Abstract:
A rotary control ( 120 ) is illuminated through a controlled illuminated indicator provided by a light guide arc reflector ( 114 ) disposed on a control panel ( 104 ) along an outer periphery of a rotary control knob ( 112 ). The controlled illuminated indicator concurrently indicates status and location of the rotary control knob. The controlled illuminated indictor generates an increased rotational arc of illumination in response to the knob being rotated in a first direction and generates a decreased rotational arc of illumination in response to the knob rotated in a second direction. The rotary control ( 120 ) utilizes a helix slider ( 304 ) to control upwards and downwards movement of a reflector shield ( 302 ) which block and unblocks light rays in response to the knob ( 112 ) being rotated.

Description:
This application is a National Stage filing under 35 U.S.C. §371 of co-pending Patent Cooperation Treaty international application having Serial No. PCT/MY2011/000239 (the ‘PCT international application’) filed on Dec. 5, 2011. This application claims priority to the PCT international application, the entire contents of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates generally to communication devices and more particularly to an illuminated rotary control for a radio communication device. 
     BACKGROUND 
     Communication devices, such as vehicular radios, often include illuminated controls for various radio functions such as volume adjustment, channel change and the like. Designing rotary illuminated controls for the vehicular radio environment is often challenging, as the rotary control can be difficult to fit within a limited form factor of the radio&#39;s control panel. 
     In a dark vehicular environment, a control knob may be insufficiently lit or not lit at all, thus making the control difficult to locate. illumination resolution is typically limited by the number of light sources and thus a light indicator may only show up as a single dot. The use of additional light sources may not be feasible for applications restricted by size and cost. Also, the use of numerous light sources further burdens electrical circuitry and software control. 
     Additionally, state or level information pertaining to the control, for example volume level, is typically displayed on a separate display which is located elsewhere on the control panel away from the volume control knob. For vehicular applications, drivers typically have to take a quick glance at the separate display to identify the current control state while driving, which can be distracting. Using independent displays in such a manner is also extremely costly. 
     Accordingly, there is a need for an improved approach to lighting a control for a communication device. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The accompanying figures where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention. 
         FIG. 1  is a radio communication device operating in accordance with the various embodiments. 
         FIG. 2  shows various illumination arcs provided by the light guide arc reflector of  FIG. 1  in accordance with the various embodiments. 
         FIG. 3  is an exploded view of the rotary control for the radio communication device of  FIG. 1  in accordance with the various embodiments. 
         FIG. 4  is a partially exploded cross sectional side view of the rotary control in accordance with the various embodiments. 
         FIG. 5  is a first cross sectional assembled side view of the rotary control rotated such that the arc illumination is blocked in accordance with the various embodiments. 
         FIG. 6  is a second cross sectional assembled side view of the rotary control rotated such that the arc is illuminated in accordance with the various embodiments. 
         FIG. 7  is a third cross sectional assembled side view of the rotary control rotated such that the arc is illuminated in accordance with the various embodiments. 
         FIG. 8  is a partially assembled view of the rotary control without the knob along with individual piece parts in accordance with the various embodiments. 
         FIG. 9A  is cut-away view of the rotary control in accordance with the various embodiments. 
         FIG. 9B  shows a back perspective view of a knob for the rotary control formed in accordance with the various embodiments. 
         FIG. 10A  shows a partially assembled view of the rotary control without the knob in accordance with the various embodiments 
         FIG. 10B  is a simplified alternative model of a reflector shield mounted within the light guide arc reflector in accordance with the various embodiment. 
       Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in apparatus components providing a purely mechanical-based solution to illuminating a control knob, thereby eliminating the cost associated with the software and electrical approaches. 
     Accordingly, the apparatus components and method steps have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. 
     Briefly, there is provided herein a communication device which provides an improved rotary control illumination interface that allows the location of the rotary control to be determined concurrently with the status of the control. 
     In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element. 
       FIG. 1  is a radio communication device  100  formed in accordance with the various embodiments. The radio communication device  100  may be a vehicular or mobile radio, portable handheld radio, radio accessory, or the like. Such radio communication devices are typically used in law enforcement, medical rescue operations, public safety environments or the like. These types of radio products are used by personnel that are often managing several tasks at one time and the need for an easy-to-interpret user interface is very important. 
