Abstract:
A system for displaying images comprises a plurality of light sources, comprising at least one non-visible light source. The system further comprises a spatial light modulator operable to modulate non-visible light from the non-visible light source to encode one or more objects and for presentation on a display. Finally, the system comprises a detector operable to detect at least a portion of the non-visible light presented on the display.

Description:
TECHNICAL FIELD 
       [0001]    This disclosure relates in general to displays, and more particularly to encoding of infrared objects within an image on the display. 
       OVERVIEW 
       [0002]    Digital light processing (DLP®) systems create images using microscopically small mirrors laid out on a digital micromirror device (DMD). A DMD is a light modulator, a class of devices that may be used to modulate a source light beam into an image suitable for display on a surface. The micromirrors on the DMD can be individually rotated to an on or off state rapidly and produce different shades of colors. The rapid changing of the colors of each pixel produces images on the display. Users of a DLP® system can then view the images on the display. Existing technologies, however, are limited in offering users a method for providing feedback to the DLP® system and interacting with the system in other ways. 
       SUMMARY OF EXAMPLE EMBODIMENTS 
       [0003]    In accordance with one embodiment of the present disclosure, a system for displaying images comprises a plurality of light sources, comprising at least one non-visible light source. The system further comprises a spatial light modulator operable to modulate non-visible light from the non-visible light source to encode one or more objects and for presentation on a display. Finally, the system comprises a detector operable to detect at least a portion of the non-visible light presented on the display. 
         [0004]    In accordance with another embodiment of the present disclosure, a method for displaying images comprises generating a visible image using one or more light sources. The method further comprises modulating, by a spatial light modulator, non-visible light from a non-visible light source with the visible image to encode one or more objects. The method further comprises displaying the visible image and the modulated non-visible light on a display. The method further comprises detecting the non-visible light on the display. 
         [0005]    Technical advantages of this disclosure include the ability to use non-visible light for built-in interaction with a DLP® system. DLP® systems provide advantages over other display systems because of their fast switching times, thus allowing the display to rapidly adjust to feedback from the detector or the participant. 
         [0006]    Other technical advantages of the present disclosure will be readily apparent to one skilled in the art from the following figures, descriptions, and claims. Moreover, while specific advantages have been enumerated above, various embodiments may include all, some, or none of the enumerated advantages. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which: 
           [0008]      FIG. 1  illustrates one embodiment of a system for creating infrared encoded objects for display; 
           [0009]      FIG. 2  illustrates another embodiment of a system for creating infrared encoded objects for display; 
           [0010]      FIG. 3  shows two embodiments of a color wheel for use with a system for creating infrared encoded objects for display; 
           [0011]      FIG. 4  illustrates one embodiment of objects on a display encoded with infrared radiation; and 
           [0012]      FIG. 5  is a flowchart illustrating an example method of creating infrared encoded objects for display. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    A DMD can modulate not only visible light, but also non-visible light, such as infrared or ultraviolet light. For example, if the source light beam in the DLP® system includes non-visible infrared light, the infrared light can be modulated and transmitted to the display along with the visible images. Infrared detectors can interact with the infrared light and allow user participation with the DLP® system. 
         [0014]      FIG. 1  shows one embodiment of a DLP® system that uses infrared light to encode objects on a display. DLP® system  100  comprises one or more light sources  102 ,  104 ,  106 , and  108 . Light sources in a DLP® system can be lamps, light emitting diodes (LEDs), infrared laser light, or any other suitable light source. System  100  can also comprise any suitable number of light sources. In  FIG. 1 , light sources shown in system  100  are red, green, blue, and infrared sources. In certain embodiments, light from light sources  102 ,  104 ,  106 , and  108  can be passed through one or more dichroic filters  110 . Dichroic filters are used to selectively pass only certain wavelengths of light, while reflecting other wavelengths. In some embodiments, system  100  also includes an integrator rod  112  that can combine the light from the light sources before they are sent to digital micromirror device  114  (DMD). The micromirrors on DMD  114  reflect the images created by light sources  102 ,  104 ,  106 , and  108  onto display  116 . Display  116  can comprise a front or rear projection screen, or any other technology suitable for displaying images. DMD  114  reflects not only visible light but also infrared light, so infrared light in system  100  is sent to display  116  as well. This allows infrared light to be sent through projection lens  140  to be emitted from display  116 , much the same way as visible light is. Observer/participant  118  using system  100  can view the visible light images from display  116 . Observer  118  can also use one or more infrared detectors  120  to detect the infrared light from system  100 . Infrared detectors  120  can react to infrared light from system  100 , and transmit information to infrared data controller  122  for processing, feedback, or other uses within system  100 . 
