Patent Publication Number: US-9848177-B2

Title: Hybrid light engine for projector

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 14/064,751, entitled “Hybrid Light Engine for Projector,” filed on Oct. 28, 2013, the disclosure of which is hereby expressly incorporated by reference in its entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure generally relates to information handling systems, and more particularly relates to image projectors for information handling systems. 
     BACKGROUND 
     As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option is an information handling system. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes. Because technology and information handling needs and requirements may vary between different applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, networking systems, and data storage systems. 
     An information handling system in a particular installation may use one or more projectors. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       It will be appreciated that for simplicity and clarity of illustration, elements illustrated in the Figures are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to other elements. Embodiments incorporating teachings of the present disclosure are shown and described with respect to the drawings herein, in which: 
         FIG. 1  is a diagram of a system for projecting images according to an embodiment of the present disclosure; 
         FIGS. 2 and 3  are graphs of light spectra according to an embodiment of the present disclosure; 
         FIG. 4  is a diagram of a projector according to an embodiment of the present disclosure; 
         FIG. 5  is a diagram of a color wheel according to an embodiment of the present disclosure; 
         FIG. 6  is a timing diagram according to an embodiment of the present disclosure; 
         FIG. 7  is a flow diagram of a method for operating a projector according to an embodiment of the present disclosure; 
         FIG. 8  is another diagram of a color wheel according to an embodiment of the present disclosure; 
         FIG. 9  is a diagram of an auxiliary light module according to an embodiment of the present disclosure; 
         FIG. 10  is a diagram of a color wheel according to another embodiment of the present disclosure; 
         FIG. 11  is another timing diagram according to an embodiment of the present disclosure; and 
         FIG. 12  is a diagram of an information handling system according to an embodiment of the present disclosure. 
     
    
    
     The use of the same reference symbols in different drawings indicates similar or identical items. 
     DETAILED DESCRIPTION OF THE DRAWINGS 
     The following description in combination with the Figures is provided to assist in understanding the teachings disclosed herein. The description is focused on specific implementations and embodiments of the teachings, and is provided to assist in describing the teachings. This focus should not be interpreted as a limitation on the scope or applicability of the teachings. However, other teachings may be utilized in this application, as well as in other applications and with several different types of architectures such as distributed computing architectures, client or server architectures, or middleware server architectures and associated components. 
       FIG. 1  shows a diagram of a system including information handling system  100 , screen  101 , external images  102  and projector  103 . Information handling system  100  includes image processor  104 , stored images  105  and image generating software  106 . Image processor  104  is coupled to projector  103  and to a plurality of image sources. Image sources include external images  102 , stored images  105  and image generating software  106 . Image processor  104  receives image data from image sources and converts the image data to an input format of projector  103 . Projector  103  projects representations of images onto screen  101 . 
     For purposes of this disclosure, an information handling system can include any instrumentality or aggregate of instrumentalities operable to compute, calculate, determine, classify, process, transmit, receive, retrieve, originate, switch, store, display, communicate, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system may be a personal computer (e.g., desktop or laptop), tablet computer, mobile device (e.g., personal digital assistant (PDA) or smart phone), server (e.g., blade server or rack server), a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, touchscreen and/or a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components. 
     In various embodiments of the present disclosure, image processor  104  can be hardware, software or a combination thereof. In an embodiment, image processor  104  can include a graphics chip capable of rendering images for projection. In an embodiment, image processor  104  can include software executable on a CPU. In an embodiment, image processor  104  can receive image data representing an image of a user interface of a program. For example, information handling system  100  can be a laptop computer. The laptop computer can show a user interface on a built-in display screen of the laptop computer and simultaneously have the user interface projected onto screen  101  using projector  103 . In various embodiments, image generating software  106  can include presentation software, video playback software, still image display software, game software, desktop display software, combinations thereof and the like. For example, a presentation to be projected can be prepared using presentation creation software. 
     In embodiments, image processor  104  can render images obtained from stored images  105  and from external images  102 . Images can include a related series of images that are projected in sequence. For example, stored images  105  can include a series of images downloaded from an online movie provider for projection as a movie. External images  102  can be a series of images streamed from an online provider of video clips. In an embodiment, images are individual still images. For example, stored images  105  can include images that have been uploaded to information handling system  100  from a camera or from a smartphone. 
     In an embodiment of the present disclosure, projector  103  produces a light beam using a light source. The light beam is directed through an optical path. A filter can be positioned in the optical path. The filter can remove wavelengths of light except those corresponding to a first primary color. The light beam of the first primary color can be directed onto a spatial image modulator that further directs portions of the light beam through projection optics to a screen. The portions of light that are directed to the screen represent pixels of the first primary color in an image. After a time interval, a filter of a second primary color can be placed into the light beam and the spatial image modulator can direct different portions of the light beam through the projection optics to the screen. In an embodiment, a projector producing light using a lamp as a primary light source can be designed for improved color performance at the expense of image brightness, or for improved image brightness at the expense of color performance. A beam of light produced by a high power lamp can have light in a wide range of visible wavelengths. Producing primary colors by filtering a beam of light reduces the intensity of much of the light produced by the lamp. In embodiments, a beam of filtered light produced by a primary light source can be combined with light from an auxiliary light source before being directed onto a spatial light modulator. 
