Abstract:
Embodiments of apparatuses, methods, and systems for a user interface to receive electromagnetic radiation as input are generally described herein. Other embodiments may be described and claimed.

Description:
FIELD  
       [0001]     Embodiments of the present invention relate generally to the field of user interfaces, and more particularly to using electromagnetic radiation as input for such user interfaces.  
       BACKGROUND  
       [0002]     User interfaces may have a wide variety of input mechanisms. One type of user interface may allow for input directly onto the screen. These user interfaces are often referred to as digitizers. Digitizers are devices that sense and convert a position of an input device on a screen surface into digital coordinate data. Prior art digitizers locate the position of the input device by using ultrasonic sensing devices, electromagnetic field location sensing devices, restive sensing devices, or capacitive sensing devices. Each of these prior art digitizers may present challenges such as imprecise tracking, electromagnetic interference, and/or the necessity of recalibration. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0003]     Embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:  
         [0004]      FIG. 1  illustrates a user interface and input device in accordance with an embodiment of the present invention;  
         [0005]      FIG. 2  illustrates a front view of a sensing device in accordance with an embodiment of the present invention;  
         [0006]      FIG. 3  illustrates an intensity distribution of electromagnetic radiation over elements of the light modulating device in accordance with an embodiment of the present invention;  
         [0007]      FIG. 4  illustrates a front view of a light modulating device in accordance with an embodiment of the present invention;  
         [0008]      FIG. 5  illustrates a front view of the user interface and input device in accordance with an embodiment of the present invention;  
         [0009]      FIG. 6  illustrates components of the user interface in accordance with an embodiment of the present invention;  
         [0010]      FIG. 7  illustrates a front view of an element of the light modulating device in accordance with an embodiment of the present invention;  
         [0011]      FIG. 8  illustrates a front view of an element of a color filter in accordance with an embodiment of the present invention;  
         [0012]      FIG. 9  illustrates components of the user interface in accordance with another embodiment of the present invention; and  
         [0013]      FIG. 10  illustrates a front view of an element of a combined modulating/color filter device in accordance with an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0014]     Illustrative embodiments of the present invention may include a user interface capable of receiving electromagnetic radiation as input.  
         [0015]     Various aspects of the illustrative embodiments will be described using terms commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art. However, it will be apparent to those skilled in the art that alternate embodiments may be practiced with only some of the described aspects. For purposes of explanation, specific devices and configurations are set forth in order to provide a thorough understanding of the illustrative embodiments. However, it will be apparent to one skilled in the art that alternate embodiments may be practiced without the specific details. In other instances, well-known features are omitted or simplified in order not to obscure the illustrative embodiments. In particular, a wide variety of optical components not specifically shown such as, but not limited to, prisms, mirrors, lenses, integrators, diffusers, and/or polarizers may be used as appropriate to fold, bend, or modify the electromagnetic radiation for the intended application.  
         [0016]     Further, various operations will be described as multiple discrete operations, in turn, in a manner that is most helpful in understanding the present invention; however, the order of description should not be construed as to imply that these operations are necessarily order dependent. In particular, these operations need not be performed in the order of presentation.  
         [0017]     The phrase “in one embodiment” is used repeatedly. The phrase generally does not refer to the same embodiment; however, it may. The terms “comprising,” “having,” and “including” are synonymous, unless the context dictates otherwise.  
         [0018]      FIG. 1  illustrates a system  100  including a user interface  102  in accordance with an embodiment of the present invention. In this embodiment, the components of the user interface  102  may cooperate to render output of an image on a screen surface  104  and/or to sense provision of electromagnetic radiation at the screen surface  104 .  FIG. 1  introduces the components of the user interface  102  in order to facilitate the discussion of interactions between the components.  FIG. 1  is not intended to necessarily present the physical layout of said components within the user interface  102 . Physical layouts of various embodiments may be described below; however, other layouts are within the teachings of embodiments of the present invention.  
         [0019]     In the present embodiment, a screen surface  104  may be optically coupled to both a sensing device  108  and a light modulating device  112 , which are disposed on a first side of the screen surface  104 , as shown. As used herein, “optically coupled” is intended to include the capability of electromagnetic radiation (EMR) to be directly or indirectly provided from one component to another. The light modulating device  112  may also be optically coupled to a light source  116 , which may provide EMR, e.g., light, to the light modulating device  112 .  
