Patent Description:
The outer surface of the cube <NUM> is formed by an aggregation of what appears to be twenty-six (<NUM>) smaller component cubes, hereinafter referred to as "cubelets," <NUM>, <NUM>, <NUM>. The cubelets <NUM>, <NUM>, <NUM> are not truly cubes but appear so from outside the cube <NUM> because their face segments <NUM> on the outer surface of the cube <NUM> resemble the faces that true cubes would have on the outer surface of the cube <NUM>, if they were the components from which cube <NUM> were made. That is, the six central cubelets <NUM> at the center positions of faces <NUM> each have one face segment <NUM>, the twelve central edge cubelets <NUM> at the edges of the faces <NUM> but not at the vertices (corners) of faces <NUM> each have two face segments <NUM>, and the eight vertex cubelets <NUM> at the vertices of the cube <NUM> each have three face segments <NUM>. Each cubelet <NUM>, <NUM>, <NUM> is free to rotate relative to an adjacent cubelet <NUM>, <NUM>, <NUM>.

Within the cube <NUM> is an inner core, which may be embodied, as non-limiting examples, as the core <NUM> of cube <NUM> in <FIG> or the core <NUM> of cube <NUM> in <FIG>. In the embodiment of <FIG>, the core <NUM> resembles a point in space from which six posts <NUM> extend outward. In the embodiment of <FIG>, the core <NUM> takes a spherical form with posts <NUM> mounted thereon. In both examples, each post <NUM> or <NUM> contacts one of the six central cubelets <NUM>, <NUM> on a different face of the cube <NUM>, <NUM>. The posts <NUM>, <NUM> are free to rotate relative to the core <NUM>, <NUM> or relative to the central cubelets <NUM>, <NUM> they contact, thereby enabling each face of the cube <NUM>, <NUM> to rotate relative to the core <NUM>, <NUM> about the axis of the post <NUM>, <NUM> it contacts. The posts <NUM>, <NUM> for these cube <NUM>, <NUM> constrain the central cubelets <NUM>, <NUM> from axial movement along the posts <NUM>, <NUM> and away from the core <NUM>, <NUM>.

The central edge cubelets and the vertex cubelets (not shown in <FIG>) do not contact the posts <NUM>, <NUM>. They however do not separate from the cube <NUM>, <NUM> due to elaborate shapes of their bases. These bases enable the cubelets to slide relative to each other and to return to form the cube shape at the completion of ninety-degree rotations (discussed below). The bases also constrain the central cubelets <NUM>, <NUM> from axial movement along the posts <NUM>, <NUM> toward the core <NUM>, <NUM>. The sophisticated details of the base construction are known and thus beyond the scope of the present disclosure.

Within a single face <NUM>, each face segment <NUM> is free to move relative to the others. As illustrated in <FIG>, two adjacent faces <NUM> share a common edge <NUM>, and a face segment <NUM> sharing an edge with a face segment <NUM> of an adjacent face <NUM> is constrained not to move relative to that face segment <NUM> of the adjacent face <NUM>. As alluded above, for each vertex face segment <NUM> there are three face segments <NUM>, in which each face segment <NUM> is adjacent to the other two face segments <NUM>, sharing a common vertex <NUM>, and the three face segments <NUM> adjacent the common vertex <NUM> are constrained not to move relative to each other. As also alluded above, for each non-vertex edge face segment <NUM> there is another non-vertex edge face segments <NUM> on an adjacent face <NUM>, and the two non-vertex edge face segments <NUM> are constrained not to move relative to each other. Accordingly, each face <NUM> has a center face segment <NUM>, four vertex face segments <NUM>, and four non-vertex edge face segments <NUM>.

With reference to the cube <NUM> in <FIG>, edge face segments <NUM> on one face <NUM> may be repositioned to an adjacent face <NUM> by rotating them ninety degrees relative to the rest of the cube <NUM>. The axis <NUM> of rotation is parallel to both the face <NUM> containing the edge face segments <NUM> before the rotation and the face <NUM> containing the edge face segments <NUM> after the rotation. This rotation repositions nine cubelets <NUM> relative to the rest of the cube <NUM>. Accordingly, the rotating face segments consist of those on one face <NUM> plus the edge face segments from the adjacent faces that share an edge with that one face <NUM>.

