PATENT DOCUMENT

Publication Number: US-10145712-B2
Application Number: US-201514841801-A
Country: US
Kind Code: B2

Title: Optical encoder including diffuser members

Abstract:
An optical encoder having diffuser members, and methods for detecting the rotational movement of the cylinder of the optical encoder are disclosed. The optical encoder may include a rotatable cylinder configured to reflect light. The rotatable cylinder may include an encoding pattern of alternating reflective stripes having distinct light-reflective properties. The optical encoder may also include a light source positioned adjacent the rotatable cylinder, and an array of optical sensors positioned adjacent the rotatable cylinder. The array of optical sensors may receive the reflected light from the rotatable cylinder. The optical encoder may include a diffuser member positioned on the rotatable cylinder, the light source, and the array of optical sensors.

Claims:
What is claimed is: 
     
       1. A watch, comprising:
 a housing having an opening; 
 a crown positioned at least partially within the opening and configured to receive rotational input; and 
 an optical encoder positioned within the housing and comprising:
 a rotatable cylinder connected to the crown; 
 an encoding pattern formed on an outer surface of the rotatable cylinder, the encoding pattern comprising:
 a group of light-reflective markings; and 
 a group of non-reflective markings interspersed with the group of light-reflective markings; 
 
 a light source positioned adjacent the rotatable cylinder and configured to provide a light beam to the outer surface of the rotatable cylinder; and 
 an array of optical sensors positioned adjacent the rotatable cylinder and configured to detect the rotational input using a portion of the light beam reflected from the rotatable cylinder along an axial direction, wherein 
 
 the light beam provided by the light source is widened by the optical encoder in the axial direction prior to being received by the array of optical sensors. 
 
     
     
       2. The watch of  claim 1 , wherein the optical encoder comprises a diffuser member configured to widen the light beam in the axial direction by diffusing at least one of: the light beam provided by the light source before being reflected, or the light beam reflected by the rotatable cylinder. 
     
     
       3. The watch of  claim 2 , wherein the diffuser member is positioned on the rotatable cylinder and comprises: at least one set of diffuser lenses positioned on the outer surface of the rotatable cylinder. 
     
     
       4. The watch of  claim 3 , wherein the at least one set of diffuser lenses is disposed along an entire length of the rotatable cylinder. 
     
     
       5. The watch of  claim 3 , wherein each of the at least one set of diffuser lenses comprises a concave lens. 
     
     
       6. The watch of  claim 3 , wherein each diffuser lens of the at least one set of diffuser lenses is positioned adjacent one another to form a scalloped pattern of diffuser lenses. 
     
     
       7. The watch of  claim 3 , wherein the at least one set of diffuser lenses is separated by a transitional portion of the rotatable cylinder, the transitional portion configured to diffuse the light beam. 
     
     
       8. The watch of  claim 3 , wherein the at least one set of diffuser lenses is disposed over a distinct light-reflective marking of the group of light-reflective markings. 
     
     
       9. The watch of  claim 1 , wherein the optical encoder comprises a wall member positioned between the light source and the array of optical sensors, the wall member configured to prevent at least one of: the light beam from the light source from being directly exposed to the array of optical sensors, or the light beam reflected from the rotatable cylinder from being reflected toward the light source. 
     
     
       10. A watch, comprising:
 a housing; 
 a display positioned within the housing and configured to depict a graphical output of the watch; 
 a rotatable cylinder extending into the housing and configured to reflect light, the rotatable cylinder comprising an encoding pattern of alternating reflective stripes having distinct light-reflective properties; 
 a light source positioned adjacent the rotatable cylinder; 
 an array of optical sensors positioned adjacent the rotatable cylinder and configured to detect a rotation of the rotatable cylinder using a portion of the light reflected from the rotatable cylinder along an axial direction; and 
 a diffuser member configured to widen light in the axial direction and positioned on at least one of:
 the rotatable cylinder; 
 the light source; or 
 the array of optical sensors, wherein 
 
 the graphical output is responsive to the rotation of the rotatable cylinder. 
 
     
     
       11. The watch of  claim 10 , wherein the diffuser member is positioned on the light source and comprises a diffuser window covering at least a portion of the light source. 
     
     
       12. The watch of  claim 11 , wherein the diffuser window is positioned between the light source and the rotatable cylinder. 
     
     
       13. The watch of  claim 11 , wherein a light beam provided by the light source passes through the diffuser window to the rotatable cylinder. 
     
     
       14. The watch of  claim 10 , wherein the diffuser member is positioned on the array of optical sensors and comprises a diffuser sheet disposed over at least a portion of the array of optical sensors. 
     
     
       15. The watch of  claim 14 , wherein the reflected light from the rotatable cylinder is configured to pass through the diffuser sheet to the array of optical sensors. 
     
     
       16. The watch of  claim 14 , wherein the diffuser sheet covers at least a portion of a surface of the array of optical sensors, the surface configured to receive the reflected light from the rotatable cylinder. 
     
     
       17. The watch of  claim 10 , wherein the encoding pattern of alternating reflective stripes comprises: a group of light colored-stripes reflecting light in a specular manner; and a group of dark colored-stripes reflecting light in a diffusive manner. 
     
     
       18. A method of detecting rotational movement of a rotatable cylinder of a watch, the method comprising:
 emitting an emitted light beam, using a light source positioned within a housing of the watch, toward a portion of the rotatable cylinder within the housing; 
 reflecting the emitted light beam off the rotatable cylinder to form a reflected light beam along an axial direction of the rotatable cylinder; 
 receiving the reflected light beam at an array of optical sensors positioned along the axial direction; and 
 prior to receiving of the reflected light beam, widening the light beam in the axial direction by diffusing at least one of the emitted light beam, or the reflected light beam using a diffuser member; and 
 estimating an amount of rotation of the rotatable cylinder based on the reflected light beam that is received at the array of optical sensors. 
 
     
     
       19. The method of  claim 18 , wherein estimating the amount of rotation of the rotatable cylinder comprises:
 determining a first electrical output of each optical sensor of the array of optical sensors at a first time; 
 receiving rotational movement of the rotatable cylinder; 
 determining a second electrical output of each optical sensor of the array of optical sensors at a second time subsequent to the received rotational movement of the rotatable cylinder; and 
 computing the amount of rotation using the first electrical output and the second electrical output. 
 
     
     
       20. The method of  claim 18 , wherein axially diffusing the emitted light beam comprises passing the emitted light beam through a diffuser window covering at least a portion of the light source to spread the emitted light beam in an axial direction. 
     
     
       21. The method of  claim 18 , wherein axially diffusing the emitted light beam comprises passing the emitted light beam through a plurality of diffuser lenses disposed around an outer surface of the rotatable cylinder to spread the reflected light beam in an axial direction. 
     
