Projection system with rotatable anamorphic lens

Abstract

Embodiments of a projection system having rotatable anamorphic lenses are disclosed. In embodiments, an optical projection system includes a light source, an optical integrator configured to receive light from the light source and distribute a uniform light pattern, a relay lens system including two or more rotatable anamorphic lenses oriented about an optical axis to transform the uniform light pattern 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 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 to form a more rectangular spatially modulated image having the specified aspect ratio.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to the following prior applications: U.S. Provisional Application 63 / 034,311 (reference number: D19051USP1), filed June 3, 2020, and European Application 20178043.4 (reference number: D19051EP), filed June 3, 2020, which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to improvements in optical projection systems. Background Technology

[0004] Digital Light Processing (DLP) projection systems are used in digital cinemas worldwide. The Digital Cinema Initiatives (DCI), established in March 2002, is a joint project of major film studios aimed at establishing system standards for digital cinemas. DLP cinema projectors following the DCI use two formats related to the way films are shot and edited. These are the "flat" (also known as the "academy standard") with an aspect ratio of 1.85:1, and the "cinemascope" (also known as the "wide scope"), which can be as wide as 2.66:1 but is nominally projected at 2.35:1.

[0005] In a DLP projector system, an image is formed using a spatial light modulator (SLM) (such as extremely small mirrors arranged in a matrix on a semiconductor chip called a digital micromirror device (DMD)). A DMD is an electromechanical device whose pixel-generating elements form an array of hundreds or thousands of tiny tilting mirrors. To allow the mirrors to tilt, each mirror is attached to one or more hinges mounted on a support post and spaced apart by an air gap above an underlying control circuit. This control circuit provides an electrostatic force that causes each mirror to tilt selectively. Incident light on the mirror array is reflected in one direction by "on" mirrors and in another direction by "off" mirrors. The pattern of "on" and "off" mirrors forms the image.

[0006] In most applications, light from the DMD is projected onto the screen through a projection lens. In a projection system with a single DLP chip, colors are produced either by placing a color wheel between the white lamp and the DLP chip, or by using a separate light source to produce primary colors. In a DLP projection system with three DLP chips, prisms are used to separate the light from the lamp, and each primary color of the light is routed to its own DMD chip, where it is recombine with other primary colors and routed out through the lens.

[0007] In a liquid crystal display (LCD) projection system, a light source emits a beam of intense white light, which passes through an optical integrator (e.g., a fly's eye integrator) that homogenizes the light. The homogenized light then reaches thin-film coated dichroic mirrors, which are designed to reflect only certain color wavelengths, thereby forming red, green, and blue light beams. Some LCD projectors have separate LEDs for each color, rather than thin-film coated dichroic mirrors. These red, green, and blue light beams pass through a transmissive LCD panel composed of tiny pixels that block or allow light to pass through when triggered by an electric current. The colored red, green, and blue images output by the LCD panel are recombined in a dichroic prism to form a single image composed of millions of colors. This single image is then projected by a projection lens onto a screen. SUMMARY

[0008] The present disclosure relates to a projection system having rotatable anamorphic lenses.

[0009] According to one aspect of the present disclosure, a digital light processing (DLP) projection system is provided. The DLP projection system includes a light source, a rectangular integrator rod configured to receive light from the light source and distribute a uniform light pattern, a relay lens system including two or more rotatable anamorphic lenses oriented about an optical axis to simultaneously transform the uniform light pattern into an image having a specified aspect ratio, and the relative angle of the anamorphic lenses to each other is less than 90 degrees to pre-distort the image, at least one spatial light modulator configured to receive the pre-distorted 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 project the spatially modulated image onto an image plane in the specified aspect ratio.

[0010] According to another aspect, a liquid crystal display (LCD) projection system is provided. The LCD projection system includes a light source, a lens array configured to receive light from the light source and distribute a uniform light pattern, a relay lens system including two or more rotatable anamorphic lenses oriented about an optical axis to transform the uniform light pattern into an image having a specified aspect ratio, wherein a compression ratio of the anamorphic lenses is 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 project the spatially modulated image onto an image plane in the specified aspect ratio.

[0011] The details of the disclosed implementations are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description, drawings, and claims.