Cubes <NUM> and <NUM> of <FIG> and <FIG> are often referred as "3x3 cubes," as they have 3x3 arrays of cubelets at each face. Three-dimensional puzzles of this nature are not limited to 3x3 cubes, though. The cubes can have different amounts of cubelets on a face, and two examples are the 2x2 and 4x4 cubes. The shells of the three-dimensional puzzles are also not limited to cubical form, and the shell segments are not limited to cubelets. Two examples are three-dimensional puzzles having spherical or pyramidal shells. Accordingly, features of the invention disclosed herein are not limited to implementations on 3x3 cubes.

With respect to cubes such as those of <FIG> and <FIG>, the face segments may have one of six colors, such as white, red, blue, orange, green, and yellow. One typical way of playing a game with cube <NUM>, <NUM> is to rearrange the cubelets of the cube <NUM>, <NUM> so that each face has face segments of only one color. Three-dimensional puzzles of other shapes and numbers of shell segments are constructed and played analogously. Also, neither the prior art nor applications of inventive concepts discussed below are limited to face segments distinguished by colors. Instead, the face segments may differ by displaying thereon differing numbers, shapes, patterns, and symbols, as non-limiting examples.

For beginners, arranging all face segments accordingly is both complicated and challenging, and many players seek assistance through a variety of text and/or video guides. These guides present solution algorithms that many players can find difficult to understand. The present inventor knows of no prior-developed system of interactive feedback to guide a new user more easily to a solution.

More advanced players can regard quickly solving these puzzles as a type of competition, sometimes referred to as "speedcubing" and "speedsolving. " Leagues and tournaments are available in which the players strive to solve the puzzles as fast as possible. Participants constantly strive to improve their performance, and such training needs some type of measurement of time and some type of monitoring of face segments relative to each other. Accordingly, there is an unmet need for interactive feedback and guidance to both new and advanced players based on the relative positions of the face segments of a cube.

<CIT> discloses a " puzzle cube having prompting and recording functions".

<CIT> describes a "magic cube with a memory function, which can direct users to finish the recovery of the magic cube".

The present invention provides a three-dimensional puzzle according to claim <NUM> and a method of determining shell pattern on a three-dimensional puzzle in line with claim <NUM>. Also disclosed are a method of correcting errors in the determination of patterns on a three-dimensional puzzle, and methods of tracking patterns on a three-dimensional puzzle.

Further disclosed are a three-dimensional puzzle having a shell, a core, multiple unique signatures, and at least one signature sensor. The shell has at least four faces and is formed by multiple shell segments, each shell segment being free to move relative to an adjacent shell segment. The core within the shell, the faces being free to rotate relative to the core about axes extending from the core toward the faces. The multiple unique signatures are located at the shell segments. At least one signature sensor within the shell provides data to processing circuitry based on sensed signatures to determine shell segment patterns.

Additionally disclosed is a method of determining patterns on a three-dimensional puzzle, the puzzle having a shell formed by multiple shell segments, each shell segment being free to move relative to an adjacent shell segment, and multiple unique signatures located at the shell segments. The method including: from within the shell using at least one signature sensor to sense the unique signatures of proximate shell segments and determining their identities based on the sensed unique signatures; rotating a puzzle face to bring other shell segments proximate the at least one signature sensor for sensing other unique signatures and determining the identities of the other proximate shell segments based on the other sensed unique signatures; using rotation sensors to determine the new location of the earlier identified shell segments after the rotation; and continuing to rotate puzzle faces to determine identities of other shell segments and continuing to determine new locations of rotated shell segments until all shell segments are identified.