     
       22. The method of  claim 18 , wherein axially diffusing the reflected light beam comprises passing the reflected light beam through a diffuser sheet disposed over at least a portion of the array of optical sensors to spread the reflected light beam in an axial direction.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a nonprovisional patent application of and claims the benefit to U.S. Provisional Patent Application No. 62/047,977, filed Sep. 9, 2014, and titled “Optical Encoder including Diffuser Members,” and U.S. Provisional Patent Application No. 62/130,038, filed Mar. 9, 2015, and titled “Optical Encoder including Diffuser Members,” the disclosures of which are hereby incorporated herein by reference in their entirety. 
    
    
     FIELD 
     The disclosure relates generally to electronic devices, and more particularly to optical encoders having diffuser members, and methods for detecting the rotational movement of an input device using the optical encoders having diffuser members. 
     BACKGROUND 
     Many devices, including mechanical, electronic, and computerized devices, may utilize various types of sensors for obtaining user input or receiving motion input from other aspects of the device. Traditionally, a rotary sensor may be used to measure rotary motion of a device or component. However, many traditional rotary sensors are not well adapted for use in a small or compact space that may be required for an electronic device having a small form factor. It is with respect to these and other general considerations that embodiments have been made. 
     SUMMARY 
     An electronic device is disclosed. The electronic device comprises a housing, a crown coupled to the housing and configured to receive rotational input, and an optical encoder positioned within the housing. The optical encoder comprises a rotatable cylinder in communication with the crown, and an encoding pattern formed on an outer surface of the rotatable cylinder. The encoding pattern comprises a group of light-reflective markings and a group of non-reflective markings interspersed with the group of light-reflective markings. The optical encoder also comprises a light source positioned adjacent the rotatable cylinder. The light source provides a light beam to the rotatable cylinder to be reflected. Additionally, the optical encoder comprises an array of optical sensors positioned adjacent the rotatable cylinder. The array of optical sensors is configured to receive a reflected light beam from the rotatable cylinder. The light beam provided by the light source is axially diffused prior to being received by the array of optical sensors. In particular, the light beam may be spread or widened in at least an axial direction along a length of the rotatable cylinder. 
     Additionally, an optical encoder for an electronic device is disclosed. The optical encoder comprises a rotatable cylinder configured to reflect light. The rotatable cylinder comprises an encoding pattern of alternating reflective stripes having distinct light-reflective properties. The optical encoder also comprises a light source positioned adjacent the rotatable cylinder and an array of optical sensors positioned adjacent the rotatable cylinder. The array of optical sensors receives the reflected light from the rotatable cylinder. Additionally, the optical encoder comprises a diffuser member positioned on the rotatable cylinder, the light source, and the array of optical sensors. 
     A method of detecting rotational movement of a rotatable cylinder of an optical encoder is disclosed. The method comprises emitting a light beam, via a light source, toward the rotatable cylinder, reflecting the emitted light beam at the rotatable cylinder, and receiving the reflected light beam at an array of optical sensors. The method also comprises axially diffusing at least one of the emitted light beams, or the reflected light beam using a diffuser member prior to receiving the reflected light beam. Additionally, the method comprises estimating an amount of rotation of the rotatable cylinder based on the received reflected light beam at the array of optical sensors. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements. 
         FIG. 1  depicts an illustrative top view of a wearable electronic device. 
         FIG. 2  depicts an enlarged cross-section view of a portion of the electronic device of  FIG. 1 , taken along line  2 - 2 . 
         FIGS. 3A-3C  depict side views of an optical encoder. 
         FIGS. 4A and 4B  depict side views of an optical encoder. 
         FIG. 5  depicts a front perspective view of an optical encoder of the electronic device of  FIG. 2 . 
         FIG. 6  depicts a side cross-section view of the cylinder of the optical encoder taken along line  6 - 6  of  FIG. 5 . 
         FIG. 7  depicts an enlarged side view of a portion of the cylinder of the optical encoder of  FIG. 6 . 
         FIGS. 8A and 8B  depict side views of the optical encoder of  FIG. 5 . 
         FIG. 9  shows a flow chart illustrating an example process for detecting rotational movement of a rotatable cylinder of an optical encoder for an electronic device, which may be performed by the optical encoders as shown in  FIGS. 3A-8B . 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     The following disclosure relates generally to electronic devices, and more particularly, to optical encoders having diffuser members and methods for detecting the rotational movement of an input device using the optical encoders having diffuser members. 
     In a particular embodiment, the use of diffuser members within the optical encoder may aid in the detection of the reflected light by the optical sensors, even when a rotatable cylinder reflecting the light is misaligned. Further, embodiments discussed herein may provide more precision in detecting rotation and/or position of an encoded cylinder or other encoded structure. By utilizing diffuser members, the light provided to, and reflected from, the misaligned rotatable cylinder may be diffused and/or spread out prior to reaching or contacting the optical sensors to ensure the optical sensors detect some of the reflected light. The diffuser members may include a diffuser covering the light source, a diffuser disposed over the optical sensors and/or a plurality of diffusers disposed around the rotatable cylinder. 
     The diffusion process may expand, spread-out, or otherwise widen a beam of light into a widened beam and/or may form an axially-widened beam from the single beam of light. The light diffusion process may be referred to herein axially diffusing a beam of light, which may include spreading, widening or otherwise diffusing the light along at least an axial direction along the length of the encoded cylinder. Additionally, the diffuser members may be configured to focus and/or group a majority of the diffused beams into a centralized cluster of light beams. By focusing and/or grouping the majority of the diffused beams to a centralized cluster of light beams, the optical encoder including the diffuser members may reduce over exposure of the optical sensor, which may result in insufficient or inaccurate detection. 
     These and other embodiments are discussed below with reference to  FIGS. 1-9 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these Figures is for explanatory purposes only and should not be construed as limiting. 
       FIG. 1  shows an illustrative top view of a portable or wearable electronic device  100  (hereafter, “electronic device”), according to embodiments. Electronic device  100 , as shown in  FIG. 1 , may be configured as a wearable device such as a smart watch. However, it is understood that electronic device  100  can be configured as a smart phone, a laptop or desktop computer, a tablet computing device, a gaming device, a display, a digital music player, a wearable computing device or display, a health monitoring device, and so on. 
