Fast opto-mechanical attenuator for high power projector system

Abstract

A projector system includes: an optomechanical attenuator configured to variably attenuate source light directed to an optical output thereof; an optical modulator configured to generate spatially modulated light by modulating the illumination light received from the optical output, the modulation being performed in accordance with image data representing a sequence of image frames, each image frame having a constant duration; and optics configured to optically couple the optical output to the optical modulator, and further configured to project the spatially modulated light, thereby projecting a sequence of image frames. The optical mechanical attenuator is configured to change an optical power of the illumination light from a first fixed power level to a second fixed power level for a time shorter than a constant duration.

Description

[0001] 1. Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 340,699, filed May 11, 2022, which is incorporated by reference in its entirety. Technical Field

[0003] Various example embodiments relate to optical attenuators, and more particularly, but not exclusively, to optical attenuators for projector systems. Background Art

[0004] An optical attenuator is a device that can be used to reduce the power level of a beam or signal in free space or in an optical fiber. Power reduction can be achieved using absorption, reflection, diffusion, scattering, redirection, diffraction, dispersion, or other suitable means. Optical attenuators can be fixed, gradually variable, or continuously variable. A variety of optical attenuators covering various spectral bands are commonly used, for example, in fiber-optic communication systems, image projectors, laser cutting machines, and many other laser-related technologies. Summary of the Invention

[0005] Disclosed herein are various embodiments of a projector system having a global optomechanical dimmer of illumination light applied to its spatial optical modulator. In an example embodiment, the dimmer includes a motion actuator (such as a voice coil actuator (VCA)) and one or more reflective surfaces that are movable by the motion actuator to reflect a variable portion of the source light away from the spatial optical modulator, for example, to a light collector. The dimmer is configured to vary the total optical power of the illumination light by a factor of more than ten in a time shorter than the inverse of the frame rate of the projected video stream (e.g., shorter than approximately 20 ms). Because the dimmer can be operated separately from the system's light source, the corresponding projector system can advantageously employ essentially any suitable laser source while still being able to meet operability goals regarding fast, variable global dimming. In at least some embodiments, the projector system can be a high-power cinema-grade laser projector system configured to operate in accordance with the SMPTE 431-1-2006 standard.

[0006] According to an example embodiment, a projector system is provided, comprising: an optomechanical attenuator configured to variably attenuate source light directed to an optical output thereof; an optical modulator configured to generate spatially modulated light by modulating illumination light received from the optical output, the modulation being performed according to image data representing a sequence of image frames, each image frame having a constant duration; and an optical device configured to optically couple the optical output to the optical modulator and further configured to project the spatially modulated light, thereby projecting the sequence of image frames. The optomechanical attenuator is configured to change the optical power of the illumination light from a first fixed power level to a second fixed power level within a time shorter than the constant duration.

[0007] According to another example embodiment, a method of variably attenuating illumination light applied to an optical modulator of a projector system is provided, the optical modulator being configured to generate spatially modulated light by modulating the illumination light according to image data representing a sequence of image frames, each image frame having a constant duration, the method comprising the steps of: moving one or more reflective surfaces to reflect a variable portion of source light away from the optical modulator and directing the illumination light toward the optical modulator, the illumination light comprising a remaining portion of the source light, the moving being performed using a motion actuator; and operating the motion actuator to change an optical power of the illumination light from a first fixed power level to a second fixed power level within a time shorter than the constant duration.

[0008] According to another example embodiment, a projector system is provided, comprising: an optomechanical attenuator configured to variably attenuate source light directed to its optical output; an optical modulator configured to generate spatially modulated light by modulating illumination light received from the optical output, the modulation being performed in accordance with image data; and a first optical device configured to optically couple the optical output to the optical modulator; wherein the optomechanical attenuator is configured to change the optical power of the illumination light from a first fixed power level to a second fixed power level; and wherein the optomechanical attenuator and the first optical device are configured to uniformly illuminate the optical modulator with the illumination light such that a relative brightness in all geometrically modulated portions of the optical modulator, expressed as a percentage of the brightness in an intermediate geometrically modulated portion of the optical modulator, is greater than 75% at both the first fixed power level and the second fixed power level.

[0009] In some embodiments, the projector system includes a second optical device configured to project spatially modulated light onto a screen; and wherein the optomechanical attenuator and the first and second optical devices are configured such that the screen is uniformly illuminated such that for unmodulated light, the relative brightness at the edges and corners of the screen, expressed as a percentage of the brightness at the geometric center of the screen, is greater than 75% at both the first fixed power level and the second fixed power level. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Other aspects, features, and advantages of the various disclosed embodiments will become more fully apparent from the following detailed description and the accompanying drawings, in which:

[0011] Figure 1 is a block diagram illustrating a projector system according to various embodiments.

[0012] Figure 2 is a diagram illustrating a method for Figure 1 A plan view of the optomechanical components in the projector system.

[0013] Figure 3 It's a picture Figure 2 A plan view of an optomechanical assembly in an example non-zero attenuation configuration.

[0014] Figure 4 The diagram shows a method for Figure 2 The shape of the mirrors in the optomechanical assembly.

[0015] Figure 5 FIG. 1 shows a method for using a Figure 2 The shape of the mirrors in the optomechanical assembly.

[0016] Figure 6 FIG. 1 shows a method for Figure 2 The shape of the mirrors in the optomechanical assembly.

[0017] Figure 7 FIG. 1 shows a method for Figure 2 The shape of the mirrors in the optomechanical assembly.

[0018] Figure 8 is a diagram illustrating a method for Figure 1 3D stereogram of the optomechanical components in a projector system.

[0019] Figure 9 FIG. 1 shows a method for using a Figure 8 The shape of the optical aperture in the optomechanical assembly.

[0020] Figure 10 FIG. 1 shows a method for Figure 8 The shape of the optical aperture in the optomechanical assembly.

[0021] Figure 11 is a diagram illustrating a method for Figure 1 Schematic diagram of the optical components in the projector system.

[0022] Figure 12 is a diagram illustrating a method for Figure 1 Schematic diagram of the optical model of the dimmer in the projector system.

[0023] Figures 13 and 14 is a diagram illustrating a method for Figure 1 Schematic diagram of the optical model of the dimmer in the projector system.

[0024] Figures 15 and 16 The diagrams respectively illustrate the Figure 1 Time dimming characteristics and time de-dimming characteristics of a dimmer in a projector system. DETAILED DESCRIPTION

[0025] In the following description, many details such as optical device configuration, timing, operation, etc. are set forth to provide an understanding of one or more aspects of the present disclosure. It will be apparent to those skilled in the relevant art that these specific details are merely examples and are not intended to limit the scope of the present application.

[0026] Furthermore, while the present disclosure primarily focuses on examples of using various circuits in digital projection systems, it should be understood that these are merely examples. It should also be further understood that the disclosed systems and methods can be used in any device requiring projected light, such as cinemas, consumer and other commercial projection systems, heads-up displays, virtual reality displays, and the like. The disclosed systems and methods can be implemented in additional display devices, such as OLED displays, LCD displays, quantum dot displays, and the like.

[0027] Light-steering modulators can create images in a plane different from the modulator plane itself. This plane can be virtual or real. Light-steering modulators can have a flat reflector surface and therefore generally have no inherent illumination angle other than a certain configuration that allows normal illumination. Light-steering modulators can also create images or objects on the modulator itself and have angled reflectors.

