Rectangular optical fiber for projection system

Abstract

Systems and methods for rectangular optical fibers within a projection system. A projection system includes a rectangular optical fiber and a first modulator. The rectangular optical fiber is configured to emit light in response to image data. The rectangular optical fiber has a first aspect ratio. The first modulator is configured to receive light from the rectangular optical fiber and apply spatial variation modulation to the light to steer the light and generate first steered light. The first modulator has a second aspect ratio.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 327,399, filed on April 5, 2022, and European Patent Application No. 22166775.1, filed on April 5, 2022. Background Art

[0003] 1. Public Domain

[0004] The present application relates generally to projection systems and more particularly to rectangular optical fibers as light sources in projection systems.

[0005] 2. Description of related technologies

[0006] Digital projection systems typically utilize a light source and an optical system to project an image onto a surface or screen. The light source is typically a laser light source, a light emitting diode, or some other light source. An integrating rod is implemented to homogenize the light from the light source. The optical system includes components such as a mirror, a lens, a waveguide, an optical fiber, a beam splitter, a diffuser, a spatial light modulator (SLM), a phase light modulator (PLM). The modulator can be configured as a digital light processor (DLP), a digital micromirror device (DMD), a liquid crystal on silicon (LCOS) modulator, or another suitable modulator. Summary of the invention

[0007] Optical fibers can be used to transmit light from an illumination source to a projector. These optical fibers are smaller than typical integrated rods with a diameter greater than 2 mm. Optical fibers are typically circular in structure, and the circular cross-section of the fiber core causes the output beam to be circular. The projector includes an optical system having one or more modulators that spatially modulate the light provided by the optical fiber. The modulator is typically rectangular, has an aspect ratio, and works to construct an image projected by the projector. However, since the light beam output by the optical fiber is circular, light is lost in the use of the modulator. The embodiments described herein utilize rectangular optical fibers to improve the optical efficiency of the optical system.

[0008] Various aspects of the present disclosure relate to devices, systems, and methods for the implementation of rectangular optical fibers for projectors.

[0009] In one aspect of the present disclosure, a projection system including a rectangular optical fiber and a first modulator is provided. The rectangular optical fiber is configured to emit light in response to image data. The rectangular optical fiber has a first aspect ratio. The first modulator is configured to receive light from the rectangular optical fiber and apply spatial variation modulation to the light, thereby steering the light and generating a first steering light. The first modulator has a second aspect ratio.

[0010] In another aspect of the present disclosure, a method for controlling a projection system is provided, the method comprising receiving light from a rectangular optical fiber using a phase light modulator, wherein the rectangular optical fiber is configured to emit light in response to image data and has a first aspect ratio, and wherein the phase light modulator has a second aspect ratio, and steering the light at an illumination angle using the phase light modulator to generate first steered light.

[0011] In another aspect of the present disclosure, a non-transitory computer-readable medium storing instructions is provided, which, when executed by a processor of the projection system, causes the projection system to perform operations, including: receiving light from a rectangular optical fiber using a first modulator, and steering the light at an illumination angle using a phase light modulator to generate a first steered light.

[0012] In this way, various aspects of the present disclosure provide for the display of images with high dynamic range and high resolution, and achieve improvements in at least the technical fields of image projection, holography, signal processing, and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] These and other more detailed and specific features are more fully disclosed in the following description, with reference to the accompanying drawings, in which:

[0014] Figure 1 A block diagram of an example projection system according to various aspects of the present disclosure is shown;

[0015] Figure 2A shows a plan view of an example spatial light modulator for use in various aspects of the present disclosure;

[0016] Figure 2B Shown along Figure 2A A cross-sectional view taken along line II-B in FIG.

[0017] Figure 3 shows a plan view of an example phase light modulator for use in various aspects of the present disclosure;

[0018] Figure 4 shows a cross-sectional view of another example phase light modulator for use in various aspects of the present disclosure;

[0019] Figure 5 shows an example side view of an optical fiber according to various aspects of the present disclosure;

[0020] Fig. 6A The present invention shows various aspects of the present invention. Figure 5 a cross-sectional view of a circular portion of an optical fiber in;

[0021] Figure 6B The present invention shows various aspects of the present invention. Figure 5a cross-sectional view of a rectangular portion of an optical fiber in;

[0022] Fig. 7A shows an example cross-sectional view of a circular optical fiber matrix according to various aspects of the present disclosure;

[0023] Figure 7B shows an example cross-sectional view of a rectangular optical fiber matrix according to various aspects of the present disclosure;

[0024] Figure 8 Example optical states in an example projection system according to various aspects of the present disclosure are shown. DETAILED DESCRIPTION

[0025] The present disclosure and its aspects may be embodied in a variety of forms, including hardware, devices or circuits controlled by computer-implemented methods, computer program products, computer systems and networks, user interfaces, and application programming interfaces; as well as hardware-implemented methods, signal processing circuits, memory arrays, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), etc. The above summary is intended only to provide an overall concept of various aspects of the present disclosure and does not limit the scope of the disclosure in any way.

[0026] In the following description, in order to provide an understanding of one or more aspects of the present disclosure, numerous details are set forth, such as optical device configuration, timing, operation, etc. It will be apparent to one skilled in the art that these specific details are merely examples and are not intended to limit the scope of the present application.