     The term “color” as used herein refers to ranges of wavelengths of light. For example, light having wavelengths in a range from approximately 620 nm to approximately 750 nm can be described as red, while light having wavelengths in a range from approximately 450 nm to approximately 495 nm can be described as blue. A light beam described herein as having a particular color is to be understood as having higher intensity at wavelengths of light in a range corresponding to the particular color, however the light beam can include light at a lower intensity having wavelengths outside of the range corresponding to the particular color. For example, a red beam of light includes light having wavelengths in a range corresponding to the color red and can also include light having wavelengths in a range corresponding to the color blue, however light in the blue range will be less intense than light in the red range such that the light in the blue range will not be perceivable by a person viewing the beam of light. 
     The term “filter” as used herein refers to a device that changes the spectrum of a beam of light by reducing the intensity of light of particular wavelengths. A filter can be described by a range or ranges of wavelengths of light that it does not reduce in intensity. A range of wavelengths can be described as a color as discussed previously. For example, a filter can be described as a “red filter.” A red filter reduces the intensity of light having wavelengths corresponding to the color red by a relatively small amount, while reducing the intensity of light having wavelengths corresponding to other colors by a relatively large amount. A filter can reduce the intensity of all wavelengths of visible light by a relatively large amount. Such a filter is described herein as “opaque,” as an opaque filter or as a black filter. A filter can reduce the intensity of all wavelengths of visible light by a relatively small amount. Such a filter is described herein as “transparent” or as a white filter. The term “filtering” as used herein refers to the process of reducing the intensity of light in particular ranges of wavelengths. A beam of light having passed through a filter can be described as having been “filtered.” 
       FIG. 2  shows a graph  200  of a spectrum  201  of light produced by a primary light source in a projector. The horizontal axis represents wavelengths of light produced by the primary light source. The vertical axis represents the intensity of light. Spectrum  201  has three peaks. The peak between wavelengths 380 nm and 500 nm represents blue light. The peak between 500 nm and 650 nm represents green light. The peak at 650 nm represents red light. In an embodiment, a projector uses filters to remove colors of light except for a single primary color from light produced by a primary light source. The result of filtering light from a primary light source is illustrated at graph  210 . 
     Graph  210  shows two spectra produced by filtering light from a primary light source. The horizontal axis represents wavelengths of light in a light beam after passing through a filter. The vertical axis represents the intensity of light. Spectrum  211  shows the spectrum of light from the primary light source after passing through a green filter. The green filter reduces the intensity of light having wavelengths less than approximately 500 nm and above approximately 600 nm. The primary light source of the present example produces a relatively high intensity of green light, thus the light beam after passing through the green filter is relatively bright. Spectrum  212  shows the spectrum of light from the primary light source after passing through a red filter. The red filter reduces the intensity of light having wavelengths less than approximately 600 nm. The primary light source produces a relatively low intensity of red light, thus the light beam after passing through the red filter is relatively dim. In an embodiment of the present invention, light from an auxiliary light source having a spectrum similar to the spectrum of a filtered light beam can be combined with the filtered light beam. 
       FIG. 3  shows a graph  300  of a spectrum  301  of an auxiliary light source. The horizontal axis represents wavelengths of light in a light beam produced by the auxiliary light source. The vertical axis represents the intensity of light. The auxiliary light source can produce a light beam having a high intensity at wavelengths of approximately 650 nm, corresponding to red light. Similar to spectrum  212 , spectrum  301  shows light from the auxiliary light source having low intensity at wavelengths corresponding to colors other than red. Light from the auxiliary light source can be combined with filtered light from a primary light source to produce a more intense beam of red light. Graph  310  shows a spectrum  311  of a combined beam of light. The beam of light represented by spectrum  311  is obtained by combining filtered light, represented by spectrum  211 , with light produced by an auxiliary light source, represented by spectrum  301 . In an embodiment, a combined light beam represented by spectrum  311  can be directed through an optical path to a spatial light multiplexer. In an embodiment, light from auxiliary light sources having colors other than red can be combined with filtered light. For example, light from a primary light source can be filtered using a blue filter and the filtered light can be combined with light from an auxiliary light source producing blue light. In a similar fashion, a green filter can be used in combination with an auxiliary light source producing green light. In an embodiment, an auxiliary light source can include a light emitting diode (LED). In an embodiment, an auxiliary light source can include a laser diode. 