[0028] Figure 1 is a block diagram illustrating a projector system 100 according to various embodiments. Figure 1As shown, projector system 100 includes a light source 110, a variable optical attenuator (dimmer) 114, illumination optics 130, a first light valve 134, transmission optics 138, a second light valve 142, and projection optics 146. Projector system 100 may also include an electronic controller 170 and a screen 150. In some embodiments, screen 150 may be an external component, i.e., it may be located in the environment in which projector system 100 is deployed. An example of such a screen 150 may be a theater screen in a movie theater. In some embodiments, controller 170 may enable at least some components of projector system 100 to be remotely located, with these components connected to other components of the projector system using a suitable network link.

[0029] In operation, the dimmer 114 can attenuate the first light 112 emitted by the light source 110, thereby generating the second light 116. The optical attenuation applied by the dimmer 114 can be dynamically changed based on a control signal 174 applied to the dimmer by the controller 170. When the dimmer 114 is configured to apply an optical attenuation of substantially 0 dB, the second light 116 can be substantially the same as the first light 112. In other configurations, the attenuation controllably applied by the dimmer 114 can have any value selected from a range between, for example, 0 dB and -40 dB (or 99.9%). The actual value of the optical attenuation applied by the dimmer 114 can be measured using a fixed optical tap 118 and a photodetector (PD) 120. For example, the optical tap can direct a relatively small portion (e.g., <5%) of the second light 116 to the PD 120, and the electrical output signal (e.g., current or voltage) 122 generated by the PD 120 in response to the light portion can be processed by the controller 170 to determine the intensity of the second light 116. In some embodiments, the optical tap 118 and the PD 120 can be absent, e.g., optional. In some embodiments, the optical tap 118 can be placed further downstream than shown, e.g., downstream of the illumination optics 130. Various embodiments of the projector system 100 can provide a DCI contrast ratio in the range of approximately 1000:1 to approximately 1,000,000:1. Some embodiments of the dimmer 114 can be used in the projector system 100 to provide a dimming ratio of approximately 100:1 without causing noticeable artifacts in the projected image. Some other embodiments of the dimmer 114 can be used in the projector system 100 to provide a dimming ratio of approximately 33:1 or 10:1 without causing such artifacts. In this article, the acronym DCI stands for Digital Cinema Initiative.

[0030] Illumination optics 130 are configured to receive second light 116 and redirect or otherwise modify the received light to generate third light 132. First light valve 134 is configured to apply spatially varying (e.g., phase) modulation to third light 132 to generate fourth light 136. First light valve 134 can steer fourth light 136, for example, by changing its phase modulation pattern in response to a control signal 176 received from controller 170. Transmission optics 138 are configured to receive fourth light 136 and redirect or otherwise modify the received light to generate fifth light 140. Second light valve 142 is configured to apply spatially varying (e.g., amplitude) modulation to fifth light 140 to generate sixth light 144. Second light valve 142 can change its amplitude modulation pattern in response to a control signal 178 received from controller 170. Projection optics 146 are configured to receive sixth light 144 and project the received light as seventh light 148 onto screen 150. In various embodiments, each of the light valves 134 and 142 can be implemented using a corresponding suitable modulation device, such as a device selected from the group consisting of a spatial optical modulator (SLM), a liquid crystal on silicon (LCoS) modulator, a MEMS optical modulator, a digital micromirror device (DMD), a digital light processor (DLP), and other suitable optical modulators. In some embodiments, the transmission optical device 138 and one of the light valves 134 and 142 may not be present. For example, in embodiments where the light valve 134 and the transmission optical device 138 are absent, the third light 132 is directly applied to the light valve 142.

[0031] In addition to generating the above control signals 174, 176, 178, the electronic controller 170 may also generate a control signal 172 for controlling the light source 110 to emit the first light 112, such as Figure 1 As shown. In some embodiments, the controller 170 may additionally or alternatively control some other components of the projector system 100, including but not limited to the illumination optics 130, the transmission optics 138, and / or the projection optics 146. In an example embodiment, the controller 170 may be implemented using one or more processors (e.g., a central processing unit (CPU) of the projector system 100). The illumination optics 130, the transmission optics 138, and the projection optics 146 may each include one or more corresponding optical components such as reflectors, lenses, waveguides, optical fibers, beam splitters, diffusers, etc. In addition to the screen 150, Figure 1 Some or all of the other system components shown in the figure may be integrated into the housing ( Figure 1 Such a projection device may include additional components such as memory, input / output ports, communication circuits, power supplies, etc. (not explicitly shown in FIG. Figure 1 not explicitly shown).

[0032] In some embodiments, light source 110 can be, for example, a laser source, an LED, or other coherent light source. In such embodiments, first light 112 can be coherent light or partially coherent light. In some embodiments, any suitable light emitter (coherent or incoherent) can be adapted to function as light source 110 in projector system 100. In some embodiments, light source 110 can include multiple individual light emitters, each capable of emitting light corresponding to a different respective wavelength or spectral band (e.g., red, green, or blue). Controller 170 can generate control signals 172, 174, 176, 178 in response to image signal 168 comprising image data. Image signal 168 can correspond to a single image frame or a sequence of image frames. Image signal 168 can originate from (i) an external source, such as a streaming service or cloud-based file repository, (ii) internal memory of projector system 100, such as a hard drive or solid-state drive, (iii) a removable machine-readable medium connectable to projector system 100, or (iv) any suitable combination thereof.

[0033] In an exemplary embodiment, the transmission optics 138 and / or the projection optics 146 may include optical filters configured to mitigate certain adverse effects caused by some components of the projector system 100. For example, the first light valve 134 may include a cover glass that may cause stray reflections. The switching of the light valves 134 and 142 may intermittently cause undesirable steering angles. Various components of the projector system 100 may cause light scattering. To counteract these and other adverse effects and to reduce the light floor (black level) of the projector system 100, the optical filters may be Fourier ("DC") filter components configured to block a portion of the fourth light 136 and / or a portion of the sixth light 144. In operation, such optical filters may help improve contrast by reducing the black level of light near a zero-degree angle and may be used to prevent some light from reaching the screen 150. Additionally, such optical filters may mitigate modal noise from the light source 110. In some cases, an optical filter may prevent some of the undesired light from reaching screen 150 by diverting it to a light collector located outside the active image area or optical path, for example, in response to an appropriate control signal from controller 170 .

[0034] although Figure 1The block diagram of FIG. 1 illustrates a generally linear optical path between the laser source 110 and the projection optics 146, but various embodiments are not limited thereto. More specifically, in some embodiments, the optical path between the laser source 110 and the projection optics 146 may deviate significantly from a straight line and may have a more complex topology overall. For example, in the projector system 100, the third light 132 may be directed at an oblique angle to the light valve 134. The fifth light 140 may similarly be directed at an oblique angle to the light valve 142. To ensure that the image on the screen 150 has acceptable clarity and contrast, the illumination optics 130 may be designed, configured, and / or controlled to maintain the incident angle on the light valve 134 within a desired (e.g., expected) range while also centered on the third light 132. The light valve 134 and / or the transmission optics 138 may be designed, configured, and / or controlled to ensure that the incident angle on the light valve 142 is also correct while also centered on the fifth light 140. In at least some embodiments, projector system 100 can substantially conform to the SMPTE 431-1-2006 standard, which is incorporated herein by reference in its entirety.