[0027] In addition, although the present disclosure focuses primarily on examples of various circuits used in digital projection systems, it will be understood that this is only an example implementation. It will be further understood that the disclosed systems and methods can be used in any device that requires projection light; for example, movie theaters, consumer and other commercial projection systems, head-up displays, virtual reality displays, etc.

[0028] Projector System

[0029] The optical system described herein uses a rectangular optical fiber to transmit light from a light source to an optical device within a projector. Although the light source and the rectangular optical fiber may be referred to separately, it is understood that the rectangular optical fiber is a component of the light source. Therefore, referring only to the light source does not exclude the rectangular optical fiber.

[0030] Figure 1 An example high contrast projection system 100 is shown in accordance with various aspects of the present disclosure. In particular, Figure 1A projection system 100 is shown, which includes: a light source 101 (e.g., an optical fiber) configured to emit a first light 102; an illumination optical device 103 (an example of an illumination optical system according to the present disclosure), which is configured to receive the first light 102 and redirect it or otherwise modify it to generate a second light 104; a first modulator 105, which is configured to apply spatial variation modulation to the second light 104, thereby turning the second light 104 and generating a third light 106; a first projection optical device 107, which is configured to receive the third light 106 and redirect it or otherwise modify it to generate a fourth light 108; a second modulator 109, which is configured to modulate the fourth light 108 to generate a fifth light 110; and a second projection optical device 111, which is configured to receive the fifth light 110 and project it as a sixth light 112 onto a screen 113. The first modulator 105 may be a phase-based modulator or other modulator. The second modulator 109 may be an amplitude-based modulator or other modulator. In some embodiments, the projection system 100 may not include the illumination optics 103; instead, the first light 102 is directly received by the first modulator 105.

[0031] The projection system 100 further includes a controller 114 configured to control various components of the projection system 100, such as the light source 101, the first modulator 105, and / or the second modulator 109. In some embodiments, the controller 114 may additionally or alternatively control other components of the projection system 100, including but not limited to the illumination optics 103, the first projection optics 107, and / or the second projection optics 111. The controller 114 may be one or more processors, such as a central processing unit (CPU) of the projection system 100. The illumination optics 103, the first projection optics 107, and the second projection optics 111 may respectively include one or more optical components, such as mirrors, lenses, waveguides, optical fibers, beam splitters, diffusers, etc. Figure 1 The components shown, except for the screen 113, can be integrated into the housing to provide a projection device. Such a projection device may include additional components such as memory, input / output ports, communication circuits, power supplies, etc. In some embodiments, the light source 101 includes a laser light source, an LED, or some other light emitter that emits light outside the housing of the projection device, and the light emitter is combined with a fiber optic cable that is configured to transmit the light output by the light emitter to the illumination optical device 103 located within the housing of the projection device. In other embodiments, both the light emitter and its corresponding fiber optic cable are located within the housing of the projection device.

[0032] In some embodiments, the light output by the light source 101 is coherent light. In some aspects of the present disclosure, the light source 101 may include a plurality of separate light emitters, each corresponding to a different wavelength or wavelength band. The light source 101 emits light in response to an image signal provided by a controller 114 (e.g., one or more processors such as a central processing unit (CPU) of the projection system 100). The image signal includes image data corresponding to a plurality of frames to be displayed continuously. Individual elements in the projection system, including the illumination optical device 103, the first modulator 105, and / or the second modulator 109, may be controlled by the controller 114. The image signal may be derived from an external source in a streaming or cloud-based manner, may be derived from an internal memory of the projection system 100 such as a hard disk, may be derived from a removable medium operably connected to the operating system 100, or a combination thereof.

[0033] The first projection optical device 107 and / or the second projection optical device 111 may include filters to mitigate effects caused by components inside the projection system 100. In some systems, the first modulator 105 (described in more detail below) and / or the second modulator 109 may include a cover glass and cause reflections, device switching may temporarily cause unwanted steering angles, and various components may cause scattering. To offset these and reduce the floor level of the projection system 100, the filter may be a Fourier ("DC") filter component configured to block a portion of the third light 106 and / or the fifth light 110. Thus, the filter can increase contrast by reducing the floor level of light near zero angle, which will correspond to elements such as cover glass reflections, process transition states, etc. This DC blocking area can be actively used to prevent certain light from reaching the screen 113. In some aspects of the present disclosure, the filter prevents unwanted light from reaching the screen 113 by redirecting light to a light dump located outside the active image area in response to control by the controller 114.

[0034] although Figure 1A generally linear optical path is shown, but in practice, the optical path is typically more complex. For example, in the projection system 100, the second light 104 from the illumination optics 103 is diverted at an oblique angle to the first modulator 105, and the fourth light 108 diverted by the first projection optics 107 is diverted at an oblique angle to the second modulator 109. In order to ensure that the image on the screen 113 has acceptable clarity and contrast, the illumination optics 103 can be designed and / or controlled to ensure that the angle of incidence on the first modulator 105 is correct while keeping the position of the second light 104 centered on the first modulator 105. The first modulator 105 and / or the first projection optics 107 can be designed and / or controlled to ensure that the angle of incidence on the second modulator 109 is correct while keeping the position of the fourth light 108 centered on the second modulator 109.