     Electronic device  100  may include a housing  102  at least partially surrounding a display  104  and one or more buttons or input devices. As shown in  FIG. 1 , and discussed herein, the input device may be a crown  106  for electronic device  100 . Crown  106  may be configured as a multi-input device, such as a rotary sensor configured to receive multiple forms of input. Specifically, crown  106  of electronic device  100  may be configured to receive and/or provide input to electronic device  100  based on rotational input to crown  106  and/or force or displacement input applied to crown  106 . As a result, crown  106  may be used to select, adjust or change various images that are output on the display  104 . For example, if the display  104  of the electronic device  100  is displaying a time-keeping application, the crown  106  may be rotated in either direction to change or adjust the position of the hands or the digits that are displayed for the time keeping application. In other embodiments, the crown  106  may be rotated to move a cursor or other type of selection mechanism from a first displayed location to a second displayed location in order to select an icon or move the selection mechanism between various icons that are output on the display  104 . 
     As discussed herein, crown  106  may include and/or be coupled to an optical encoder (see,  FIG. 2 ) positioned within housing  102  for detecting various forms of input to electronic device  100 , including rotational input provided to crown  106 . Additionally, and as discussed herein in detail, the optical encoder coupled to and/or included with crown  106  may include a diffuser member to aid in the detection of the rotational input provided to crown  106 . The inclusion of a diffuser member within the optical encoder may provide more precision in detecting rotation and/or position of encoded structures of the optical encoder, even when portions of the optical encoder become misaligned. This is achieved by diffusing and/or spreading out light emitted and/or detected by the optical encoder to ensure the optical encoder detects a sufficient amount of reflected light to determine the rotation and/or position of crown  106  during operation of the optical encoder. 
     The housing  102  may form an outer surface, partial outer surface, and/or protective case for the internal components of electronic device  100 , and may at least partially surround the display  104 . Housing  102  may be formed from a plurality of distinct materials including, but not limited to, metal, glass or plastic. As shown in  FIG. 1 , housing  102  may also have recesses  108  formed on opposite ends to connect a wearable band  110  to electronic device  100 . Wearable band  110  may be used to secure electronic device  100  to a user, or any other object capable of receiving electronic device  100 . 
     Display  104  is positioned at least partially within an opening formed in housing  102 . Display  104  may be implemented with any suitable technology, including, but not limited to, a multi-touch sensing touchscreen that uses liquid crystal display (LCD) technology, light emitting diode (LED) technology, organic light-emitting display (OLED) technology, organic electroluminescence (OEL) technology, or another type of display technology. A cover  112  may be positioned above the touchscreen of display  104 . That is, cover  112  may be positioned above the touchscreen of display  104  and may be at least partially positioned within an opening of housing  102  and coupled to housing  102 . Cover  112  may protect display  104  from contaminants, without obstructing a user&#39;s view and/or ability to interact with display  104  and/or electronic device  100 . As such, cover  112  may be transparent or translucent, fully or partially, in certain embodiments. 
       FIG. 2  illustrates a cross-section view of electronic device  100  of  FIG. 1  according to one or more embodiments. As shown in  FIG. 2 , the electronic device  100  includes an optical encoder  118  that includes of a rotatable cylinder  120  having an encoding pattern  122 , a light source  124 , and optical sensors  126 . Although optical sensors  126  are specifically mentioned, embodiments disclosed herein may use various types of sensors that are arranged in various configurations for detecting the movement described herein. For example, the movement of the cylinder  120  may be detected by an image sensor, a photodiode array, a photovoltaic cell or system, photo resistive component, a laser scanner and the like. 
     In embodiments, and as will be discussed below, the optical encoder  118  is used to determine positional data of the cylinder  120 , which may be manipulated by the crown  106 . More specifically, the optical encoder  118  may be used to detect movement of the cylinder  120  (and indirectly the crown  106 ) including the direction of the movement, speed of the movement and so on. The movement may be rotational movement, translational movement, angular movement and, so on. The optical encoder  118  may also be used to detect the rotation of the cylinder  120 , and the speed and the direction of rotation of the cylinder  120 . 
     Once the movement data of the cylinder  120  is determined, one or more graphics, images or icons on the display  104  of the electronic device  100  may be updated or altered accordingly, and/or the movement data may be used to interpret a user input. For example, and as discussed herein, crown  106  may be rotated in a clockwise manner in order to change the displayed time. In another non-limiting example where electronic device  100  includes a scrollable menu or options, crown  106  may be rotated by the user to scroll or move through the scrollable menu or options. The optical encoder  118  may detect the original starting position of the crown  106  and cylinder  120 , the rotational movement of the cylinder  120  (and thus crown  106 ) in the clockwise direction, and may also detect the speed at which the cylinder  120  (and thus crown  106 ) is being rotated. 
     As shown  FIG. 2 , the optical encoder  118  may include a rotatable cylinder  120 . The cylinder  120  may be coupled to the crown  106 . In another embodiment the cylinder  120  may be an extension of the crown  106 . That is, the crown  106  and the cylinder  120  may be manufactured as a single piece. As the cylinder  120  is coupled to, or is otherwise a part of the crown  106 , as the crown  106  rotates or moves in a particular direction and at a particular speed, the cylinder  120  also rotates or moves in the same direction and with the same speed. In a non-limiting example shown in  FIG. 2 , cylinder  120  is an elongated shaft configured to rotate and/or be rotated as crown  106  rotates. In another non-limiting example, cylinder  120  is a drum coupled to a rotatable shaft (not shown) positioned through the drum. In the non-limiting example, the shaft coupled to the drum is configured to rotate the drum. 
     The cylinder  120  of the optical encoder may include an encoding pattern  122 . As discussed, the encoding pattern  122  is used to determine positional information about the cylinder  120  including rotational movement, angular displacement and movement speed, which may be correlated to motion of the crown  106  and may be used as input to the electronic device. The encoding pattern  122  may include a plurality of light and dark stripes such as shown in  FIG. 2 . 
     Although light stripes and dark stripes are specifically mentioned and shown, the encoding pattern may consist of various types of stripes having various shades or colors that provide surface contrasts. For example, the encoding pattern may include a stripe or marking that has a high reflective surface and another stripe that has a low reflective surface regardless of the color or shading of the stripes or markings. In another embodiment, a first stripe of the encoding pattern may cause specular reflection while a second stripe of the encoding pattern may cause beam-dispersive reflection. When the reflected light is received by the photodiode array, a determination may be made as to the position and movement of the cylinder such as described below. In embodiments where a holographic or diffractive pattern is used, the light from the light source will diffract from the cylinder. Based on the diffracted light, the photodiode array may determine the position, movement and direction of movement of the cylinder. 
     In embodiments, the stripes of the encoding pattern  122  extend axially along the cylinder  120 . The stripes may extend along the entire length of the cylinder  120  or partially along a length of cylinder  120 . In addition, the encoding pattern  122  may also be disposed around the entire outer surface of the cylinder  120 . 
     The light and dark stripes of the encoding pattern  122  may alternate between a light stripe and a dark stripe. In another embodiment, the light stripes and the dark stripes of the encoding pattern  122  may be arranged in a particular pattern or order. In such embodiments, each section of the pattern may be used to indicate a position of the cylinder  120 . 
