Projection of motion pictures in theatres is still primarily done based on film and projection technology little changed since the dawn of motion pictures. However, compared to film, digital media allows for much easier storage of representations of an image. In order to move beyond film-based projection, it would be useful to provide a digital projector which fits general theater requirements.
Furthermore, a Consortium of studios has set forth a standard for future digital projection systems. While this standard is by no means final, it provides a rough guide as to what a system must do—what specifications must be met. Thus, it may be useful to provide a digital projection system which meets the standards of the studio Consortium.
The present invention is illustrated by way of example in the accompanying drawings. The drawings should be understood as illustrative rather than limiting.
A system, method and apparatus is provided for a projector with three dimensional simulation and extended dynamic range. The specific embodiments described in this document represent exemplary instances of the present invention, and are illustrative in nature rather than restrictive.
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one skilled in the art that the invention can be practiced without these specific details. In other instances, structures and devices are shown in block diagram form in order to avoid obscuring the invention.
Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
A moderate sized (e.g. 2×3 m) image of modest brightness can be projected onto a surface by three Light Emitting Diodes (LEDs), or Laser Diodes (LDs), each of a different color, e.g. red, green, blue, or yellow, cyan, magenta, repetitively pulsed in rapid sequence so as to simultaneously illuminate two LCoS image generation chips with the same color light pulse, but with complimentary optical polarization as determined by the light pulse passing through a broadband polarizing beam splitter cube as shown in
Turning to the specific components of
Polarizing beam splitter 150 splits the light into two orthogonally polarized light beams, with each polarized light beam bouncing off of an LCoS image chip 160. LCoS image chips 160 modulate the light based on data supplied from an outside source, to create two images (one for each polarized beam). Polarizing beam splitter 150 combines the beams coming from LCoS image chips 160, providing an output beam that passes through output optics 170 and creates an output beam 180 which may be projected on a screen.
Another option for producing a 3D image simulation is to pass the output images through a single Liquid Crystal phase plate which converts the two linearly polarized output beams of each color sequence into opposed circularly polarized beams, eliminating image degradation by rotation of the viewer's head as occurs with linearly polarized 3D viewing systems. The wave plate voltage may be optimized for each color in turn and sequenced in synchronization with the illuminating LEDs/LDs.
The optical projection system shown in
When a dark scene is projected the image dynamic range of the projected display may be extended by reducing the output power of the light sources and simultaneously increasing the image chip transmission to precisely compensate for the reduced LED/LD outputs. For digitally generated masters, the scene brightness can be coded directly to the three light sources if desired, eliminating the need to pre-scan the image and build a file of source intensity values synchronized with image chip modulation states.
The LEDs/LDs can also be replaced by a white light source and a rotating colored filter wheel with each color filter appropriately synchronized with the image chip signals. Moreover, the three color display can be extended to include the use of near infra red images if desired for simulation and training purposes. This would involve extending the light sequence to four or more pulses with a corresponding increase in the pulse repetition rate for any given frame rate. Combining a fourth light source (or fourth filter for a white light source) can be accomplished based on the design shown in
An alternative is the use of a single image chip illuminated with laser diodes whose outputs, unlike LEDs, are optically polarized. This allows both images of a 3D display to be generated from the same image chip with full optical efficiency but requires the color sequence be cycled at twice the rate, 144 Hertz for a 24 frames per second display, and an electrically driven wave plate be positioned at the output to switch the polarization state prior to each color sequence, i.e. at a 48 Hertz rate. In this configuration the optics is the same as in
A similar display system using sequentially pulsed LEDs can be configured using a single image generation chip (LCoS) with maximum light efficiency if both polarizations from the light sources can be directed to the same image chip. This can be accomplished by means of a polarization combining prism which separates an input beam into two polarizations, and rotates one to be oriented similarly to the other. The two halves of the input beam illuminate the two halves of an image generating chip as shown in
Using a light source similar to that of
The eye sensitivity to frame rates flicker increases with display brightness, requiring faster frame rates for comfortable viewing. The display frame rate is limited by the time to refresh the LCoS imaging chip and the duration of the light pulse for the refreshed image. One means of maximizing the frame rate is to alternately refresh the two polarization states and illuminate the chip not being refreshed, i.e. one chip is being refreshed while the other is being illuminated. This is accomplished by a slightly modified laser diode illumination system where a polarization switch (e.g. a liquid crystal wave plate), is used to alternate the light pulses between two image chips as in
In the circumstance where the image is projected onto a screen which does not preserve the polarization of the projected light the viewer will not perceive a 3D effect even with polarized glasses. If the 3D images are projected sequentially the 3D effect will be perceived if viewed through active light blocking glasses, operating synchronously with projection of the image. The two sets of images which provide 3D information are seen by the viewer with the glasses alternately blocking and passing the appropriate image sequence to each eye. In such an embodiment, this requires the projected images and the transmission of the glasses be synchronized so the appropriate image is seen. The alternate sides of the glasses are blocked/opened so a different image sequence passes through each side of the viewers glasses. The synchronization of the projected image and the viewer's glasses is achieved by a signal transmitted by the projector and received by the viewer's glasses. One option for achieving this is by a very low power radio frequency signal.