     Radio communication device  100  is formed of a housing  102  comprising a plurality of functional radio features mounted on a control panel  104 . Such functional features may comprise, for example, a display  106 , a keypad  108 , speaker porting  110 , and at least one rotary control  120 , such as a volume control knob, channel change knob or other rotary control function. In accordance with the various embodiments, the rotary control  120  is formed and operates to provide an improved illuminated user interface which is easy to interpret even under dark conditions, such as those within a vehicular environment. 
     Rotary control  120  includes knob  112  and light guide arc reflector  114 . The light guide arc reflector  114  is coupled along an outer periphery of the knob  112  on the control panel  104  to provide a continuous arc of illumination without any segmentation. The light guide arc reflector  114  is coupled to the control panel  104  and remains stationary while illumination spreads within the reflector&#39;s arc shape in response to rotation of the knob  112 . 
       FIG. 2  shows an example of various illumination arcs  200  provided by the light guide arc reflector  114  of  FIG. 1  in accordance with the various embodiments. In response to rotation of knob  112 , arc illumination of 25% is shown at  202 , arc illumination of 50% is shown at  204 , arc illumination of 75% is shown at  206 , and arc illumination of 100% is shown at  208 . As knob  112  is rotated from a minimum to maximum position, the illumination of the arc follows the rotation of the control knob  112  without delay or lag. Thus, the light guide arc reflector  114  provides an accurate indicator of the current level or state of the control feature. For example, when implemented within a volume control feature, the illumination provided by light guide arc reflector  114  increasingly spreads around knob  112  as the knob is rotated in a first direction to increase volume. The illumination spread decreases as the knob is rotated in a second direction to decrease the volume. 
     Accordingly, the light guide are reflector  114  provides an accurate indicator of the current volume level of a volume control feature. The knob  112  is rotatable in a continuous motion, and as the knob rotates the arc of light is veiled and unveiled in a corresponding continuous motion. Regardless of the type of control feature, a user is now able to accurately interpret the current level or state of the control knob  112 . 
       FIG. 3  is an exploded view of an assembly for the rotary control  120  for the radio communication device  100  device of  FIG. 1  in accordance with the various embodiments. The rotary control assembly  300  comprises knob  112  and light guide arc reflector  114 , and a sub-system comprising reflector shield  302 , helix slider  304 , light guide base  306 , seal  308 , and switch  310 . 
     The knob  112  and light guide arc reflector  114  are the two components visible from the control panel  104 . Knob  112  is formed of a unitarily molded piece part, made of plastic, metal or other suitably rigid material. Knob  112  will be shown in further detail in subsequent views. The light guide arc reflector  114  may be formed of clear plastic or other suitable material through which light can be transmitted. 
     The reflector shield  302  is formed of a unitarily molded piece part with non-light transmission characteristics, for example an opaque plastic. The reflector shield  302  structure comprises a graduated cylindrical side wall having two tabs  802 ,  804  (tab  804  is shown in subsequent views) formed on an interior surface of the side wall. The tabs,  802   804  of reflector shield  302  are formed to align within the helix slider  304  to enable rotation of the reflector shield  302  up and down the helix slider in response to rotation of the knob  112 . 
     The helix slider  304  may be formed of a unitarily molded piece part formed of plastic, punched and bended sheet metal or casted material to maintain a predetermined rigidity. The helix slider  304  comprises helical slots  810 ,  812  formed therein which provide a helical slide for receiving the tabs  802 ,  804  of reflector shield  302 . In accordance with the various embodiments, the reflector shield  302  slides and rotates up and down the helical slide of the helix slider  302  in response to rotation of the knob  112 . 
     The light guide base  306  comprises a prism structure providing a helix sweep prism surface  320  formed thereon. The light guide base  306  is formed clear or light diffusive plastic or other suitable light guide material. The helix sweep prism surface  320  enables internal light reflection, complying with Total Internal Reflection (TIR). Total internal reflection is an optical phenomenon that happens when a ray of light strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface. If the refractive index is lower on the other side of the boundary and the incident angle is greater than the critical angle, no light can pass through and all of the light is reflected. The critical angle is the angle of incidence above which the total internal reflection occurs. 