[0012] The particular embodiments disclosed herein provide one or more of the following advantages. The use of two or more rotatable anamorphic lenses to change the aspect ratio of the illumination in a projection system (e.g., aspect ratio from 2.35 to 1.85). The change in aspect ratio allows only the pixels displaying data to be illuminated on the image plane, thereby increasing the brightness of the projected image. Additionally, for DLP projection systems, the use of rotatable anamorphic lenses pre-distorts the image projected on the DMD chip, thereby forming a more rectangular spatially modulated image. BRIEF DESCRIPTION OF DRAWINGS

[0013] In the drawings referenced hereafter, various embodiments are illustrated by block diagrams, flow charts and other diagrams. Each block of the flowchart or block diagram can represent a module, a procedure, or a portion of code that comprises one or more executable instructions for performing the specified logical functions. Although the blocks are illustrated in a particular order, they can not necessarily be executed in the order illustrated. For example, depending on the nature of the corresponding operations, the blocks can be executed in reverse order or simultaneously. It should also be noted that each block of the block diagrams and / or flowcharts, and combinations thereof, can be implemented by a dedicated system, either software-based or hardware-based, for performing the specified functions / operations, or by a combination of dedicated hardware and computer instructions.

[0014] Figure 1A is a side view of an example illumination system for an optical projection system.

[0015] Figure 1B illustrates a typical illumination area showing a parallelogram image of a rectangular integrator bar projected onto the SLM surface.

[0016] Figure 2 is a conceptual diagram illustrating a relay lens system using a paraxial lens according to an embodiment, showing the orientation when the cylindrical optics (rectangular) stretch the image vertically.

[0017] Figure 3 is a conceptual diagram illustrating a relay lens system using a paraxial lens according to an embodiment, showing the orientation when the cylindrical optics (rectangular) stretch the image horizontally. Figure 2

[0018] Figure 4 illustrates the resulting rectangular illumination spot when the cylindrical lens is rotated to a first position to reduce distortion according to an embodiment.

[0019] Figure 5 ​Fig. 3 illustrates the resulting rectangular illumination spot when the cylindrical lens is rotated to a second position to reduce distortion, according to an embodiment.

[0020] Figure 6 Fig. 4 is a conceptual diagram of a DLP projection system using a relay lens system with a rotatable anamorphic lens, according to an embodiment.

[0021] Figure 7 Fig. 5 is a conceptual diagram of an LCD projection system using a relay lens system with a rotatable anamorphic lens, according to an embodiment.

[0022] The same reference numbers in the figures indicate the same elements. DETAILED DESCRIPTION

[0023] SUMMARY

[0024] Since the aspect ratio of the cinema microdisplay is 2048x1080 (or 4096x2160), which does not match the shape of either DCI format, some pixels are not used. In the case of a wide aspect ratio, tens of rows of pixels on the top and bottom of the microdisplay do not display any data, but they are still illuminated by the optics, which are currently optimized to illuminate the entire chip for both formats. In a masked projection system, some columns of pixels are not used, but are still illuminated.

[0025] A typical projection system uses one of two methods to homogenize the light and produce uniform illumination. The first method uses a rectangular integrator bar (solid or hollow). The second method uses a lens array, as used in most LCD projectors. For the first method, the image of the rectangular integrator bar is projected on the image plane. For a DLP projection system, the DMD surface is illuminated at an angle of 24 degrees (off the vertical or y-axis when the z-axis is the optical axis) and a 45 degree clock angle (off the horizontal or x-axis), resulting in some distortion of the image of the rectangular integrator bar. When the imaging optics are telecentric, the projected image is not rectangular, but a parallelogram.

[0026] For DLP projection systems and LCD projection systems, an anamorphic telescope is placed in the illumination relay optics of the projection system. The anamorphic telescope "compresses" the image of the rectangular integrator bar by a specified amount. Anamorphic optics magnify an image in one axis but do not change the image size along the orthogonal axis. By using an optical integrator with a specified aspect ratio and compression (e.g., an aspect ratio of 2.08: 1 and a compression of 1.13: 1), the image formed on the SLM surface has the desired DCI-compliant aspect ratio (e.g., an aspect ratio of 2.35: 1 or 1.85: 1) depending on the orientation of the anamorphic optics (e.g., 2.08 x 1.13 = 2.35 and 2.08 / 1.13 = 1.85).