     Depending on the use of the cylinder  120 , the length of the cylinder  120  may vary between embodiments. For example, in some embodiments, the length of the cylinder  120  may extend along a length and/or width of the housing  102 . In another embodiment, the cylinder  120  may have a length that is substantially less than a length and/or width of the housing  102 . 
     The optical encoder  118  may also include a light source  124  positioned adjacent rotatable cylinder  120 . The light source  124 , as shown in  FIG. 2 , may provide light to cylinder  120  to detect the movement and/or rotation of cylinder  120 . Specifically, light source  124  may provide a continuous beam of light angularly toward cylinder  120  to be subsequently reflected toward optical sensors  126 , as discussed herein. The light source  124  may include an suitable light-emitting device. In a non-limiting examples, light source  124  may include a light emitting diode (LED) or an infrared (IR) light source (e.g., IR LED). 
     Optical encoder  118  may include optical sensors  126  (one of which is shown) positioned adjacent rotatable cylinder  120  and light source  124 . The optical sensors  126  are configured to receive light that is reflected off of the cylinder  120 . Specifically, the optical sensors  126  are configured to receive light of different intensity values based on whether the light has been reflected off of the encoding pattern  122  and in a direction toward optical sensors  126  in a diffusive manner, a dispersive manner, a specular manner or a combination thereof. As discussed herein, optical sensors  126  may be radially aligned and offset from cylinder  120  of optical encoder  118 . 
     In a non-limiting example, the optical sensors  126  may receive light that is reflected off of the encoding pattern  122 . That is, as light from the light source  124  hits the various stripes of the encoding pattern  122 , the light is reflected off of the light stripes in a specular manner and is reflected off of the dark stripes in a dispersive manner. The various intensities of the reflected light are then received by the optical sensors  126  which then convert the reflected light into an output current. 
     Optical encoder  118  may also include a wall member  128  positioned between light source  124  and optical sensors  126 . As shown in  FIG. 2 , wall member  128  may form a barrier between light source  124  and optical sensors  126 , and may be positioned proximate to and/or below cylinder  120 . As discussed herein, the light emitted by light source  124  may pass over and/or above wall member  128  to contact and reflect from cylinder  120  toward optical sensors  126 . Additionally as discussed herein, wall member  128  may prevent the light from light source  124  from being directly exposed to optical sensors  126 , and/or may prevent light from being reflected back toward light source  124  during operation of optical encoder  118 . 
     Although not shown in  FIG. 2 , optical encoder  118  may also include diffuser members (see,  FIGS. 3A-8B ). As discussed herein in detail, diffuser members may be positioned on cylinder  120 , light source  124  and/or optical sensors  126  to aid in the axial diffusion of the light within optical encoder  118  when cylinder  120  may be misaligned or displaced within housing  102  of electronic device  100 . 
       FIGS. 3A-3C  illustrate side views of optical encoder  218  having optical sensor  226  radially aligned with respect to the cylinder  220  of the optical encoder  218 . In embodiments, the optical encoder  218  may be similar to the optical encoder shown and described with respect to  FIG. 2 . It is understood that similarly numbered and/or named components may function in a substantially similar fashion. Redundant explanation of these components has been omitted for clarity. 
     During operation or with time, or due to impact events, cylinder  220  of optical encoder  218  may become misaligned or angled from its standard operating position. In the non-limiting example shown in  FIGS. 3A-3C , cylinder  220  may be angled such that the center (C) of cylinder  220  may be misaligned from a desired, planar position (DPP) for cylinder  220  (e.g., aligned position). As shown in  FIGS. 3A-3C , cylinder  220  may be substantially angled away from light source  224 . Cylinder  220  may be misaligned for a number of reasons. In non-limiting examples, cylinder  220  may be misaligned due to nominal movement within the device, or more drastically, electronic device  100  may undergo a shock event (e.g., drop, high-impact contact), that may shift and/or misalign cylinder  220  and/or crown  106  within housing  102  of electronic device  100  (see,  FIGS. 1 and 2 ). 
     In embodiments, the light source  224  and the optical sensors  226  are axially aligned with respect to the cylinder  220 . As a result, and as discussed in detail herein, light beam emitted from light source  224  may be axially diffused, diffused along an axis of cylinder  220  when emitted toward cylinder  220 , and ultimately optical sensors  226  and/or the light beam may be axially widened. For example, the light beam may be widened in at least an axial direction along a length of the cylinder  220 .  FIGS. 3A-3C  only depict a single optical sensor  226  representing the array or plurality of optical sensors  226  of optical encoder  218 . Although only one sensor is shown and described, any number of sensors may be used for the array or plurality of optical sensors  226 . For example, the number of sensors may increase or decrease depending on the size of the collection area of each of the photodiodes forming optical sensors  226 , as described above. 
     As discussed herein, the encoding pattern  222  of cylinder  220  may include a plurality of different colored stripes or shaded stripes. In the non-limiting example shown in and discussed with respect to  FIGS. 3A-3C , a first stripe of the encoding pattern may be in a first color and/or have a first reflective quality, and a second stripe of the encoding pattern  222  may be in a second color and/or have a second reflective quality (for example, one stripe may reflect light in a specular fashion and one may reflect light in a dispersive fashion). As different colors or reflective qualities may be used, the optical sensors  126  may be color-sensitive. Accordingly, the change in color or reflective quality in the encoding pattern  222  as the cylinder rotates about its axis may be used to determine rotational movement and speed of the cylinder  220 . 
     In certain embodiments, and as shown in  FIGS. 3A-3C , the stripes of the encoding pattern  222  are axially aligned with respect to the cylinder  220  and/or aligned along a longitudinal axis of cylinder  220 . In addition, the markings of the encoding pattern  222  are arranged around an outer surface of the cylinder  220 . As discussed in detail herein,  FIG. 3A  shows diffused emitted light  230  reflecting from a first marking of the encoding pattern  222  that reflects the light in a specular manner, and  FIG. 3B  shows diffused emitted light  230  reflecting from a second marking of the encoding pattern  222  that disperses the beam of reflected light  232 . Additionally, and as discussed herein in detail,  FIG. 3C  shows diffused emitted light  230  reflecting from a second marking of the encoding pattern  222  that substantially absorbs diffused, emitted light  230 , such that reflected light  232  is not formed and/or achieved within optical encoder  218 . 
     As discussed above, the markings of the encoding pattern  222  may be configured to cause specular reflection and/or dispersive reflection. For example, as shown in  FIG. 3A  and discussed in detail below, encoding pattern  222  of cylinder  220  may include a light stripe or color (or stripe having a first reflective quality), which may reflect emitted light  230  provided by light source  224  in a specular manner from the cylinder  220  to the optical sensors  226 . The emitted light  230  may be reflected in a specular manner toward optical sensors  226  as a result of the light stripe of encoding pattern  222  having specular reflective properties, as discussed herein. 