Further disclosed is a method of correcting errors in the determination of patterns on a three-dimensional puzzle, the puzzle having a shell formed by multiple shell segments, each shell segment being free to move relative to an adjacent shell segment, and multiple unique signatures located at the shell segments. The method includes: after a perceived rotation of a puzzle face, (<NUM>) tracking the rotation of shell segments as if the rotation were completed and (<NUM>) tracking the rotation of shell segments as if the rotation were not completed; from within the shell using at least one signature sensor to sense the unique signatures of proximate shell segments and determining their identities based on the sensed unique signatures; dismissing a tracking controverted by the identification of the proximate shell segments; and confirming the tracking that is not dismissed.

The disclosure also provides a method of tracking patterns on a three-dimensional puzzle, the puzzle having a shell formed by multiple shell segments, each shell segment being free to move relative to an adjacent shell segment, and multiple unique signatures located at the shell segments. The method includes: obtaining an initial pattern; from within the shell using at least two signature sensors to sense the unique signatures of shell segments moving into proximity; and providing data to processing circuitry based on the sensed signatures; wherein the processing circuitry determines from the data the identification of the proximate shell segments to determine a new shell segment pattern.

There is further disclosed a method of tracking patterns on a three-dimensional puzzle, the puzzle having a shell that has at least four faces and is formed by multiple shell segments, each shell segment being free to move relative to an adjacent shell segment, and the faces being free to rotate about axes extending from a core toward the faces. The method includes: obtaining an initial pattern; sensing rotation of the faces; and providing data to processing circuitry based on the rotation of the faces; wherein the processing circuitry determines from the face rotation data the movement of the shell segments to determine a new shell segment pattern.

Embodiments of the present invention are described in detail below with reference to the accompanying drawings, which are briefly described as follows:.

The invention is described below in the appended claims, which are read in view of the accompanying description including the following drawings, wherein:.

The invention summarized above and defined by the claims below will be better understood by referring to the present detailed description of embodiments of the invention. This description is not intended to limit the scope of claims but instead to provide examples of the invention.

In a first exemplary embodiment of the invention, the shell of the three-dimensional puzzle has six faces, which form a cube resembling the 3x3 type illustrated in <FIG>. Accordingly, the shell segments for this puzzle are six central cubelets, eight vertex cubelets, and twelve central edge cubelets, and each cubelet is free to move relative to an adjacent cubelet. The central cubelets are each located at a different face of the cube and are each contact a separate post extending from a core at the center of the cube. The individual faces of the cube are free to rotate relative to the core about axes that extend from the core through the posts and toward the faces.

<FIG> provides a cross-sectional illustration of the cube <NUM> of this embodiment. Visible are the four faces 76u, 76r, 76d, <NUM> and their associated central cubelets 78u, 78r, 78d, <NUM>, respectively. Central edge cubelets 80ul, 80ur, 80dr, 80dl are shown each in dashed lines between two central cubelets. Central cubelets 78u, 78r, 78d, <NUM> contact and rotate relative to posts 82u, 82r, 82d, <NUM>, respectively, extending from core <NUM>. That is, in this embodiment, the central cubelets 78u, 78r, 78d, <NUM> rotate relative to the posts 82u, 82r, 82d, <NUM> and the core <NUM>, but the posts 82u, 82r, 82d, <NUM> do not rotate relative to the core <NUM>.

As illustrated in <FIG>, the central cubelets 78u, 78r, 78d, <NUM> ends of the posts 82u, 82r, 82d, <NUM> penetrate the bases of the central cubelets 78u, 78r, 78d, <NUM> and have a greater diameter than the majority of the shaft. The changing diameter provides a shape that resembles to some extent the shape of a nail. Accordingly, the greater diameter of the ends of the posts 82u, 82r, 82d, <NUM> constrains the central cubelets 78u, 78r, 78d, <NUM> from axial movement away from the core <NUM> while allowing rotational movement of the central cubelets 78u, 78r, 78d, <NUM> with respect to the core <NUM>. The posts 82u, 82r, 82d, <NUM> may be made of a low-friction plastic material to enable a smooth rotation.