     It will be appreciated by those skilled in the art that the graphs at  FIGS. 2 and 3  have been simplified for clarity and are representative of the spectra of light produced using primary light sources, auxiliary light sources and filters. The graphs do not represent the intensity curves of any particular device. For example, a primary light source used in a projector can produce light having a more uniform spectrum with peaks that are less distinct than shown at spectrum  201 . In another example, an auxiliary light source can produce light having a spectrum with a sharper peak than that shown at spectrum  301 . 
       FIG. 4  is diagram of a projector  400  having three auxiliary light sources to augment light produced by a projector using a lamp as a primary light source. Projector  400  includes lamp module  401 , auxiliary light source module  402 , projection optics module  403  and projector lens assembly  404 . Lamp module  401  includes a lamp  405 , a reflector  406 , a lens  407  and a color wheel  408 . Lamp  405  can be of any type suitable for projecting images. In various embodiments, lamp  405  can be a metal halide lamp, a mercury lamp, an ultra high performance lamp (UHP), a light emitting diode, a fluorescent lamp, a combination thereof, or the like. Lamp  405  is partially surrounded by reflector  406 . Lamp  405  produces light having a spectrum. The spectrum produced by lamp  405  is characteristic of a particular type of lamp. As discussed with respect to  FIG. 2  a spectrum of light produced by a light source in a projector can include a plurality of peaks. In an embodiment, the plurality of peaks corresponds to a plurality of colors. In an embodiment, a spectrum has peaks corresponding to the primary colors red, green and blue. 
     Light from lamp  405  is directed through lens  407  onto color wheel  408 . Color wheel  408  includes filter sections  409 ,  410  and  411 . During operation of the projector  400 , color wheel  408  rotates. Each rotation successively places each one of filter sections  409 - 411  in an optical path of the light produced by lamp  405  for a time interval. During the time interval in which a filter section is positioned in the optical path, the filter section filters light produced by lamp  405  to produce a filtered light beam having a color corresponding to the respective filter section. In an embodiment, each filter section  409 - 411  of color wheel  408  reduces the intensity of light in a range of wavelengths other than a range of wavelengths corresponding to the color of the respective filter section. For example, filter section  411  can be a red filter. The filter section  411  reduces the intensity of wavelengths of light in the light beam, other than wavelengths corresponding to red light, as discussed with respect to spectrum  212 . Color wheel  408  is illustrated as having three filter sections. More or fewer filter sections can be used in embodiments of the present disclosure. In an embodiment, a color wheel has two sections. In various embodiments, a color wheel has more than three sections. In an embodiment, more than one filter section of a color wheel has a particular color. In an embodiment, a filter section of a color wheel is transparent. 
     Auxiliary light source module  402  includes auxiliary light sources  412 - 414  and beam combiners  415 - 417 . Auxiliary light sources  412 - 414  produce light which can be combined with light produced by lamp  405 . In an embodiment, each one of auxiliary light sources  412 - 414  produces light of a single primary color. For example, auxiliary light source  412  can produce red light, auxiliary light source  413  can produce green light and auxiliary light source  414  can produce blue light.  FIG. 4  illustrates auxiliary light module  402  having three auxiliary light sources. In an embodiment, an auxiliary light module can have fewer than three auxiliary light sources. For example, an auxiliary light module can have a first auxiliary light source to produce blue light and a second auxiliary light source to produce red light. Auxiliary light sources  412 - 414  can be any light source capable of producing light primarily of a single color. In an embodiment, auxiliary light sources  412 - 414  include light emitting diodes. In an embodiment, auxiliary light sources  412 - 414  include laser diodes. 
     During operation of projector  400 , auxiliary light sources  412 - 414  produce light intermittently. Each auxiliary light source  412 - 414  produces light only when a filter section in a particular subset of filter sections  409 - 411  is positioned in a light beam produced by lamp  405 . In an embodiment, an auxiliary light source  412 - 414  produces light only when a filter segment  409 - 411  having a color similar to a color of light produced by the auxiliary light source is positioned in the light beam produced by lamp  405 . For example, auxiliary light source  412  can produce red light during a time interval that a red filter segment  411  is positioned in the light beam. In response to red filter segment  411  rotating out of the light beam and blue filter segment  410  rotating into the light beam, auxiliary light source  412  can stop producing red light. 
     Beam combiners  415 - 417  combine the beam of light produced by lamp  405 , as filtered by the filter segments  409 - 411  of color wheel  408 , with light produced by auxiliary light sources  412 - 414 . Beam combiners  415 - 417  are positioned in an optical path of a beam of light produced by lamp  405 . Light produced by lamp  405  passes through beam combiners  415 - 417  in the optical path. Beam combiners  415 - 417  can reflect light produced by auxiliary light sources  412 - 414 , respectively, into the optical path of the light produced by lamp  405 . Beam combiners  415 - 417  can be any device known in the art suitable for combining beams of visible light. In an embodiment, beam combiners  415 - 417  are dichroic mirrors. 