         [0020]     In one embodiment the light source  116  may be, but is not limited to, a gaseous discharge lamp (e.g., high-pressure mercury, tungsten, halogen, or metal halide) and/or solid-state radiation sources (e.g., light-emitting diodes, laser diodes, etc.).  
         [0021]     A processing device  120  may be coupled to the light modulating device  112  and configured to transmit control signals to the light modulating device  112 . The control signals may cause matrix-addressable elements of the light modulating device  112  to modulate the light in a manner to output an image on the screen surface  104 . Modulation of the light may be done by selectively transmitting portions of the light provided by the light source  116 .  
         [0022]     In one embodiment, the light modulating device  112  may include, e.g., a liquid crystal display. Examples of these types of displays include, but are not limited to, transmissive displays, such as thin film transistor (TFT), polysilicon (P-Si), and Silicon-on-insulator (SOI) as well as reflective displays such as LCoS (Liquid Crystal on Silicon). In other embodiments, the light modulating device  112  may additionally/alternatively employ other types of displays such as, but not limited to, a digital micromirror display (DMD), an organic light-emitting diode (OLED) display, which may also include the light source  116 , etc.  
         [0023]     In various embodiments, the processing device  120  may be a processor, an application-specific integrated circuit, a controller, etc. The processing device  120  may either be a resource dedicated to functions of the user interface  102  or shared with one or more other components of the system  100 . Furthermore, in one embodiment the processing device  120  may include various processing sub-units to control the operation of various components of the user interface  102 .  
         [0024]     The processing device  120  may also be coupled to the sensing device  108 . The sensing device  108  may be configured to receive and sense input in the form of EMR provided at the screen surface  104  from a second side of the screen surface  104  that is opposite the first side.  
         [0025]     The processing device  120  may also be coupled to a storage medium  122 . The storage medium  122  may store instructions that the processing device  120  may execute to cause one or more components of the user interface  102  to perform various functions. In various embodiments, the storage medium  122  may include, but is not limited to, read-only memory (ROM); random-access memory (RAM); magnetic disk storage media; optical storage media (e.g., Digital Versatile Disk, Compact Disk); and flash memory devices (e.g., USB flash drive, Secure Digital (SD) memory card, Compact Flash (CF) memory card, Smart Media (SM) memory card, Multi Media Card (MMC), MemoryStick (MS) card).  
         [0026]     In one embodiment, EMR may be provided at the screen surface  104  by an input device  124 : Use of EMR as input may facilitate the reduction of certain interference challenges such as electromagnetic interference. The input device  124  may have a radiation source  128  such as, but not limited to, a gaseous discharge lamp (e.g., high-pressure mercury, tungsten, halogen, metal halide, etc.) and/or solid-state radiation sources (e.g., light-emitting diodes, laser diodes, etc.).  
         [0027]     In various embodiments, the user interface  102  may be, but is not limited to, a general-purpose computing device (e.g., a desktop computing device, a laptop computing device, a palm-sized computing device) or a peripheral computing device (e.g., a graphics tablet). In various embodiments, the user interface  102  may be employed in applications for use in medical imaging, military procedures, graphics editing, general computer input, etc.  
         [0028]      FIG. 2  illustrates a front view of the sensing device  108  in accordance with an embodiment of the present invention. The sensing device  108  may have a number of elements, e.g., sensing elements  201 - 209 , capable of sensing EMR at a given area and generating an electronic signal in response. Although  FIG. 2  illustrates a 3×3 array of sensing elements, other embodiments may have any other sized array, which may or may not be symmetrical or even rectangular.  
         [0029]     Each of these sensing elements  201 - 209  may correspond to a different area of the screen surface  104 . An EMR pattern  210  provided from the input device  124  at the screen surface may be incident upon the one or more of the sensing elements  201 - 209  that correspond to the area the input device  124  is located. Because each of the sensing elements  201 - 209  correspond to a known area of the screen surface  104 , recalibration, as required by prior art digitizers, is not necessary.  
