or more anamorphic lenses are cylindrical lenses and an anamorphic ratio, AR, of the anamorphic lenses satisfies the conditions: AR>1/cos(θ), where θ is an illumination angle of the spatial light modulator, nominally 24 degrees.
9 . The system of claim 1 , further comprising:
a lens controller for controlling rotation of the two or more of the anamorphic lenses about the optical axis.
10 . The system claim 9 , further comprising:
one or more processors that communicate with the lens controller to command the controller to rotate the two or more of the anamorphic lenses about the optical axis, and to control the reflection of the pre-distorted image by the spatial light modulator.
11 . The system of claim 1 , wherein the spatial light modulator is a digital micro-mirror device (DMD).
12 . The system of claim 1 , wherein the specified aspect ratio is compliant with Digital Cinema Initiatives (DCI) illumination format specifications.
13 . The system of claim 1 , wherein the optical integrator has an aspect ratio of approximately 2.08:1.
14 . The system of claim 1 , wherein the anamorphic lenses have a compression ratio of approximately 1.13:1.
15 . The system of claim 1 , wherein the pre-distorted image received by the spatial light modulator has an aspect ratio of approximately 1.85:1 or approximately 2.35:1.
16 . The system of claim 7 , wherein the two or more anamorphic lenses are cylindrical lenses.
17 . The system of claim 1 , wherein an anamorphic ratio, AR, of the anamorphic lenses satisfies the conditions: AR>1/cos(θ), where θ is an illumination angle of the spatial light modulator, nominally 24 degrees.
18 . A liquid-crystal display, LCD; projection system comprising:
a light source;
a lens array configured to receive light from the light source and to distribute a uniform pattern of light;
a relay lens system including two or more rotatable anamorphic lenses, the anamorphic lenses oriented about an optical axis to transform the uniform pattern of light into an image having a specified aspect ratio, wherein the anamorphic lenses have a compression ratio of about 1.13:1;
at least one spatial light modulator configured to receive the image and direct a spatially modulated image along an optical path; and
at least one projection lens configured to receive the spatially modulated image from the optical path and to project the spatially modulated image onto an image plane with the specified aspect ratio.
19 . The system of claim 18 , wherein the anamorphic lenses are configured to be rotated together to a first angular position to stretch the image vertically, and then rotated together to a second angular position to stretch the image horizontally.
20 . The system of claim 18 , wherein the spatial light modulator is a transmissive liquid crystal display (LCD) panel or liquid crystal on silicon (LCoS).