[0035] Spatial Light Modulator

[0036] In some embodiments, the first modulator 105 and / or the second modulator 109 is a digital micromirror device (DMD), which is composed of a plurality of mirrors for adjusting the incident angle of light (e.g., the fourth light 108). To illustrate the effect of the incident angle and the DMD mirrors, Figure 2A and Figure 2B An example DMD 200 is shown in accordance with various aspects of the present disclosure. In particular, Figure 2A 2 shows a plan view of the DMD 200, Figure 2B shows that the DMD 200 is Figure 2A 2-B. The DMD 200 includes a plurality of square micromirrors 202 arranged in a two-dimensional rectangular array on a substrate 204. In some examples, the DMD 200 may be a digital light processor (DLP). Each micromirror 202 may correspond to a pixel of a final projected image and may be configured to tilt around a rotation axis 208 by electrostatic or other types of actuation, and the rotation axis 208 is shown for a specific subset of the micromirrors 202. A single micromirror 202 has a width 212 and a gap of width 210 is provided between them. The micromirrors 202 may be formed or coated by any highly reflective material (such as aluminum or silver) to reflect light specularly. The gaps between the micromirrors 202 may be absorptive so that the input light entering the gaps is absorbed by the substrate 204.

[0037] Although Figure 2AOnly some representative micromirrors 202 are explicitly shown, but in practice the DMD 200 may include more individual micromirrors, the number of which is equal to the resolution of the projection system 100. In some examples, the resolution may be 2K (2048×1080), 4K (4096×2160), 1080p (1920×1080), consumer-level 4K (3840×2160), etc. In addition, in some examples, the micromirrors 202 may be rectangular and arranged in a rectangular array; they may also be hexagonal and arranged in a hexagonal array, etc. In addition, although Figure 2A The rotation axis 208 is shown extending in an oblique direction, but in some embodiments, the rotation axis 208 may extend vertically or horizontally.

[0038] from Figure 2B As can be seen in FIG. 1 , each micromirror 202 can be connected to a substrate 204 via a yoke 214, and the yoke 214 is rotatably connected to the micromirror 202. The substrate 204 includes a plurality of electrodes 216. Figure 2B In the cross-sectional view of FIG. 2 , it can be seen that each micromirror 202 has only two electrodes 216, but in practice each micromirror 202 may include additional electrodes. Figure 2B Although not specifically shown, DMD 200 may further include a spacer layer, a support layer, a hinge member for controlling the height or direction of micromirror 202, etc. Substrate 204 may include electronic circuits associated with DMD 200, such as complementary metal oxide semiconductor (CMOS) transistors, memory elements, etc.

[0039] Depending on the specific operation and control of the electrode 216, a single micromirror 202 can be switched between an "on" position, an "off" position, and an unactuated or neutral position. If the micromirror 202 is in the on position, it is actuated to an angle of, for example, -12° (i.e., 12° counterclockwise relative to the neutral position) to mirror-reflect the input light 206 into on-state light 218. If the micromirror 202 is in the off position, it is actuated to an angle of, for example, +12° (i.e., 12° clockwise relative to the neutral position) to mirror-reflect the input light 206 into off-state light 220. The off-state light 220 can be directed to a light absorber that absorbs the off-state light 220. In some examples, the micromirror 202 can be unactuated and parallel to the substrate 204. Figure 2A and Figure 2B The specific angles shown in and described herein are examples only and are not limiting. In some embodiments, the open position angle and the closed position angle may be between ±11 degrees and ±13 degrees (inclusive) respectively.

[0040] Phase Optical Modulator

[0041] The first modulator 105 and / or the second modulator 109 may be a phase light modulator instead of a spatial light modulator. A phase light modulator (PLM) imparts a spatially varying phase modulation to light and redirects the modulated light to a corresponding projection optical device. The phase light modulator may be a reflective type, in which the phase light modulator reflects incident light with a spatially varying phase; alternatively, the phase light modulator may be a transmissive type, in which the phase light modulator imparts a spatially varying phase to light as the light passes through the phase light modulator. In some aspects of the present disclosure, the phase light modulator has a liquid crystal on silicon (LCOS) structure. In other aspects of the present disclosure, the phase light modulator has a microelectromechanical system (MEMS) structure, such as a DMD.

[0042] Figure 3 An example of a first modulator 105 and / or a second modulator 109 is shown, which are implemented as a reflective LCOS PLM 300 and are shown in a partial cross-sectional view. Figure 3 As shown, the PLM 300 includes a silicon backplane 310, a first electrode layer 320, a second electrode layer 330, a liquid crystal layer 340, a cover glass 350, and a spacer 360. The silicon backplane 310 includes electronic circuits associated with the PLM 300, such as CMOS transistors, etc. The first electrode layer 320 includes an array of reflective elements 321 arranged in a transparent matrix 322. The reflective elements 321 can be formed of any highly optically reflective material, such as aluminum or silver. The transparent matrix 322 can be formed of any highly optically transmissive material, such as transparent oxide. The second electrode layer 330 can be formed of any optically transparent conductive material, such as an indium tin oxide (ITO) film. The second electrode layer 330 can serve as a common electrode corresponding to the multiple reflective elements 321 of the first electrode layer 320. In this configuration, each of the multiple reflective elements 321 will be coupled to the second electrode layer 330 through a corresponding electric field, thereby dividing the PLM 300 into an array of pixel elements. Therefore, a single reflective element (or a subset of reflective elements) among the plurality of reflective elements 321 may be addressed by electronic circuitry arranged in the silicon backplate 310 , thereby modifying the state of the corresponding reflective element 321 .