         [0030]      FIG. 3  illustrates a histogram of the intensities of the EMR at the sensing elements  201 - 209  in accordance with an embodiment of the present invention. In this embodiment, the sensing elements  201 - 209  may each send an electronic signal to the processing device  120  corresponding to the intensity of the EMR received at that element. The electronic signal sent to the processing device  120  from the sensing element  205  may reflect that it has received the greatest portion of EMR. Therefore, the processing device  120  may interpret this to mean that the input was centered at the area of the screen surface  104  corresponding to the sensing element  205 .  
         [0031]     Various signal processing techniques may be used in the processing of the electronic signals received from the sensing elements  201 - 209  depending on the objectives of a particular embodiment. In one embodiment radiative noise cancellation techniques may be used to account for ambient EMR by developing, e.g., a threshold intensity level.  
         [0032]     Furthermore, the processing of the electronic signals received from the sensing elements  201 - 209  may be done in reference to the state of other components of the user interface  102 . For example, in one embodiment, each of the sensing elements  201 - 209  may be optically coupled to receive the input EMR through a corresponding light modulating element. If a modulating element is transmitting only a relatively small amount of radiation, an electronic signal from a sensing element corresponding to that particular modulating element may be processed by taking this into account, e.g., by reducing a threshold intensity level.  
         [0033]     In one embodiment, the input received by the sensing elements  201 - 209  may be synchronized with the image that is output on the screen surface  104  at the time of reception. For example, in one embodiment, the image output on the screen surface  104  may provide an input location, e.g., a dialog box having an “OK” button. If a sensing element senses the provision of EMR at that input location, the electronic signal transmitted to the processing device  120  may be interpreted by the processing device  120  to indicate a selection of that particular input command.  
         [0034]      FIG. 4  illustrates a front view of the light modulating device  112  in accordance with an embodiment of the present invention. In this embodiment, the light modulating device may have a number of elements, e.g., modulating elements  401 - 409 , capable of selectively transmitting portions of the light provided by the light source  116 . In this embodiment the modulating elements  401 - 409  may respectively correspond to the sensing elements  201 - 209  in a 1:1 manner, which may, in turn facilitate having a sensing resolution commensurate with display resolution, e.g., a 1 dot resolution. Other embodiments may have other degrees of correspondence between sensing elements and light modulating elements, e.g., 1:n or n:1. The degrees of correspondence may be a factor of specific design implementations factoring in, e.g., market requirements and/or cost.  
         [0035]     In this embodiment, the processing device  120  may receive an electronic signal from the sensing elements  201 - 209  as input and may generate and transmit, in response, control signals to the light modulating device  112  to activate corresponding modulating elements  401 - 409 . In this manner, an image output on the screen surface  104  may provide visual feedback, to a user, of the input provided by the input device  124 .  
         [0036]     In various embodiments, the modulating elements  401 - 409  may create a visual representation of the EMR pattern  210  input to the sensing elements  201 - 209  in a number of ways. For example, in one embodiment, only the modulating element  405  corresponding to the sensing element  205  that receives the greatest amount of EMR may be activated. In another embodiment, the amount of light transmitted by each modulating element  401 - 409  may be proportional to the intensity of the EMR (over the threshold noise level) received at corresponding ones of the sensing elements  201 - 209 . For example, in the above embodiment the modulating element  405  may transmit a first amount of light with each of the rest of the modulating elements  401 - 404  and  406 - 409  transmitting a reduced amount that is proportional to the reduced intensity on corresponding sensing elements  201 - 204  and  206 - 209 .  
         [0037]     In one embodiment, the light modulating device  112  may be manufactured separately from the sensing device  108  and coupled to one another post-manufacturing. In other embodiments, the light modulating device  112  may be integrally formed with the sensing device  108 . Whether these components are separately or integrally formed may relate to a number of factors of particular embodiments including, e.g., temperatures involved in the deposition of elements, etc.  
         [0038]     In various embodiments, the design of the light modulating device  112  and/or the sensing device  108  may facilitate incorporation into other types of computing devices, which could reduce manufacturing costs. For example, the light modulating device  112  may be designed such that the same device could be used in the user interface  102  as well as in a display not having the same input functionalities as the user interface  102 , e.g., a display not having the sensing device  108 .  