Turning to
The process of some of these embodiments can be further illustrated with reference to
Process 500 initiates with programming of an LCoS chip with data for display of a blue image at module 510. At module 520, a blue light source is illuminated (or a color wheel is turned to blue). This, through use of appropriate optics, results in display of the blue image as modulated by the LCoS chip. At module 530, the LCoS chip is programmed for display of a red image. Likewise, at module 540, a red light source is illuminated (or a color wheel is turned to red), and the corresponding red image as modulated by the LCoS chip is displayed. At module 550, the LCoS chip is programmed for display of a green image. Likewise, at module 560, a green light source is illuminated (or a color wheel is turned to green), and the corresponding green image as modulated by the LCoS chip is displayed. This process can then be repeated for each frame (or multiple times for each frame) as needed. Moreover, the process can be expanded for other colors or light sources (e.g. infrared) or changed for a different set of colors (e.g. cyan, magenta, yellow).
Process 600 of
Process 600 initiates with programming of a half-wave plate for a first polarization at module 610. Thus may involve a time-varying polarization or a constant polarization, and thus may involve production of a biasing voltage. At module 620, an LCoS chip is programmed with data for display of a blue image. At module 625, a blue light source is illuminated (or a color wheel is turned to blue). Through use of appropriate optics, the blue image as modulated by the LCoS chip is displayed. At module 630, the LCoS chip is programmed for display of a red image. At module 635, a red light source is illuminated (or a color wheel is turned to red), and the corresponding red image as modulated by the LCoS chip is displayed. At module 640, the LCoS chip is programmed for display of a green image. Likewise, at module 645, a green light source is illuminated (or a color wheel is turned to green), and the corresponding green image as modulated by the LCoS chip is displayed.
Process 600 continues with programming of a half-wave plate for a second polarization at module 650. The process then proceeds to programming an LCoS chip with data for display of a blue image at module 660. At module 665, a blue light source is illuminated (or a color wheel is turned to blue), and the blue image as modulated is displated. The LCoS chip is programmed for display of a red image at module 670. At module 675, a red light source is illuminated (or a color wheel is turned to red), and the corresponding red image as modulated by the LCoS chip is displayed. At module 680, the LCoS chip is programmed for display of a green image. Likewise, at module 685, a green light source is illuminated (or a color wheel is turned to green), and the corresponding green image as modulated by the LCoS chip is displayed. This process can then be repeated for each frame (or multiple times for each frame) as needed, and can be expanded or changed for other light sources.
The external communications interface 773 may use a proprietary (a standard developed for such a device but not publicized by its developer), or a publicly available communications standard, and may be used to receive both digital image data and commands from a user. The projector communications interface 776 provides for communication with projector subsystem 780, allowing for control of LCoS chips (not shown) included in projector subsystem 780, for example. Thus, projector communications interface 776 may be implemented with cables coupled to LCoS chips, or with other communications technology (e.g. wires or traces on a printed circuit board) coupled to included LCoS chips. Other components of computer subsystem 760, such as dedicated user input and output modules, may be included, depending on the needs for functionality of a conventional computer system in system 750. System 750 may be used as an integrated, standalone system—thus allowing for the possibility that each theater may use its own projector with a built-in control system, for example.