The posts 82u, 82r, 82d, <NUM> are hollow, and leads <NUM> extend within the posts 82u, 82r, 82d, <NUM> to connect rotation sensors (discussed next) to processing circuitry <NUM> located within the core <NUM>. In alternate implementations, the processing circuitry may be located in the space bounded the surface of the core <NUM> and the faces 76u, 76r, 76d, <NUM> the cube <NUM>, for example, on the outer surface of the core <NUM>. The processing circuitry <NUM> includes a rechargeable battery (not shown for clarity) as its power source. A charging interface <NUM> located in central cubelet 78u and accessed by opening central cubelet 78u (details of access hatch not shown for clarity) is electrically connected to the battery by leads (not shown for clarity), which extend through hollow post 82u. The charging interface <NUM> may be a commercial off the shelf standard socket or a custom made socket as decided by one skilled in the art.

This embodiment has for each face 76u, 76r, 76d, <NUM> a rotation sensor, respectively, that senses the rotations of the face 76u, 76r, 76d, <NUM> relative to the core <NUM>. The rotation sensors typically comprise sensing circuitry <NUM> mounted at the ends of the posts 82u, 82r, 82d, <NUM> and rotation indicating discs <NUM> mounted in the interior of the central cubelets 78u, 78r, 78d, <NUM> adjacent the face segments.

Rotations sensors may be implemented in a variety of ways. The rotation sensors used in this embodiment measure the rotation amplitude as well as the direction. Examples of such rotation sensors include quadrature sensors (quadrature encoders) and absolute sensors (absolute rotation angle provided relative to a known initial state).

For example, rotation sensor <NUM> in <FIG> has as sensing circuity an optical sensor <NUM> and as a rotation indicating disc a toothed wheel <NUM> (or slotted/coded disc). The toothed wheel <NUM> is positioned to block or to allow light to pass from an LED to the optical sensor <NUM> as the central cubelet <NUM> and thus the associated face rotate, and the sensor <NUM> sends its readings to the processing circuity.

As another example, a rotation sensor may be implemented as rotation sensor <NUM> in <FIG>, in which the sensing circuitry is a reflective optical sensor <NUM> , and the rotation indicating disc is a slotted disc <NUM>. The disc <NUM> rotates with the cubelet <NUM> and the reflective sensor <NUM> sends signals indicative of the rotation to the processing circuity.

As another example, a rotation sensor may be implemented with the sensing circuitry being a magnetic sensor, and the rotation indicating disc being a multi-pole disc magnet. The multi-pole disc magnet rotates with the cubelet and the magnetic sensor sends signals indicative of the rotation to the processing circuity. Other contactless sensor examples include capacitive and inductive sensors with the rotation indicating disc being the corresponding technology for the specific sensor, as non-limiting examples. Contacting (mechanical) rotation sensors may be used instead.

<FIG> and <FIG> show two more alternate implementations of rotation sensors. In both rotation sensors <NUM>, <NUM> of <FIG> and <FIG>, respectively, the sensing circuitry <NUM>, <NUM> is mounted outside the cubelet <NUM>, <NUM> and closer to the core. For rotation sensor <NUM> of <FIG>, the rotation indicating disc <NUM> is mounted in the interior of the cubelet <NUM> adjacent to its face segment, as in the implementation of <FIG>, but for rotation sensor <NUM> of <FIG>, the rotation indicating disc <NUM> is mounted still in the interior of the cubelet <NUM> but closer to the sensing circuitry.

<FIG> illustrate other alternate implementations of rotation sensors <NUM>, <NUM>, respectively. Here, both the sensing circuitry <NUM>, <NUM> and the rotation indicating disc <NUM>, <NUM> are positioned within the core <NUM>, <NUM>. The sensing circuitry <NUM>, <NUM> remains stationary with respect to the core <NUM>, <NUM>. The post <NUM>, cubelet <NUM>, and rotation indicating disc <NUM> of rotation sensor <NUM> rotate together relative to the core <NUM>. In contrast, the post <NUM> of rotation sensor <NUM> is non-rotatively fixed to the core <NUM>. An interior rod <NUM> connects the cubelet <NUM> to the rotation indicating disc <NUM>, and thus the three elements rotate together.