     The seal  308  may be a rubber seal or other suitable type gasket material. The seal will couple the base of the light guide  306  to an interior surface of the control panel  104 , as shown in other views. 
       FIG. 4  is a partially exploded cross sectional side view  400  of the rotary control  120  in accordance with the various embodiments. View  400  is provided to show a stack-up for a top assembly  402  and bottom assembly  404  of the rotary control  120 . The top assembly  402  comprises knob  112 , helix slider  304 , switch nut  406 , reflector shield  302 , and light guide arc reflector  114 . The bottom assembly  404  comprises seal  308 , light guide base  306 , switch  310 , printed circuit board (PCB)  410 , and light sources  412 . The top assembly  402  is mounted to control panel  104  of housing  102 , and the bottom assembly  404  is mounted within the housing  102  behind the control panel  104 . 
     The bottom assembly  404  is structured to assemble from the bottom direction towards control panel  104 . The light guide base  306  is structured for assembly from the bottom direction, by means of the radio communication device&#39;s  100  main printed circuit board (PCB)  410  towards the housing  102 , compressing seal  308  to provide water sealing and retention. The light guide  306  has an interior cavity  416  for receiving the base  312  of switch  310 . The light guide  306  further comprises an aperture  418  through which the rotatable portion of the switch  310  will protrude. Thus, the switch  310  is insertable into the light guide base  306 . The reflector shield  302  is formed of a graduated cylindrical side wall  408 . As will be shown in subsequent views, as the reflector shield  302  is rotated, the graduated cylindrical side wall  408  will shield and un-shield (block/unblock) light reflections from the prism surface  320 . 
     The bottom assembly  404  is preferably mounted towards the control panel  104  via the PCB  410  such that seal  308  compresses to provide the sealing and retention of the light guide  306  to an interior surface of the control panel  104 . Alternative mounting means can also be used or incorporated such as adhesives, mechanical bonding, ultrasound welding, screw tightening etc. The bottom assembly  404  thus provides a static platform for receiving the top assembly  402 . Light guide base  306  will be shown lit up in subsequent views by a light source. The PCB  410  provides the electrical contact with the switch  310  and light sources  412 ,  414 . 
     The top assembly  402  may be assembled after the bottom assembly  404  is mounted within the housing  102 . The light guide arc reflector  114  may be coupled to housing  102  using mechanical bonding, ultrasound welding, or the like. The reflector shield  302  is insertable into the light guide arc reflector  114 , followed by the helix slider  304 . The helix slider  304  is mounted to the top of the light guide  306  by using switch nut  406 . This will secure the helix slider  304  to the light guide  306 . The prism surface  320  of light guide  306  will thus be located along an outer periphery of the bottom of the helix slider  304 . 
     The tabs  802  and  804  of the reflector shield  302  will slide into the corresponding helical slots  810 ,  812  of the helix slider  304 . Other views of the helix slider  304  having two helical slots  810 ,  812  will be shown later in conjunction with  FIG. 8 . The reflector shield  302  is able to rotate and travel upwards and downwards about the helical slots  810 ,  812 . 
     Top assembly  402  is assembled such that the light guide mechanism is hid under the knob  112 , and therefore only the light guide arc reflector  114  and knob  112  are visible to a user. The reflector shield  302  unveils glowing light from light guide base  306 , allowing light to illuminate the light guide arc reflector  114 . Only a predetermined arc area is unveiled to shine while the remainder of the arc remains dark. The reflector shield  302  rotates following knob  112  rotation, unveiling reflected light from the prism surface  320  of light guide  306 . 
       FIG. 5  is a first cross sectional assembled side view  500  of the rotary control  120  rotated such that the arc illumination is blocked in accordance with the various embodiments. View  500  shows the graduated cylindrical side wall  408  of reflector shield  302  (i.e. portion of the wall  408  of reflector shield  302  shown on the left side is longer than the portion of the wall shown on the right side). Light sources  412 ,  414 , may comprise for example, separate LEDs, multiple LEDs, florescent tube (s), OLED, EL, light guide film or other light providing source for light guide  306 . 