     Projection optics module  403  includes lenses  418  and  420 , mirror  419 , and spatial image modulator  421 . Lens  418 , mirror  419  and lens  420  focus and direct the light beam produced by lamp  405 , as filtered by color wheel  408  and augmented by light from auxiliary light sources  412 - 414 , onto spatial light modulator  421 . Those skilled in the art will appreciate that the particular optical elements shown at  FIG. 4  can be replaced with other optical elements performing a similar function. The selection of optical elements can be influenced by factors such as a shape of a physical enclosure for the projector, a desired size of the projector, and illumination requirements for a particular spatial light modulator employed. Spatial light modulator  421  selectively directs portions of light directed onto it through projector lens assembly  404 . In an embodiment, spatial light modulator  421  includes sections corresponding to pixels of an image. In an embodiment, a section corresponding to a pixel can be oriented to reflect light through projector lens assembly  404  or to reflect light away from projector lens assembly  404 . In an embodiment, the spatial light modulator  421  reflects light using a plurality of movable mirrors. Each mirror of the plurality of movable mirrors can have a first position reflecting light into projection lens assembly  404  and a second position reflecting light away from projection lens assembly  404 . In another embodiment, not shown, a light beam can pass through a spatial light modulator. Sections of the spatial light modulator corresponding to pixels can be opaque or transparent. A transparent section allows light to pass through into the projector lens assembly. 
     Projector  400  operates by directing a light beam from lamp  405  through color wheel  408 . Color wheel  408  rotates to position one of filter sections  409 - 411  in the path of the light beam. Each of filter sections  409 - 411  can modify a spectrum of the light beam by reducing the intensity of wavelengths of light in a range or ranges of wavelengths. After passing through the color wheel  408 , the light beam enters auxiliary light source module  402 . In response to particular filters being positioned in the light beam, the projector turns on one or more of auxiliary light sources  412 - 415 . Beam combiners  415 - 417  combine light generated by auxiliary light sources  412 - 414 , respectively, with the light beam generated by lamp  405 . At  FIG. 4 , auxiliary light source  412  is illustrated as generating an auxiliary light beam. Beam combiner  415  combines light from auxiliary light source  412  with the light beam produced by the lamp  405 . For example, filter section  411  can be a red filter and auxiliary light source  412  can produce red light. The light beam exiting beam combiner  415  contains red light generated by lamp  405  and red light generated by red auxiliary light source  412 . 
     After exiting the auxiliary light source module  402 , the light beam enters projection optics module  403  and is directed onto spatial light modulator  421 . Spatial light modulator  421  can have sections corresponding to pixels of an image to be projected. Sections corresponding to pixels that are to be illuminated in a projected image direct light through projection lens assembly  404 . Sections corresponding to pixels that are not to be illuminated direct light away from projection lens assembly  404 . 
     In an embodiment, control logic (not shown) coordinates timing of the color wheel  408 , auxiliary light sources  412 - 414 , and spatial light modulator  421 . In an embodiment, control logic detects that a red filter section of color wheel  408  is positioned in the light beam from lamp  405 . In response to detecting a red filter the control logic turns on a red auxiliary light source. For example, auxiliary light source  412  can be turned on. Control logic also configures spatial light modulator  421  to direct light for pixels that are to be illuminated with red light into projection lens assembly  404 . As color wheel  408  rotates, a second filter section is positioned in the light beam. In an embodiment, the second filter section can be blue. In response to detecting a blue filter, control logic can turn off the red auxiliary light source, turn on a blue auxiliary light source and configure the spatial light modulator to direct light for pixels that are to be blue into projection lens assembly  404 . In an embodiment, control logic can detect filter sections, turn on auxiliary light sources and configure spatial light modulator  421  for additional colors. In other embodiments, one of auxiliary light sources  412 - 414  having a first color can be turned on in response to a filter section of color wheel  408  having a second color being positioned in a light beam from lamp  405 . In an embodiment, an auxiliary light source can be turned on in response to a transparent filter being positioned in a light beam from lamp  405 . In an embodiment, an auxiliary light source can be turned on at less than full power. In an embodiment, an auxiliary light source can be turned on at 50% of full power. 
     In an embodiment of the present disclosure, the use of auxiliary light sources in addition to a lamp can be a selectable option. Use of auxiliary light sources can be selected, for example, by a switch on a projector or by a control program executing on an information handling system coupled to the projector. In an embodiment, the use of individual auxiliary light sources can be a selectable option. For example, the use of a red auxiliary light source can be enabled and the use of a blue auxiliary light source can be disabled. In an embodiment, auxiliary light source module  402  can be removed from an optical path of a light beam from lamp  405 . For example, a projector can have a lever which, when operated, retracts the auxiliary light source module  402  from the optical path. In an embodiment, the beam combiners can be removed from an optical path of a light beam from lamp  405 . 