[0035] In some cases, it may be advantageous for the projector system 100 to be able to improve the black level in certain movie scenes, for example, by global dimming, in which the amount of light directed downstream from the light source 110 is significantly and controllably reduced. According to various possible approaches, global dimming can be achieved, for example, by electronically adjusting the electrical drive level of the laser and / or by deflecting a portion of the first light 112 away from the main optical path by acousto-optical, electro-optical, or opto-mechanical means. However, some types of light sources 110 may not be suitable for electronically controlled light attenuation or adjustment in a manner sufficient for movie imaging. For example, some laser systems may have a relatively narrow operating configuration space, which may not provide sufficient adjustable room to achieve a desired brightness variation range, for example, between full brightness and an ideal black (i.e., no light) level. In addition, some laser systems may be relatively slow to respond and stabilize to the adjusted optical power level, i.e., may not inherently exhibit sufficiently fast brightness dynamics suitable for video imaging.

[0036] At least some of the aforementioned problems in the prior art, as well as potentially some other related problems, can be advantageously addressed using embodiments of the projector system 100 and / or dimmer 114 disclosed herein. In example embodiments, the dimmer 114 can be designed, configured, and / or controlled to optomechanically deflect or clip a variable amount of the first light 112 in response to a control signal 172. Because the dimmer 114 can be operated separately from the light source 110, its use enables the projector system 100 to employ substantially any suitable type of laser in the light source 110 while meeting the aforementioned operability goals for fast, variable global dimming.

[0037] Figure 2 is a plan view illustrating an optomechanical assembly 200 that may be used in the dimmer 114 according to an embodiment. The assembly 200 includes a rotatable holder 210 having a pair of knife-edge mirrors 220 mounted thereon, labeled 2201 and 2202, respectively. The holder 210 is rotatably connected to a pivot pin 208, which is attached to a fixed base 201. Also attached to the base 201 is a linear motion actuator 230 having a movable shaft 232. In operation, the actuator 230 can controllably translate the shaft 232 along its longitudinal dimension, as indicated by the double-headed arrow 234. Figure 2 As shown, a connector 236 is movably connected between the shaft 232 and the retainer 210, enabling linear translation of the shaft to be converted into rotation of the retainer. More specifically, the connector 236 is rotatably connected to the retainer 210 at a pivot point 212, which is offset a non-zero distance from the pivot pin 208. This offset provides leverage for the shaft 232, allowing the retainer 210 to rotate about the pivot pin 208 in response to linear translation of the shaft caused by the actuator 230.

[0038] In an example embodiment, the actuator 230 may be implemented using a linear VCA comprising a permanent magnet and a wire coil in the magnetic field of the permanent magnet. Figure 1 When the current 174 is applied to the coil, a Lorentz force is generated, which can move the coil and the shaft 232 attached thereto. In operation, the current 174 can be appropriately adjusted by the controller 170 to control the translation distance of the shaft 232, thereby controlling the rotation angle of the holder 210 about the pivot pin 208. In alternative embodiments, the actuator 230 can also use other types of linear motion actuators. In some embodiments, a coil spring ( Figure 2 (not explicitly shown) to generate an elastic return force that counteracts the force of VCA 230. In alternative embodiments, actuator 230 may also use other types of linear motion actuators.

[0039] The assembly 200 can be positioned in the dimmer 114 so that the collimated light beam 202 passes through a middle portion of the holder 210, such as through the pivot pin 208, as shown. Figure 2 In an example embodiment, the collimated light beam 202 may carry the first light 112 or may be formed by collimating the first light (see also Figure 12 ). The knife edge mirrors 2201 and 2202 are attached to the holder 210 in an elevated position so that rotation of the holder about the pivot pin 208 can bring the mirrors into and out of the path of the light beam 202 as needed. Figure 2In FIG. 5 , the holder 210 is shown oriented at an angle such that the light beam 202 avoids the reflectors 2201 and 2202, which does not cause the light beam to attenuate.

[0040] Figure 3 is a plan view illustrating the optomechanical assembly 200 in an example non-zero attenuation configuration. Figure 2 Compared to the configuration shown, the shaft 232 extends an additional distance d away from the fixed body of the actuator 230, thereby rotating the holder 210 about the pivot pin 208 by a corresponding angle. This rotation moves the leading edges of the mirrors 2201 and 2202 into the path of the light beam 202, thereby intercepting the outer portion of the light beam, such as Figure 3 Depending on the distance d, the cross-sectional area of ​​the light beam 202 may be truncated more or less, causing the corresponding optical attenuation to vary. The distance d may be controlled by the control signal 174, for example, as indicated above.

[0041] In an example embodiment, the surfaces 320 facing the stream of light beam 202 (i.e., 3201 on reflector 2201 and 3202 on reflector 2202) can have a relatively high reflectivity. For example, in different embodiments, the reflectivity of surfaces 3201, 3202 can be greater than about 90%, greater than about 95%, greater than about 98%, or even greater than 99%. In comparison, the visible light reflectivity of a typical polished aluminum surface may be less than 90%. In various embodiments, the highly reflective surfaces 3201, 3202 can be implemented using high-quality metal mirrors or dielectric mirrors. In operation, reflective surfaces 3201, 3202 reflect light, thereby splitting off some of the optical power of light beam 202 in the form of reflected light beams 3021, 3022. Projector system 110 can typically have a light collector configured to receive reflected light beams 3021, 3022. As is known in the relevant art, a light collector is a heat sink that has a relatively high absorption coefficient for the intended light wavelength (e.g., the wavelength of light beam 202). The light collector may typically be black in color and have a shape that efficiently dissipates heat, for example, a shape characterized by a relatively high surface to volume ratio.

[0042] In an exemplary embodiment, the mirrors 2201 and 2202 are configured to act substantially symmetrically on each side of the beam 202, such that the symmetry of the truncated / attenuated beam is maintained regardless of the attenuation level. Additionally, the shapes of the mirrors 2201 and 2202 can be designed such that the beam truncation thereby does not significantly or even appreciably degrade the uniformity of the light at the output of a corresponding homogenizing element, such as an integrating rod, light pipe, or fly's eye homogenizer (see also Figure 11 In some embodiments, based on the electrical output signal 122 generated by the PD 120 (see also Figure 1 ), the relative rotation angle of the holder 210 can be controlled more accurately.

[0043] Figure 4 The reflector 220 according to the embodiment is shown. More specifically, Figure 4 The view of the reflector 220 is shown from the side of its reflective surface 320 (see also Figure 3 In an example embodiment, the assembly 200 may employ one instance of the reflector 220 as the reflector 2201 and another instance of the reflector 220 as the reflector 2202 .

[0044] Figure 4 The shape of the reflector 220 is an irregular pentagon, and the five vertices of the pentagon are marked as AE. Sides BC and DE are the same length, parallel to each other, and orthogonal to side CD. The lengths of sides AB and AE are also the same and are greater than the length of side CD. In various embodiments, the lengths of sides AB and AE can be greater than, less than, or equal to the lengths of sides BC and DE. The angle at vertex A can be in the range of, for example, 30 degrees to 150 degrees. The pentagonal shape of the reflector 220 shown has mirror symmetry about an axis of symmetry AF passing through vertex A and the midpoint F of side CD. In some embodiments, the reflector 220 can also have a conical (e.g., triangular) groove 402 along the axis of symmetry AF relatively close to vertex A, as shown. Figure 4 As shown. The taper angle of the groove 402 can be, for example, in the range of 5 degrees to 45 degrees. In some embodiments, the tapered groove 402 may not exist.