         [0015]    A brief overview of a DLP® system will be useful in understanding the present disclosure. Micromirrors are laid out in a matrix on DMD  114 . Each micromirror on DMD  114  represents one or more pixels of the image projected onto display  116 . Each individual micromirror can be repositioned rapidly, tilting toward the light source to turn it “ON” and away from the light source to turn it “OFF.” The greater the ratio of “ON” time to “OFF” time produces a lighter pixel. More “OFF” time produces a darker pixel. In some embodiments, colors can be added to the visible light by the use of a color wheel. The micromirrors can be repositioned rapidly and synchronized to create the images projected on display  116 . While they are reflecting visible light to create images, the micromirrors can also reflect infrared light onto display  116 . This infrared light can be detected by infrared detectors  120  and used by system  100  to perform a variety of actions. 
         [0016]    Infrared data controller  122  can be used to perform a number of functions in system  100 . For example, infrared detectors  120  can detect the location of objects on display  116  that have been encoded with infrared light. Infrared detectors  120  can then transmit that location information to data controller  122 . This location information can be used by data controller  122  and/or data formatter  124  to modify the objects on display  116 . In one embodiment, infrared detector  120  may take the form of a game controller with input buttons for use by user  118  in a video game. One or more objects on display  116  may be encoded with infrared information for detection by infrared detector  120 . If user  118  pushes a button while the one or more objects are detected by infrared detector  120 , the infrared detector  120  can transmit that information to data controller  122 . Data controller  122  and/or data formatter  124  can then direct the video game system to take an appropriate action. 
         [0017]    Infrared detectors  120  can take a variety of forms and perform a variety of detecting functions, all of which fall within the scope of this disclosure. For example, infrared detectors  120  can receive X and Y coordinate information from the infrared encoded objects on display  116 . The X and Y coordinate information can be used by system  100  to determine the absolute or relative position of objects on display  116 . This position information might, for example, be used by a recreational or educational program utilizing system  100 . Infrared detectors  120  can also be configured to detect movement of one or more objects on display  116 . When an infrared-encoded object moves on display  116 , X and Y coordinate information can be detected by one or more infrared detectors  120  and can be compared to previous coordinate information, allowing infrared detector  120 , data controller  122 , and/or data formatter  124  to determine the speed and/or direction of motion of the infrared encoded object on display  116 . Velocity or motion data can be used to provide feedback to user  118 , modify the images on display  116 , or take any other action as requested by system  100 . 
         [0018]    Infrared detectors  120  in certain embodiments may also detect the intensity of infrared radiation from an infrared-encoded object. One or more objects on display  116  can be encoded with an intensity level selected from two or more degrees of intensity. Infrared detector  120  can differentiate among those degrees of intensity and transmit that information to data controller  122 . Intensity information can be used to differentiate between infrared-encoded objects on the display. For example, infrared detector  120  and/or data controller  122  can take a certain action when a high-intensity encoded object is detected, and can take a different action if a low-intensity encoded object is detected. The intensity of infrared radiation of an object on display  116  can also be used in conjunction with the intensity of visible light of the object. In this embodiment, the visible light intensity can serve as a proxy for infrared intensity. This allows user  118  to interact with system  100  based upon infrared intensity even though user  118  cannot directly see the infrared radiation. 
         [0019]    In another embodiment, infrared radiation can be input into the system using infrared source  130 . Infrared source  130  can be comprised of one or more lamps, LEDs, infrared laser light sources, or any other suitable light sources. In some embodiments, infrared radiation is not passed through dichroic filters  110  and integrator rod  112 . Instead, infrared source  130  inputs infrared light directly to DMD  114  during an off-state. The infrared light is then sent to the display where it can be detected by infrared detectors  120 . In yet another embodiment, infrared light source  130  can pass light through one or more dichroic filters, integrator rods, or colorwheels to filter the light before the light reaches DMD  114 . 
         [0020]      FIG. 2  shows another embodiment  200  of the present disclosure. Here, the DLP® system works similarly to the system described in  FIG. 1 . However, in  FIG. 2  a lamp  132  is used as a light source instead of the separate light sources as described in  FIG. 1 . Infrared laser source  134  can comprise the infrared radiation source. In certain embodiments, lamp  132  can produce infrared light in addition to, or instead of, infrared laser source  134 . Visible light from lamp  132  is passed through a color wheel  136 . Color wheel  136  rotates to provide color to the light from lamp  132 , depending on which color needs to be sent to display  116  at any given time. The light then passes through integrator rod  112  and on to DMD  114 , where it is reflected by the micromirrors onto display  116 . Otherwise system  200  operates in an analogous fashion to the operation of system  100 , illustrated in  FIG. 1 . 
         [0021]      FIG. 3  shows two examples of color wheels that allow infrared light to pass.  FIG. 3A  is a color wheel with filters for red, green, blue, infrared filter  1 , and infrared filter  2 . The red, green, and blue filters pass the respective wavelengths of visible light associated with those colors, and the infrared filters pass the infrared wavelengths of the light. Red light has a wavelength of about 650 nanometers. Green light has a wavelength of about 510 nanometers, and blue light has a wavelength of about 475 nanometers. Infrared radiation has wavelengths approximately between 750 and 1000 nanometers and is largely invisible to the human eye. A color wheel can have one or more infrared filters. As an example, two infrared filters are shown in  FIG. 3A . Two infrared filters can be used instead of one so that two different wavelengths of infrared light can be passed separately. Passing two separate wavelengths of infrared light allows for greater control over infrared-encoded objects than merely utilizing one infrared filter. Infrared detectors  120  can be designed to detect these two distinct wavelengths of infrared light, allowing for greater differentiation among objects encoded with infrared radiation on display  116 . Some objects can be encoded with infrared wavelength  1 , and other objects encoded with infrared wavelength  2 . Infrared detectors  120  can provide feedback to data controller  122  based upon which infrared wavelength is detected. 
         [0022]    Alternatively, the infrared radiation can be passed by a “long” red filter as depicted in  FIG. 3B . Here, the bandwidth of the red filter is extended so that it passes not only red wavelengths but also any infrared wavelengths for use in system  100 . Either of the filters depicted in  FIG. 3 , or any other appropriate filter, can be used as the color wheel in  FIG. 2 . 
         [0023]    Infrared light is a suitable choice for use in a DLP® system to encode objects for a variety of reasons. Infrared light does not cause harm like other types of radiation, for example ultraviolet light. Also, infrared lasers are well-developed and used in a variety of applications, so they have become efficient and relatively inexpensive to use compared to other technologies. 
         [0024]      FIG. 4  shows an example embodiment of infrared-encoded objects on a display  116 .  FIG. 4A  shows an image on display  116  created by a DLP® system  100 . When the red, green, and blue wavelengths are passed through system  100 , the images in  FIG. 4A  are transmitted to display  116 . The red, green, and blue wavelengths are displayed at a rate sufficiently high so that a user  118  (not shown) viewing display  116  sees a solid image. For example, user  118  could see sun  410 , boy  412 , bull  414 , and motion  418  on display  116 . Motion  418  is not an object on the display like the other objects. The arrow is used to symbolize the movement of bull  414  across the screen towards boy  412 . User  118  would not see the arrow, but would instead see bull  414  move across display  116 . 
         [0025]    While those visible images are displayed on display  116 , the infrared radiation used to encode the objects is also transmitted through system  100  and sent to display  116 . An example of this is shown in  FIG. 4B . The infrared radiation is non-visible to participant  118 , but will be detected by infrared detectors  120 . For example, in  FIG. 4B  sun  410  may appear yellow to an observer, but it is also encoded with infrared radiation. Infrared detector  120  will detect that infrared radiation and then interact with system  100  in a variety of ways. Infrared detector  120  might transmit a signal to data controller  122  notifying data controller  122  that the sun  410  has been detected. Data controller  122  and/or data formatter  124  may then take one or more actions based on this information. Data controller  122  may, for example, move the sun  410  across the display. Data controller may also increase or decrease the intensity of visible light associated with sun  410 , thus providing visible feedback to user  118 . Infrared radiation representing boy  412  and bull  414  can also be detected by one or more infrared detectors  120 . 
         [0026]    In some embodiments, infrared detectors like infrared detector  120  can also be used to sense motion of an object on display  116 . For example, if bull  414  moves across display  116  toward boy  412 , infrared detector  120  can detect that movement and send information regarding that movement to data controller  122  for use within system  100 . User  118  in system  100  can use infrared detector  120  and infrared data controller  122  to respond to the motion of the objects on display  116 . In certain embodiments user  118  might use a button on infrared detector  120  to send a response to data controller  122  to indicate that user  118  sees the motion. That response can then be used to alter the location or movement of one or more objects on display  116 . 