     Those skilled in the art will appreciate that color wheel  408  can rotate rapidly to position multiple filter sections per second in a light beam from lamp  405 , that auxiliary light sources  412 - 414  can be turned on and off multiple times per second, and that positions of sections of spatial light modulator  421  can be positioned multiple times per second. Skilled practitioners will also appreciate that techniques well known in the art for creating colors other than the colors on a color wheel can be used with the disclosed apparatus. For example, when color wheel  408  contains only primary colors a projector can project a pixel having a secondary color by illuminating the pixel with more than one primary color in rapid succession. A yellow pixel can be projected by having the section of the spatial light modulator  421  corresponding to the pixel direct both red light and green light into the projection lens assembly  404 . 
       FIG. 5  shows a layout of filter sections for a color wheel  500 . Color wheel  500  includes three filter sections. Filter section  501  is a red section, filter section  502  is a green section, and filter section  503  is a blue section. Color wheel  500  rotates as indicated by the arrows. Each of filter sections  501 - 503  reduces the intensity of one or more ranges of wavelengths of visible light. In an embodiment, filter section  501  can reduce the intensity of light having wavelengths outside of a range of approximately 620 nm to approximately 750 nm. Although filter section  501  can reduce the intensity of light within the range, the reduction in intensity of light having wavelengths within the range is less than the reduction in intensity of light having wavelengths outside of the range. In an embodiment, filter section  502  can reduce the intensity of light having wavelengths outside of a range of approximately 495 nm to approximately 570 nm. The range corresponds to green light. Similar to filter section  501 , filter section  502  can reduce the intensity of light within the range while primarily reducing the intensity of light outside the range. In an embodiment, filter section  503  can reduce the intensity of light having wavelengths outside of a range of approximately 450 nm to approximately 495 nm. The range corresponds to blue light. Similar to filter section  501 , filter section  503  can reduce the intensity of light within the range while primarily reducing the intensity of light outside the range. In embodiments, other ranges of wavelengths can correspond to particular colors. 
       FIG. 6  shows timing diagram  600  illustrating the operation of projector  400  using color wheel  500 . The horizontal axis represents time. Color wheel timing curve  601  indicates which filter of filter sections  501 - 503  is positioned in the light beam from lamp  405  during a time interval. Timing curves  602 - 604  indicate the states of auxiliary light sources  312 - 314 , respectively. Color wheel  500  rotates. As it rotates filter sections  501 - 503  are successively positioned in the light beam once on each rotation. Auxiliary light source timing curves  602 - 604  indicate the state of auxiliary light sources  412 - 414  as on or off. At time  605 , red filter section  501  is positioned in the light beam from lamp  405  and a red auxiliary light source  412  is turned on. Green auxiliary light source  413  and blue auxiliary light source  414  are turned off. At time  606 , green filter section  502  is positioned in the light beam. Red auxiliary light source  412  is turned off and green auxiliary light source  413  is turned on. At time  607 , blue filter section  503  is positioned in the light beam. Green auxiliary light source  413  is turned off and blue auxiliary light source  414  is turned on. At time  608 , red filter section  501  is again positioned in the light beam as the color wheel rotates and the sequence repeats. 
     It will be appreciated by those skilled in the art that the ordering of colors on the color wheel  500  is arbitrary. A different ordering of colors can be used with appropriate modifications to the timing of auxiliary light sources. As illustrated at  FIG. 5 , filter sections of color wheel  500  are the same size. In embodiments of the present disclosure, filter sections of a color wheel have different sizes. For example, in a color wheel having three filter sections a red filter section can be twice as large as blue and green filter sections. 
       FIG. 7  shows flow diagram  700  of a method for producing a combined light beam in a projector. At step  701 , a first light beam is produced. The first light beam can be produced by a light source as described with respect to lamp  405 . At step  702 , the first light beam is filtered. In an embodiment, the first light beam is filtered as described with respect to color wheel  408 . In an embodiment, the light beam is filtered to create a light beam having a single primary color corresponding to a range of wavelengths of light. In an embodiment, the light beam is filtered to create a light beam having a color other than a primary color. At step  703 , an auxiliary light beam is produced. In an embodiment, the auxiliary light beam and the filtered first light beam have spectra with the greatest intensity of light in a first range of wavelengths. In an embodiment, the auxiliary light beam is produced only when the light beam is filtered in a particular manner at step  702 . In an embodiment, the auxiliary light beam can be produced only when the first beam is filtered by a particular filter section of a color wheel. At step  704 , the filtered first light beam and the auxiliary light beam are combined. In an embodiment, the beams are combined using a dichroic mirror. 