[0045] Figure 4 The shape of the reflector 220 shown is advantageous in reducing the amount of current flowing through the output of the averaging element (e.g., Figure 11 If appropriate precautions are not properly implemented, such spatial intensity non-uniformity may potentially be caused by the pair of mirrors 220 (i.e., 2201, 2202 ( Figure 3 )) causes the truncation of the light beam 102. More specifically, the homogenizing element (e.g., an integrator rod) can be located in the illumination optics 130 and can have a rectangular cross-section with an aspect ratio of approximately 2:1. In order to have a spatially uniform light output at the rectangular output end facets of the integrator rod, its input end facets preferably need to be filled with light having a sufficiently diverse spatial and / or angular distribution. Advantageously, Figure 4 The shape of the reflector 220 shown is such that these criteria are substantially met for a number of different positions of the reflectors 2201, 2202 relative to the beam 202. For example, when the depth of insertion of the vertex A into the beam 202 is relatively shallow, the beam truncation of the beam circumference by the "sharp" leading edge of the reflector 220 is limited, which is different from when the beam 202 is not truncated (e.g., Figure 2Similarly, when the depth of apex A inserted into light beam 202 is relatively large, the diversity of the spatial and angular light distribution at the input facet of the integrator rod can be maintained at a sufficient level because the light around the circumference of light beam 202 passes through the two tapered grooves 402 of reflectors 2201 and 2202.

[0046] Figure 5 A reflector 220 according to another embodiment is illustrated. Figure 5 The view of the reflector 220 shown is similar in nature to Figure 4 5. The view shown is similar to that shown in FIG. 2. In this particular embodiment, the reflector 220 has a generally rectangular shape with a V-shaped notch 502 in the middle of the leading edge 504 of the reflector. In operation, the V-shaped notch 502 can help maintain a sufficient level of diversity in the spatial and angular light distribution at the input end facets of the integrator rod when the leading edge 504 is inserted into the light beam 202 at a relatively large depth, thereby reducing spatial intensity non-uniformity that may occur at the output end facets of the integrator rod.

[0047] Figure 6 A reflector 220 according to yet another embodiment is illustrated. Figure 6 The view of the reflector 220 shown is similar in nature to Figure 4 1 and 2. In this particular embodiment, the reflector 220 has a generally rectangular shape with a stepped notch 602 in the middle of the leading edge 604 of the reflector. The stepped notch 602 is designed to provide three different discrete attenuation levels. The stepped nature of the notch 602 can be advantageously used to make the dimmer 114 less sensitive to the positioning accuracy of the reflectors 2201, 2202 relative to the light beam 202, thereby avoiding interference with the actuator feedback path (e.g., via the optical tap 118, the PD 120, and the feedback signal 122 (see FIG. 1 ). Figure 1 )). For example, even if the first stepped opening 606 of the notch 602 is positioned approximately at the circumference of the light beam 202, a first discrete attenuation level will result. Similarly, even if the second stepped opening 608 of the notch 602 is positioned approximately at the circumference of the light beam 202, a second discrete attenuation level will result, and even if the third stepped opening 610 of the notch 602 is positioned approximately at the circumference of the light beam 202, a third discrete attenuation level will result. Accordingly, using Figure 6 Embodiments of the reflector 220 may not need to have the optical tap 118 and the PD 120 therein. In addition, similar to the V-shaped notch 502 ( Figure 5 ), the overall shape of the stepped recess 602 can help provide sufficient spatial and angular light distribution diversity at the output end facet of the integrator rod for multiple different positions of the reflector 220 relative to the light beam 202.

[0048] Figure 7 A reflector 220 according to yet another embodiment is illustrated. Figure 7 The view of the reflector 220 shown is similar in nature to Figure 4 . In this particular embodiment, the reflector 220 has a generally rectangular shape with a plurality of openings therein. The first opening 706 is a semicircular notch located in the middle of the leading edge 704 of the reflector 220. When the two first openings 706 of the reflectors 2201, 2202 are properly aligned in the assembly 200, an approximately circular effective aperture can be created. Each of the additional openings 708, 710, and 712 is a circular opening having a different respective diameter. In operation, the openings 706, 708, 710, and 712 can be used to achieve the same effect as described above with reference to FIG. Figure 6 The performance characteristics of the embodiments described are similar to the performance characteristics.

[0049] In various alternative embodiments, other shapes of openings, notches, and leading edges may also be used. For example, in some embodiments, such shapes may be designed so that the attenuation level is linearly dependent on the depth of the reflector inserted into the beam 202. Other relevant considerations, such as performance optimization, may also be taken into account when designing these shapes.

[0050] Figure 8 1 is a three-dimensional perspective view illustrating an optomechanical assembly 800 that can be used in the dimmer 114 according to another embodiment. Figure 2 ), assembly 800 includes an actuator 230, such as a linear VCA. However, in this particular embodiment, a shaft 232 of actuator 230 is connected to an optical carriage 810 mounted on an optical track 812. In operation, movement of shaft 232 causes corresponding translation of optical carriage 810 along optical track 812.

[0051] In the dimmer 114, the assembly 800 may be positioned such that the longitudinal direction of the optical track 812 is parallel to the propagation axis of the light beam 802, as shown in FIG. Figure 8 In an example embodiment, the light beam 802 may carry the first light 112 ( Figure 1 ) or can be formed by shaping (eg, focusing) the first light (eg, see Figure 13 1302 in FIG). Assembly 800 further includes an optical aperture 820 located in the optical path of light beam 802. Optical aperture 820 is mounted on optical bracket 810, as shown in FIG. Figure 8 As shown, it can therefore move along the beam 802.

[0052] In an example embodiment, the optical aperture 820 includes a generally conical reflective front surface 822, whose reflective properties may be generally similar to the reflective properties of the reflective surface 320 described above (e.g., see Figure 3 824). The conical front surface 822 has a small circular opening 824 at its apex. When the opening 824 is located at the focal point of the light beam 802, substantially no optical attenuation occurs, and substantially all of the light of the light beam passes through the opening to the back side of the optical aperture 820. However, when the opening 824 is positioned a meaningful non-zero distance from the focal point, some light is reflected from the conical front surface 822 toward the light collector, thereby causing attenuation of the light beam 802. The level of attenuation can be varied by controllably translating the optical carriage 810 along the optical track 812, for example, in response to the control signal 174 applied to the actuator 230 as previously described.

[0053] Figure 9 is a three-dimensional perspective diagram illustrating an optical aperture 820 according to another embodiment. Figure 9 An embodiment is roughly similar to Figure 8 The embodiment of the optical aperture 820 shown, and similarly has a generally conical reflective front surface 822. However, Figure 9 The embodiment has an approximately diamond-shaped opening 924 instead of a circular opening 824. In operation, Figure 9 The embodiment of the optical aperture 820 shown above may provide Figure 5 The illustrated embodiment of the reflector 220 provides at least some of the benefits described above. In particular, it can be noted that the two notches 502 of the reflectors 2201, 2202 form an effective opening similar in shape to the opening 924 when properly positioned.