Although not present in some embodiments of the invention, the cube of the embodiment of <FIG> includes a signature sensor within the cube and multiple unique signatures located at the cubelets. As constructed, the signature sensor provides data to the processing circuitry <NUM> based on sensed signatures to determine cubelet patterns on the cube. That is, the data enables the determination of both the identity of a cubelet and its orientation.

An example of a signature sensor is an optical sensor, and a corresponding example of a unique sensor is a specific shade of color, as represented in <FIG>. A vertex cubelet <NUM> has three face segments, each having a separate color. A spherical segment <NUM> is the part of the cubelet <NUM> that is closest to the core, and the segment <NUM> has colors <NUM>, <NUM>, <NUM> that each correspond to a different color of the three face segments <NUM>, <NUM>, <NUM> that are visible externally. The spherical segment <NUM> is visible from the cube's core. An optical sensor positioned within the cube, for example, at the core can sense the colors on the part of the spherical segment <NUM> within the field of view of the optical sensor and provide data to processing circuitry accordingly to determine the color of the corresponding face segment(s). (Color determination may be limited to one face segment depending on what part of the spherical segment passed within the field of view of the optical sensor and the type of optical sensor used. ) The central edge cubelets 80ul, 80ur, 80dr, 80dl of the cube <NUM> of <FIG> also have colors on spherical segments that each corresponds to a different color of the two face segments that are visible externally. The optical sensor can sense the colors on the part of the spherical segment of a central edge cubelet within its field of view and provide data to the processing circuitry to determine the color of the corresponding face segment(s).

The colors on the spherical segment matching the colors of the face segments is a natural result, if the vertex cubelets and the central edge cubelets are manufactured using three and two, respectively, separate solid-colored pieces. For example, such configuration is common when manufacturing the Dayan Cube, which competes with the Rubik's Cube. <FIG> illustrates a top face <NUM> of such type of cube in which all face segments have the same color, and two rows of cubelets <NUM>,<NUM> on the front left and front right faces have colors that differ from the color of the top face <NUM> <FIG> illustrates the sides of these cubelets that face the core, so it is clear that the colors on the spherical segments <NUM> match colors of the sides of the cubelets that form the exterior faces.

Some cubes, though, such as the Rubik's Cube, are manufactured using plastic of a single color, and the face segments are later colored, for example, by placing stickers thereon. Note the cubelet <NUM> in <FIG>, which has stickers <NUM> ,<NUM>, 188_ on the face segments to provide a variety of colors. Alternately, paints or other visually-distinctive means may be applied. The spherical segment <NUM> also has applied thereon stickers <NUM>,<NUM>,<NUM> of colors that correspond to the stickers <NUM>,<NUM>,188on the face segments. <FIG> illustrates a top face <NUM> of such type of cube in which all face segments have the same color, and two rows of cubelets <NUM>,<NUM>__ on the front left and front right faces have colors that differ from the color of the top face <NUM>. <FIG> illustrates the sides of these cubelets that face the core, so it is clear that the colors on the spherical segments <NUM> match colors of the sides of the cubelets that form the exterior faces.

<FIG> indicate the optical sensor's view of a vertex element's unique signatures. The vertex element can rotate, with a face, in three planes. Knowing which face rotates provides an indication of the new positions (the positions after the rotation) of each of the face segments of the rotated face and new positions of twelve adjacent face segments that share edges with the rotated face. Because employing one sensor enables the tracking of the face segments of three faces, employing two sensors, positioned at opposite vertices of the cube, enables the tracking of the face segments of each of the six faces. Reference is made to the following:.

<FIG> illustrate three face rotations that one optical sensor can view when facing a vertex element's coded region. Such configuration was modeled such that the optical sensor viewed a vertex element's region of unique signatures as shown below in <FIG>.

In some embodiments, the unique signatures are unique color signatures, and the optical sensor is an RGB sensor. The ability to distinguish between multiple colors may be used to uniquely code any piece of the puzzle in a way that the sensor can identify the colors of that piece and its absolute orientation. For example, consider the sample vertex element that is coded by three unique colors as in <FIG>. A focused RGB sensor with a narrowly-focused field of view (achievable by optical accessories, such as a lens and focused light beam) integrates the colors within that field of view to output a specific color that is associated with both a particular puzzle element (the colors of the face segments) and the element's particular orientation.

In yet other embodiments, three-dimensional puzzles can be constructed such that the unique signatures are RFID or NFC codes, and the signature sensor is an RFID or NFC sensor.

In some embodiments, the processing circuitry is located at the core and includes sensory indicators for the user. Examples of indicators are LEDs, lights, speakers, and/or vibration mechanism, as non-limiting examples, to provide the user a variety of messages, such as a low battery and time to "start playing. " The processing circuitry may also have an IMU sensor operative to sense the orientation of the shell.

The three-dimensional puzzle may include communication circuitry to transmit shell segment pattern data to an external client, such as a smartphone or tablet. The shell segment pattern data may be transmitted using Wi-Fi technology or Bluetooth technology.

The invention may be embodied as any of the three-dimensional puzzles disclosed herein plus the external client. The external client may have a display to show the shell segment pattern and/or the orientation of the shell based on data from the IMU. Not in accordance with the claimed invention, the external client may have the processing circuitry to receive the data from the signature sensor to determine shell segment patterns. The external client may have circuitry to transmit shell segment pattern data via the Internet.

Some embodiments of the invention may include a reset and error correction mechanism, to respond to a situation in which a rotation was not properly sensed. For example, if the left face were rotated but not sensed, the determination of the resulting face segment pattern would be incorrect, and so would any subsequent rotation if the unsensed rotation remained unnoticed. Accordingly, embodiments of the invention include dedicated absolute sensors, which detect unique pieces in pre-defined locations. A single sensor is sufficient, but additional similar sensors may be employed for faster error correction.

Some embodiments of reset and error correction of a 3x3 cube position a single face segment determination sensor in a position, such as in or on the core, where it may monitor a corner location. Each face segment has on or near its base an element to be sensed (such as a unique color to be sensed by an RGB sensor) to provide to the face segment determination sensor the unique identification of the face segment. Upon execution of a short sequence of movements, the system may determine the entire face segment pattern of the cube using data from the face segment determination sensor and the face rotation sensors discussed above.

One method of determining patterns, which is useful for reset/initializations, is discussed with reference to <FIG> and <FIG>. As shown, in which the up, down, left, right, front, and back faces are shown represented by U, D, L, R, F, and B, respectively. Initially, only the colors of the central face segments and the face segment at the sensed corner are known. That face segment at the corner is denoted with a check, and the face segments in which the colors are unknown are represented as blank squares. The initial state is shown in the top-left face segment mapping in <FIG>.

During a single clockwise rotation of the "Up" face, the sensor detects the identities of the three face segments that pass by it, while in parallel the system calculates the new location of the face segment that was detected before the rotation. Accordingly, the top-right face segment mapping in <FIG> indicates with the check the new position of the first detected face segment and indicates the newly detected face segments with a "<NUM>" in each square. With the next "Up" rotation (see bottom-right face segment mapping in <FIG>), three more face segments are identified (each marked by "<NUM>"), and after the third "Up" rotation (bottom-left face segment mapping in <FIG>) three more face segments are identified (each marked by "<NUM>"). After four "Up" rotations (not shown), the cube returns to its initial state, and 4x3 (twelve) face segments are identified.

Next, with reference to <FIG>, the "Right" face is rotated four times, and ten additional face segments are identified. The right face segment map indicates the newly identified face segments by a vertical line in the square.

To identify additional face segments, the user simply needs to continue playing the cube to eventually cause the remaining unidentified face segment to pass by the sensor. For example, if the user makes two "U" rotations, a subsequent clockwise "R" rotation enables the sensor to identify three additional face segments. After enough rotations, all face segments are identified.

The system may be embodied so that the sensor identifies a face passing near it and also faces sharing the same supporting base. Such system provides information regarding the one or two adjacent faces constrained in a fixed position relative to the one face. (All faces to be sensed are permanently adjacent a face sharing a common edge, and a face located at a vertex is permanently adjacent two faces. ) <FIG> illustrates the effect of a system designed accordingly.