       FIG. 8  shows a color wheel  800  including filter sections  801 - 803 . Color wheel  800  includes two filter sections of each primary color. Filter sections  801  are red, filter sections  802  are green and filter sections  803  are blue. Similar to filter sections  501 - 503 , each filter of filter sections  801 - 803  reduces the intensity of light in one or more ranges of wavelengths. Color wheel  800  rotates as indicated by the arrows. The rotation of color wheel  800  positions each filter section of filter sections  801 - 803  in the path of a light beam of a lamp once during each rotation of color wheel  800 . Similar to color wheel  500 , in response to a particular filter being positioned in the light beam a projector turns on an auxiliary light source having a color similar to the color of the filter. Color wheel  800  includes filter sections having the same colors in the same sequence as color wheel  500 , thus timing diagram  600  illustrates the coordination of filter sections and auxiliary light sources for both color wheel  500  and color wheel  800 . 
     In an embodiment, different primary colors can have different numbers of filter sections in a color wheel. For example, a color wheel can have three red sections, two blue sections and one green section. It will be apparent to those skilled in the art to modify the timing illustrated at  FIG. 6  for turning auxiliary light sources on and off with the appropriate filter sections. 
       FIG. 9  shows an auxiliary light module  901 . Auxiliary light module  901  can be used in place of auxiliary light module  402  in embodiments of the present disclosure. Auxiliary light module  901  includes red auxiliary light source  902  and beam combiner  903 . Similar to auxiliary light module  402 , a filtered beam of light produced by a lamp enters auxiliary light module  901 . Red auxiliary light module  901  can produce a beam of red light using red auxiliary light source  902 , and can combine the beam of red light with the filtered beam of light using beam combiner  903 . The filtered beam of light exits auxiliary light module  901  and can be directed to a projection optics module. Red auxiliary light source  902  produces light having higher intensity in a range of wavelengths corresponding to the color red and having lower intensity outside the range of wavelengths. Control circuitry, not shown, can coordinate the position of a color wheel in a lamp module with the illumination of the red auxiliary light source  902 . In an embodiment, the red auxiliary light source  902  is illuminated when a particular filter section of a color wheel is positioned in a light beam produced by a lamp. 
     In embodiments, auxiliary light module  901  can be used in conjunction with color wheel  500  or with color wheel  800 . When used with a color wheel having a red filter, a projector can turn on red light source  902  when a red filter of the color wheel is positioned in a light beam from a primary light source. 
       FIG. 10  shows a color wheel  1000  for use with a projector in an embodiment of the present disclosure. Color wheel  1000  includes primary color filter sections  1001 ,  1003  and  1005 . Filter section  1001  is red, filter section  1003  is green and filter section  1005  is blue. Color wheel  1000  further includes secondary color filters  1002 ,  1004  and  1006 . Filter section  1002  is yellow, filter section  1004  is cyan and filter section  1006  is magenta. Filter sections  1001 - 1006  reduce the intensity of wavelengths of light in particular ranges. In an embodiment, filter section  1002  can reduce the intensity of light having wavelengths outside of a range of 570 nm to 590 nm, corresponding to the color yellow. Although filter section  1002  can reduce the intensity of light within the range 570 nm to 590 nm, the reduction in intensity of light having wavelengths within the range is less than the reduction in intensity of light having wavelengths outside of the range. In an embodiment, filter section  1004  can reduce the intensity of light having wavelengths outside of a range of 490 nm to 520 nm. The range corresponds to the color cyan. Similar to filter section  1002 , filter section  1004  primarily reduces the intensity of light outside the range. In an embodiment, filter section  1006  can reduce the intensity of light having wavelengths in the range of 500 nm to 590 nm. The range corresponds to green light. Reducing the intensity of green light in a white light beam produces the color magenta. 
       FIG. 11  shows timing diagram  1100 , illustrating the coordination of color wheel  1000  with auxiliary light sources in a projector. The horizontal axis of timing diagram  1100  represents time. Timing curves  1101 - 1104  indicate the states of color wheel  1000  and of auxiliary light sources. Color wheel timing curve  1101  indicates which filter of filter sections  1001 - 1006  is positioned in the light beam from a lamp during a time interval. As color wheel  1000  rotates, the filter sections  1001 - 1006  are successively positioned into the light beam once on each rotation. Auxiliary light source timing curves  1102 - 1104  indicate the states of auxiliary light sources as on or off. At time  1105 , filter section  1001  is positioned in a light beam from a lamp and a red auxiliary light source is turned on. Filter section  1001  is a red section thus light sent though an optical path to a spatial light modulator is a combination of light produced by the lamp and by the red auxiliary light source. At time  1106 , filter section  1002  is positioned in the light beam and the red auxiliary light source is turned off. Filter section  1002  includes a yellow filter. Pixels in the final image that are to be yellow can be projected while filter section  1002  is positioned in the light beam from the lamp instead of being projected as a combination of red and green light as described with respect to color wheel  400 . At time  1107 , filter section  1003  is positioned in the light beam and a green auxiliary light source is turned on. Filter section  1003  is a green section. Thus, similarly to the operation of the projector using filter section  1001  and the red auxiliary light source, the light sent through the optical path is a combination of light produced by the lamp and light from the green auxiliary light source. 