[0054] Figure 10 is a three-dimensional perspective diagram illustrating an optical aperture 820 according to yet another embodiment. Figure 10 An embodiment is roughly similar to Figure 8 The embodiment of the optical aperture 820 shown, and similarly has a generally conical reflective front surface 822. However, Figure 10 The embodiment has a stepped opening 1024 instead of a circular opening 824. In operation, Figure 10 The embodiment of the optical aperture 820 shown above may provide Figure 6 The illustrated embodiment of the reflector 220 provides at least some of the benefits described above. In particular, it can be noted that the two stepped recesses 602 of the reflectors 2201, 2202 form an effective opening similar in shape to the opening 1024 when properly positioned.

[0055] Figure 11is a schematic diagram illustrating an optical assembly 1100 that can be used for illumination optical device 130 according to an embodiment. Optical assembly 1100 includes a first optical group 1110, an integrator rod 1120, and a second optical group 1130. Integrator rod 1120 can include a substantially reflective surface within its interior such that light entering the integrator rod through input end facet 1118 of the integrator rod is internally reflected and re-reflected until the light exits the integrator rod at output end facet 1122 of the integrator rod. First optical group 1110 can include various optical elements, such as lenses, filters, and / or polarizers, that can perform appropriate optical operations on second light 116 before applying the resulting light to input end facet 1118 of integrator rod 1120. Second optical group 1130 can similarly include various optical elements, such as lenses, filters, and / or polarizers, that can perform appropriate optical operations on light exiting output end facet 1122 of integrator rod 1120 before applying the resulting light to light valve 134 (see also FIG. 1 ). Figure 1 As already indicated above, the input end facet 1118 and the output end facet 1122 can have various shapes, including a rectangular shape in some embodiments.

[0056] In various embodiments, the optomechanical assemblies 200, 800, and optical assembly 1100 can be configured to provide good brightness uniformity across the spatial optical modulator 142 and also across the screen 150 at different light attenuation levels of the dimmer 114. For example, the brightness across the spatial optical modulator 142 can be symmetrically distributed about the geometric center of the modulating surface without exhibiting abrupt changes. For a rectangular modulating surface, the percentage of brightness values ​​at its edges and corners to the brightness value at its center can be in a range of about 75% to about 90%, or in a range of about 80% to about 90%, for different light attenuation levels of the dimmer 114. Further, in some embodiments, when unmodulated light is projected onto the screen 150, the percentage of brightness values ​​at the edges and corners of the screen 150 to the brightness value at its center can be in a range of about 75% to about 90%, or in a range of about 80% to about 90%, for different light attenuation levels of the dimmer 114.

[0057] Figure 12 1 is a schematic diagram illustrating an optical model 1200 of the dimmer 114 according to an embodiment. The optical model 1200 represents an optical component 200 ( Figure 2 ) of the dimmer 114, wherein each of the reflectors 2201, 2202 is Figure 5 A corresponding example of the reflector 220 is shown. Figure 5In the illustrated configuration, the depth of the insertion of the reflectors 2201 and 2202 into the light beam 202 is relatively large, resulting in a relatively strong attenuation of the light power of the light beam. The resulting attenuated light beam is labeled 1202. The reflective surfaces 3201 and 3202 of the reflectors 2201 and 2202 reflect the truncated portion of the light beam 202 toward the light collector. The corresponding reflected light is labeled 1204.

[0058] According to the optical model 1200, the light modulator 114 includes a relay optical device, which includes a first relay lens 1210 and a second relay lens 1220. Reflectors 2201 and 2202 are located in the relay space between the first relay lens 1210 and the second relay lens 1220. The first relay lens 1210 operates to collimate the first light 112 to form a collimated light beam 202. The second relay lens 1210 and possible additional optical elements ( Figure 1 ) processes the attenuated light beam 1202 to produce the second light 116.

[0059] Figure 13 1 is a schematic diagram illustrating an optical model 1300 of a dimmer 114 according to another embodiment. The optical model 1300 represents an optical component 800 ( Figure 8 ) is an embodiment of a dimmer 114. According to the optical model 1300, the dimmer 114 includes lenses 1210, 1310, and 1320. As already indicated above, the first lens 1210 operates to collimate the first light 112 to form the collimated light beam 202. The second lens 1310 focuses the collimated light beam 202 at its focal point F. The circular opening 824 of the optical aperture 820 is located at the focal point F, wherein the neck of the focused light beam 1302 fits into the circular opening, thereby allowing the corresponding light to pass substantially unattenuated toward the third lens 1320. The third lens 1320 operates to partially collimate the transmitted light beam 1304 for further processing downstream (e.g., in the illumination optics 130).

[0060] Figure 14 is a schematic diagram illustrating an optical model 1300, wherein the optical aperture 820 is Figure 13 The position shown is translated by a distance D. In this position, the circular opening 824 of the optical aperture 820 is smaller than the diameter of the focused beam 1302 and does not allow all of the light to pass through it, causing the conical reflective front surface 822 of the optical aperture to reflect a truncated portion of the focused beam toward the light collector. The corresponding reflected light ray is labeled 1404. As a result, Figure 14 The optical power ratio of the transmitted beam 1304 Figure 13 The optical power of the transmitted light beam 1304 is low.

[0061] Figure 15FIG2 graphically illustrates the temporal dimming characteristics of the optomechanical assembly 200 according to an embodiment. More specifically, Figure 15 The diagram illustrates an example of optomechanical assembly 200 operating to change the optical power of second light 116 from a level of approximately 100% to a level of approximately 10%. In this example, the transition time between the stable 100% level and the stable 10% level is approximately 15.5 ms. In comparison, at a standard film frame rate of 24 fps, the duration of a single frame of a video stream is approximately 41.7 ms. Thus, optomechanical assembly 200 advantageously enables global dimming of second light 116 on a timescale shorter than 40% of the frame duration corresponding to the standard film frame rate. Optomechanical assembly 200 also advantageously enables global dimming of second light 116 on a timescale shorter than the frame duration at film frame rates of 30 fps or 50 fps.

[0062] Figure 16 The time release dimming characteristics of the optomechanical assembly 200 according to an embodiment are graphically illustrated. More specifically, Figure 16 The diagram illustrates an example of optomechanical assembly 200 operating to change the optical power of second light 116 from a 10% level to a 100% level. In this example, the transition time between the stable 10% level and the stable 100% level is approximately 6.7 ms. Thus, optomechanical assembly 200 advantageously enables global de-dimming of second light 116 on a timescale shorter than approximately 20% of the frame duration corresponding to a standard film frame rate. Optomechanical assembly 200 also advantageously enables global de-dimming of second light 116 on a timescale shorter than the frame duration at a film frame rate of 30 fps or 50 fps.

[0063] Consumer and commercial projectors can employ global dimming. In the case of cinema projectors, film studios typically need to control the final (projected) image parameters so that the projected image matches the intent of the colorist and other artists who created the image. Dimming algorithms that can change image parameters with unpredictable results are generally unacceptable to film studios. To address this issue, image stream metadata can be used to instruct the dimming algorithm so that the image on the screen meets the expectations. Colorists can participate in the generation of such metadata when grading / mastering content. Alternatively or in addition, automatic display mapping can be used to regrade image content according to a preselected fixed algorithm approved by the colorist. The latter approach can be particularly useful when regrading between high dynamic range (HDR) content and standard dynamic range (SDR) content. In some cases, automatic display mapping can be used in combination with manual adjustments to the content ("trimming") to meet the colorist's requirements. The use of metadata in system 100 can further facilitate the application of global dimming in cinema projection.

[0064] According to the example embodiments disclosed above, for example in the Summary section and / or with reference to Figures 1 to 16 Any one or any combination of some or all of the , provides a device comprising: an optomechanical attenuator (e.g., Figure 1 114), the optomechanical attenuator being configured to variably attenuate source light directed to its optical output; an optical modulator (e.g., Figure 1 134, 142 in one or both), the optical modulator is configured to generate spatially modulated light by modulating illumination light received from the optical output, the modulation being based on image data representing a sequence of image frames (e.g., Figure 1 168), each image frame having a constant duration; and a first optical device (e.g., Figure 1 130, 146), the first optical device is configured to optically couple the optical output to the optical modulator and is further configured to project spatially modulated light to project the sequence of image frames; and wherein the optomechanical attenuator is configured to change the optical power of the illumination light from a first fixed power level to a second fixed power level within a time shorter than a constant duration.

[0065] In some embodiments of the foregoing apparatus, the difference between the first fixed power level and the second fixed power level is at least 90% of the unattenuated optical power at the optical output.

[0066] In some embodiments of any of the foregoing apparatus, the first fixed power level is greater than the second fixed power level (e.g., Figure 15 ).

[0067] In some embodiments of any of the above apparatus, the optomechanical attenuator includes a motion actuator and one or more surfaces movable by the motion actuator to attenuate a variable portion of the source light.

[0068] In some embodiments of any of the above-described devices, the optomechanical attenuator and the first optical device are configured to uniformly illuminate the optical modulator with illumination light such that a relative brightness in all geometrically modulated portions of the optical modulator, expressed as a percentage of the brightness in an intermediate geometrically modulated portion of the optical modulator, is greater than 75% at both the first fixed power level and the second fixed power level.

[0069] In some embodiments of any of the foregoing apparatus, the first fixed power level is lower than the second fixed power level (e.g., Figure 16 ).

[0070] In some embodiments of any of the apparatus above, the constant duration is approximately 20 ms or approximately 40 ms.

[0071] In some embodiments of any of the above apparatuses, the optomechanical attenuator includes a motion actuator (e.g., Figure 2 or Figure 8 230) and one or more reflective surfaces (e.g., Figure 2 3201, 3202; Figure 8 822 in), the one or more surfaces are capable of being moved by a motion actuator to reflect a variable portion of the source light away from the optical modulator.

[0072] In some embodiments of any of the foregoing apparatus, the motion actuator comprises a linear voice coil actuator.

[0073] In some embodiments of any of the above apparatuses, the optomechanical attenuator further comprises a holder (eg, Figure 2 210), the holder is rotatably connected to a fixed base (e.g., Figure 2 201), at least one reflector (eg, Figures 4 to 7 220), the at least one reflector having the one or more reflective surfaces; and wherein the motion actuator is configured to rotate the holder relative to the fixed base to change the portion.

[0074] In some embodiments of any of the above apparatuses, the optomechanical attenuator further comprises an optical bracket (e.g., Figure 8 810 in the figure), the optical bracket can be arranged along a fixed optical track (e.g., Figure 8 812) translation, the optical bracket is mounted with an optical aperture (e.g., Figures 8 to 10 820), the optical aperture having the one or more reflective surfaces; and wherein the motion actuator is configured to translate the optical carriage along the fixed optical track to change the portion.

[0075] In some embodiments of any of the foregoing apparatuses, the one or more reflective surfaces include an approximately conical reflective surface (e.g., Figures 8 to 10 822 in ).

[0076] In some embodiments of any of the foregoing devices, one of the one or more reflective surfaces has an opening therein that is shaped like a tapered slot (e.g., Figure 4 402); two or more circles having different respective diameters (e.g., Figure 7 708, 710 in ); diamond (e.g., Figure 9 924 in ); or stepped polygons (e.g., Figure 10 1024 in ).

[0077] In some embodiments of any of the foregoing devices, one of the one or more reflective surfaces has an edge cutout therein that is shaped like a V-shaped notch (e.g., Figure 5 502 in); stepped notch (e.g., Figure 6 602); or a semicircular notch (e.g., Figure 7 706 in the ).

[0078] In some embodiments of any of the above apparatuses, the apparatus further comprises a second optical device (e.g., Figure 12 1210), the second optical device is configured to generate a collimated light beam (e.g., Figure 2 、 Figure 12 202 in); and wherein the one or more reflective surfaces are configured to reflect a portion (e.g., Figure 3 3021, 3022) collimated light beam.

[0079] In some embodiments of any of the above apparatuses, the apparatus further comprises a second optical device (e.g., Figure 13 1210, 1310), the second optical device is configured to generate a focused light beam by focusing the source light (e.g., Figure 13 1302); and wherein the one or more reflective surfaces are configured to reflect a portion (e.g., Figure 14 1404) focuses the beam.

[0080] In some embodiments of any of the above apparatus, the apparatus further comprises: wherein the first optical device comprises an integrating rod (e.g., Figure 11 1120 in), the output end face of the integrating rod (e.g., Figure 11 1122 in) is configured to direct the illumination light toward the optical modulator; and wherein the shape of the one or more reflective surfaces (e.g., as Figures 4 to 10 (as shown in one of the figures) is arranged so as to keep the spatial uniformity of the illumination light within the output end facet approximately the same at the first fixed power level and at the second fixed power level.

[0081] In some embodiments of any of the foregoing apparatus, the projector system is configured such that the spatial uniformity substantially complies with the SMPTE 431-1-2006 standard.

[0082] In some embodiments of any of the foregoing devices, the one or more reflective surfaces have a reflectivity of at least 90% (or 95%, or 98%, or 99%) for the source light.

[0083] In some embodiments of any of the above apparatuses, the apparatus further comprises: a photodetector (e.g., Figure 1 120 in the embodiment of the present invention), the photodetector is configured to generate an electrical signal (e.g., Figure 1 122); and an electronic controller (e.g., Figure 1 170), the electronic controller is configured to control based on the electrical signal (e.g., via Figure 1 174) Attenuation of source light in an optomechanical attenuator.

[0084] In some embodiments of any of the above devices, the electronic controller is further configured to control (e.g., via Figure 1 174, 178) optical modulator.

[0085] According to another exemplary embodiment disclosed above, for example in the Summary of the Invention section and / or with reference to Figures 1 to 16 Any one or any combination of some or all of the above provides a method for variably attenuating the signal applied to a projector system (e.g., Figure 1 100) of an optical modulator (e.g., Figure 1 The method of illuminating light by one or both of 134, 142 in the embodiment of the present invention, the optical modulator is configured to transmit the illumination light according to the image data representing the sequence of image frames (for example, Figure 1 168) modulates the illumination light to generate spatially modulated light, each image frame having a constant duration, the method comprising the steps of: (A) moving one or more reflective surfaces (e.g., Figure 2 3201, 3202; Figure 8 822 in ) to reflect a variable portion of the source light away from the optical modulator and direct illumination light to the optical modulator, the illumination light including the remaining portion of the source light, the movement being performed using a motion actuator (e.g., Figure 2 or Figure 8 and (B) operating the motion actuator to change the optical power of the illumination light from a first fixed power level to a second fixed power level within a time shorter than the constant duration.

[0086] According to another exemplary embodiment disclosed above, for example in the Summary of the Invention section and / or with reference to Figures 1 to 16 Any one or any combination of some or all of the foregoing provides a non-transitory machine-readable medium storing instructions that, when executed by a processor of a projector system, cause the projector system to perform operations including the above-described method.

[0087] According to another exemplary embodiment disclosed above, for example in the Summary of the Invention section and / or with reference to Figures 1 to 16Any one or any combination of some or all of the , providing a projector system comprising: an optomechanical attenuator (e.g., Figure 1 114), the optomechanical attenuator being configured to variably attenuate source light directed to its optical output; an optical modulator (e.g., Figure 1 142), the optical modulator being configured to generate spatially modulated light by modulating illumination light received from the optical output, the modulation being performed according to image data; and a first optical device (e.g., Figure 1 130), the first optical device is configured to optically couple the optical output to the optical modulator; wherein the optomechanical attenuator is configured to change the optical power of the illumination light from a first fixed power level to a second fixed power level; and wherein the optomechanical attenuator and the first optical device are configured to uniformly illuminate the optical modulator with the illumination light such that the relative brightness in all geometrically modulated portions of the optical modulator, expressed as a percentage of the brightness in an intermediate geometrically modulated portion of the optical modulator, is greater than 75% at both the first fixed power level and the second fixed power level. For example, the geometrically modulated portions (e.g., pixel elements) of the optical modulator can be arranged in a rectangular array. The intermediate geometrically modulated portion can be located near the intersection of two diagonals of a rectangle corresponding to (outlining) the rectangular array. Other geometrically modulated portions can include pixel elements located near the sides of the rectangle, in and near the corners of the rectangle, between the geometric center and the perimeter of the rectangle, etc. As used herein, the term "all geometrically modulated portions" generally and primarily refers only to pixel elements that are configured and used to generate an image based on image data (168).

[0088] In some embodiments of the above projector system, the system further includes a second optical device (e.g., Figure 1 146), the second optical device is configured to project spatially modulated light onto a screen; and wherein the optomechanical attenuator and the first optical device and the second optical device are configured so as to illuminate the screen uniformly so that for unmodulated light, the relative brightness in all geometric parts of the screen expressed as a percentage of the brightness at the geometric center of the screen is higher than 75% at both the first fixed power level and the second fixed power level.

[0089] All terms used in the claims are intended to be given their broadest reasonable constructions and ordinary meanings as understood by those skilled in the art unless an explicit indication to the contrary appears herein. In particular, use of singular articles such as "a," "the," and "said" should be understood to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary.

[0090] The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Additionally, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of linking the disclosure together as a whole. The disclosed approach should not be interpreted as reflecting an intention that the claimed embodiments incorporate more features than are expressly recited in each claim. On the contrary, as reflected in the appended claims, the inventive subject matter lies in less than all the features of a single disclosed embodiment. Accordingly, the appended claims are hereby incorporated into the Detailed Description, with each claim standing on its own as separately claimed subject matter.

[0091] Although the present disclosure includes references to illustrative embodiments, this description is not intended to be construed as limiting. Various modifications of the described embodiments, as well as other embodiments within the scope of the present disclosure, that are apparent to those skilled in the art to which the present disclosure relates are deemed to be within the principles and scope of the present disclosure, for example, as expressed in the claims.

[0092] For the purposes of this specification, a MEMS device is a device having two or more parts adapted to move relative to one another, where the motion is based on any suitable interaction or combination of interactions, such as mechanical, thermal, electrical, magnetic, optical, and / or chemical interactions. MEMS devices are manufactured using micro or smaller manufacturing techniques (including nanofabrication techniques), which may include, but are not limited to: (1) self-assembly techniques, such as using self-assembled monolayers, chemical coatings with high affinity for the desired chemical species, and creating and saturating dangling chemical bonds; and (2) wafer / material processing techniques, such as using photolithography, chemical vapor deposition, patterning and selective etching of materials, and treating, shaping, plating, and texturing surfaces. The scale / size of certain elements in a MEMS device may allow quantum effects to be manifested. Examples of MEMS devices include, but are not limited to, nanoelectromechanical systems (NEMS) devices, micro-opto-electromechanical systems (MOEMS) devices, micromachines, microsystems, and devices produced using microsystems technology or microsystems integration.

[0093] Although the present disclosure has been described in the context of implementation as a MEMS device, in theory, some embodiments may be implemented at any scale, including scales larger than a microscopic scale.

[0094] Unless expressly stated otherwise, each numerical value and range should be interpreted as being approximate as if the value or range were preceded by the word "about" or "approximately."

[0095] The use of figure numbers and / or reference numerals in the claims is intended to identify one or more possible embodiments of the claimed subject matter to facilitate interpretation of the claims. Such use should not be construed as necessarily limiting the scope of the claims to the embodiments shown in the corresponding figures.

[0096] Although elements in the method claims (if any) are recited in a specific order with corresponding labels, these elements are not necessarily intended to be implemented in that specific order unless the claim recitation otherwise implies a specific order for implementing some or all of these elements.

[0097] Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present disclosure. The appearances of the phrase "in one embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. The same applies to the term "implementation."

[0098] Unless otherwise specified herein, the use of ordinal adjectives "first," "second," "third," etc. to refer to an object among a plurality of similar objects indicates merely that different instances of such similar objects are being referred to and is not intended to imply that the similar objects so referred to are necessarily in a corresponding order or sequence, whether temporally, spatially, in ranking, or in any other manner.

[0099] Unless otherwise specified herein, in addition to its plain meaning, the conjunction "if" may also or alternatively be interpreted to mean "when" or "at the time" or "in response to determining" or "in response to detecting," which interpretation may depend on the specific context. For example, the phrase "if it is determined that" or "if [stated condition] is detected" may be interpreted to mean "upon determining that" or "in response to determining that" or "upon detecting [stated condition or event]" or "in response to detecting [stated condition or event]."

[0100] Also for the purposes of this description, the terms "couple," "coupling," "coupled," "connect," "connecting," or "connected" refer to any means known in the art or later developed that allow energy to be transferred between two or more elements, and the insertion of one or more additional elements is contemplated, although not required. In contrast, the terms "directly coupled," "directly connected," etc., imply the absence of such additional elements.

[0101] As used herein with respect to components and standards, the term "compliant" means that the component communicates with other components in a manner specified in whole or in part by the standard and will be recognized by other components as sufficiently capable of communicating with other components in the manner specified by the standard. A compliant component is not required to operate internally in the manner specified by the standard.

[0102] The functions of the various elements shown in the figure, including any functional blocks marked as "processors" and / or "controllers", can be provided by using dedicated hardware and hardware capable of executing software associated with appropriate software. When provided by a processor, the function can be provided by a single dedicated processor, by a single shared processor, or by multiple separate processors (some of which can be shared). In addition, the explicit use of the term "processor" or "controller" should not be interpreted as referring exclusively to hardware capable of executing software, and can implicitly include but are not limited to digital signal processor (DSP) hardware, network processors, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), read-only memories (ROMs), random access memories (RAMs), and non-volatile memories for storing software. Other traditional and / or customized hardware may also be included. Similarly, any switches shown in the figure are only conceptual. Their functions can be performed by the operation of program logic, by dedicated logic, by the interaction of program control and dedicated logic, or even manually, and specific techniques can be selected by the implementer, as more specifically understood from the context.