         [0039]      FIG. 5  illustrates a front view of the user interface  102  in accordance with one embodiment of the present invention. As the input device  124  is moved over the face of the screen surface  104  the user interface  102  may sense the movement and output an image including a line  504  that serves as a visual indicator of the input received. In various drawing applications, it may be desirable to change attributes of the line, e.g., thickness. Therefore, in an embodiment the input parameters, e.g., the intensity and/or pattern of the EMR provided at the screen surface  104 , may be adapted to effectuate the desired input. In one embodiment, the dynamic adjustment of the provided EMR may be through, e.g., squeezing the input device  124 , to adjust the intensity and/or pattern of emitted EMR.  
         [0040]      FIG. 6  illustrates a cross-sectional view of components of the user interface  102  in accordance with an embodiment of the present invention. In this embodiment the light source  116  may provide light into an end  604  of a light guide  608 . The light guide  608  may direct the light out of a first surface  612  toward the modulating element  405 . The light guide  608  may be tapered to facilitate gradual transmission of the light from the surface  612 . Light hitting the surface  612  at an incident angle that is less than the critical angle may be transmitted, while light that is incident at an angle greater than the critical angle may experience total internal reflection. The internally reflected light may also experience total internal reflection at a second surface  616 . In one embodiment, a coating may be applied to the second surface  616  to facilitate this internal reflection. Due to the taper of the light guide  608  the incident angle in which the light strikes the surface  612  may be incrementally decreased until it is less than the critical angle, at which point it may be transmitted to the modulating element  405 , which may be a liquid crystal element in the present embodiment.  
         [0041]      FIG. 7  illustrates a front view of the modulating element  405  in accordance with an embodiment of the present invention. The modulating element  405  may have a first section  704 , a second section  708 , and a third section  712 . Each of these sections  704 ,  708 , and  712  may be capable of selectively modulating light by transmitting selected amounts of the light. Referring also to  FIG. 6 , the light that is transmitted through the light modulating element  405  may be presented to a light filter element  620 .  
         [0042]      FIG. 8  illustrates a front view of the light filter element  620 , in accordance with an embodiment of the present invention. The light filter element  620  may have sections  804 ,  808 , and  812  that respectively correspond to the sections  704 ,  708 , and  712  of the modulating element  405 . In one embodiment, the filter section  804  may be configured to transmit light of a red spectrum, e.g., EMR having wavelengths approximately between 625-740 nanometers (nm), the filter section  808  may be configured to transmit light within a green spectrum, e.g., EMR having wavelengths of approximately 500-565 nm, and the filter section  812  may be configured to transmit light within a blue spectrum, e.g., EMR having wavelengths of approximately 440-485 nm. In various embodiments edge and/or notch filters may be used for the filtering out of undesired EMR.  
         [0043]     In an embodiment where the filter section  804  is an edge filter, it may transmit EMR having wavelengths over 625 nm, which may include both the red spectrum and an infrared spectrum. Likewise, in an embodiment where the filter section  812  is an edge filter, it may transmit EMR having wavelengths under 485 nm, which may include the blue spectrum and an ultraviolet spectrum.  
         [0044]     In one embodiment, the input device  124  may provide EMR of a spectrum that may encompass one or more of the wavelengths transmittable through the filter sections  804 ,  808 , and/or  812 . Referring also to  FIG. 6 , in one embodiment the input device  124  may provide broad spectrum EMR  624 , e.g., white light, at the screen surface  104 . The EMR  624  may be transmitted through the screen surface  104  to the color filter  620 . Different portions of the EMR  624  may be transmitted through the different filter sections  804 ,  808 , and  812 . The modulating element  405  may receive the different portions of the EMR  624  from the filter sections  804 ,  808 , and  812  and modulate the EMR  624 . The modulated EMR  624  may enter the light guide  608 . Due to the angles at which the EMR  624  enters the light guide, at least a portion may be transmitted through to the sensing element  205 .  
         [0045]     In this embodiment, if all of the modulating sections  704 ,  708 , and  712  happened to be closed, e.g., configured to transmit no light in either direction, the EMR  624  may be prevented from being transmitted through the modulating element  405 . However, the instances of this happening may be rare enough, both in the frequency of occurrence and in the time that such an occurrence would last, that it may not have a noticeable impact on the consistent receipt of input. An embodiment may transmit a certain level of backlight even through the darkest modulating elements, such that EMR provided by the input device  124  may be transmitted through the modulating elements. Additionally, in various embodiments, radiative noise cancellation techniques may be adapted to accommodate darker modulating elements, e.g., the threshold level may be reduced.  