     At time  1108 , filter section  1004  is position in the light beam and the green auxiliary light source is turned off. Filter section  1004  is colored cyan. Cyan colored pixels can be projected using filter section  1004  instead of being projected as a combination of blue and green. At time  1109 , blue filter section  1005  is positioned in the light beam and a blue auxiliary light source is turned on. At time  1110 , magenta filter section  1006  is positioned in the light beam and the blue auxiliary light source is turned off. At time  1111 , the color wheel  1000  has completed a revolution, red filter section  1001  is positioned in the light beam, the red auxiliary light source is turned on and the sequence repeats. 
     Skilled practitioners will appreciate that additional variations on filter color and auxiliary light source color can be constructed in accordance with the present disclosure. For example, in an embodiment a projector can augment only the color red. Such an embodiment can have color wheel  400  with only red auxiliary light source  312 . Auxiliary light sources  313 - 314  can be omitted from the projector in such an embodiment. A projector can use auxiliary light sources to augment some or all of the primary colors of light produced by a lamp. The projector can also augment some or all of the secondary colors. For example, in a projector using color wheel  1000 , a red auxiliary light source can be used to augment light from the lamp when a filter section of a secondary color containing red, such as magenta, is positioned in a light beam from the lamp. In an embodiment, light from auxiliary light sources can be combined with light having secondary colors produced by a lamp to adjust a white point of a projector. 
       FIG. 12  is a block diagram illustrating an embodiment of an information handling system  1200 , including a processor  1210 , a chipset  1220 , a memory  1230 , a graphics interface  1240 , an input/output (I/O) interface  1250 , a disk controller  1260 , a network interface  1270 , and a disk emulator  1280 . In a particular embodiment, information handling system  1200  is used to carry out one or more of the methods described herein. In another embodiment, one or more of the systems described herein are implemented in the form of information handling system  1200 . 
     Chipset  1220  is connected to and supports processor  1210 , allowing the processor to execute machine-executable code. In a particular embodiment, information handling system  1200  includes one or more additional processors, and chipset  1220  supports the multiple processors, allowing for simultaneous processing by each of the processors and permitting the exchange of information among the processors and the other elements of the information handling system. Chipset  1220  can be connected to processor  1210  via a unique channel, or via a bus that shares information among the processor, the chipset, and other elements of information handling system  1200 . 
     Memory  1230  is connected to chipset  1220 . Memory  1230  and chipset  1220  can be connected via a unique channel, or via a bus that shares information among the chipset, the memory, and other elements of information handling system  1200 . In another embodiment (not illustrated), processor  1210  is connected to memory  1230  via a unique channel. In another embodiment (not illustrated), information handling system  1200  includes separate memory dedicated to each of the one or more additional processors. A non-limiting example of memory  1230  includes static random access memory (SRAM), dynamic random access memory (DRAM), non-volatile random access memory (NVRAM), read only memory (ROM), flash memory, another type of memory, or any combination thereof. 
     Graphics interface  1240  is connected to chipset  1220 . Graphics interface  1240  and chipset  1220  can be connected via a unique channel, or via a bus that shares information among the chipset, the graphics interface, and other elements of information handling system  1200 . Graphics interface  1240  is connected to a video display  1242 . Other graphics interfaces (not illustrated) can also be used in addition to graphics interface  1240  as needed or desired. Video display  1242  includes one or more types of video displays, such as a flat panel display, another type of display device, or any combination thereof. 
     I/O interface  1250  is connected to chipset  1220 . I/O interface  1250  and chipset  1220  can be connected via a unique channel, or via a bus that shares information among the chipset, the I/O interface, and other elements of information handling system  1200 . Other I/O interfaces (not illustrated) can also be used in addition to I/O interface  1250  as needed or desired. I/O interface  1250  is connected via an I/O interface  1252  to one or more add-on resources  1254 . Add-on resource  1254  is connected to a storage system  1290 , and can also include another data storage system, a graphics interface, a network interface card (NIC), a sound/video processing card, another suitable add-on resource or any combination thereof. I/O interface  1250  is also connected via I/O interface  1252  to one or more platform fuses  1256  and to a security resource  1258 . Platform fuses  1256  function to set or modify the functionality of information handling system  1200  in hardware. Security resource  1258  provides a secure cryptographic functionality and includes secure storage of cryptographic keys. A non-limiting example of security resource  1258  includes a Unified Security Hub (USH), a Trusted Platform Module (TPM), a General Purpose Encryption (GPE) engine, another security resource, or a combination thereof. 