[0027] For DLP projection systems, if cylindrical anamorphic lenses are placed in the relay lens system in the proper orientation relative to each other (e.g., less than 90 degrees), they will pre-distort the image so that the illumination spot formed on the DMD surface becomes more rectangular. Thus, in addition to solving the dual-format projection problem for movie theaters, the rotatable anamorphic lenses can also be used at a particular orientation to rectangularize the illumination shape in DLP projection systems. This reduces the magnification needed to illuminate the DMD surface and results in about 8-10% efficiency improvement.

[0028] Although the example embodiments disclosed herein are optimized for only one color, more complex optical system using various glasses can be used to simultaneously focus the three primary colors (red, green, blue) onto their respective SLMs.

[0029] Example Embodiments

[0030] Figure 1A is an example illumination system 100 for an optical projection system. The illumination system 100 includes an optical integrator 101, a relay lens system 102, and an SLM 103. In embodiments for DLP projection systems, the optical integrator 101 is a rectangular integrator bar. A rectangular integrator bar is a hollow or solid, internally reflecting "light pipe" that uses multiple reflections of a focused light source to obtain homogenization of circular or irregular illumination patterns and convert them into a uniform rectangular pattern. This pattern is imaged by the relay lens system 102 onto the SLM 103 (e.g., a DMD chip) and then projected by a projection lens (not shown) to an image plane (e.g., a theater screen). The rectangular integrator bar 101 is used to improve uniformity and efficiently match the aspect ratio of the illumination source to the SLM 103. The relay lens system 102 includes relay optics for positioning the uniform rectangular pattern onto the SLM 103.

[0031] For DLP projection systems, the SLM 103 is illuminated at an angle typically twice the tilt angle of the micromirrors (e.g., 24 degrees for a 12-degree tilt device) (offset from the normal) and a 45-degree clock angle (offset from the horizontal), resulting in some image distortion. This distortion is typical of light rod-based DLP projection systems and reduces efficiency. See below for reference. Figure 2 and Figure 3 The described relay lens system 200 includes two or more rotatable image-distorting lenses to change the aspect ratio of the image projected onto the SLM 103 (e.g., a DMD chip) and to eliminate image distortion, thereby obtaining a substantially rectangular image utilizing all pixels of that aspect ratio. In practice, image-distorting optics produce a parallelogram-shaped image on a flat surface, but when this image is incident on the SLM 103 at 24 degrees, the parallelogram distortion is canceled out. Ideally, the distortion ratio (AR, the ratio of the focal lengths of the illumination relay in directions parallel and perpendicular to the cylindrical lens axis) of the cylindrical lens group should satisfy the condition: AR > 1 / cos(θ), where θ is the illumination angle of the SLM 103 (nominally 24 degrees).

[0032] Figure 1B The illustration shows a typical illumination area, showing a parallelogram image of a rectangular integral bar 101 projected onto an SLM 103.

[0033] Figure 2 The illustration shows a relay lens system 200 using paraxial lenses according to an embodiment, which shows the orientation of the cylindrical optics (rectangular) when vertically stretching an image. Figure 3 The illustration shows an embodiment. Figure 2 The relay lens system shows the orientation of the cylindrical optics (rectangular) when horizontally stretching the image.

[0034] Figure 2 and Figure 3 The exemplary relay lens system 200 shown includes rotatable image distortion lenses 201, 202 (forming an "image distortion telescope"), spherical illumination lenses 203, 204, and an SLM 205. Figure 2 The lines shown in the diagram that penetrate the optics represent light rays from a light source (not shown). The light source can be any coherent light source, such as white light, a high-power light-emitting diode (LED), or a laser.

[0035] In an embodiment, spherical illumination lenses 203 and 204 project an image of a rectangular integrating bar (not shown) without affecting the aspect ratio of the image. Conversely, image-distorting lenses 201 and 202 project a version of the image of the rectangular integrating bar that is compressed (typically twice) along its longer dimension. In the illustrated embodiment, image-distorting lenses 201 and 202 are cylindrical lenses having any desired surface type, including but not limited to: convex, concave, biconcave, or a combination of convex and concave surfaces (“meniscus” surface type). In an embodiment, the dual-image element can be used to reduce light loss and improve the contrast ratio of the displayed image.