     In the illustration of  FIG. 5 , the first and second light sources  412 ,  414  shine light rays  506 ,  508  respectively. When the knob  112  is positioned such that the reflector shield provides a zero (0) percent opening, the light rays  506 ,  508  from the light source  412  travel to prism surface  320  of light guide base  306  and are reflected sideways but are blocked by the graduated side wall  408  of reflector shield  302 , Thus, light only travels within the light guide base  306  and no arc of light is visible when viewed from the control panel  104  of  FIG. 1 . 
     Alternatively, depending on the environment within which the radio communication device  100  is being incorporated, it may be desirable to leave the reflector shield  302  slightly offset to allow a small arc of illumination to remain lit at the minimum angle of rotation. The small arc of illumination would facilitate determining the location of the knob  112  even if the rotary control is switched off or at a zero degree rotation setting. The power consumption imposed on a vehicular battery, for example, would be minimal and in some embodiments, if desired, the light sources may be turned off entirely when the radio is turned off. 
       FIG. 6  is a second cross sectional assembled side view  600  of the rotary control  120  rotated such that the light guide arc reflector  114  is illuminated in accordance with the various embodiments. An active illuminated indicator  602  provides illuminated indicator movement in response to rotation of the knob  112 . With the reflector shield  302  rotated to a half opened position, the light rays  506  travel from light source  412  to the prism surface  320  of the light guide base  306 . The light rays  506  are reflected to a reflective surface  604  of control panel  104  to provide an appropriate viewing angle upon the light guide arc reflector  114 . The light rays  508  travelling from light source  414  are blocked by the reflector shield  302 . 
       FIG. 7  is a third cross sectional assembled side view  700  of the rotary control knob  112  rotated such that the light guide arc reflector  114  is illuminated in accordance with the various embodiments. An active illuminated indicator  702  is based on the rotary motion of the knob  112 , in the manner previously described. With the reflector shield  302  rotated to a fully opened position, the light rays  506  travel from light source  412  to the prism surface  320  of the light guide base  306 . The light rays  506  are reflected to the reflective surface  604  of control panel  104  to provide an appropriate viewing angle upon the light guide arc reflector  114 . The light rays  508  travel from light source  414  to the prism surface  320  of the light guide base  306 . The light rays  508  are reflected to a reflective surface  704  of control panel  104  to provide an appropriate viewing angle upon the light guide arc reflector  114 . 
     A variety of illuminated indicator embodiments can be achieved using the illuminated rotary control in accordance with the various embodiments. For example, by using multiple color lights, 25% could be green, 50%˜75% could be yellow (the 1 st  25% remain green, such that two color regions can be seen, and during the maximum knob rotation position, the 75%˜100% arc section can be red in color, and thus three colors sections can be seen. Depending on the design and user interface requirements, the arc color can be discrete to one color (for example, changing from green to red during the transition from min to max rotation) by using tricolor LED, avoiding any color mixing issues. For example, when the arc is illuminated 25%, the color is green, when the arc is illuminated in the 50%˜75% range of rotation, the whole are can be yellow, and for 100% rotation, the whole arc can be red. 
       FIG. 8  is shows a partially assembled view of the rotary control without the knob  112  along with individual piece parts in accordance with the various embodiments. View  800  shows the light guide are reflector  114  coupled to the control panel  104 . The reflector shield  302  is mounted within the light guide arc reflector  114 . The helix slider  304  is mounted within the reflector shield  302 . The switch  310  protrudes through the helix slide  304 . 
     The reflector shield&#39;s graduated side wall  408  veils and gradually unveils light as the shield is rotated. The cylindrical shaping has an opening within the side wall  408  which allows for complete unveiling of light. 