     Disk controller  1260  is connected to chipset  1220 . Disk controller  1260  and chipset  1220  can be connected via a unique channel, or via a bus that shares information among the chipset, the disk controller, and other elements of information handling system  1200 . Other disk controllers (not illustrated) can also be used in addition to disk controller  1260  as needed or desired. Disk controller  1260  includes a disk interface  1262 . Disk controller  1260  is connected to one or more disk drives via disk interface  1262 . Such disk drives include a hard disk drive (HDD)  1264 , and an optical disk drive (ODD)  1266 , and can include one or more disk drive as needed or desired. ODD  1266  can include a Read/Write Compact Disk (R/W-CD), a Read/Write Digital Video Disk (R/W-DVD), a Read/Write mini Digital Video Disk (R/W mini-DVD, another type of optical disk drive, or any combination thereof. Additionally, disk controller  1260  is connected to disk emulator  1280 . Disk emulator  1280  permits a solid-state drive  1284  to be coupled to information handling system  1200  via an external interface  1282 . External interface  1282  can include industry standard busses such as USB or IEEE 1294 (Firewire) or proprietary busses, or any combination thereof. Alternatively, solid-state drive  1284  can be disposed within information handling system  1200 . 
     Network interface device  1270  is connected to I/O interface  1250 . Network interface  1270  and I/O interface  1250  can be coupled via a unique channel, or via a bus that shares information among the I/O interface, the network interface, and other elements of information handling system  1200 . Other network interfaces (not illustrated) can also be used in addition to network interface  1270  as needed or desired. Network interface  1270  can be a network interface card (NIC) disposed within information handling system  1200 , on a main circuit board such as a baseboard, a motherboard, or any combination thereof, integrated onto another component such as chipset  1220 , in another suitable location, or any combination thereof. Network interface  1270  includes a network channel  1272  that provide interfaces between information handling system  1200  and other devices (not illustrated) that are external to information handling system  1200 . Network interface  1270  can also include additional network channels (not illustrated). 
     Information handling system  1200  includes one or more application programs  1232 , and Basic Input/Output System and Firmware (BIOS/FW) code  1234 . BIOS/FW code  1234  functions to initialize information handling system  1200  on power up, to launch an operating system, and to manage input and output interactions between the operating system and the other elements of information handling system  1200 . In a particular embodiment, application programs  1232  and BIOS/FW code  1234  reside in memory  1230 , and include machine-executable code that is executed by processor  1210  to perform various functions of information handling system  1200 . In another embodiment (not illustrated), application programs and BIOS/FW code reside in another storage medium of information handling system  1200 . For example, application programs and BIOS/FW code can reside in HDD  1264 , in a ROM (not illustrated) associated with information handling system  1200 , in an option-ROM (not illustrated) associated with various devices of information handling system  1200 , in storage system  1290 , in a storage system (not illustrated) associated with network channel  1272 , in another storage medium of information handling system  1200 , or a combination thereof. Application programs  1232  and BIOS/FW code  1234  can each be implemented as single programs, or as separate programs carrying out the various features as described herein. 
     In the embodiments described herein, an information handling system includes any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or use any form of information, intelligence, or data for business, scientific, control, entertainment, or other purposes. For example, an information handling system can be a personal computer, a consumer electronic device, a network server or storage device, a switch router, wireless router, or other network communication device, a network connected device (cellular telephone, tablet device, etc.), or any other suitable device, and can vary in size, shape, performance, price, and functionality. The information handling system can include memory (volatile (e.g. random-access memory, etc.), nonvolatile (read-only memory, flash memory etc.) or any combination thereof), one or more processing resources, such as a central processing unit (CPU), a graphics processing unit (GPU), hardware or software control logic, or any combination thereof. Additional components of the information handling system can include one or more storage devices, one or more communications ports for communicating with external devices, as well as, various input and output (I/O) devices, such as a keyboard, a mouse, a video/graphic display, or any combination thereof. The information handling system can also include one or more buses operable to transmit communications between the various hardware components. Portions of an information handling system may themselves be considered information handling systems. 
     When referred to as a “device,” a “module,” or the like, the embodiments described herein can be configured as hardware. For example, a portion of an information handling system device may be hardware such as, for example, an integrated circuit (such as an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a structured ASIC, or a device embedded on a larger chip), a card (such as a Peripheral Component Interface (PCI) card, a PCI-express card, a Personal Computer Memory Card International Association (PCMCIA) card, or other such expansion card), or a system (such as a motherboard, a system-on-a-chip (SoC), or a stand-alone device). The device or module can include software, including firmware embedded at a device, such as a Pentium class or PowerPC™ brand processor, or other such device, or software capable of operating a relevant environment of the information handling system. The device or module can also include a combination of the foregoing examples of hardware or software. Note that an information handling system can include an integrated circuit or a board-level product having portions thereof that can also be any combination of hardware and software. 
     Devices, modules, resources, or programs that are in communication with one another need not be in continuous communication with each other, unless expressly specified otherwise. In addition, devices, modules, resources, or programs that are in communication with one another can communicate directly or indirectly through one or more intermediaries. 
     Although only a few exemplary embodiments have been described in detail herein, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of the embodiments of the present disclosure. Accordingly, all such modifications are intended to be included within the scope of the embodiments of the present disclosure as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures.