# Patent

## Title
Optical jog wheel with spiral coding element

## Abstract

A user navigational apparatus. The user navigational apparatus includes a dial, a coding element, and an encoder. The coding element is coupled to a dial. The coding element includes a track of alternating reflective and non-reflective sections, each having a substantially oblique leading edge relative to a direction of movement of the coding element. The encoder includes an emitter and a detector. The emitter generates a light signal incident on the track of the coding element. The detector detects a reflected light signal which corresponds to a portion of the incident light signal that is reflected off of the reflective sections of the track. The detector also generates a channel signal corresponding to the reflected light signal.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a divisional of patent application Ser. No. 11/842,775, filed Aug. 21, 2007 now U.S. Pat. No. 7,675,026, which is a continuation-in-part of patent application Ser. No. 11/591,799, filed Nov. 1, 2006 now U.S. Pat. No. 7,732,756, which is incorporated by reference herein.


BACKGROUND OF THE INVENTION
A jog wheel is a type of device to allow a user to navigate through audio or video content. As the jog wheel is turned, the media typically shifts in a direction (e.g., fast-forward, reverse, left, and right) according to which way the wheel is turned. For example, if the user turns the jog wheel clockwise, then the media typically advances. In contrast, if the user turns the jog wheel counter-clockwise, then the media typically reverses. Jog wheels also have been implemented as scroll wheels on computer mice. More recently, jog wheels also have been implemented as menu selection interfaces on devices such as personal digital assistants and music players. For example, jog wheels may be used to scroll through menu entries and to make menu selections.
The speed at which the media advances or reverses (or the menu selections scroll) typically depends on how the jog wheel is turned. How the user turns, or simulates turning, the jog wheel is a function of the type of jog wheel that is implemented. For multi-spin jog wheels, the jog wheel may be rotated endlessly, so that the speed at which the media advances or reverses usually corresponds to how fast the user rotates the jog wheel. For single-turn jog wheels, the rotational movement of the jog wheel is limited (e.g., typically limited to less than one full rotation) by fixed stops, and the speed at which the media advances or reverses usually corresponds to how far toward one side the user rotates the jog wheel.
A jog wheel also may be referred to as a jog dial, a shuttle dial, or a shuttle wheel. In some instances, the term “jog” is used to refer to slow navigational speeds, while the term “shuttle” is used to refer to fast navigational speeds. However, no distinction between “jog” and “shuttle” is made in the present description.
Conventionally, two technologies have been used to implement jog wheels. Specifically, conventional jog wheels are typically implemented using either capacitive sensing or magnetic sensing. In one conventional implementation of capacitive sensing, the jog wheel has a capacitive circuit such as one or more layers of conductive traces built into it to detect a change in capacitance due to the movement of a nearby conductive object such as a user's finger. In some instances, the capacitive jog wheel does not actually rotate, but the capacitive circuitry senses the simulated rotation by a finger, stylus, or other conductive object.
In magnetic sensing implementations, the jog wheel may be implemented with a hall effect sensor. A hall effect sensor is a transducer that generates a voltage in response to a change in the magnetic field density. Typically, the hall-effect sensor detects a magnetic field from a passing current-carrying conductor (or, alternatively, detects a changing current in a fixed conductor). By arranging the current-carrying conductor and the sensor in relative positions on an off the jog wheel, the hall effect sensor can detect the rotation of the jog wheel. If multiple hall effect sensors are used, the circuitry may be able to indicate partial rotation of the jog wheel and the rotational direction of the jog wheel.
The use of these conventional technologies may result in relatively thick jog wheels. In other words, the size of the jog wheel may be relatively big. Having a jog wheel that is large in size limits the potential use of jog wheels in some applications, especially in small handheld computer devices or other small devices. Also, the resolution of conventional jog wheels may be limited to the resolution of the capacitive traces or the number of hall effect sensors implemented in the jog wheel. In the case of capacitive jog wheels, the resolution is typically limited by the size of the conductive object, e.g., fingertip, used as the input device. In the case of hall effect jog wheels, increasing resolution by implementing several hall effect sensors is generally cost-prohibitive.
In view of this, what is needed is a jog wheel to overcome the physical size and resolution limitations of conventional jog wheels.
SUMMARY OF THE INVENTION
Embodiments of a user navigational apparatus are described. The user navigational apparatus includes a dial, a coding element, and an encoder. The coding element is coupled to a dial. The coding element includes a track of alternating reflective and non-reflective sections, each having a substantially oblique leading edge relative to a direction of movement of the coding element. The encoder includes an emitter and a detector. The emitter generates a light signal incident on the track of the coding element. The detector detects a reflected light signal which corresponds to a portion of the incident light signal that is reflected off of the reflective sections of the track. The detector also generates a channel signal corresponding to the reflected light signal.
In some embodiments, the user navigational apparatus also includes a decoder and a microprocessor. The decoder generates a count signal corresponding to the channel signal. The microprocessor implements a user navigational operation on a controlled device in response to a movement of the dial by a user. The user navigational apparatus also may include an independent button, an illumination ring, a back plate, a circuit substrate, and a mounting bracket. Other embodiments of the user navigational apparatus are also described.
Embodiments of a method for making a user navigational apparatus are also described. In one embodiment, the method includes coupling a spiral code wheel to a rotary dial, mounting an emitter on a circuit substrate relative to the spiral code wheel, and mounting a detector on the circuit substrate relative to the spiral code wheel. Other embodiments of the method for making a user navigational apparatus are also described.
Other aspects and advantages of embodiments of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrated by way of example of the principles of the invention.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a schematic circuit diagram of one embodiment of an optical reflective jog wheel.
FIG. 2 depicts a partial schematic diagram of one embodiment of a code wheel.
FIG. 3 depicts a perspective view of one embodiment of an optical jog wheel.
FIG. 4 depicts a side view of the optical jog wheel of FIG. 3.
FIG. 5 depicts an exploded perspective view of the optical jog wheel of FIG. 3.
FIG. 6 depicts one embodiment of a layout of an encoder on a circuit substrate.
FIG. 7 depicts a side view of one embodiment of a layout of an encoder with an air gap between the encoder and the code wheel.
FIG. 8 depicts a side view of one embodiment of a layout of an encoder with a fully encapsulated encoder.
FIG. 9 depicts a side view of one embodiment of a layout of an encoder with an individually encapsulated emitter and detector.
FIG. 10 depicts a side view of one embodiment of a layout of an encoder with an individually encapsulated emitter and a partially encapsulated detector.
FIG. 11 depicts one embodiment of a method of making an optical jog wheel.
FIG. 12 depicts one embodiment of a method of using an optical jog wheel.
FIG. 13 depicts a perspective view of another embodiment of an optical jog wheel.
FIG. 14 depicts a side view of the optical jog wheel of FIG. 13.
FIG. 15 depicts an exploded perspective view of the optical jog wheel of FIG. 13.
FIG. 16 depicts a partial schematic diagram of another embodiment of a code wheel with spiral track sections.
FIG. 17 depicts a layout of one embodiment of a photodetector array relative to spiral track sections of the code wheel of FIG. 16.
FIG. 18 depicts a schematic diagram of one embodiment of a code strip with diagonal track elements.
FIG. 19 depicts one embodiment of a method of making an optical jog wheel with the spiral code wheel of FIG. 16.



Throughout the description, similar reference numbers may be used to identify similar elements.
DETAILED DESCRIPTION
FIG. 1 depicts a schematic circuit diagram of one embodiment of an optical jog wheel 100. The illustrated optical jog wheel 100 includes a rotary dial 102, a code wheel 104, an encoder 106, a decoder 108, and a microprocessor 110. In one embodiment, the rotary dial 102 is physically coupled to the code wheel 104 and provides a tactile interface for a user to manually turn the code wheel 104. In some embodiments, the rotary dial 102 is a multiple-turn dial that may be turned endlessly. Alternatively, the rotary dial 102 may be a single-turn dial with a range of motion that is limited to approximately one revolution (i.e., 360 degrees) or less. The type of code wheel 104 implemented—multiple-turn or single-turn—corresponds to the type of rotary dial 102 that is used.
Although a more detailed illustration of the code wheel 104 is provided in FIG. 2, a brief explanation is provided here as context for the operation of the optical jog wheel 100 shown in FIG. 1. In general, the code wheel 104 includes a track 140 of non-reflective sections 142 and reflective sections 144. An emitter 120 in the encoder 106 produces light that is incident on the code wheel track 140. As the rotary dial 102 is rotated, the incident light is reflected by the reflective sections 144 of the track 140, but is not reflected by the non-reflective sections 142 of the track 140. Thus, the light is reflected by the track 140 in a modulated pattern (i.e., on-off-on-off . . . ). A detector 130 in the encoder 106 detects the modulated, reflected light signal and, in response, generates one or more channel signals (e.g., CHA and CHB). In one embodiment, these channel signals are then transmitted to the decoder 108, which generates a count signal and transmits the count signal to the microprocessor 110. The microprocessor 110 uses the count signal to implement a user navigational operation such as scrolling or menu selection corresponding to the movement of the rotary dial 102.
In one embodiment, the encoder 106 includes the emitter 120 and the detector 130. The emitter 120 includes a light source 122 such as a light-emitting diode (LED). For convenience, the light source 122 is described herein as an LED, although other light sources, or multiple light sources, may be implemented. In one embodiment, the LED 122 is driven by a driver signal, VLED, through a current-limiting resistor, RL. The details of such driver circuits are well-known. Some embodiments of the emitter 120 also may include a lens 124 aligned with the LED 122 to direct the projected light in a particular path or pattern. For example, the lens 124 may focus the light onto the code wheel track 140.
In one embodiment, the detector 130 includes one or more photodetectors 132 such as photodiodes. The photodetectors may be implemented, for example, in an integrated circuit (IC). For convenience, the photodetectors 132 are described herein as photodiodes, although other types of photodetectors may be implemented. In one embodiment, the photodiodes 132 are uniquely configured to detect a specific pattern or wavelength of reflected light. In some embodiments, several photodiodes 132 may be used to detect modulated, reflected light signals from multiple tracks 140, including positional tracks and index tracks. Also, the photodiodes 132 may be arranged in a pattern that corresponds to the radius and design of the code wheel 104.
The signals produced by the photodiodes 132 are processed by signal processing circuitry 134 which generates the channel signals, CHA and CHB. In one embodiment, the detector 130 also includes one or more comparators (not shown) to facilitate generation of the channel signals. For example, analog signals (and their complements) from the photodiodes 132 may be converted by the comparators to transistor-transistor logic (TTL) compatible, digital output signals. In one embodiment, these output channel signals may indicate count and direction information for the modulated, reflected light signal. Additionally, the detector 130 may include a lens 136 to direct the reflected light signal toward the photodiodes 132.
Additional details of emitters, detectors, and optical encoders, generally, may be referenced in U.S. Pat. Nos. 4,451,731, 4,691,101, 5,017,776, and 5,241,172, which are incorporated by reference herein.
FIG. 2 depicts a partial schematic diagram of one embodiment of a code wheel 104. In particular, FIG. 2 illustrates a portion of a circular code wheel 104 in the shape of a disc. In some embodiments, the code wheel 104 may be in the shape of a ring, rather than a disc. The illustrated code wheel 104 includes a track 140, which may be a circular track that is concentric with the code wheel 104. In one embodiment, the track 140 includes a continuous repeating pattern that goes all the way around the code wheel 104. The depicted pattern includes alternating non-reflective sections 142 and reflective sections 144, although other patterns may be implemented. In one embodiment, the non-reflective sections 142 are transparent sections of the code wheel 104 or, alternatively, are voids (e.g., holes) in the code wheel 104. The reflective sections 144 are, for example, opaque sections in the code wheel 104. In one embodiment, the surface areas corresponding to the reflective sections 144 are coated with a reflective material.
Also, it should be noted that, in some embodiments, the circular code wheel 104 could be replaced with a coding element that is not circular. For example, a linear coding element such as a code strip may be used, in which case a linear slider (not shown) may be implemented instead of the rotary dial 102. In another embodiment, a circular coding element may be implemented with a spiral bar pattern, as described in U.S. Pat. No. 5,017,776, as shown in FIG. 16 and described in more detail below. Furthermore, a linear coding element such as a code strip may be implemented with a spiral, or diagonal, bar pattern, as shown in FIG. 17 and described in more detail below. Alternatively, other light modulation patterns may be implemented on various shapes of coding elements.
As described above, rotation of the code wheel 104 and, hence, the track 140 results in modulation of the reflected light signal at the detector 130 to measure positional changes of the code wheel 104 and the dial 102. Other embodiments of the code wheel 104 may include other tracks such as additional positional tracks or an index track, as are known in the art.
In the depicted embodiment, the track sections 142 and 144 have the same circumferential dimensions (also referred to as the width dimension). The resolution of the code wheel 104 is a function of the width dimensions (as indicated by the span “x”) of the track sections 140 and 142. The radial, or height, dimensions (as indicated by the span “y”) of the track sections 140 and 142 are a function of the amount of area required to generate a sufficient amount of photocurrent (e.g., the more photocurrent that is required, the larger the area required and hence the larger “y” needs to be since area equals “x” times “y”). Additionally, the radial dimensions of the track sections 140 and 142 may be a function of the amount of area required to produce a detectable gap between consecutive, reflected light pulses.
In another embodiment, the code wheel 104 may be at least partially integrated with the dial 102, rather than being a separate component coupled to the dial 102. For example, the underside of the dial 102 may be coated with reflective material such as bright nickel (Ni) or chrome, and a non-reflective track pattern can be applied to the reflective material. The non-reflective pattern may be silk-screened, stamped, ink jet printed, or otherwise applied directly onto the reflective surface on the dial 102. Alternatively, the non-reflective pattern may be formed as a separate part such as by injection molding, die-cutting, punching (e.g., film), or otherwise forming a non-reflective component which has opaque spokes on it. Whether the non-reflective material is applied directly to the reflective material or formed as a separate component, the combined reflective and non-reflective materials function similar to the code wheel 104 described above, having alternative reflective and non-reflective sections 142 and 144. In another embodiment, the reflective and non-reflective materials may be reversed so that the underside of the dial 102 is used for the non-reflective material and a separate reflective material is applied to or formed separately from the non-reflective material.
FIG. 3 depicts a perspective view of one embodiment of an optical jog wheel 150. The illustrated optical jog wheel 150 includes a rotary dial 102, a code wheel 104 (not shown in FIG. 3), a circuit substrate 152, and a back plate 154. FIG. 4 depicts a side view of the optical jog wheel 150 of FIG. 3.
In one embodiment, the rotary dial 102 includes a tactile surface to facilitate rotation of the rotary dial 102 by a user. For example, the rotary dial 102 may include raised or dimpled portions, a rough surface, a tacky surface, or another tactile surface to make it relatively easy for a user's finger to engage the surface of the rotary dial 102. As described above, the code wheel 104 is coupled to the rotary dial 102 so that the rotation of the rotary dial 102 results in a corresponding rotation of the code wheel 104.
In one embodiment, the circuit substrate 152 is used to mount the encoder 106, including the emitter 120 and the detector 130. Some exemplary types of circuit substrates 152 include, but are not limited to, printed circuit board (PCB), flexible circuit, leadframe, insert molded leadframe, glass substrate, ceramic substrate, molded interconnect device (MID), and so forth. Alternatively, other types of circuit substrates 152 may be implemented. In some embodiments, other circuitry also may be mounted on the circuit substrate 152. However, in some embodiments, the amount of circuitry mounted to the circuit substrate 152 under the rotary dial 102 may be limited to keep the thickness of the optical jog wheel 150 small. The circuit substrate 152 is mounted to the back plate 154. Alternatively, the circuit substrate 152 also may be used as the back plate, in some embodiments, so that a separate back plate 154 may be omitted.
The illustrated optical jog wheel 150 also includes an independent button 154 and an illumination ring 156, although some embodiments may omit the independent button 156, or the illumination ring 158, or both. The independent button 156 may be implemented with a dome switch (not shown) or another well-known type of actuator. Alternatively, the independent button 156 may be implemented using an optical sensor which generates a button click signal in response to depression of the independent button. In a similar manner, some embodiments implement the encoder 106 to detect one or more button click operations corresponding to a depression of at least a portion of the rotary dial 102. In an embodiment, depression of the independent button or the rotary dial corresponds to a directional selection or to an item selection.
In one embodiment, the illumination ring 158 illuminates upon user interaction with the optical jog wheel 150, including rotation of the rotary dial 102, depression of the rotary dial 102, or depression of the independent button 156. The illumination ring 158 also may be used to engage with the back plate 154 to secure the other components of the optical jog wheel 150 such as the code wheel 104, rotary dial 102, and independent button 156 to the back plate 154. In some embodiments, the illumination ring 158 may function as a mounting ring, as described, without having illumination functionality.
FIG. 5 depicts an exploded perspective view of the optical jog wheel 150 of FIG. 3. As described above, the optical jog wheel 150 includes a back plate 154, a circuit substrate 152, a code wheel 104, a rotary dial 102, an independent button 156, and an illumination ring 158. In contrast to the code wheel 102 of FIG. 2, the code wheel 102 shown in FIG. 5 is embodied in a ring implementation, rather than a disc implementation, although different shapes may be used.
In one embodiment, the optical jog wheel 150 also includes a mounting bracket 160. The mounting bracket 160 may function to secure the circuit substrate 152 to the back plate 154. The mounting bracket also may provide a predetermined mounting location for the code wheel 104. In one embodiment, the illumination ring 158 includes an upper flange and one or more lower fasteners such as plastic tabs to secure the several components between the illumination ring 158 and the base plate 154. For example, the lower fasteners may be inserted through holes in the circuit substrate 152 and into fastener openings in the base plate 152, at which point the lower fasteners of the illumination ring 158 may engage with the base plate 152.
FIG. 6 depicts one embodiment of a layout of an encoder 106 on a circuit substrate 152. The illustrated encoder 106 includes an emitter 120 and a detector 130. The detector 130 includes four photodiodes 132 arranged relative to the emitter 120, although fewer or more photodiodes 132 may be used. In one embodiment, the photodiodes 132 are arranged so that light is incident on and reflected from the code wheel 104 approximately at a centerline 162 between the LED 122 of the emitter 120 and the photodiodes 132 of the detector 130.
Various methods may be used to implement the emitter 120 and detector 130. In one embodiment, the emitter 120 and detector 130 may be implemented using chip-on-board technology. Alternatively, the emitter 120 and detector 130 may be implemented as a discrete transfer molded emitter-detector package. In one embodiment, the emitter 120 and decoder 130 may be attached as bare dice onto the circuit substrate 152 to achieve a particular thickness of the optical jog wheel 150. In this way, the emitter 120 and detector 130 may be die-attached close together to reduce or minimize the potential loss of light power. Additionally, the mounting of the emitter 120 and detector 130 may enable a small gap between the encoder 106 and the code wheel 104. The gap between the encoder 106 and the code wheel 104 also may depend on the use of an encapsulant, if any, to encapsulate part or all of the encoder 106.
FIG. 7 depicts a side view of one embodiment of a layout of an encoder 106 with an air gap between the encoder 106 and the code wheel 104. In particular, the encoder 106 is not encapsulated by an encapsulant. More specifically, the emitter 120 and the decoder 130, including the photodiodes 132, are not encapsulated, so the distance between the encoder 106 and the code wheel 104 may be reduced or minimized. Since the code wheel 104 is coupled to the rotary dial 102, and the encoder 106 is coupled to the circuit substrate 152, the overall thickness of the optical jog wheel 150 may be reduced by reducing the distance between the encoder 106 and the code wheel 104.
FIG. 8 depicts a side view of one embodiment of a layout of an encoder 106 with a fully encapsulated encoder 106. In particular, the emitter 120 and detector 130, including the photodiodes 132, are encapsulated by a single encapsulant 164. In some embodiments, using a single encapsulant may result in an increased distance between the encoder 106 and the code wheel 104 because of the resulting height of the encapsulant 164. However, in some embodiments, the encapsulant may be formed using techniques to reduce the thickness of the encapsulant 164.
FIG. 9 depicts a side view of one embodiment of a layout of an encoder 106 with an individually encapsulated emitter 120 and detector 130. In particular, the emitter 120 is encapsulated by a first encapsulant 164, and the detector 130 is encapsulated by a separate encapsulant 166 that is distinct from the first encapsulant 164. In some embodiments, the first and second encapsulants 164 and 166 may be the same material, although different encapsulating materials may be used.
FIG. 10 depicts a side view of one embodiment of a layout of an encoder 106 with an individually encapsulated emitter 120 and a partially encapsulated detector 130. In particular, the emitter 120 is encapsulated by a first encapsulant 164, and a portion of the detector 130 is encapsulated by a second encapsulant 166. In one embodiment, the second encapsulant 166 encapsulates a wire bond 168 of the detector 130, but does not encapsulate the photodiodes 132. In other words, one or more of the photodiodes 132 remains exposed.
FIG. 11 depicts one embodiment of a method 170 of making an optical jog wheel 150. While the method 170 depicts several operations, other embodiments of the method 170 may include fewer or more operations for making an optical jog wheel 150 or similar optical navigational device.
At block 172, a base plate 154 is provided. At block 174, a circuit substrate 152 is provided and coupled to the base plate 154. In one embodiment, the circuit substrate 152 has an encoder 106, including an emitter 120 and detector 130, as described above. At block 176, a mounting bracket 160 is coupled to the base plate 154. Various types of conventional fasteners or coupling technologies may be used to couple the mounting bracket 160 to the base plate 154. At block 178, a code wheel 104, a rotary dial 102, an independent button 156, and an illumination ring 158 are mounted to the mounting bracket 160. Alternatively, the code wheel 104, rotary dial 102, independent button 156, and illumination ring 158 may be mounted to the base plate 154, as described above.
FIG. 12 depicts one embodiment of a method 180 of using an optical jog wheel 150. However, it should be noted that this method 180 is exemplary and other operations not discussed in conjunction with this method 180 may be implemented by one or more embodiments of an optical jog wheel 150 or similar optical navigational device.
At block 182, the emitter 120 emits a light signal incident on the track 140 of the code wheel 104. At block 184, the incident light signal reflects off of the reflective sections 144 of the track 140, and the reflected light signal is detected by the detector 130. In one embodiment, the reflected light signal is modulated according to the resolution and rotational speed of the code wheel 104. As explained above, the rotational speed of the code wheel 104 is the same as, or otherwise related to, the rotational speed of the rotary dial 102 because the code wheel 104 is coupled to the rotary dial 102.
At block 186, the detector 130 generates one or more channel signals corresponding to the modulated, reflected light signal. At block 188, the decoder 108 generates a count signal corresponding to the channel signal(s) from the detector 130. At block 190, the microprocessor 110 implements a user navigational operation in response to the count signal from the decoder 108. In this way, the microprocessor 110 implements a user navigational operation in response to a user navigational input using the rotary dial 102. The user navigational operation may be a scrolling operation, a selection operation, or another type of navigational operation on an electronic device.