         [0046]     In one embodiment, the EMR  624  may include non-visible EMR, e.g., radiation of the infrared spectrum. The infrared portion of the EMR  624  may be transmitted through the filter section  804  if it is, e.g., an edge filter that allows radiation of both the red spectrum and the infrared spectrum. The infrared EMR  624  may pass through the modulating element  405 , through the light guide  608  and be incident upon the sensing element  205 .  
         [0047]     In one embodiment, a coating, e.g., a dichroic coating may be applied to a surface, e.g., the surface  616 , of the light guide  608 . The dichroic coating may transmit EMR within the IR spectrum while reflecting light with wavelengths that are below the IR spectrum. This may facilitate the internal reflection of the EMR provided by the light source  116 , while allowing the IR portion of the EMR  624  to be transmitted to the sensing element  205 . In an embodiment where the light source  116  emits broad spectrum EMR, steps may be taken to filter out the IR EMR prior to the internal reflections within the light guide  608 . This may be done, e.g., by a filter coating on the end  604 .  
         [0048]      FIG. 9  illustrates components of the user interface  102  in accordance with another embodiment of the present invention. In this embodiment, a light guide  904  may be used to direct light provided by the light source  116  towards the modulating element  405 , and to transmit EMR  624  from the input device  124  to the sensing element  205 , similar to the light guide  608  illustrated and described above. However, in this embodiment, the light guide  904  may be a dichroic mirror configured to transmit certain wavelengths of EMR, e.g., over 740 nm, while reflecting other wavelengths, e.g., under 740 nm. This embodiment may allow for infrared portions of the EMR  624  to be incident upon the sensing element  205  while directing the non-infrared portions of EMR from the light source  116  towards the modulating element  405 . In one embodiment, a filter  908  may be placed adjacent to the light source  116  to filter infrared portions of EMR so that the sensing element  205  does not inadvertently sense infrared EMR from the light source  116 .  
         [0049]     As shown in  FIG. 7  and in  FIG. 8 , the sections configured for the various colored light may be approximately the same dimensions. However, in other embodiments one or more of the sections may have different dimensions. Furthermore, various embodiments may have more or less than the three sections shown above.  
         [0050]      FIG. 10  illustrates a front view of a combined modulating/filtering element  1000  in accordance with an embodiment of the present invention. In this embodiment, a section  1004  may be configured for modulating/filtering EMR in the green spectrum, section  1008  may be configured for modulating/filtering EMR in the red spectrum, and section  1012  may be configured for modulating/filtering EMR in the blue spectrum. In this embodiment, there may be an additional section  1016  that may be configured for the transmitting of EMR provided by the input device  124 .  
         [0051]     In one embodiment, the section  1016  may have a filter to facilitate differentiation of the EMR provided from the input device  124  from ambient EMR. For example, the input device  124  may provide EMR within the infrared spectrum and the filter segment of section  1016  may filter out substantially all of the non-infrared EMR. In various embodiments, the section  1016  may or may not be capable of modulating the EMR provided by the input device  124 .  
         [0052]     An embodiment having the section  1016  transmit only non-visible radiation, e.g., IR EMR, may facilitate the filtering out of visible radiation from the light source  116 . This may, in turn, facilitate the input of EMR from the input device  124  without adversely affecting the output of an image on the screen surface  104 .  
         [0053]     The varying dimensions of the sections of this embodiment may be based at least in part on a motivation to have more EMR of the green spectrum transmitted as output to facilitate a desired color balance. This embodiment may, therefore, use the area provided by the reduced dimensions of sections  1008  and  1012  for section  1016 .  
         [0054]     Although the present invention has been described in terms of the above-illustrated embodiments, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations calculated to achieve the same purposes may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. Those with skill in the art will readily appreciate that the present invention may be implemented in a very wide variety of embodiments. This description is intended to be regarded as illustrative instead of restrictive on embodiments of the present invention.