[0036] The extent to which the image-distorting lenses 201 and 202 modify the aspect ratio (referred to herein as the "aspect ratio") of the image they receive is determined by several factors. These factors include the radius, thickness, and glass type of each element of the lens. Therefore, image-distorting lenses 201 and 202 of the same configuration can be modified to have different optical specifications, thereby providing other aspect ratios. Image-distorting lenses 201 and 202 can be of any desired size, as long as that size is sufficient to capture all or most of the light from the light source. For example, the size of image-distorting lens 201 can be the same as or different from the size of image-distorting lens 202.

[0037] As previously described, Figure 2 The orientation of the image-distorting lenses 201 and 202 shown will vertically "stretch" the image, while Figure 3 The orientation of the image-distorting lenses 201 and 202 shown will horizontally "stretch" the image. It should be noted that... Figure 3 The orientation of the image-distorting lenses 201 and 202 shown is from their position in... Figure 2 The orientation shown is rotated 90 degrees around the optical axis. In embodiments where the aspect ratio of the rectangular integrating bar is 2.08:1 and the distorting lenses 201 and 202 provide a compression of 1.13:1, the image projected onto the image plane 205 will have an aspect ratio of 2.35:1 or 1.85:1 following the DCI (because 2.08 × 1.13 = 2.35, and 2.08 / 1.13 = 1.85). Therefore, by stretching the image projected onto the image plane 205, the illumination of the projection system will be changed to allow only the pixels displaying data to be illuminated, and the brightness of the projected image will be increased by up to 20%. In fact, in the case of DLP illumination, because the image is stretched at an oblique angle onto the DMD plane, the aspect ratio of the rectangular integrating bar 101 is not exactly the same as the desired illumination spot. In the case of LCD projection, the illumination is perpendicular to the LCD modulator panel, and the aspect ratio of the integrator more closely matches the desired illumination shape.

[0038] In an embodiment, the distorted lenses 201 and 202 are mounted in a lens barrel having bearings or other mechanical means to facilitate the rotation of the distorted lenses 201 and 202 about an optical axis, thereby allowing the lenses 201 and 202 to be rotated manually or automatically using a suitable control system, as referenced. Figure 6 As described herein, for example, whenever a change in DCI format is required, the distorting lenses 201 and 202 can be rotated 90 degrees about the optical axis. In an embodiment, the distorting lenses 201 and 202 are mounted on a lens swivel stage, which is mounted on the projector and can be rotated manually or automatically to orient the lenses about the optical axis. As used herein, "optical axis" is an imaginary line defining the path along which light propagates through the projection system, up to a first approximation. As used herein, "optical path" is the path along which light travels in an optical medium or system.

[0039] In a DLP projection system, if the image distortion lenses 201 and 202 are placed in the relay lens system 200 with a specific orientation, then the image distortion lenses 201 and 202 can be used to pre-distort the image projected onto the SLM 205, making the image more rectangular.

[0040] Figure 4 The illustration shows a rectangular illumination spot obtained when the cylindrical image-distorting lenses 201 and 202 are rotated to a first position according to an embodiment. Figure 5 The illustration shows a rectangular illumination spot obtained when the cylindrical image-distorting lenses 201 and 202 are rotated to a second position according to an embodiment. For specific applications and projection system illumination optics, the first and second positions can be empirically determined using computer-based modeling and simulation.

[0041] Therefore, in addition to solving the dual-format projection problem in cinemas, the addition of rotatable image-distorting lenses 201, 202 that rotate with a specific relative orientation (e.g., less than 90 degrees) also makes the illuminated image in the DLP projection system more rectangular. A more rectangular image reduces the magnification required to illuminate the DMD chip and improves efficiency by approximately 8-10%.

[0042] Although the example embodiments disclosed herein are optimized for only one color, more sophisticated optical systems utilizing various glasses can be used to simultaneously focus the three primary colors (red, green, and blue) onto their respective SLMs (e.g., DMD chips, LCD panels).