The computer system 800 includes a processor 810, which can be a conventional microprocessor such as microprocessors available from Intel or Motorola. Memory 840 is coupled to the processor 810 by a bus 870. Memory 840 can be dynamic random access memory (dram) and can also include static ram (sram). The bus 870 couples the processor 810 to the memory 840, also to non-volatile storage 850, to display controller 830, and to the input/output (I/O) controller 860.
The display controller 830 controls in the conventional manner a display on a display device 835 which can be a cathode ray tube (CRT) or liquid crystal display (LCD). Display controller 830 can, in some embodiments, also control a projector such as those illustrated in
The non-volatile storage 850 is often a magnetic hard disk, an optical disk, or another form of storage for large amounts of data. Some of this data is often written, by a direct memory access process, into memory 840 during execution of software in the computer system 800. One of skill in the art will immediately recognize that the terms “machine-readable medium” or “computer-readable medium” includes any type of storage device that is accessible by the processor 810 and also encompasses a carrier wave that encodes a data signal.
The computer system 800 is one example of many possible computer systems which have different architectures. For example, personal computers based on an Intel microprocessor often have multiple buses, one of which can be an input/output (I/O) bus for the peripherals and one that directly connects the processor 810 and the memory 840 (often referred to as a memory bus). The buses are connected together through bridge components that perform any necessary translation due to differing bus protocols.
Network computers are another type of computer system that can be used with the present invention. Network computers do not usually include a hard disk or other mass storage, and the executable programs are loaded from a network connection into the memory 840 for execution by the processor 810. A Web TV system, which is known in the art, is also considered to be a computer system according to the present invention, but it may lack some of the features shown in
In addition, the computer system 800 is controlled by operating system software which includes a file management system, such as a disk operating system, which is part of the operating system software. One example of an operating system software with its associated file management system software is the family of operating systems known as Windows(r) from Microsoft Corporation of Redmond, Wash., and their associated file management systems. Another example of an operating system software with its associated file management system software is the Linux operating system and its associated file management system. The file management system is typically stored in the non-volatile storage 850 and causes the processor 810 to execute the various acts required by the operating system to input and output data and to store data in memory, including storing files on the non-volatile storage 850.
Some portions of the detailed description are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of operations leading to a desired result. The operations are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
The present invention, in some embodiments, also relates to apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-roms, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus.
The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will appear from the description below. In addition, the present invention is not described with reference to any particular programming language, and various embodiments may thus be implemented using a variety of programming languages.
Further consideration of various embodiments may provide additional insights. In one embodiment, an apparatus is provided. The apparatus includes a first polarizing beam splitter to receive light from an input source and provide a first output with a first polarization and a second output with a second polarization. The apparatus further includes a half-wave plate arranged to receive the first output of the first polarizing beam splitter and provide a half-wave plate output having the second polarization. The apparatus also includes a mirror arranged to receive the second output beam of the first polarizing beam splitter and provide a mirror output having the second polarization. The apparatus may further include a second polarizing beam splitter to receive the half-wave plate output and the mirror output and transmit the half-wave plate output and the mirror output to an external reflective component. The second polarizing beam splitter is further to receive reflected light from the reflective component and to transmit the light from the reflective component as an external output beam. The apparatus may use a reflective component which is an image modulation component.
In another embodiment, a system is provided. The system includes a housing. The system further includes a first light source coupled to the housing, the first light source providing red light. The system also includes a second light source coupled to the housing, the second light source providing green light. The system further includes a third light source coupled to the housing, the third light source providing blue light. The system also includes a first beam combining optical element and a second beam combining optical element both coupled to the housing. The first beam combining optical element is arranged to receive light from the first light source and the second light source. The second beam combining optical element is arranged to receive light from the first beam combining optical element and from the third light source.