         [0027]    In one embodiment of this disclosure, the infrared-encoded objects can be used in a video game system. For example, infrared detectors  120  can be in the form of a gun for use in a shooting game. When an infrared encoded target appears on the screen, user  118  can pull a trigger or perform some other action to send a signal to infrared data controller  122  to provide feedback to the video game. Data controller  122  and/or data formatter  124  can use all or at least a portion of this feedback to alter one or more of the objects displayed on display  116 . For example, the infrared encoded target may move on display  116  or may be removed from display  116  because of user  118 &#39;s actions. A variety of other movements or actions can be taken by user  118  in response to objects or motion on display  116 . Similarly, numerous types of video games can be used in conjunction with system  100 , including sports, action, adventure, strategy, or simulation games. 
         [0028]    In certain embodiments, system  100  can be used for educational purposes as well. The infrared information and the visual objects on display  116  can provide feedback to user  118  in response to actions taken by user  118 . In addition, data controller  122  and/or data formatter  124  can be used to alter the images or objects on display  116 . As an example, infrared detector  120  can be in the shape of a pen that user  118  uses to interact with system  100 . The pen can be used to track an object on display  116 , or can be used to relay location information of an object on display  116  to data controller  122  so that the objects can be altered in response to the movement of the pen. In certain embodiments, system  100  can also be used with 3D glasses. The infrared signals can be used to synchronize 3D glasses for use with a DLP® display. 
         [0029]      FIG. 5  is a flowchart describing one method  500  of displaying objects encoded with non-visible light. In particular, the illustrated technique can encode one or more objects with non-visible light for display and detection. The steps illustrated in  FIG. 5  may be combined, modified, or deleted where appropriate. Additional steps may also be added to the example operation. Furthermore, the described steps may be performed in any suitable order. In step  510 , visible and non-visible light are emitted from one or more light sources  102 ,  104 ,  106 , and  108  (which can be red, green, blue, and infrared sources, respectively). Light can also be emitted from lamp  132  and a non-visible light source like infrared laser source  134 . The light sources in step  510  can be lamps or light-emitting diodes or any other suitable light source. The light sources can also comprise any suitable number of light sources. The visible light from the light sources can be used to create the images on display  116 , and the non-visible light can be used to encode one or more of the objects on display  116 . 
         [0030]    In step  520  the visible and non-visible light is filtered using a color wheel  136  or dichroic filters  110 . In certain embodiments, light from a light source can be passed through color wheel  136 . Color wheel  136  rotates to provide color to the light from lamp  132 , depending on which color needs to be sent to display  116  at any given time. Color wheel  132  may also filter wavelengths corresponding to non-visible light, so that non-visible light can also be sent through the system. Some embodiments may utilize one or more dichroic filters  110  to filter one or more wavelengths separately. In certain dichroic filters  110 , non-visible light can be filtered along with visible light. For example, red light and infrared light can be filtered together with a properly designed dichroic filter  110 . 
         [0031]    In step  530  the visible and non-visible light is combined with an integrator rod  112 . Integrator rod  112  can homogenize the filtered light output from dichroic filters  110  or color wheel  132  into a single stream of light consisting of visible and non-visible wavelengths. Integrator rod  112  can also convert the visible and non-visible light into a uniform pattern, such as a rectangle, for use with DMD  114 . 
         [0032]    In step  540  the visible and non-visible light is selectively reflected with the micromirrors on DMD  114  to produce an image on display  116 . The micromirrors are rotated between ON and OFF positions to produce the desired images on display  116 . While the visible light is being reflected to produce an image that can be seen by a user, the non-visible light can also be sent to display  116  in patterns suitable for use with system  100 . 
         [0033]    In step  550  the reflected visible and non-visible light is sent through projections lens  140  for projection onto display  116 . Projection lens  140  comprises any type of projection lens operable to project the image onto display  116 . Projection lens  140  is also operable to project non-visible light onto display  116 . Display  116  comprises a front or rear projection screen, or any other technology suitable for displaying images. 
         [0034]    In step  560  the non-visible light projected to display  116  is detected with one or more detectors  120 . Detectors  120  comprise any suitable apparatus or device operable to sense any type of non-visible light. For example, detectors  120  could be handheld devices that detect infrared radiation emitted according to method  500 . Detectors  120  can also be any suitable shape or size, such as in the shape of a pen, a video game controller, or a toy gun. Detectors  120  can also be operable to transmit information about the detected non-visible light, or input information from user  118 , to data controller  122  or another device for further use with system  100  or system  200 . In certain embodiments, detectors  120  can provide feedback to user  118  via lights or sounds. Detectors  120  may also employ a motion feedback system to provide information to user  118 . 
         [0035]    Although the present disclosure has been described with several embodiments, a myriad of changes, variations, alterations, transformations, and modifications may be suggested to one skilled in the art, and it is intended that the present disclosure encompass such changes, variations, alterations, transformations, and modifications as fall within the scope of the appended claims.