Patent ID: 12228886

DETAILED DESCRIPTION

Throughout the following description, specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.

As utilized herein, terms “component,” “system,” “interface,” “controller” and the like are intended to refer to a computer-related entity, either hardware, software (e.g., in execution), and/or firmware. For example, any of these terms can be a process running on a processor, a processor, an object, an executable, a program, and/or a computer. By way of illustration, both an application running on a server and the server can be a component and/or controller. One or more components/controllers can reside within a process and a component/controller can be localized on one computer and/or distributed between two or more computers.

The claimed subject matter is described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the subject innovation. It may be evident, however, that the claimed subject matter may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing the subject innovation.

Introduction

Current dual/multi-modulator projector display systems comprise two or more modulation stages where illuminating light is passed in order to form a final projected image upon a projection screen. For the most part, such modulation stages comprise mechanical beam steering architectures—e.g., DMD, MEMS or some mechanically actuated set of mirrors.FIG.1depicts an embodiment of a dual/multi-modulator projector display system that employs mechanical beam steering modulators.

Projector system100employs a light source102that supplies the projector system with a desired illumination such that a final projected image will be sufficiently bright for the intended viewers of the projected image. Light source102may comprise any suitable light source possible—including, but not limited to: Xenon lamp, laser(s), LEDs, coherent light source, partially coherent light sources.

Light104may illuminate a first modulator106that may, in turn, illuminate a second modulator110, via a set of optional optical components108. Light from second modulator110may be projected by a projection lens112(or other suitable optical components) to form a final projected image upon a screen114. First and second modulators may be controlled by a controller116—which may receive input image and/or video data. Controller116may perform certain image processing algorithms, gamut mapping algorithms or other such suitable processing upon the input image/video data and output control/data signals to first and second modulators in order to achieve a desired final projected image114. In addition, in some projector systems, it may be possible, depending on the light source, to modulate light source102(control line not shown) in order to achieve additional control of the image quality of the final projected image.

First modulator106and second modulator110may comprise a set of mechanically moveable mirrors106aand110a,respectively—e.g., as may form a DMD or MEMS array. These mirrors may be moved or otherwise actuated according to control signals received from the controller116. Light may be steered by the first and second modulators as desired by such mechanical actuation.

Dual modulation projector and display systems have been described in commonly-owned patents and patent applications, including:

(1) U.S. Pat. No. 8,125,702 to Ward et al., issued on Feb. 28, 2012 and entitled “SERIAL MODULATION DISPLAY HAVING BINARY LIGHT MODULATION STAGE”;

(2) U.S. Patent Application 20130148037 to Whitehead et al., published on Jun. 13, 2013 and entitled “PROJECTION DISPLAYS”;

(3) U.S. Patent Application 20110227900 to Wallener, published on Sep. 22, 2011 and entitled “CUSTOM PSFs USING CLUSTERED LIGHT SOURCES”;

(4) U.S. Patent Application 20130106923 to Shields et al., published on May 2, 2013 and entitled “SYSTEMS AND METHODS FOR ACCURATELY REPRESENTING HIGH CONTRAST IMAGERY ON HIGH DYNAMIC RANGE DISPLAY SYSTEMS”;

(5) U.S. Patent Application 20110279749 to Erinjippurath et al., published on Nov. 17, 2011 and entitled “HIGH DYNAMIC RANGE DISPLAYS USING FILTERLESS LCD(S) FOR INCREASING CONTRAST AND RESOLUTION” and (6) U.S. Patent Application 20120133689 to Kwong, published on May 31, 2012 and entitled “REFLECTORS WITH SPATIALLY VARYING REFLECTANCE/ABSORPTION GRADIENTS FOR COLOR AND LUMINANCE COMPENSATION”.

all of which are hereby incorporated by reference in their entirety.

In addition, there are references that disclose the use of holographic projection and the Fourier nature of the illumination to create projector display system such as:

(1) U.S. Patent Application 20140043352 to Damberg et al., published on Feb. 13, 2014 and entitled “HIGH LUMINANCE PROJECTION DISPLAYS AND ASSOCIATED METHODS”;

(2) U.S. Patent Application 20100157399 to Kroll et al., published on Jun. 24, 2010 and entitled “HOLOGRAPHIC DISPLAY”;

(3) U.S. Patent Application 20100046050 to Kroll et al., published on Feb. 25, 2010 and entitled “COMPACT HOLOGRAPHIC DISPLAY DEVICE”;

(4) U.S. Patent Application 20120008181 Cable et al., published on Jan. 12, 2012 and entitled “HOLOGRAPHIC IMAGE DISPLAY SYSTEMS”;

(5) U.S. Patent Application 20120188620 to De Echaniz et al., published on Jul. 26, 2012 and entitled “LASER IMAGE PROJECTION SYSTEM APPLICABLE TO THE MARKING OF OBJECTS AND METHOD FOR GENERATING HOLOGRAMS”

all of which are hereby incorporated by reference in their entirety.

Non-Mechanical Beam Steering Embodiments

Non-mechanical beam steering modulators, as opposed to mechanical modulators, may not have need of MEMS devices but instead leverage more common imaging devices such as LCD modulators. In particular, it may be desirable to have at least one or more modulator stages that do not comprise a moveable arrangement of mirrors.

FIG.2depicts one embodiment of a suitable projector system (200) comprising at least one non-mechanical beam steering module. Projector system200comprises a light source202that may comprise laser(s), LEDs, coherent or partially coherent light source(s)—e.g., where the light may be of the same wavelength and phase. It suffices that, whatever light is produced from source202, that light is able to sufficiently interact with a holographic image to affect the beam of the light.

Light from source202illuminates first holographic modulator204. First modulator204may comprise an LCD panel or any other module that is capable of forming a holographic image thereon and interacting with the light from source202. First modulator204may receive its holographic image from controller201—which, in turn, may either derive holographic data and/or control signals from input image data—or may receive holographic data from the input data stream that may accompany the input image data, if needed. As will be discussed further herein, holographic data may be derived through an iterative process that may reside inside the controller or may be sent to the controller from an outside process.

The light passing through the first modulator204may illuminate a lens (and/or optical subsystem)206. Lens206may affect a Fourier transformation of the illumination such that desired beam steering may be affected onto a second modulator208. The light from lens206may be beam steered in a desired spatio-temporal fashion that allows the projector system to perform a highlight illumination of any desired feature within the projected image. For example, if there is a desired specular reflection (or any other suitable feature with higher luminance that other features) within an finally projected image, then non-mechanical beam steering employing holographic image processing is capable of steering the beam in a timely fashion to provide additional illumination to the highlight features in the finally projected image.

Second modulator208may be any known modulator—e.g., DMD, MEMS and/or any set of moveable mirrors, such that the light modulated by modulator208(according to control signals from controller201) may be processed by projection lens210and finally projected onto screen212for viewing.

One Holographic Data Processing Embodiment

As mentioned above, the holographic data may be derived from input image data in on-board or off-line process.FIG.3depicts one embodiment of an iterative processing system300(called the Gerchberg-Saxton algorithm, a description of which may be found at http://en.wikipedia.org/wiki/Gerchberg%E2%80%93Saxton_algorithm) by which holographic data may be derived from input image data.

Suppose input image302is the desired image to be modeled and/or rendered by a display system. The holographic processing system300would input image data302into a circuit and would be placed through an inverse Fourier Transform process306in order to create a holographic representation310of the input image302.

As may be seen, holographic image310may appear to a human viewer as a jumbled and perhaps disordered image, it in fact captures the information content of the input image—but in the frequency domain. This frequency information (e.g., Fourier coefficients) may be input into a processing block314—together with amplitude model of the light from source202(312). The output of processing block314may be taken into a Fourier Transform process316producing the resulting320which is an approximation of302. The difference between is302and320is calculated in processing block304and used to refine the image sent to306to reiterate the process until the error between320and302is within tolerance. Once this is achieved310can be used as the holographic data applied to204.

As mentioned, this process may be performed in real-time at the controller201based on input image data—or it may be supplied to the controller via some off-line process.

FIG.4is one embodiment of a hologram image generator400, as made in accordance with the principles of the present application. Generator400may comprise a laser light source402(or some suitable coherent or partially coherent light source). The light may transmit through one or more optional polarizers404to adjust the intensity of the light from source402. It should be noted that this may not be a requirement of a generic system; but may provide a sort of global dimming feature. The light may be spread out accordingly with optical element406. This light may then pass through a half-wave plate408to polarize the light as desired to be used by the polarizing beam splitter410. Splitter410allows the polarized light from408to reach Spatial Light Modulator (SLM)412and then redirects the light reflected off412to414. SLM412phase shifts the light from408according to the holographic data applied to it. Lens414performs an inverse Fourier transform on the phase shifted light producing the desired image at image capture416. Image capture416is shown as a camera but may also be a subsequent modulator in a multi-modulation system.

Rotatable Polarization Plate Embodiment for Beam Steering

Apart from holographic means of beam steering, there are other non-mechanical beam steering modules that may be suitable in a dual/multi-modulation projection display system.

There are described in the following reference the use of a rotatable polarizer as a means to affect beam steering:(1) U.S. Patent Application 20130265554 to BARANEC et al., published on Oct. 10, 2013 and entitled “COMPACT LASER PROJECTION SYSTEMS AND METHODS”‘; and(2) U.S. Patent Application 20120188467 to Escuti et al., published on Jul. 26, 2012 and entitled “BEAM STEERING DEVICES INCLUDING STACKED LIQUID CRYSTAL POLARIZATION GRATINGS AND RELATED METHODS OF OPERATION”all of which are hereby incorporated by reference in their entirety.

FIG.5Adepicts one such embodiment that may employ a polarization plate (e.g., either fixed or rotatable) that affects desired beam steering as discussed herein. In one embodiment, projection display system500may comprise a laser (or some coherent/partially coherent) light source502, polarization recovery optics (PRO)504, rotatable polarizer506, beam forming/expanding lenses508, integrating rod (or alternatively, a beam expander)510, partial beam splitter512a,mirror514, MEMS array516, lens518, stack rod array520, partial beam splitter512b,and DMD array522.

Array522may serve as a second and/or additional modulator to provide additional light processing for finally projection of a final image (and possibly, through additional optical elements and/or components). The components from502to512amay provide a light path directly to512b—e.g., as a main beam providing substantially all of the desired illumination for the finally projected image. However, depending on polarization of the light from integrating rod(s)510, a second light path (e.g., down to element514) may be employed, e.g., for a highlight illumination path that eventually may be recombined with the main beam at512b—e.g., to provide a desired amount and placement of highlight illumination.

FIG.5Adepicts using polarization to control the amount of uniform light directly reaching the next stage of modulation and the amount of light reaching the highlights modulator which is then sorted into discrete bins (e.g., as seen as the segments comprising520) and that resulting non-uniform light field may be applied to the next stage of modulation. As may also be seen, MEMS device516may be used to sort the light reaching it into discrete segments in520. In another embodiment, it may be possible to replace516,518, and520with elements410,412and414—e.g., in the case of non-mechanical beam steering.

In operation, laser light from502illuminates the optical subsystem504and506. The light illuminates rotatable polarizer506—which may be made to rotate under control signals from a controller (not shown).506polarizes the light from502and adjusts the polarization orientation relative to polarizing beam splitter512a.504is an optional polarization recycling subsystem which may be used to improve the efficiency of the polarization.510is used to make the light more uniform such that it can be used with modulators516and522.512awill divert a portion of the light reaching it from510to514and the remainder to512b.The amount of each proportion will be dependent on the polarization orientation set by506.514is an optional fold mirror used to redirect the light from512ato516.516is a MEMS device with independently controllable mirrors which can divert the light reaching them to anyone of the segments of integrating rod520. More light is diverted to segments which correspond to brighter areas of the image to be reproduced.518is a lens used to image the light reflected off the mirrors on516into the segmented integrating rod520.512bis used to combine the uniform light field from512awith the typically non-uniform light field from520onto the next modulator522.522modulates the combined light field from512bto create the desired image. Typically there is a projection lens system and screen following522, similar to112and114inFIG.1A, which are used to realize the desired image.

The controller (not shown) analyzes the desired image to be produced and provide control to the506,516and522to generate that image.506can be used to divert the amount of light required to establish the uniform illumination necessary at522to produce the image. The remaining light is routed to516. Control to516determines how much light is directed to each segment of520. The brighter parts of the image will have more light directed to their corresponding segments. The combined light field from512bis compensated with the control sent to modulator522in order to create the desired image. In the case were the source502has more light then required either502can be reduced in intensity or516can be used to divert unused light outside of520so it doesn't reach522.

In another embodiment, polarizer506may be a fixed element and the amount of light split to the highlight path may be substantially a fixed percentage of the total light—e.g., 90% to main light path and 10% to highlight light path. The amount of highlight light to be recombined with the main light may be controlled by allowing a desired amount of highlight light to go to a light dump—or to the highlight path and recombined with the main light path.

FIG.5Bdepicts yet another embodiment of a projector display system that may employ a non-mechanical beam steering module in the highlight light path. In this embodiment, light from element514may be passed through a beam splitter516bto a SLM517b.This light may be holographically modulated as discussed above in reference toFIGS.2,3and4above. Lens518bmay provide a suitable Fourier transformation as previously discussed and the resulting light may provide the highlight as desired—and combined onto the main light path at beam splitter512b.

A detailed description of one or more embodiments of the invention, read along with accompanying figures, that illustrate the principles of the invention has now been given. It is to be appreciated that the invention is described in connection with such embodiments, but the invention is not limited to any embodiment. The scope of the invention is limited only by the claims and the invention encompasses numerous alternatives, modifications and equivalents. Numerous specific details have been set forth in this description in order to provide a thorough understanding of the invention. These details are provided for the purpose of example and the invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in detail so that the invention is not unnecessarily obscured.