FIG. 13 depicts a perspective view of another embodiment of an optical jog wheel 150. The illustrated optical jog wheel 150 includes a rotary dial 102, a code wheel 104 (not shown in FIG. 3), a circuit substrate 152, and a back plate 154. FIG. 14 depicts a side view of the optical jog wheel 150 of FIG. 13.
FIG. 15 depicts an exploded perspective view of the optical jog wheel 150 of FIG. 13. As described above, the optical jog wheel 150 includes a back plate 154, a circuit substrate 152, a mounting ring 160, a code wheel 104, a rotary dial 102, an independent button 156, and an illumination ring 158. In contrast to the optical jog wheel 150 of FIG. 5, the optical jog wheel 150 of FIG. 15 reverses the order of the independent button 156 and the illumination ring 158. In some embodiments, the order of the various components may be rearranged to accommodate different mounting and securing combinations.
In one embodiment, the optical jog wheel 150 of FIG. 15 also includes a metal dome array 192. The metal dome array 150 includes one or more metal dome switches to allow the rotary dial 102 to be used to make selections. In one embodiment, a metal dome switch may be activated to generate a switch signal when the rotary dial 102 is depressed at approximately the location of a corresponding metal dome switch. For example, a user may activate a metal dome switch by tilting, or depressing, a portion of the rotary dial 102 near the metal dome switch. The movement of the depressed portion of the rotary dial 102 toward the metal dome switch may engage and activate the metal dome switch. Various arrangements for the metal dome array 192 may be implemented. As described above, the metal dome array 192 may be used in conjunction with the rotary dial 102 to allow a user to make a selection or implement a user navigational operation.
FIG. 16 depicts a partial schematic diagram of another embodiment of a code wheel 200 with spiral track sections. In particular, FIG. 16 illustrates a portion of a circular code wheel 200 in the shape of a disc. In some embodiments, the code wheel 200 may be in the shape of a ring, rather than a disc. The illustrated code wheel 200 includes a track 202, which may be a circular track that is concentric with the code wheel 200. In one embodiment, the track 202 includes a continuous repeating pattern that goes all the way around the code wheel 200. The depicted pattern includes alternating non-reflective sections 204 and reflective sections 206, although other patterns may be implemented. In one embodiment, the non-reflective sections 204 are transparent sections of the code wheel 200 or, alternatively, are voids (e.g., holes) in the code wheel 200. The reflective sections 206 are, for example, opaque sections in the code wheel 200. In one embodiment, the surface areas corresponding to the reflective sections 206 are coated with a reflective material.
As described above, rotation of the code wheel 200 and, hence, the track 202 results in modulation of the reflected light signal at the detector 130 to measure positional changes of the code wheel 200 and the dial 102. Other embodiments of the code wheel 200 may include other tracks such as additional positional tracks or an index track, as are known in the art.
In contrast to the code wheel 104 of FIG. 2, which is described above, the code wheel 200 of FIG. 16 includes a track 202 of alternating spiral-shaped track sections 204 and 206 which form a circumferential path on the code wheel 200. In some embodiments, the reflective sections 206 and the non-reflective sections 204 are approximately the same size. Other embodiments may use different sizes of reflective sections 206 and/or non-reflective sections 204.
Each track section has a leading edge 208, a trailing edge 210, an outside boundary 212 and an inside boundary 214. The edges 208 and 210 and boundaries 212 and 214 may be curved or straight, depending on the method of manufacture used to fabricate the code wheel 200. Some embodiments implement the boundaries 212 and 214 with circular arc segments having a center coincidental with the center of the code wheel 200. Additionally, in some embodiments, the trailing edge 210 is substantially parallel to the leading edge 208. Other embodiments may include non-parallel leading and trailing edges 208 and 210. It should be noted that the leading edge of each of the track sections 208 and 210 is substantially oblique to the direction of movement (indicated by the arrow) of the code wheel 200. Additionally, although an exemplary direction of movement is shown, other embodiments may have a different direction of movement (e.g., the reverse direction), which may result in different designations for the leading and trailing edges of the track sections 208 and 210.
FIG. 17 depicts a schematic layout 220 of one embodiment of a photodetector array 222 relative to spiral track sections 204a-c of the code wheel 200 of FIG. 16. The spiral track sections 204a-c may represent either non-reflective track sections 204 or reflective track sections 206. Although various shapes and sizes of photodetectors are adaptable for use in combination with the code wheel 200, some embodiments of the photodetector array 222 include interdigitated photodetectors formed on an integrated circuit substrate to maintain a relatively low production cost. In general, interdigitated photodetectors are substantially adjacent to one another and receive information corresponding to more than one channel, as described above. The actual sizes, shapes, and layouts of the photodetectors may vary depending on the implementation of the code wheel 200 used with the photodetector array 222. Signals from the photodetector array 222 may be processed as described above.
In one embodiment, the photodetector array 222 is located in a plane that is substantially parallel to the plane of the code wheel 200. As the code wheel 200 rotates, the circumferential track 202 of reflective and non-reflective sections 204 and 206 generates spiral-shaped light images (either through reflection or transmission) that are detected by one or more photodetectors of the photodetector array 222. In one embodiment, the photodetector array 222 is oriented relative to the reflective sections 206 of the code wheel 200 so that the length of the photodetectors are substantially parallel to the leading and trailing edges 208 and 210 of the reflective sections 206. Various geometrical equations may be used to determine the orientation of the photodetector array 222 relative to the reflective sections 206 of the code wheel 200. Some exemplary equations are described in U.S. Pat. No. 5,017,776, which is incorporated by reference herein.
FIG. 18 depicts a schematic diagram of one embodiment of a code strip 230 with a code track 232 which includes diagonal track sections 234 and 236. Thus, in some embodiments, a linear coding element such as the code strip 230 may be used instead of the circular code wheel 200. Similar to the track sections 204 and 206 of the code wheel 200, the track section 234 and 236 of the code strip 230 also have a leading edge 238, a trailing edge 240, an upper boundary 242, and a lower boundary 244. However, it should be noted that the designations of leading, trailing, upper, and lower are not restrictive of the physical layout of the track sections 234 and 236. These designations merely indicate a direction of movement (indicated by the arrow) and/or a physical orientation of the encoder in which the code strip 230 might be implemented.
FIG. 19 depicts one embodiment of a method 250 of making an optical jog wheel 150 with the spiral code wheel 200 of FIG. 16. While the method 250 depicts several operations, other embodiments of the method 250 may include fewer or more operations for making an optical jog wheel 150 with the spiral code wheel 200.
At block 252, the spiral code wheel 200 is coupled to a rotary dial 102. At block 254, an emitter 120 is mounted on a circuit substrate 152. As described above, the emitter 120 generates a light signal incident on the track 202 of the spiral code wheel 200. At block 256, a detector 130 is mounted on the circuit substrate 152. As described above, the detector 130 detects a reflected spiral-shaped light signal reflected off of the track 202 of the spiral code wheel 200.
Other embodiments of the encoder also may include components for determining absolute position. For example, the encoder may include additional tracks, photodetectors, LEDs, or other components to allow the encoder to determine an absolute angular position of the code wheel upon power up. The absolute angular position can be determined using many known techniques. One exemplary technique, with corresponding hardware, is described in more detail in U.S. patent Ser. No. 11/445,661, filed on Jun. 2, 2006, entitled “Multi-bit absolute position optical encoder with reduced number of tracks,” which is incorporated by reference herein.
Although the operations of the method(s) herein are shown and described in a particular order, the order of the operations of each method may be altered so that certain operations may be performed in an inverse order or so that certain operations may be performed, at least in part, concurrently with other operations. In another embodiment, instructions or sub-operations of distinct operations may be implemented in an intermittent and/or alternating manner.
Although specific embodiments of the invention have been described and illustrated, the invention is not to be limited to the specific forms or arrangements of parts so described and illustrated. The scope of the invention is to be defined by the claims appended hereto and their equivalents.