[0043] The liquid crystal layer 340 is located between the first electrode layer 320 and the second electrode layer 330, and includes a plurality of liquid crystals 341. The liquid crystals 341 are particles in a phase between a solid state and a liquid state. In other words, the liquid crystals 341 exhibit a certain degree of directional order, but no positional order. The direction in which the liquid crystals 341 tend to point is called a "director". The liquid crystal layer 34 changes the incident light entering from the cover glass 350 according to the birefringence Δn of the liquid crystals 341. The birefringence Δn can be expressed as the difference between the refractive index parallel to the direction of the director and the refractive index perpendicular to the direction of the director. Thus, the maximum optical path difference can be expressed as the birefringence multiplied by the thickness of the liquid crystal layer 340. The thickness is set by the spacer 360, which seals the PLM 300 and ensures a set distance between the cover glass 350 and the silicon backplane 310. The liquid crystals 341 are generally oriented along the electric field lines between the first electrode layer 320 and the second electrode layer 330. As Figure 3 As shown, liquid crystal near the center of PLM 300 is oriented in this manner, while liquid crystal 341 near the periphery of PLM 300 is substantially unequally oriented in the absence of electric field lines. The orientation of liquid crystal 341 can be determined on a pixel-by-pixel basis by addressing individual elements of multiple reflective elements 321 with a phase drive signal.

[0044] Figure 4 Another example of a first modulator 105 and / or a second modulator 109 is shown, which are implemented as a DMDPLM 400 and are shown in a partial cross-sectional view. Figure 4 As shown, the PLM 400 includes a back plate 410 and a plurality of controllable reflective elements as pixel elements, each of which includes a yoke 421, a mirror plate 422 and a pair of electrodes 430. Figure 4 Only two electrodes 430 can be seen in the cross-sectional view of FIG. , but in practice each reflective element may include additional electrodes. Figure 4 Although not specifically shown, the PLM 400 may further include a spacer layer, a support layer, a hinge component for controlling the height or direction of the mirror plate 422, etc. The backplane 410 includes electronic circuits associated with the PLM 400, such as CMOS transistors, a memory array, etc.

[0045] The yoke 421 may be formed of or include a conductive material to allow a bias voltage to be applied to the mirror plate 422. The mirror plate 422 may be formed of any highly reflective material, such as aluminum or silver. The electrodes 430 are configured to receive a first voltage and a second voltage, respectively, and are individually addressable. Depending on the value of the voltage on the electrode 430 and the voltage on the mirror plate 422 (e.g., the bias voltage), there is a potential difference between the mirror plate 422 and the electrode 430, which generates an electrostatic force acting on the mirror plate 422. The yoke 421 is configured to allow the mirror plate 422 to move vertically in response to the electrostatic force. When the electrostatic force and the spring force of the yoke 421 are equal, the equilibrium position of the mirror plate 422 determines the optical path length of the light reflected from the upper surface of the mirror plate 422. Therefore, a single element of the plurality of controllable reflective elements is controlled to provide a certain number (three as shown) of discrete heights, thereby providing a certain number of discrete phase configurations or phase states. As shown, each phase state has a flat profile. In some aspects of the disclosure, electrodes 430 may be provided with different voltages from one another in order to impart a tilt to mirror plate 422. Such a tilt may be used with light absorbers of the type described above.

[0046] The PLM 400 may have high-speed switching capability, for example, the time for the PLM 400 to switch from one phase state to another phase state is about tens of microseconds. In order to provide a complete phase control cycle, the total optical path difference between the state where the reflector plate 422 is at its highest point and the state where the reflector plate 422 is at its lowest point should be approximately equal to the wavelength λ of the incident light. Therefore, the height range between the highest point and the lowest point should be approximately equal to λ / 2.

[0047] optical fiber

[0048] As previously mentioned, the light source 101 may include both a light emitter and an optical fiber. Figure 5 An example of an optical fiber 500 for use with the light source 101 is shown. The optical fiber 500 includes a circular portion 510 and a rectangular portion 540. The circular portion 510 and the rectangular portion 540 are coupled together by a splice portion 530. The circular portion 510 includes a circular outer cladding 515, a circular inner cladding 525, and a circular core 520. The rectangular portion 540 includes a rectangular outer cladding 555, a rectangular inner cladding 565, and a rectangular core 560. In some embodiments, the rectangular portion 540 does not include the rectangular inner cladding 565.

[0049] Light from a light transmitter passes through circular core 520 and reflects off circular inner cladding 525 as it passes through. The light then passes through splice section 530 and enters rectangular core 560. The light exits optical fiber 500 through projection end 550. Any light that may escape from either inner cladding (due to misalignment, excessive fiber bends, or the like) is reflected by the corresponding outer cladding. In some embodiments, the entire length of optical fiber 500 has a rectangular cross-section (e.g., consisting of only rectangular section 540), rather than splicing rectangular section 540 with circular section 510.

[0050] Fig. 6A The circular portion 510 is along Figure 5 A partial cross-sectional view of line VA is shown. Fig. 6A As shown, circular portion 510 has a circular cross-section with a diameter 600. Diameter 600 is less than 2 millimeters. Figure 6B The rectangular portion 540 is along Figure 5 A partial cross-sectional view of line VB is shown. Rectangular portion 540 includes a width 605 and a length 610 that together form a rectangular aspect ratio.

[0051] In some embodiments, rather than splicing the rectangular portion 540 onto the circular portion 510, the rectangular optical fiber is formed by creating a circular array of optical fibers. Fig. 7A An example of an optical fiber 700 formed of a plurality of circular optical fibers 715 is shown. The plurality of circular optical fibers 715 form an array having a width 705 and a length 710. In the illustrated embodiment, the optical fiber 700 has an aspect ratio of 16×9 for the array of circular optical fibers 715. However, the optical fiber 700 may have a different aspect ratio. For example, the aspect ratio of the optical fiber 700 may be 1. In some examples, one axis of the optical fiber 700 is optically stretched to match the aspect ratio of a downstream modulator (e.g., the first modulator 105).

[0052] In some embodiments, optical fiber 700 may be comprised of a plurality of rectangular optical fibers rather than an array of circular optical fibers. Figure 7B An optical fiber 750 is shown formed of a plurality of rectangular optical fibers 765. The plurality of rectangular optical fibers 765 form an array having a width 755 and a length 760. In the embodiment shown, the optical fiber 750 has an aspect ratio of 16×9 for the array of rectangular optical fibers 765. The aspect ratio of the optical fiber 750 can match the aspect ratio of the first modulator 105. While some embodiments use an array of optical fibers to achieve a desired aspect ratio, a low-etendue optical system may benefit from a single optical fiber 500 to achieve a small bright spot in the projected image.

[0053] Example Optical System

[0054] One example implementation of the present disclosure provides an optical system having a first light turning modulator, such as a PLM or SLM, that receives light from a rectangular optical fiber. Figure 8 An example optical state of a local optical system 800 according to the present disclosure is shown. The local optical system 800 may be, at least in part, an example of the projection system 100.

[0055] In particular, Figure 8 A light source 801, a first light 802, an illumination optics 803, a second light 804, a first modulator 805, a third light 806, a first projection optics 807, a fourth light 808, a second modulator 809, a fifth light 810, a second projection optics 811, a sixth light 812 and an optical output 813 are shown. Figure 8 The various elements shown in FIG. 1 may correspond to Figure 1 805 is a PLM device and the second modulator 809 is a SLM device. In some examples, the second modulator 809 is attached to a prism 821, such as a prism that combines light in the RGB color domain into white light.

[0056] Light source 801 is the output end of a rectangular optical fiber, for example, Figure 5 Described projection end 550. Therefore, the first light 802 has an aspect ratio equal to the aspect ratio of the rectangular optical fiber (eg, light source 801).

[0057] exist Figure 8 In the illustrated embodiment, the illumination optical device 803 includes a first diffuser 814, a first lens 815, and a second lens 816. The first diffuser 814 can change the first light 802 and create a desired point spread function (PSF) for the second light 804 received by the first modulator 805. In some embodiments, the first diffuser 814 is synchronized with the first modulator 805 and / or the second modulator 809. In addition, in some examples, the first diffuser 814 is rotating. In other examples, the first diffuser 814 is stationary. In some embodiments, the first diffuser 814 may blur the image projected by the light source 801, thereby eliminating the coherence of the first light 802 and avoiding the precise alignment requirements.

[0058] Although shown as including two lenses, the illumination optical device 803 can be composed of any number of lenses to guide the first light 802 to the first modulator 805 at a predetermined illumination angle θ. In addition, although each individual lens is shown separately, these individual lenses can be bonded together. In addition, each lens group can be composed of any type of lens, such as a concave lens, a collimating lens, a negative meniscus lens, and a positive meniscus lens. In some embodiments, the illumination optical device 803 includes a cylindrical lens for changing the aspect ratio of the first light 802 projected by the light source 801. In other embodiments, the local optical system 800 does not include the illumination optical device 803, so that the first light 802 directly contacts the first modulator 805. The aspect ratio of the first light 802 can be the same as the aspect ratio of the first modulator 805 (e.g., the second aspect ratio).

[0059] Although the aspect ratio of the light source 801 can match the aspect ratio of the first modulator 805, in many embodiments, the second light 804 (or the first light 802) affects the first modulator 805 at a predetermined illumination angle. Therefore, from the perspective of the light source 801, the first modulator 805 is tilted (e.g., not perpendicular). In order to adjust for this "tilt", the aspect ratio of the first modulator 805 can be selected to be equal to the aspect ratio of the "tilted" first modulator 805. For example, the first modulator 805 is located on an axis that is not perpendicular to the axis defined by the first light source 802, and the aspect ratio of the first modulator 805 is a tilted aspect ratio from the perspective of the light source 801. The aspect ratio of the light source 801 is equal to the tilted aspect ratio of the first modulator 805, so that the entire area of ​​the first modulator 805 can receive light.