[0043] Figure 6This is a conceptual block diagram of a DLP projection system 600 using a relay lens system with a rotatable image distortion lens according to an embodiment. System 600 is designed for only one color. Those skilled in the art will recognize that the DLP projection system can be applied to three colors by using a color wheel or total internal reflection (TIR) ​​prism to separate light into primary colors and by using a separate DLD chip for each color. The relay lens system may include separate lens assemblies for each color, or three separate relay lens systems may be used to change the format and correct image distortion.

[0044] System 600 includes a light source 601, an optical integrator 602, a relay lens system 603, a spatial light modulator 604, a projection lens or lens group 605, a lens controller 607, a processor 608, and a memory 609. Figure 6 The dashed arrows in the diagram represent the optical path. It should be noted that... Figure 6 For clarity, a simplification has been made, and an actual DLP projection system will include other components such as light reflectors, mirrors (e.g., folding mirrors, dichroic mirrors, front mirrors), and / or lenses (e.g., focusing lenses, shaping lenses, collimating lenses, condenser lenses), and / or apertures for guiding and / or focusing light (e.g., vignetting apertures), diffraction beam shapers, light converging devices, and color wheels or prism assemblies (e.g., TIR prisms) for processing the light paths of the three primary colors (red, green, and blue).

[0045] In this illustrated example embodiment, light source 601 illuminates optical integrator 602. In this embodiment, optical integrator 602 is a solid or hollow rectangular integrating bar. Light source 601 may be a high-pressure xenon arc lamp unit, an LED, or a laser. Optical integrator 602 outputs a uniform rectangular pattern, which is imaged onto spatial light modulator 604 by relay lens system 603 and then projected onto image plane 606 (e.g., a theater screen) by projection lens 605. In this embodiment, spatial light modulator 604 is a DMD, liquid crystal display (LCD), or liquid crystal on silicon (LCoS).

[0046] The relay lens system 604 includes two or more rotatable image-distorting lenses (as referenced). Figure 2 and Figure 3 (As described). In an embodiment, the image-distorting lens is cylindrical. In an embodiment, the relay lens system 603 includes a lens barrel for housing the image-distorting lens and optionally other illumination optics. The image-distorting lens is mounted on a bearing in the lens barrel or on other suitable mechanical means that facilitates rotation of these lenses in two different orientations (as described in the reference). Figure 2 and Figure 3(As described). In one embodiment, the rotation of the distorting lens is controlled by a lens controller 607, which is controlled by a processor 608. In another embodiment, the processor 608 also controls the operation of the spatial light modulator 604 based on software or firmware instructions stored in memory 609. In other embodiments, a separate processor is used to control the operation of the spatial light modulator 604, rather than to control the rotation of the distorting lens in the relay lens system 603.

[0047] During operation, the projectionist can use an input device (e.g., a computer graphical user interface) to change the format and set the angular position of the distorted lens to eliminate distortion. The input provided by the projectionist is processed by a processor 608, which commands a lens controller 607 to send control signals to a relay lens system 603 to rotate the distorted lens. In an embodiment, the relay lens system 603 includes a rotation actuator coupled to a lens holder for holding the distorted lens in the optical path and one or more feedback sensors (e.g., angular rate sensors) for providing closed-loop feedback to the lens controller 607. The lens controller 607 may be a processor executing software or firmware instructions, or an application-specific integrated circuit (ASIC). The lens controller 607 may implement a state machine and / or a suitable control algorithm to control the lens to rotate in a stable manner. In an alternative embodiment, the distorted lens is manually rotated by the user using a hardware mechanism (e.g., a joystick) attached to the relay lens system 603.

[0048] Figure 7 This is a conceptual block diagram of an LCD projection system 700 using a relay lens system with a rotatable image distortion lens, according to an embodiment.

[0049] A light source 701 emits a beam of intense white light, which passes through an optical integrator 702 (e.g., a fly-eye integrator) that homogenizes the light. The homogenized light reaches dichroic mirrors 703 coated with a thin film, designed to reflect only specific color wavelengths, thus forming red, green, and blue beams. In some LCD projection systems, the white light and dichroic mirrors are replaced by red, blue, and green LEDs. The red, green, and blue beams pass through a relay lens system 707. The output of the relay lens system 707 is fed to a transmissive LCD panel 708 composed of tiny pixels that either block or allow light to pass through when triggered by an electric current. The image output from the transmissive LCD panel 708, colored red, green, and blue, is recombine in a dichroic prism 709 to form a single image composed of millions of colors. This single image is then projected onto a screen by a projection lens 710.