     In another example shown in  FIG. 3B  and discussed in detail below, encoding pattern  222  of cylinder  220  may include a dark stripe or color (or stripe having a second reflective quality), which may reflect emitted light  230  provided by light source  224  in a dispersive manner from cylinder  220  to form reflected light  232 . Reflected light  232  may be reflected from cylinder  220  to the optical sensors  226  in a dispersive manner. The reflected light  232  may be dispersed in various directions toward optical sensors  226 . The reflected light  232  may be reflected in a dispersive manner toward optical sensors  226  as a result of the stripe of encoding pattern  122  having dispersive-reflection properties, as discussed herein. 
     As shown in  FIGS. 3A-3C , emitted light  230  provided by light source  224  may be provided to cylinder  220  over, or without obstruction by wall member  228 . Additionally, as shown in  FIGS. 3A-3C , reflected light  232  may be reflected toward optical sensors  226  without obstruction from wall member  228 . As discussed herein, wall member  228  may prevent dispersive reflected light  232  from being reflected back toward light source  224  and/or from crossing or interfering with emitted light  230 . The path in which light travels from light source  224  to optical sensors  226  indicates the light path for optical encoder  218 . That is, the combination of emitted light  230  and reflected light  232 , and the direction and/or space in which it travels in, may be considered the light path for optical encoder  218 , which may determine the amount and/or speed of rotation for cylinder  220  of optical encoder  218 , as discussed herein. 
     As shown in  FIGS. 3A-3C , optical encoder  218  may include a diffuser member  238  positioned on light source  224  and/or on a housing enclosing light source  224 . Diffuser member  238  positioned on light source  224  may include a diffuser window  244  covering at least a portion of light source  224 . Diffuser window  244  may cover a top surface of light source  224  (or its housing), and may be positioned between light source  224  and cylinder  220 . As shown in  FIGS. 3A-3C , by positioning diffuser window  244  over a top surface of light source  224 , emitted light  230  provided by light source  224  may pass through diffuser window  244  before contacting cylinder  220 . In a non-limiting example, emitted light  230  may pass through diffuser window  244 , and may undergo a diffusing process, prior to being provided to cylinder  220 . In the non-limiting example shown in  FIGS. 3A-3C , diffuser window  244  may diffuse axially and/or widen the light-emission area of emitted light  230  in an axial direction with respect to cylinder  220 . As such, diffused, emitted light  230  may contact cylinder  220  in a wider area for reflection toward optical sensor  226 . 
     As used herein, the terms “diffuse” or “diffusing” refer to spreading-out, expanding, directing and/or scattering light beams that are emitted from light source  224  and/or reflected from cylinder  220 . Specifically, diffusing light as discussed herein may equate to directing and/or dispersing light such that when a single beam of light that is either emitted or reflected is diffused the area of emission for the light beam is widened to cover and/or contact a larger area of optical sensors  226 , for example. In addition to directing the light, diffusing light, as discussed herein, may also include varying and/or altering the light intensity of each diffused light beam. 
     Diffuser member  238 , as shown in  FIG. 3A-3C  may be configured as any suitable component that is configured to axially diffuse light emitted by light source  224  of optical encoder  218 . In a non-limiting example, diffuser member  238  may be formed as a lens having a convex or a concave shape in at least a portion of the lens for axially diffusing light. The lens may be positioned completely over light source  224 , such that any light emitted by light source  224  must pass through diffuser member  238  and subsequently the light beam may be axially diffused and/or widened in an axial direction, prior to contacting cylinder  220  of optical encoder  218 . For example, the diffuser member  238  may be configured to widen the light bean in an axial direction that is along a length of the cylinder  220 . 
     Each of the non-limiting examples shown in  FIGS. 3A-3C  are now discussed in additional detail. As shown in  FIG. 3A , emitted light  230  may be diffused by diffuser window  244 . In a non-limiting example, diffuser window  244  may be configured to diffuse emitted light  230  in an axial direction that may be parallel to a strip of encoding pattern  222  formed on cylinder  220 . Subsequent to the diffusing of emitted light  230  by diffuser window  244 , axially diffused emitted light  230  may contact and reflect from a portion of cylinder  220  including a light stripe or color. As discussed herein, light stripe or color may reflect the axially diffused emitted light  230  in a specular manner. However, as shown in  FIG. 3A , as a result of emitted light  230  being axially diffused by diffuser window  244  before contacting cylinder  220 , light stripe or color of cylinder  220  may reflect beams of light of reflected lights  232  that may be directed toward optical sensor  226  and may cover a larger region than would be the case if the diffuser window  244  were absent. As such, a portion of the reflected beam of light  232  may contact optical sensor  226  even if the cylinder is misaligned, as shown. Thus, the diffuser may increase a range of angles of the cylinder at which the optical sensor  226  may receive reflected light, and thus increase a range of angles at which the optical encoder works to determine a movement or rotation of cylinder  220 , as discussed herein. 
     As shown in  FIG. 3B , cylinder  220  of optical encoder  218  may be substantially rotated, such that a dark stripe or color of cylinder  220  may be contacted by axially diffused emitted light  230 . As discussed herein, dark stripe or color of cylinder  220  may reflect light in a dispersive manner. As such, diffused emitted light  230  may undergo a dispersive process when reflected from the dark stripe or color of cylinder  220 . In some embodiments, the dark stripe or color of cylinder  220  may disperse emitted light  230 , such that reflected light  232  is dispersed toward optical sensors  226  in a variety of different directions. As shown in  FIG. 3B , the dispersive process performed in optical encoder  218  may result in reflected light  232  being dispersed throughout the housing of the electronic device (see,  FIG. 2 ). This may ultimately result in only a minimal portion of the dispersed reflected light  232  contacting optical sensor  226  of optical encoder  218 . The variance in the amount of light received by any one of the optical sensors  226 , and the pattern in which the light varies between or among optical sensors  226  (or with respect to a single sensor), may provide data regarding the rotation of the cylinder. Such data may include, but is not limited to, speed of rotation, direction of rotation, rotational position, and/or angular offset of the cylinder. Some or all of these may be used as input to the associated electronic device. 
     In another non-limiting example, a dark stripe or color of encoding pattern  222  formed on cylinder  220  may absorb emitted light  230  provided by light source  224 . In a non-limiting example shown in  FIG. 3C , emitted light  230  may be provided to cylinder  220 , and may contact dark stripe or color of encoding pattern  222 , where the dark stripe or color has light absorbent properties. As a result, when emitted light  230  contacts the dark stripe or color of encoding pattern  222 , no (or very little) reflective light may be provided to optical sensors  226 . As such, when no reflective light is provided to optical sensors  226 , optical sensors  226  may detect a drop in current or exposure, and may determine that light source  224  is providing emitted light to the dark stripe or color of encoding pattern  222  formed on cylinder  220  having light absorbent properties. This, again, may be used to determine various data regarding rotation of the cylinder and, in turn, input to the electronic device. 
       FIGS. 4A and 4B  depict side views of another non-limiting example of an optical encoder  318 . Optical encoder  318  may include cylinder  320  misaligned or angled similar to cylinder  220  in  FIGS. 3A-3C . Additionally, cylinder  320  may include encoding pattern  322  substantially similar to that of the encoding pattern  222  of cylinder  220  discussed herein with respect to  FIGS. 3A-3C . Redundant explanation of these components has been omitted for clarity. 