[0060] exist Figure 8 In the illustrated embodiment, the first projection optical device 807 (e.g., imaging relay optical device) includes a third lens 818, a first filter 819, and a fourth lens 820. In other embodiments, the first projection optical device 807 may not include the first filter 819. The first filter 819 may include an aperture configured to pass a predetermined diffraction order or a predetermined illumination angle of the third light 806. For example, the first filter 819 may include a "Fourier section" or a "Fourier lens assembly", which refers to an optical system that performs a spatial Fourier transform on modulated light (e.g., light from the first modulator 805) by focusing the modulated light onto a Fourier plane. The spatial Fourier transform applied by the Fourier section converts the propagation angle of each diffraction order of the modulated light into a corresponding spatial position on the Fourier plane. Therefore, the Fourier section is able to select the desired diffraction order and reject the unwanted diffraction order by performing spatial filtering on the Fourier plane.

[0061] Although shown as including two lenses, the first projection optical device 807 can be composed of any number of lenses to guide the fourth light 808 to the second modulator 809 at the second predetermined illumination angle φ. In addition, although each individual lens is shown separately, the individual lenses can be bonded to each other. In some examples, the third lens 818 and the fourth lens 820 can be composed of a lens group consisting of multiple lenses. In addition, each lens or lens group can be composed of any type of lens, such as a concave lens, a negative meniscus lens, and a positive meniscus lens.

[0062] exist Figure 8 In some embodiments, the second projection optical device 811 includes a fifth lens 823, a sixth lens 824, a second filter 825, a seventh lens 826, and an eighth lens 827. In other embodiments, the second projection optical device 811 may not include the second filter 825. The second filter 825 can be functionally similar to the first filter 819 (e.g., including a "Fourier part"). In some embodiments, the second filter 825 is configured to improve the black level of the second modulator 809. In some embodiments, the optical system 800 includes a window actuator 822 optically located between the second modulator 809 and the second projection optical device 811. The window actuator 822 is configured to amplify the image reflected by the second modulator 809 (e.g., the fifth light 810). For example, the window actuator 822 can amplify the image reflected by the second modulator 809 from a 720p image to a 1080p image, from a 1080p image to a 2K image, from a 2K image to a 4K image, etc.

[0063] In some embodiments, the optical system 800 includes a second diffuser 817. The second diffuser 817 can increase the angular diversity of the third light 806 after image reconstruction, thereby reducing the impact of dust and other obstacles within the optical system 800. In some embodiments, the second diffuser 817 is synchronized with the first modulator 805 and / or the second modulator 809. In addition, in some examples, the second diffuser 817 is rotating. In other examples, the second diffuser 817 is stationary.

[0064] The image output by the light source 801 is constructed on a plane (such as a reconstructed image plane) between the first modulator 805 and the second modulator 809. The angle between the reconstructed image formed on the reconstructed image plane and the optical axis is controlled by the first illumination angle θ. The reconstructed image from the first modulator 805 is then imaged onto the second modulator 809, but the plane of the second modulator 809 is tilted relative to the reconstructed image plane. In order to take into account this tilt of the reconstructed image, in some embodiments, the first illumination angle θ is selected to meet the Scheimpflug criterion of the second modulator 809. As previously described, when the second modulator 809 is a DMD, the micromirror 202 is tilted by about 12°. In this embodiment, the first illumination angle θ is selected to be approximately 24°. In an embodiment where the second modulator 809 is a DLP, the second modulator has a diagonally tilted (i.e., azimuthally tilted 45°) reflector. In this case, the first illumination angle θ at the first modulator 805 is also selected to be 45°. By selecting the first illumination angle θ that meets the Scheimpflug criterion, the reconstructed image is fully focused on the second modulator 809.

[0065] In some embodiments, the distortion of the reconstructed image may cause the image to appear as a trapezoid on the second modulator 809. This distortion may prevent the second modulator 809 from being effectively filled, because the trapezoid cannot fill the rectangle of the second modulator 809. Therefore, the first illumination angle θ may be selected so that the reconstructed image provided by the first modulator 805 is approximately rectangular on the second modulator 809, thereby improving optical efficiency.

[0066] To achieve or adjust the first illumination angle θ, the positions of the light source 801, the illumination optics 803, the first modulator 805, the first projection optics 807, and the second modulator 809 may be set during the construction of the optical system 800. In some embodiments, the positions of the light source 801, the illumination optics 803, and the first projection optics 807 may be set or adjusted by corresponding tracks and actuators controlled by the controller 114 to change the first illumination angle θ. In some embodiments, the reflective properties of the illumination optics 803 and the first projection optics 807 are electrically controlled by the controller 114 to change the first illumination angle θ.

[0067] In some embodiments, optical system 800 represents only a single color channel of projection system 100. Thus, each color channel in projection system 100 can have its own optical system configured similarly to optical system 800, with each color channel having its own corresponding first modulator 105 and second modulator 109. Each color channel can be combined according to a corresponding optical output 813 before being projected onto screen 113. Optical output 813 can be a three-channel prism, such as the three-channel prism in U.S. Patent No. 10,197,902, "High Contrast Discrete Input Prism for Image Projector," which is incorporated herein by reference in its entirety.

[0068] The above-described projection system can provide an optical configuration that utilizes rectangular optical fibers to provide light to modulators having the same aspect ratio, thereby improving the optical efficiency of the system and increasing the amount of light reflected by the modulator.

[0069] The systems, methods, and devices according to the present disclosure may adopt any one or more of the following configurations.

[0070] (1) A projection system comprising: a rectangular optical fiber configured to emit light in response to image data, the rectangular optical fiber having a first aspect ratio; and a first modulator configured to receive light from the rectangular optical fiber and apply spatially varying modulation to the light, thereby steering the light and generating first steered light, the first modulator having a second aspect ratio.

[0071] (2) The projection system according to (1), wherein the first aspect ratio is different from the second aspect ratio.

[0072] (3) The projection system according to (1) or (2), further includes a first projection optical device arranged between the rectangular optical fiber and the first modulator, and the first projection optical device is configured to convert the aspect ratio of the light emitted by the rectangular optical fiber from the first aspect ratio to a second aspect ratio.

[0073] (4) The projection system according to (3), wherein the first projection optical device includes a cylindrical lens.

[0074] (5) The projection system according to any one of (1) to (4), wherein the first aspect ratio is the same as the second aspect ratio.

[0075] (6) A projection system according to any one of (1) to (5), wherein the rectangular optical fiber includes: a first optical fiber portion having a circular shape; and a second optical fiber portion having a rectangular shape, the second optical fiber portion being spliced ​​to one end of the first optical fiber portion.

[0076] (7) The projection system according to any one of (1) to (6), wherein the rectangular optical fiber includes a plurality of optical fiber portions arranged in a rectangular array.

[0077] (8) The projection system according to any one of (1) to (7), further comprising: a second modulator configured to receive the first deflected light and apply spatially varying modulation to the first deflected light to generate second deflected light, wherein an image contained in the light emitted by the rectangular optical fiber is optically constructed between the first modulator and the second modulator.

[0078] (9) The projection system of (8), wherein the first modulator applies spatially varying phase modulation to the light, and wherein the second modulator applies spatially varying amplitude modulation to the first redirected light.

[0079] (10) A projection system according to any one of (1) to (9), wherein the rectangular optical fiber is configured to emit light on a first axis, wherein the first modulator is located on a plane defined by a second axis, and wherein the second axis is not perpendicular to the first axis, so that the first modulator is tilted relative to the rectangular optical fiber.

[0080] (11) The projection system according to (10), wherein the second aspect ratio of the first modulator is an oblique aspect ratio from the perspective of the rectangular optical fiber, and the first aspect ratio of the rectangular optical fiber is equal to the oblique aspect ratio.

[0081] (12) A method for controlling a projection system, the method comprising: receiving light from a rectangular optical fiber using a phase light modulator, wherein the rectangular optical fiber is configured to emit light in response to image data and has a first aspect ratio, and wherein the phase light modulator has a second aspect ratio, and steering the light at an illumination angle using the phase light modulator to generate a first steered light.

[0082] (13) The method according to (12), wherein the first aspect ratio is different from the second aspect ratio.

[0083] (14) The method according to (12) or (13) further includes: using a first projection optical device arranged between the rectangular optical fiber and the phase light modulator to convert the aspect ratio of the light emitted by the rectangular optical fiber from a first aspect ratio to a second aspect ratio.

[0084] (15) The method according to (14), wherein the first projection optical device includes a cylindrical lens.

[0085] (16) A method according to any one of (12) to (15), wherein the rectangular optical fiber comprises: a first optical fiber portion having a circular shape; and a second optical fiber portion having a rectangular shape, the second optical fiber portion being spliced ​​at one end of the first optical fiber portion.

[0086] (17) The method described in any one of (12) to (16) further includes: receiving the first steered light using a spatial light modulator, and steering the first steered light using the spatial light modulator to generate a second steered light, wherein the image contained in the light emitted by the rectangular optical fiber is optically constructed between the phase light modulator and the spatial light modulator.

[0087] (18) The method according to (17) also includes: applying spatially varying phase modulation to the light using a phase light modulator, and applying spatially varying amplitude modulation to the first redirected light using a spatial light modulator.

[0088] (19) A method according to any one of (12) to (18), wherein the rectangular optical fiber is configured to emit light on a first axis, and the phase light modulator is located on a second axis, wherein the second axis is not perpendicular to the first axis, so that the phase light modulator is tilted relative to the rectangular optical fiber, and so that from the perspective of the rectangular optical fiber, the second aspect ratio of the phase light modulator is the tilted aspect ratio, and wherein the first aspect ratio of the rectangular optical fiber is equal to the tilted aspect ratio.

[0089] (20) A non-transitory computer-readable medium storing instructions that, when executed by a processor of a projection system, cause the projection system to perform operations including the method according to any one of (12) to (19).