[0103] As used in this application, the terms "circuit" and "circuitry" may refer to one or more or all of the following: (a) a pure hardware circuit implementation (such as an implementation in a pure analog circuit and / or digital circuit); (b) a combination of hardware circuitry and software, such as (if applicable): (i) a combination of analog hardware circuitry and / or digital hardware circuitry with software / firmware, and (ii) any portion of a hardware processor with software (including a digital signal processor), software, and memory that work together to enable a device (such as a mobile phone or server, etc.) to perform various functions; and (c) a hardware circuitry and / or processor, such as a microprocessor or a portion of a microprocessor, that requires software (e.g., firmware) to operate, but may not be present when the software is not required for operation. This definition of circuitry applies to all uses of the term in this application (including all claims). As a further example, as used in this application, the term "circuitry" also covers implementations of only one hardware circuitry or one processor (or multiple processors) or a portion of a hardware circuitry or processor and its accompanying software and / or firmware. The term "circuitry" also covers, for example, a baseband integrated circuit or a processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or networking device, if applicable to a particular claim element.

[0104] Those skilled in the art will recognize that any block diagrams herein represent conceptual views of illustrative circuitry embodying the principles of the present disclosure. Similarly, it will be recognized that any flow charts, flow diagrams, state transition diagrams, pseudocode, etc. represent various processes that can be substantially represented in a computer-readable medium and thus executed by a computer or processor, whether or not the computer or processor is explicitly shown.

[0105] The Summary of the Invention in this specification is intended to introduce some example embodiments, and additional embodiments are described in the Detailed Description and / or with reference to one or more of the accompanying drawings. The Summary is not intended to identify essential elements or features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

Claims

1. A projector system, comprising: an optomechanical attenuator configured to variably attenuate source light directed to its optical output; an optical modulator configured to generate spatially modulated light by modulating illumination light received from the optical output, the modulation being performed in accordance with image data representing a sequence of image frames, each image frame having a constant duration; as well as first optics configured to optically couple the optical output to the optical modulator, and the first optics further configured to project the spatially modulated light to project the sequence of image frames; as well as The optomechanical attenuator is configured to change the optical power of the illumination light from a first fixed power level to a second fixed power level within a time shorter than the constant duration.

2. The projector system of claim 1, wherein: The difference between the first fixed power level and the second fixed power level is at least 90% of the unattenuated optical power at the optical output.

3. The projector system of claim 1, wherein: The optomechanical attenuator includes a motion actuator and one or more surfaces movable by the motion actuator to attenuate a variable portion of the source light.

4. The projector system of claim 1, wherein: The optomechanical attenuator and the first optical device are configured to cause the illumination light to uniformly illuminate the optical modulator so that the relative brightness in all geometric modulation parts of the optical modulator, expressed as a percentage of the brightness in an intermediate geometric modulation part of the optical modulator, is higher than 75% at both the first fixed power level and the second fixed power level.

5. The projector system of claim 1, wherein: The constant duration is about 20 ms or about 40 ms.

6. The projector system of claim 1, wherein: The optomechanical attenuator includes a motion actuator and one or more reflective surfaces movable by the motion actuator to reflect a variable portion of the source light away from the optical modulator.

7. The projector system of claim 6, wherein: The motion actuator includes a linear actuator.

8. The projector system according to claim 6, in, The optomechanical attenuator further comprises a holder, the holder being rotatably connected to a fixed base, at least one reflector being mounted on the holder, the at least one reflector having the one or more reflective surfaces; as well as Wherein, the motion actuator is configured to rotate the holder relative to the fixed base to change the variable portion.

9. The projector system according to claim 6, in, The optomechanical attenuator further comprises an optical bracket, the optical bracket being capable of translating along a fixed optical track, an optical aperture being mounted on the optical bracket, the optical aperture having the one or more reflective surfaces; as well as Wherein, the motion actuator is configured to translate the optical bracket along the fixed optical track to change the variable portion.

10. The projector system of claim 6, wherein: The one or more reflective surfaces include an approximately conical reflective surface.

11. The projector system of claim 6, wherein: One of the one or more reflective surfaces has an opening therein having the following shape: Conical groove; two or more circles having different respective diameters; rhombus; or Stepped polygon.

12. The projector system of claim 6, wherein: One of the one or more reflective surfaces has an edge cutout in the shape of: V-shaped notch; a stepped notch; or Semicircular notch.

13. The projector system of claim 6, further comprising a second optical device configured to generate a collimated light beam by collimating the source light; and in, The one or more reflective surfaces are configured to reflect a portion of the collimated light beam.

14. The projector system of claim 6, further comprising a second optical device configured to generate a focused light beam by focusing the source light; and in, The one or more reflective surfaces are configured to reflect a portion of the focused light beam.

15. The projector system according to claim 6, in, The first optical device includes an integrator rod optically located between the optical output and the optical modulator, the output end facet of the integrator rod being configured to direct the illumination light toward the optical modulator; as well as The shape of the one or more reflective surfaces is configured to maintain approximately the same spatial uniformity of the illumination light within the output end facet at the first fixed power level and at the second fixed power level.

16. The projector system of claim 6, wherein: The one or more reflective surfaces have a reflectivity of at least 90% for the source light.

17. The projector system of claim 1, further comprising: a photodetector configured to generate an electrical signal in response to a change in the optical power; as well as An electronic controller is configured to control attenuation of the source light in the optomechanical attenuator based on the electrical signal.

18. The projector system of claim 17, wherein: The electronic controller is also configured to control the optical modulator based on the image data.

19. A method of variably attenuating illumination light applied to an optical modulator of a projector system, the optical modulator being configured to generate spatially modulated light by modulating the illumination light according to image data representing a sequence of image frames, each image frame having a constant duration, the method comprising: moving one or more reflective surfaces to reflect a variable portion of the source light away from the optical modulator and direct the illumination light toward the optical modulator, the illumination light comprising a remaining portion of the source light, the moving being performed using a motion actuator; as well as The motion actuator is operated to change the optical power of the illumination light from a first fixed power level to a second fixed power level within a time shorter than the constant duration.

20. A non-transitory computer readable medium storing instructions that, when executed by a processor of a projector system, cause the projector system to perform operations including the method of claim 19.

21. A projector system, comprising: an optomechanical attenuator configured to variably attenuate source light directed to its optical output; an optical modulator configured to generate spatially modulated light by modulating illumination light received from the optical output, the modulation being performed in accordance with image data; as well as a first optic configured to optically couple the optical output to the optical modulator; wherein the optomechanical attenuator is configured to change the optical power of the illumination light from a first fixed power level to a second fixed power level; and wherein the optomechanical attenuator and the first optical device are configured to cause the illumination light to uniformly illuminate the optical modulator so that a relative brightness in a geometric modulation portion of the optical modulator expressed as a percentage of a brightness in an intermediate geometric modulation portion of the optical modulator is higher than 75% at both the first fixed power level and the second fixed power level.

22. The projector system further comprising a second optical device configured to project the spatially modulated light onto a screen; and in, The optomechanical attenuator and the first and second optical devices are configured to illuminate the screen uniformly so that for unmodulated light, the relative brightness in all geometric parts of the unmodulated light projected onto the screen, expressed as a percentage of the brightness at the geometric center of the unmodulated light projected onto the screen, is higher than 75% at both the first fixed power level and the second fixed power level.

Images