[0050] The relay lens system 707 includes two or more rotatable image-distorting lenses (as referenced). Figure 2 andFigure 3 (As described). In an embodiment, the image-distorting lens is cylindrical. In an embodiment, the relay lens system 707 includes a lens barrel for housing the image-distorting lens and optionally other illumination optics. The image-distorting lens is mounted on a bearing in the lens barrel or on other suitable mechanical means that facilitates rotation of these lenses in two different orientations (as described in the reference). Figure 2 and Figure 3 (As described). In one embodiment, the rotation of the distorting lens is controlled by a lens controller 704, which is controlled by a processor 705. In another embodiment, the processor 705 also controls the operation of the transmissive LCD panel 708 based on software or firmware instructions stored in memory 706. In other embodiments, a separate processor is used to control the operation of the transmissive LCD panel 708, and not to control the rotation of the distorting lens in the relay lens system 707.

[0051] During operation, the projectionist can use an input device (e.g., a computer graphical user interface) to change the format and set the angular position of the distorted lens to eliminate distortion. The input provided by the projectionist is processed by a processor 705, which commands a lens controller 704 to send control signals to a relay lens system 707 to rotate the distorted lens. In an embodiment, the relay lens system 707 includes a rotation actuator coupled to a lens holder for holding the distorted lens in the optical path and one or more feedback sensors (e.g., angular rate sensors) for providing closed-loop feedback to the lens controller 704. The lens controller 704 may be a processor executing software or firmware instructions, or an application-specific integrated circuit (ASIC). The lens controller 704 may implement a state machine and / or a suitable control algorithm to control the lens to rotate in a stable manner. In an alternative embodiment, the distorted lens is manually rotated by the user using a hardware mechanism (e.g., a joystick) attached to the relay lens system 707.

[0052] While this document contains numerous details of specific implementations, these details should not be construed as limiting the scope of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments. Certain features described herein in the context of a single embodiment may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. Furthermore, although features may be described above as operating in certain combinations and even initially stated so, in some cases one or more features of a claimed combination may be removed from the combination, and the claimed combination may involve sub-combinations or variations thereof. The logical flow depicted in the drawings does not require the specific order or ordered sequence shown to achieve the desired result. Additionally, other steps may be provided from the described flow, or steps may be deleted, and other components may be added to or removed from the described system. Therefore, other implementations are within the scope of the following claims.

[0053] Various aspects of the invention can be understood from the following enumerated example embodiments (EEE):

[0054] EEE1. An optical projection system, comprising:

[0055] light source;

[0056] An optical integrator configured to receive light from the light source and distribute a uniform light pattern;

[0057] A relay lens system comprising two or more rotatable image-distorting lenses oriented about the optical axis to simultaneously transform the uniform light pattern into an image with a specified aspect ratio and to pre-distort the image.

[0058] At least one spatial light modulator, configured to receive a pre-distorted image and guide the spatially modulated image along an optical path; and

[0059] At least one projection lens is configured to receive the spatially modulated image from the optical path and project the spatially modulated image onto an image plane at the specified aspect ratio.

[0060] EEE2. The system of claim 1, wherein the light source is one or more lasers.

[0061] EEE3. The system as described in any one of claims 1 or 2, wherein the optical integrator is a rectangular integrating bar and the calibrated image has a substantially rectangular shape.

[0062] EEE4. The system as described in any one of claims 1 to 3, wherein the aspect ratio of the optical integrator is about 2.08:1, the compression ratio of the distorting lenses is about 1.13:1, and the aspect ratio of the pre-distorted image received by the spatial light modulator is about 1.85:1 or about 2.35:1.

[0063] EEE5. The system as described in any one of claims 1 to 4, wherein the distorting lenses are configured to rotate together to a first angular position to vertically stretch the image, and then rotate together to a second angular position to horizontally stretch the image.

[0064] EEE6. The system as described in any one of claims 1 to 5, wherein at least one of the image distortion lenses has at least one convex surface arranged perpendicular to the optical axis.

[0065] EEE7. The system as described in any one of claims 1 to 6, wherein at least one of the image-distorting lenses is a cylindrical lens.