     As shown in  FIGS. 4A and 4B , optical encoder  318  may include a diffuser member  338  positioned on the optical sensors  326  (or in a housing of the optical sensors). As shown in  FIGS. 4A and 4B , diffuser member  338  may be formed from a diffuser sheet  346  disposed over at least a portion of the array or plurality of optical sensors  326  (or their housing(s)). Diffuser sheet  346  may cover at least a portion of the exposed surface of the plurality of optical sensors  326  that may receive the reflected light  332  from cylinder  320 . Additionally, diffuser sheet  346  may be positioned between cylinder  320  and optical sensors  326 , such that reflected light  332  may pass through diffuser sheet  346  prior to contacting optical sensors  326 . By passing through diffuser sheet  346 , reflected light  332  may undergo a diffusing process to provide axially diffused or axially widened light beams to optical sensors  326 . In a non-limiting example, diffuser sheet  346  may diffuse reflected light  332  in an axial direction with respect to cylinder  320 . 
       FIG. 4A  depicts a side view of optical encoder  318 . As shown in  FIG. 4A , emitted light  330  may contact and reflect from a portion of cylinder  320  including a light stripe or color. As discussed herein, light stripe or color may reflect the emitted light  330  in a specular manner. Emitted light  330  may reflect from cylinder  320  in a specular manner toward optical sensors  326  in a similar fashion as discussed herein with respect to  FIG. 3A . However, as shown in  FIG. 4A , prior to reaching optical sensors  326 , reflected light  332  may first pass through diffuser sheet  346  disposed over optical sensor  326 . Reflected light  332  may pass through diffuser sheet  346  and undergo a diffusing process. In a non-limiting example, diffuser sheet  346  positioned on optical sensors  326  may diffuse reflected light  332  in an axial direction that may be parallel to the longitudinal axis of cylinder  320 , prior to the reflected light  332  reaching optical sensors  326 . In the non-limiting example shown in  FIG. 4A , reflected light  332  may expand, spread-out or otherwise axially diffuse a single beam of reflected light  332  into a widened spread of reflected light  348 . As a result, the diffused reflect light  348  formed by passing through diffuser sheet  346  may subsequently be directed toward optical sensors  326  for determining a movement and/or rotation of cylinder  320 , as discussed herein. 
     As shown in  FIG. 4B , cylinder  320  of optical encoder  318  may be substantially rotated, such that a dark stripe or color of cylinder  320  may be contacted by emitted light  330 . As discussed herein, dark stripe or color of cylinder  320  may reflect light in a dispersive manner. As such, emitted light  330  may undergo a dispersive process when reflected from the dark stripe or color of cylinder  320 , as similarly discussed herein. As shown in  FIG. 4B , the dispersive process performed in optical encoder  318  by the dark stripe or color of cylinder  320  may result in reflected light  332  being dispersed throughout the housing of the electronic device (see,  FIG. 2 ). As a result, and as shown in  FIG. 4B , dispersed reflected light  332  may not pass through diffuser sheet  346  to contact optical sensors  326  of optical encoder  318 . 
       FIG. 5  depicts an illustrative prospective view of optical encoder  418  according to another non-limiting example. As shown in  FIG. 5 , cylinder  420  may be substantially misaligned from a desired position. As shown in  FIGS. 5, 8A and 8B , cylinder  420  may be misaligned and substantially angled toward light source  424 . Also shown in  FIGS. 5, 8A and 8B , light source  424  may emit multiple beams of emitted light  430 . Multiple beams of emitted light  430  may be a result of diffusing light from light source  424  using a diffuser member as discussed herein with respect to  FIGS. 3A-3C , or alternatively, light source  424  may include a plurality of lights, each light emitting a single, individual beam of emitted light  430 . 
     In  FIG. 5 , cylinder  420  may include a plurality of recesses  434 . The plurality of recesses  434  may be formed circumferentially around, and partially through, cylinder  420 . Each recess  434  may be separated by a transitional portion  436  of cylinder  420 . As shown in  FIG. 5 , and discussed herein, the plurality of recesses  434  of cylinder  420  may include a light stripe or color that may reflect light in a specular manner, and transitional portion  436  may include a dark stripe or color that may reflect light in a dispersive manner. Each recess  434  may be formed in cylinder  420  along the entire length of cylinder  420 , as shown in  FIG. 5 , or alternatively, along a portion of the length of cylinder  420  (not shown). 
     Optical encoder  418  may also include diffuser members  438  to aid in the reflecting of reflected light  432  toward optical sensors  426 , as discussed herein. As shown in  FIG. 5 , diffuser members  438  may include at least one set of diffuser lenses  440  positioned on the outer surface of cylinder  420 . In the non-limiting example shown in  FIG. 5 , a plurality of sets of diffuser lenses  440  may be disposed along an entire length of cylinder  420 , and each lens of each individual set of diffuser lenses  440  may be positioned adjacent one another spanning over the length of cylinder  420 . Additionally as shown in  FIG. 5 , where cylinder  420  includes recesses  434 , a single set of diffuser lenses  440  may be positioned within a corresponding recess  434  formed on cylinder  420 . 
     Diffuser lenses  440  may be substantially transparent to allow emitted light  430  to shine through. The transparency of diffuser lenses  440  may be dependent on, at least in part, a geometry or shape of diffuser lenses  440 , the reflective properties of cylinder  420 , and the reflective properties of the stripe or color formed within recesses  434 . In a non-limiting example as shown in  FIG. 4 , and discussed in detail herein, diffuser lenses  440  may be substantially transparent to allow emitted light  430  to contact and reflect off of recesses  434  of cylinder  420 , and subsequently, through diffuser lenses  440  to form diffused reflective light  432 . 
     Each diffuser lens  440  may be formed with distinct, non-linear geometries or shapes. In a non-limiting example shown in  FIGS. 5-8B , each lens of diffuser lenses  440  may be formed from a substantially concave lens. The concave lens forming each of the set of diffuser lenses  440  may allow diffuser lenses  440  to be nested within recesses  434  formed in cylinder  420 . In the non-limiting example, the concave lens may allow each of the set of diffuser lenses  440  to be positioned completely within recesses  434  formed within cylinder  420  to maintain a substantially uniform diameter of cylinder  420 . 
       FIG. 6  shows a side cross-section view of cylinder  420  of  FIG. 5  taken along line  6 - 6 . As discussed herein, each lens in the set of diffuser lenses  440  forming diffuser member  438  may be positioned adjacent one another within recess  434 . In the non-limiting example shown in  FIG. 6 , positioning the concave, diffuser lenses  440  adjacent one another within recess  434  may form a scalloped pattern  441  of lenses. That is, and as shown in  FIG. 6 , by forming each lens of diffuser lenses  440  from a concave lens, and subsequently positioning each lens adjacent one another, each set of diffuser lenses  440  may form scalloped pattern  441  of lenses within cylinder  420 . 
     With continued reference to  FIGS. 5 and 6 ,  FIG. 7  shows an enlarged portion of cylinder  420  including diffuser lenses  440  formed in a scalloped pattern  441 . Diffuser lenses  440  may aid in reflecting the reflected light  432  toward optical sensors  426  (see,  FIG. 5 ). In a non-limiting example shown in  FIGS. 5 and 7 , when emitted light  430  is provided to cylinder  420  having sets of diffuser lenses  440 , reflected light  432  reflected toward optical sensors  426  may be axially diffused and/or may diffuse in an axial direction with respect to cylinder  420  toward optical sensors  426 . In the non-limiting example, transparent diffuser lenses  440  may allow emitted light  430  to pass through diffuser lenses  440  to contact the surface of recess  434  formed within cylinder  420 . The surface of recess  434  formed in cylinder  420  may include a light stripe or color that may reflect the emitted light  430  in a specular manner. 
     In a non-limiting example, when passing through diffuser lenses  440 , emitted light  430  may undergo an axial diffusion process, which may cause emitted light  430  to expand, spread-out or otherwise disperse (not shown). As a result, the axially diffused emitted light  430  passing through transparent diffuser lenses  440  may contact recess  434  of cylinder  420  in an expanded area. Similarly discussed herein with respect to  FIG. 3A , axially diffused emitted light  430  that passes through diffuser lenses  440  may be reflected from the surface of recess  434  in a specular manner. However, because emitted light  430  is axially diffused prior to reflecting from the surface of recess  434 , reflected light  432  may include axially diffused light. Axially diffused, reflected light  432  may pass through diffuser lenses  440 , and undergo another diffusion process, which may result in further or additional, axially diffused reflected light  432 . Similar to the emitted light  430 , and shown in  FIGS. 5 and 7 , reflected light  432  reflected from recess  434  may expand, spread-out or otherwise axially disperse through diffuser lenses  440 . Diffused reflected light  432  may expand or axially diffuse into a widened reflected light beam, and may be reflected away from cylinder  420 . In the non-limiting example shown in  FIGS. 5 and 7 , the widened or diffused reflected light  432  may be reflected away from cylinder  420 , and substantially toward optical sensors  426 , as discussed herein. 
     Additionally in the example embodiment shown in  FIGS. 5 and 7 , a concentrated portion  442  of the plurality of axially diffused reflected light  432  may be directed toward optical sensors  426  (see,  FIG. 5 ). As shown in  FIG. 7 , the concave geometry of diffuser lenses  440  may allow for a concentrated portion  442  of diffused reflected light  432  to be reflected toward optical sensors  426 . In an embodiment, and as a result of diffuser lenses  440  being formed from a concave lens, diffused reflective light  432  exiting and/or being reflected from diffuser lenses  440  may be primarily reflected from diffuser lenses  440  through the portion of the lens having the greatest concavity. Alternatively, the concave shape of diffuser lenses  440  results in diffusing the light over a limited angle. That is, as a result of the surface angle changing because of the concave geometry of diffuser lens  440 , the angle of incidence and the output angle for reflective light  432  also changes. The output angles of reflected light  432  are within a select range, which is limited by the range of the surface angles formed by the concave geometry of diffuser lens  440 . As such, diffuser lenses  440  may both axially diffuse reflected light  432  as well as concentrate or “focus” the majority of the axially diffused reflected light  432  to a concentrated portion  442  to aid in the detection of reflected light  432  by optical sensors  426  when cylinder  420  is misaligned. Focusing the majority of reflected light  432  refers to the limited range of the output angles of which reflected light  432  may be reflected from diffuser lenses  440 . 
     The depth (D) of concavity in the concave lens forming each of the sets of diffuser lenses  440  may determine the size and/or dispersion of concentrated portion  442  of the plurality of axially diffused reflected light  432 . That is, the larger the depth (D) of the concave lens forming each lens in the set of diffuser lenses  440 , the larger the concentrated portion  442  of the plurality of axially diffused reflected light  432  may be. As discussed herein, the dispersion of concentrated portion  442  of reflected light  432  may be critical to accurately detect diffused reflective light  432  when determining the movement and/or rotation of cylinder  420 . 
     Although discussed herein as diffusing both emitted light  430  and reflected light  432 , it is understood that diffuser lenses  440  may axially diffuse the light in only one direction. That is, diffuser lenses  440  positioned within cylinder  420  may axially diffuse emitted light  430  prior to the light contacting the surface of recess  434 , or diffuser lenses  440  may axially diffuse the specularly reflected light  432  reflected from recess  434  prior to the reflected light  432  from contacting optical sensors  426 . 
       FIGS. 8A and 8B  depict side views of optical encoder  418  of  FIGS. 5-7 . As shown in  FIG. 8A , and as similarly discussed herein with respect to  FIGS. 8 and 10 , emitted light  430  may be emitted towards cylinder  420  having sets of diffuser lenses  440  positioned thereon. As discussed above, emitted light  430  and reflected light  432  may pass through diffuser lenses  440  and undergo an axial diffusion process, which may ultimately result in a widened or axially diffused, reflected light  432  from being reflected away from cylinder  420  toward optical sensors  426 . As shown in  FIG. 8A , concentrated portion  442  of the widened or axially diffused reflected light  432  may contact optical sensors  426  of optical encoder  418 , as a result of diffuser lenses  440  being formed from concave lenses, as discussed herein. 
     Additionally, as a result of the misalignment and/or angle of cylinder  420 , portions of the widened or diffused, reflected light  432  may also be reflected back towards light source  424 . However, as shown in  FIG. 8A , wall member  428  may prevent diffused, reflected light  432  from being reflected back toward light source  424 . That is, reflected light  432  reflected back toward light source  424  may contact and/or be absorbed by wall member  128 , and may not be reflected back to interfere with the emitted light  430  from light source  424 . 
     As shown in  FIG. 8B , cylinder  420  of optical encoder  418  may be substantially rotated, such that transitional portion  436  of cylinder  420  may be contacted by emitted light  430 . As similarly discussed herein with respect to  FIG. 3B , transitional portion  436  may include a dark stripe or color, which may reflect light in a dispersive manner. As shown in  FIG. 8B , when emitted light  430  contacts transitional portion  436 , emitted light  430  may be dispersed, and may reflect away from cylinder  420 . Distinct from the diffusion process occurring as a result of diffuser lenses  440 , the widened or diffused, reflected light  432  reflected from transitional portion  436  may expand, spread-out or disperse evenly away from cylinder  420  toward optical sensors  426  and other portions of the housing (see,  FIG. 2 ) containing optical encoder  418 . That is, transitional portion  436  of cylinder  420  may disperse emitted light  430  to form evenly dispersed reflected light  432  within optical encoder  418 . As shown in  FIG. 8B , this may result in minimal reflected light  432  from contacting optical sensors  426 , and the majority of the dispersed, reflected light  432  being distributed throughout optical encoder  418 . By comparison, and as discussed herein with respect to  FIG. 8A , concave diffuser lenses  440  may form a concentrated portion  442  of diffused reflected light  432  to contact optical sensors  426 , and only a minimal portion of diffused reflected light  432  reflected from diffuser lenses  440  may be dispersed throughout optical encoder  418 . 
     In another non-limiting example, not shown, dark stripe or color of transitional portion  436  of cylinder  420  may absorb emitted light  430 . That is, and as similarly discussed herein with respect to  FIG. 3C , transitional portion  436  on cylinder  420  may substantially absorb emitted light  430 , and may not subsequently reflect light (e.g., reflected light  432 ) toward optical sensors  426  for detection by optical encoder  418 . 
     In another non-limiting example, and similar to  FIGS. 5-8B , diffuser members  438  may be formed from sets of diffuser lenses  440  positioned on cylinder  420 . However, in the non-limiting example and distinct from  FIGS. 5-8B , diffuser lenses  440  may be positioned directly on the surface of cylinder  420 . That is, diffuser lenses  440  may be positioned on, and may protrude from the surface of cylinder  420 . As a result, cylinder  420  may include a varying diameter, where the diameter is larger in the portions including diffuser lenses  440 , than the diameter having transitional portions  436 . 
     In another non-limiting example, transitional portion  436  of cylinder  420  may not have a dark stripe or color, but rather may include a light stripe or color. That is, the entire surface of cylinder  420  may include a light stripe or color, where diffuser lenses  440  may only cover portions of cylinder  420 . In the non-limiting example, when emitted light  430  contacts and reflects from a portion of cylinder  420  including sets of diffuser lenses  440 , reflected light  432  may be axially diffused in a similar manner as discussed herein. 
     However, in the non-limiting example, when emitted light  430  contacts and reflects from transitional portion  436  of cylinder  420 , reflected light  432  may be reflected in a specular manner as discussed herein with respect to  FIG. 3A . That is, as a result of transitional portion  436  having a light stripe or color, which may reflect light in a specular manner, reflected light  432  may mirror emitted light  430 , and may be reflected without undergoing an axial diffusion process. As a result of the reflective properties and the misalignment of cylinder  420  from a desired, planar position (DPP), reflected light  432  may be reflected within housing  102  of the electronic device  100  (see,  FIG. 2 ) without contacting optical sensors  426 . 
       FIG. 9  depicts an example process for detecting rotational movement of a rotatable cylinder of an optical encoder. That is,  FIG. 9  is a flowchart depicting one example process  500  for detecting or determining the movement or rotation of the cylinder of an optical encoder included in an electronic device. 
     In operation  502 , light may be emitted from a light source toward the cylinder of the optical encoder. The light may be continuously emitted from the light source to the cylinder to continuously provide input for determining the movement of the cylinder, as discussed herein. Additionally, the light emitted from the light source toward the cylinder of the optical encoder in operation  502  may be utilized to determine an initial position of the cylinder. 
     In operation  504 , the emitted light from the light source may be axially diffused. That is, the light emitted from the light source to the cylinder may be axially diffused prior to reaching the cylinder. The emitted light may be axially diffused using a diffuser member. In a non-limiting example, the diffuser member may be a diffuser window positioned over the light source emitting the light, such that the emitted light may pass through the diffuser window and undergo a diffusion process. As discussed herein, by axially diffusing the emitted light, the light emitted in operation  502  may expand, spread-out or otherwise disperse along the longitudinal axis of the cylinder before reaching the cylinder of the optical encoder. The axial diffusing of the emitted light in operation  504  is shown in phantom as optional. Diffusing the emitted light may be optional so long as further diffusing processes are performed when detecting the rotational movement of the cylinder, as discussed herein. 
     In operation  506 , the emitted light may be reflected by the cylinder. That is, emitted light, either diffused in operation  504  or directly emitted in operation  502 , may contact and be substantially reflected from the cylinder. As discussed herein, the emitted light may be reflected from the cylinder by way of the reflective properties of the cylinder and/or reflective components positioned on the cylinder. That is, the cylinder may reflect the emitted light away from the cylinder using lenses, stripes or reflective colors formed on the cylinder. Additionally, and as discussed herein, the light may be reflected from the cylinder toward a plurality of optical sensors for detecting the reflected light. 
     In operation  508 , the reflected light may be axially diffused. That is, the light reflected from the cylinder in operation  506  may be diffused or spread along at least an axial direction along the length of the cylinder. The reflected light may be axially diffused using a variety of diffuser members positioned within the optical encoder. In a non-limiting example, the diffuser members may be a plurality of sets of diffuser lenses positioned on the cylinder. When the emitted light contacts the sets of diffuser lenses, the light may undergo a diffusion process, which may result in the reflected light being axially diffused. In another non-limiting example, the diffuser member may be a diffuser sheet positioned between the cylinder and the optical sensors. The reflected light from the cylinder may pass through the diffuser sheet and under an axial diffusion process prior to contacting the optical sensors, as discussed herein. Similarly discussed herein with respect to operation  504 , the axial diffusion process in operation  508  may be optional so long as a diffusion process occurred prior to the reflecting of the emitted light in operation  506 . 
     In operation  510 , the light may be received by optical sensors of the optical encoder. That is, previously diffused, reflected light contacts optical sensors of the optical encoder to determine a position of the cylinder. The optical sensors may receive the reflected light, and may associate the received light to indicate a specific position of the cylinder at an instantaneous detected time. That is, the optical sensor may receive the light and further determine a first output current of each optical sensor at a first time. 
     Operations  502 - 510  may be continuously performed, as shown in  FIG. 9 , to determine the movement and/or rotational change in the cylinder of the optical encoder. That is, operations  502 - 510  may be performed multiple times, where each time the diffused, reflected light is received in operation  510 , and a distinct electrical output (e.g., current, voltage, and so on) is determined for each of the optical sensors at distinct times. The distinct electrical output determined by the optical sensors corresponds to how much reflective light is being exposed to the optical sensors which, as discussed herein, varies dependent upon the position of the cylinder and the portion of the encoding pattern formed on the cylinder exposed to and/or reflecting light to the optical sensors. These distinct electrical outputs may be compared to previously determined electrical outputs at past times, to determine how much the electrical output has changed and, ultimately, how much movement and/or rotation of the cylinder has been realized. 
     For example, light intensity of the received reflected light by the optical sensors at a first time is compared against light intensity of the received reflected light by the optical sensors at a second time. If the light intensity at the second time is greater than the light intensity at the first time, the cylinder may be rotating in a counter-clockwise direction. Likewise, if the light intensity at the second time is less than light intensity at a first time, the cylinder may be rotating in a clockwise rotation. Although the example above specifies that two samples are compared to determine movement of the cylinder, the operations discussed herein may use any number of samples, sequential or otherwise, to determine a directional movement of the cylinder of the encoder. 
     The foregoing description, for purposes of explanation, uses specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not targeted to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20150901
Publication Date: 20181204
Grant Date: 20181204
Priority Date: 20140909
Inventors: RUH, RICHARD
HOLENARSIPUR, PRASHANTH S.
Assignee: APPLE INC
CPC Classifications: [{"code": "G01D5/3473", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01D5/34738", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01D5/342", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01D5/35303", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01D5/34715", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01D5/35303", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01D5/3473", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01D5/34715", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01D5/34738", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01D5/342", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 55437234