[0090] With respect to the processes, systems, methods, heuristics, etc. described herein, it should be understood that although the steps of these processes, etc. have been described as being performed in a certain ordered sequence, when implementing these processes, the steps may be performed in an order other than the order described herein. It should be further understood that certain steps may be performed simultaneously, other steps may be added, or certain steps described herein may be omitted. In other words, the description of the processes herein is intended to illustrate certain embodiments and should in no way be construed as limiting the claims.

[0091] Therefore, it should be understood that the above description is intended to be illustrative and not restrictive. After reading the above description, many embodiments and applications other than the examples provided will be apparent. When determining the scope, the above description should not be referred to, but the attached claims and the full range of equivalents enjoyed by these claims should be referred to. It is expected and hoped that the technology discussed herein will be developed in the future, and the disclosed systems and methods will be incorporated into these future implementations. In short, it should be understood that the application is capable of modification and variation.

[0092] All terms used in the claims should be given their broadest reasonable constructions and their ordinary meanings as understood by those familiar with the technology described herein unless expressly indicated to the contrary herein. In particular, use of the singular articles such as "a", "the", "said", etc. should be understood to recite one or more of the indicated elements unless expressly limited to the contrary in a claim.

[0093] An abstract of the disclosure is provided to enable the reader to quickly ascertain the nature of the technical disclosure. The abstract is submitted with the understanding that it is not used to interpret or limit the scope or meaning of the claims. In addition, it can be seen from the above detailed description that various features are combined together in different embodiments in order to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the claimed embodiments include more features than are expressly recited in each claim. On the contrary, as reflected in the following claims, the inventive subject matter lies in less than all the features of a single disclosed embodiment. Therefore, the following claims are hereby incorporated into the detailed description, with each claim existing independently as a separate claimed subject matter.

Claims

1. A projection system, comprising: a rectangular optical fiber configured to emit light in response to image data, the rectangular optical fiber having a first aspect ratio; as well as A first modulator is configured to receive the light from the rectangular optical fiber and apply spatial variation modulation to the light, thereby steering the light and generating first steered light, the first modulator having a second aspect ratio. 2 . The projection system of claim 1 , wherein the first aspect ratio is different from the second aspect ratio.

3. The projection system according to claim 1 or 2 further comprises a first projection optical device arranged between the rectangular optical fiber and the first modulator, and the first projection optical device is configured to convert the aspect ratio of the light emitted by the rectangular optical fiber from the first aspect ratio to the second aspect ratio.

4. The projection system of any one of claims 1 to 3, wherein the first aspect ratio is the same as the second aspect ratio.

5. The projection system according to any one of claims 1 to 4, wherein the rectangular optical fiber comprises: a first optical fiber portion having a circular shape; as well as A second optical fiber portion having a rectangular shape is spliced ​​to one end of the first optical fiber portion.

6. The projection system according to any one of claims 1 to 5, wherein the rectangular optical fiber comprises a plurality of optical fiber sections, the plurality of optical fiber sections being arranged in a rectangular array.

7. The projection system according to any one of claims 1 to 6, further comprising: a second modulator, the second modulator being configured to receive the first steering light and apply spatial variation modulation to the first steering light to generate second steering light, The image contained in the light emitted by the rectangular optical fiber is constructed optically between the first modulator and the second modulator.

8. A projection system according to any one of claims 1 to 7, wherein the rectangular optical fiber is configured to emit light on a first axis, wherein the first modulator is located on a second axis, and wherein the second axis is not perpendicular to the first axis, so that the first modulator is tilted relative to the rectangular optical fiber.

9. The projection system of claim 8, wherein the second aspect ratio of the first modulator is a slanted aspect ratio from the perspective of the rectangular optical fiber, and wherein the first aspect ratio of the rectangular optical fiber is equal to the slanted aspect ratio.

10. A method for controlling a projection system, the method comprising: receiving light from a rectangular optical fiber using a phase light modulator, wherein the rectangular optical fiber is configured to emit light in response to image data and the rectangular optical fiber has a first aspect ratio, and wherein the phase light modulator has a second aspect ratio, and The phase light modulator is used to steer the light at an illumination angle to generate first steered light. The method of claim 10 , wherein the first aspect ratio is different from the second aspect ratio.

12. The method according to claim 10 or 11, further comprising: The aspect ratio of the light emitted from the rectangular optical fiber is converted from the first aspect ratio to the second aspect ratio using a first projection optical device disposed between the rectangular optical fiber and the phase light modulator.

13. The method according to any one of claims 10 to 12, wherein the rectangular optical fiber comprises: a first optical fiber portion having a circular shape; as well as A second optical fiber portion having a rectangular shape is spliced ​​to one end of the first optical fiber portion.

14. The method according to any one of claims 10 to 13, wherein the rectangular optical fiber is configured to emit light on a first axis, wherein the phase light modulator is located on a second axis, wherein the second axis is not perpendicular to the first axis, so that the phase light modulator is tilted relative to the rectangular optical fiber, and so that the second aspect ratio of the phase light modulator is a tilted aspect ratio from the perspective of the rectangular optical fiber, and wherein the first aspect ratio of the rectangular optical fiber is equal to the tilted aspect ratio.

15. A non-transitory computer readable medium storing instructions which, when executed by a processor of a projection system, cause the projection system to perform operations including the method according to any one of claims 10 to 14.

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