     The helix slider  304  comprises helical slots  810 ,  812  formed therein. The helical slots  810 ,  812  of helix slider  304  provide a helical slide upon which the reflector shield  302  rotates. The first and second tabs  802 ,  804  of reflector shield  302  protrude from an interior surface of the reflector shield  302  into their respective helical slots  810 ,  812 . Tabs  802 ,  804  of reflector shield  302  align within the helical slots  810 ,  812  of helix slider  304 . Thus, the reflector shield  302  is able to rotate within the slots so as to slide up and down the helix slider  304  in response to the rotation of the knob  112 . The reflector shield  302  may be raised and lowered in accordance with the pitch of the helix slider  304 . 
     The advantage of having more than one slot is to provide a balanced and coupled constraint for the reflector shield  302 . The use of a single slot would cause the rotation and movement of tabs  802  or  804  to me misguided causing the reflector shield to tilt to one side. Having two helical slots  810 ,  812  in the helix slider  304  provides steady rotation and smooth movement of the reflector shield  302  while sliding within the helical slots  810 ,  812 . The use of two helical slots  810 ,  812  ensures proper guidance and alignment of the reflector shield  302  along the axis of rotation. 
       FIG. 9A  is cut-away view of the rotary control in accordance with the various embodiments.  FIG. 9B  shows a back perspective view of the knob  112  for the rotary control formed in accordance with the various embodiments. Knob  112  is formed of a unitarily molded piece part comprising a center core  902  for mounting to the rotating potion of switch  310 . The knob  112  also comprises an interior wall  904 . As knob  112  is rotated, the interior wall  904  of the knob  112  pushes the reflector shield  302 . Thus, the reflector shield  302  is synchronized to the rotation of the knob  112 . In response to being pushed, the reflector shield  302  slides/rotates along the helical slide provided by helix slider  304  to veil and unveil illumination generated by the light guide  306  and reflected via prism surface  320 . 
       FIG. 10A  shows a partially assembled view of the rotary control  120  without the knob  112  in accordance with the various embodiments this view shows the previously described reflector shield  302  aligned within the helical slots  810 ,  812  of helix slider  304 . The tab  802  can be seen protruding from the interior surface of the reflector shield  302  into helical slot  812  of helix slider  304 . Tabs  802 ,  804  are formed on the interior surface so as to slide within the helical slots  810 ,  812  of helix slider  304 . Thus, the reflector shield is able to rotate and slide up and down the helix slider  304  in response to the rotation of the knob  112  (not shown in this view). The reflector shield  302  includes the graduated cylindrical side wall  408  and, depending on the angle of rotation of the reflector shield, the prism surface  320  of light guide  306  may be inserted into the graduated cylindrical side wall  408  to block light reflections from prism surface  320 . The reflector shield  302  and the control knob  112  are the only elements that rotate within the assembly. All other elements, including the light guide  306  with prism sweep  320 , and the helix slider  304  are stacked in a stationary manner. The reflector shield  302  slides up and down the helical slider  304  along the helical slots  810 ,  812  in response to knob rotation such that the reflector shield  302  veils and unveils light from the light guide&#39;s prism surface  320  in a controlled manner. 
       FIG. 10B  is a simplified model of a reflector shield  1002  mounted within the light guide arc reflector  114  in accordance with another embodiment. Like the previously described reflector shield  302 , the reflector shield  1002  comprises a graduated cylindrical side wall  408  with first and second tabs formed on an interior surface of the wall for aligning within the helical slots  810 ,  812  of helix slider  304  (shown in previous views). As the knob  112  (shown in previous views) is rotated, the reflector shield  1002  slides along the helical slots  810 ,  812  thereby raising the reflector shield  1002  by the pitch of the helical slider  304 . The rotation of the graduated cylindrical side wall  408  is used to block and unblock light as previously described. 
     Accordingly, there has been provided an improved illumination interface for a rotary control. The use of the mechanical based system minimizes the need for any additional software or electronics. The rotary control location and status level are concurrently provided by the same indicator. The use of an active backlit indicator ring allows a user to effectively determine the status level of the control with a single glance without having to read a display. The improved illumination interface is particularly beneficial for communication devices utilized in the public safety arena, such as in the mobile or vehicular two-way radio environment. 
     In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.