## Claims

1. A user navigational apparatus comprising:
a rotary dial;
means for generating a light signal incident on a coded track;
means for generating a spiral-shaped light image in response to the light signal incident on the coded track;
means for illuminating an annular region adjacent to the rotary dial, wherein the annular region and the rotary dial have a common central reference point, and the annular region is disposed within the rotary dial; and
means for detecting motion of the coded track, wherein the coded track is configured to move in response to a first user movement of the rotary dial.

2. The user navigational apparatus of claim 1 further comprising:
means for implementing a user navigational operation on a controlled device in response to the first user movement of the rotary dial; and
means for activating a switch in response to a second user movement of the rotary dial.

3. The user navigational apparatus of claim 1 further comprising means for encapsulating at least a portion of an encoder mounted in conjunction with the coded track.

4. The user navigational apparatus of claim 1 further comprising means for detecting the spiral-shaped light image.

5. The user navigational apparatus of claim 1 further comprising means for activating an independent button disposed within a center of the rotary dial.

6. The user navigational apparatus of claim 5 wherein the annular region is disposed between the independent button and the rotary dial.

7. A user navigational apparatus comprising:
a rotary dial;
means for generating a light signal incident on a coded track;
means for generating a spiral-shaped light image in response to the light signal incident on the coded track;
means for activating an independent button disposed within a center of the rotary dial;
means for illuminating an annular region disposed within the rotary dial; and
means for detecting motion of the coded track, wherein the coded track is configured to move in response to a first user movement of the rotary dial.

8. The user navigational apparatus of claim 7 further comprising:
means for implementing a user navigational operation on a controlled device in response to the first user movement of the rotary dial; and
means for activating a switch in response to a second user movement of the rotary dial.

9. The user navigational apparatus of claim 7 further comprising means for encapsulating at least a portion of an encoder mounted in conjunction with the coded track.

10. The user navigational apparatus of claim 7 further comprising means for detecting the spiral-shaped light image.