The system further includes an LCoS assembly coupled to the housing and arranged to receive light from the second beam recombining element. The LCoS assembly includes a polarization beam splitter arranged to receive light from the second beam combining element. The polarization beam splitter includes a first polarizing beam splitter to receive light from the second beam combining element and provide a first output with a first polarization and a second output with a second polarization. The polarization beam splitter further includes a half-wave plate arranged to receive the first output of the first polarizing beam splitter and provide a half-wave plate output having the second polarization. The polarization beam splitter further includes a mirror arranged to receive the second output beam of the first polarizing beam splitter and provide a mirror output having the second polarization. The polarization beam splitter also includes a second polarizing beam splitter to receive the half-wave plate output and the mirror output and transmit the half-wave plate output and the mirror output to an external reflective component. The second polarizing beam splitter receives reflected light from the reflective component and transmits the light from the reflective component as an external output beam.
The LCoS assembly further includes a first LCoS chip coupled to receive light from the polarization beam splitter and to reflect modulated light to the polarization beam splitter. The LCoS assembly also includes a second LCoS chip coupled to receive light from the polarization beam splitter and to reflect modulated light to the polarization beam splitter. The LCoS assembly may alternatively include a single LCoS chip coupled to receive light from the polarization beam splitter of both the half-wave plate output and the mirror output and to reflect modulated light to the polarization beam splitter.
The system may further include a first focusing optical element interposed between the first light source and the first beam recombining optical element to focus light from the first light source on the first beam recombining element. The system may also include a second focusing optical element interposed between the second light source and the first beam recombining optical element to focus light from the second light source on the first beam recombining element. The system may further include a third focusing optical element interposed between the third light source and the second beam recombining optical element to focus light from the third light source on the second beam recombining element. The system may also include output focusing optics coupled to the housing and arranged to focus an output beam of the polarization beam splitter of the LCoS array. In some embodiments, the first beam recombining optical element is a dichroic mirror; and the second beam recombining optical element is a dichroic mirror.
The system may further include a controller coupled to the first light source, the second light source and the third light source. The controller may also be coupled to control light output of the first light source, the second light source and the third light source. The system may also include a polarization switch coupled to the controller and disposed between the second beam recombining optical element and the LCoS assembly. The polarization switch may be controlled by the controller. The system may also include an eyeglass interface coupled to the controller, the controller to determine signals output by the eyeglass interface. In some embodiments, the first light source is an LED, the second light source is an LED and the third light source is an LED. In other embodiments, the first light source is a laser diode, the second light source is a laser diode and the third light source is a laser diode. Furthermore, in some embodiments, the polarization switch is a PLZT switch.
The system may include a processor and a memory coupled to the processor. The system may also include a bus coupled to the memory and the processor. The system may further include a communications path between the processor and each of the first and second LCoS chips. The system may also include an interface coupled to the processor, the interface to receive data from a source external to the system. In some embodiments, the processor provides the controller.
In another embodiment, a system is presented. The system includes a housing. The system also includes a first light source coupled to the housing, the first light source providing red light. The system further includes a second light source coupled to the housing, the second light source providing green light. The system also includes a third light source coupled to the housing, the third light source providing blue light. Moreover, the system includes a first beam combining optical element and a second beam combining optical element both coupled to the housing. The first beam combining optical element is arranged to receive light from the first light source and the second light source. The second beam combining optical element is arranged to receive light from the first beam combining optical element and from the third light source. The system further includes an LCoS assembly coupled to the housing and arranged to receive light from the second beam recombining element.
In some embodiments, the LCoS assembly includes a polarization beam splitter arranged to receive light from the second beam combining element. The LCoS assembly further includes a first LCoS chip coupled to receive light of a first polarization from the polarization beam splitter and to reflect modulated light to the polarization beam splitter. The LCoS assembly also includes a second LCoS chip coupled to receive light of a second polarization from the polarization beam splitter and to reflect modulated light to the polarization beam splitter.
In some embodiments, the system further includes a first focusing optical element interposed between the first light source and the first beam recombining optical element to focus light from the first light source on the first beam recombining element. The system may further include a second focusing optical element interposed between the second light source and the first beam recombining optical element to focus light from the second light source on the first beam recombining element. The system may also further include a third focusing optical element interposed between the third light source and the second beam recombining optical element to focus light from the third light source on the second beam recombining element.
In some embodiments, the first beam recombining optical element is a dichroic mirror and the second beam recombining optical element is a dichroic mirror. In some embodiments, the system may further include output focusing optics coupled to the housing and arranged to focus an output beam of the polarization beam splitter of the LCoS array. Additionally, in some embodiments, the system further includes a controller coupled to the first light source, the second light source and the third light source. The controller is coupled to control light output of the first light source, the second light source and the third light source. Moreover, in some embodiments, the controller is to sequence the first light source, the second light source and the third light source.
The system may further include a polarization switch coupled to the controller and disposed between the second beam recombining optical element and the LCoS assembly, the polarization switch controlled by the controller. The system may also include an eyeglass interface coupled to the controller. The controller is to determine signals output by the eyeglass interface. The system may use a first light source, a second light source and a third light source that are LEDs. Alternatively, the system may use a first light source, a second light source and a third light source that are laser diodes. In some embodiments, the polarization switch is a PLZT switch.
Some embodiments of such systems may further include a processor and a memory coupled to the processor. Such embodiments may also include a bus coupled to the memory and the processor. Likewise, such embodiments may also include a communications path between the processor and each of the first and second LCoS chips. Additionally, such embodiments may include an interface coupled to the processor, the interface to receive data from a source external to the system.
In another embodiment, a method is provided. The method includes programming a light modulator with a blue image. The method also includes Illuminating a blue light source. The method further includes programming a light modulator with a red image. The method also includes illuminating a red light source. The method further includes programming a light modulator with a green image. The method also includes illuminating a green light source.
The method may also include programming a half-wave plate to pass light of a first polarization. The method may further include performing the programming of the blue, red and green images and the illuminating of the blue, red and green light sources. The method may likewise include programming a half-wave plate to pass light of a second polarization. The method may further include performing the programming of the blue, red and green images and the illuminating of the blue, red and green light sources. Additionally, the method may include focusing light output from the image modulator as an output beam. Moreover, the method may include controlling sequencing of the illuminating of the red, blue and green light sources.
In yet another embodiment, a system is provided. The system includes a housing. The system also includes a first light source coupled to the housing, the first light source providing red light. The system further includes a second light source coupled to the housing, the second light source providing green light. The system also includes a third light source coupled to the housing, the third light source providing blue light. The system also includes a first dichroic mirror and a second dichroic mirror both coupled to the housing. The first dichroic mirror is arranged to receive light from the first light source and the second light source, and the second dichroic mirror is arranged to receive light from the first dichroic mirror and from the third light source.
The system further includes a first focusing optical element interposed between the first light source and the first dichroic mirror to focus light from the first light source on the first beam combining element. The system also includes a second focusing optical element interposed between the second light source and the first dichroic mirror to focus light from the second light source on the first beam combining element. The system further includes a third focusing optical element interposed between the third light source and the second dichroic mirror to focus light from the third light source on the second beam combining element.
The system also includes a polarization beam splitter arranged to receive light from the second beam combining element. The system further includes a first LCoS chip coupled to receive light of a first polarization from the polarization beam splitter and to reflect modulated light to the polarization beam splitter. The system also includes a second LCoS chip coupled to receive light of a second polarization from the polarization beam splitter and to reflect modulated light to the polarization beam splitter. The system further includes Output focusing optics coupled to the housing and arranged to focus an output beam of the polarization beam splitter of the LCoS array.
The system also includes a controller coupled to the first light source, the second light source and the third light source. The controller is coupled to control light output of the first light source, the second light source and the third light source. The controller is to sequence the first light source, the second light source and the third light source. The system further includes a processor and a memory coupled to the processor. The system also includes a bus coupled to the memory and the processor. The system further includes a communications path between the processor and each of the first and second LCoS chips and the controller.
One skilled in the art will appreciate that although specific examples and embodiments of the system and methods have been described for purposes of illustration, various modifications can be made without deviating from present invention. For example, embodiments of the present invention may be applied to many different types of databases, systems and application programs. Moreover, features of one embodiment may be incorporated into other embodiments, even where those features are not described together in a single embodiment within the present document.