[0066] EEE8. The system as described in any one of claims 1 to 7, further comprising:

[0067] A lens controller for controlling the rotation of one or more of the distorting lenses about the optical axis.

[0068] EEE9. The system as described in any one of claims 1 to 8, further comprising:

[0069] One or more processors communicate with the lens controller to command the controller to rotate one or more of the distorted lenses about the optical axis and to control the spatial light modulator to reflect the pre-distorted image.

[0070] EEE10. The system as described in any one of claims 1 to 9, wherein the spatial light modulator is a digital micromirror device (DMD).

[0071] EEE11. The system as described in any one of claims 1 to 10, wherein the specified aspect ratio conforms to the Digital Cinema Initiatives (DCI) lighting format specification.

[0072] EEE12. An optical projection system, comprising:

[0073] light source;

[0074] An optical integrator configured to receive light from the light source and distribute a uniform light pattern;

[0075] A relay lens system comprising two or more rotatable image-distorting lenses oriented about the optical axis to transform the uniform light pattern into an image with a specified aspect ratio;

[0076] At least one spatial light modulator, configured to receive the image and guide the spatially modulated image along an optical path; and

[0077] At least one projection lens is configured to receive the spatially modulated image from the optical path and project the spatially modulated image onto an image plane at the specified aspect ratio.

[0078] EEE13. The system of claim 12, wherein the distorting lenses are configured to rotate together to a first angular position to vertically stretch the image, and then rotate together to a second angular position to horizontally stretch the image.

[0079] EEE14. The system as described in any one of claims 12 to 13, wherein the optical integrator is a lens array.

[0080] EEE15. The system as described in any one of claims 12 to 14, wherein the spatial light modulator is a transmissive liquid crystal display (LCD) panel or liquid crystal on silicon (LCoS).

Claims

1. A digital light processing (DLP) projection system, comprising: light source; A rectangular integrating bar, the rectangular integrating bar being configured to receive light from the light source and distribute a uniform light pattern having a rectangular shape; A relay lens system comprising two or more rotatable image-distorting lenses oriented about an optical axis to simultaneously transform the uniform light pattern into an image with a specified aspect ratio, and the relative angles of the image-distorting lenses with respect to each other being less than 90 degrees to pre-distort the image into a parallelogram shape. At least one spatial light modulator, configured to receive a pre-distorted image and guide the spatially modulated image along an optical path, wherein the at least one spatial light modulator is configured to receive the pre-distorted image at an illumination angle θ to eliminate parallelogram distortion and produce a rectangular shape; and At least one projection lens, the at least one projection lens being configured to receive the spatially modulated image from the optical path and project the spatially modulated image onto an image plane at the specified aspect ratio. The distorted lens is a cylindrical lens, and the distortion ratio AR of the distorted lens satisfies the following condition: AR>1 / cos(θ).

2. The system as claimed in claim 1, wherein, The light source is one or more lasers.

3. The system as described in claim 1 or 2, wherein, The aspect ratio of the rectangular integrating bar is approximately 2.08:1, the compression ratio of the distorted lens is approximately 1.13:1, and the aspect ratio of the pre-distorted image received by the spatial light modulator is approximately 1.85:1 or approximately 2.35:

1.

4. The system as described in claim 1 or 2, wherein, The distorting lenses are configured to rotate together to a first angular position to vertically stretch the image, and then rotate together to a second angular position to horizontally stretch the image.

5. The system as described in claim 1 or 2, wherein, At least one of the distorting lenses has at least one convex surface arranged perpendicular to the optical axis.

6. The system of claim 1, wherein, The illumination angle θ of the spatial light modulator is designated as 24 degrees.

7. The system of claim 1 or 2, further comprising: A lens controller for controlling the rotation of two or more of the distorting lenses about the optical axis.

8. The system of claim 7, further comprising: One or more processors communicate with the lens controller to command the lens controller to rotate two or more of the distorted lenses about the optical axis and to control the spatial light modulator to reflect the pre-distorted image.

9. The system as claimed in claim 1 or 2, wherein, The spatial light modulator is a digital micromirror device (DMD).

10. The system as claimed in claim 1 or 2, wherein, The specified aspect ratio follows the Digital Cinema Initiatives (DCI) lighting format specification.

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