As in the preceding embodiment, the process begins with no face segments identified beyond the fixed central face segments. <FIG> shows the effect of three consecutive "Up" rotations. A base for a vertex supports three face segments, and that is how three face segments are initially identified and marked with checks instead of just one face. After the first "Up" rotation, five additional face segments are identified as shown in the upper-right drawing. The identified faces have a "<NUM>" indicating that they were identified during the first rotation, and "a" is used for face segments that are not at a vertex and "b" is used for face segments that are at a vertex.

<FIG> illustrates a scenario for the error correction. In this case, the system received an unclear rotation indication, so there is doubt as to whether a face really did rotate <NUM> degrees. The system will consider two possibilities: (<NUM>) that the face rotated <NUM> degrees; and (<NUM>) that the face did not rotate at all. After enough subsequent rotations, the sensor will eventually identify a face or base of a face that indicates whether there was a rotation.

With reference to <FIG>, an example is considered of tracking a cube's patterns starting with a solved cube (mapping at the far left). Here, the system sensed the beginning of a rotation of the "Left" face, but due to certain circumstances it was unclear whether the move was completed or canceled. Thus, the cube may be positioned in one of the middle states in the above diagram, "Yes" indicate the move was completed and "No" indicating the move was not completed. In that state the sensor would not be able to determine whether the move was completed, because it would see the same White-Green-Red piece. In this embodiment, the system would continue to track movement understanding that either of the possibilities will eventually be proven correct.

In this example, the next move is an "Up" rotation, and the two right side drawings show that a different trio of face segments passes to the sensor. Accordingly, the face segments are identified and the system knows which of the two possibilities (the left face rotated, or it did not) is the correct one.

It is understood that, while in the simplified example above two alternative pattern possibilities were considered, the system can be implement to consider many more alternative simultaneously.

In alternate embodiments, additional sensors may be employed. Accordingly, error correction requires fewer tracked rotations.

In a 3x3 cubic puzzle of <FIG>, cube <NUM>, there are twelve possible rotations of one of the six faces relative to the rest of the cube. That is, each face can rotate in two directions, both in the same plane but opposite each other. A system that knows the initial pattern of face segments can track the twelve possible rotations to determine any subsequent face segment pattern based on the initial pattern and subsequent rotations. Such a process is analogous to dead reckoning for navigation. The inventive concept here is not limited to the 3x3 size or the cubical shape. Two exemplary non-limiting embodiments of the invention are described next. The first is a method that does not require rotation sensors. The second embodiment is a method that does not require cubelet signature sensors.

The first exemplary embodiment of pattern tracking is described with reference to the flow chart of <FIG>. The tracking is executed on a three-dimensional puzzle having a shell formed by multiple shell segments. Each shell segment is free to move relative to an adjacent shell segment, and multiple unique signatures located at the shell segments.

The first step is to obtain the initial pattern of the shell segments on the faces. ) Non-limiting examples of obtaining the initial pattern include: retrieving the pattern from the puzzle's memory, such as when the puzzle was used last; using a given value that results from a factory reset; manual data entry from a peripheral device, such as a smartphone; determined data produce by photographing the puzzle; and using the initialization of the present invention.

The next step is to use at least two signature sensors within the shell to sense the unique signatures of the shell segments moving into the proximity of the sensors.

The following step is to provide data to processing circuitry based on the sensed signatures. ) The processing circuitry determines from the data the identification of the proximate shell segments to determine a new shell segment pattern.

One exemplary use of the method is on three-dimensional puzzles in which the shell has six faces, which collectively form a cube. In this particular case, the shell segments comprise six central cubelets, eight vertex cubelets, and twelve central edge cubelets. The central cubelets each are on a different face of the shell and each contact a separate post extending from a core along the axis of rotation of the face. The unique signatures are located at the vertex and central edge cubelets.

The second exemplary embodiment of pattern tracking briefly mentions above is described with reference to the flow chart of <FIG>. The tracking is executed on a three-dimensional puzzle having a shell that has at least four faces and is formed by multiple shell segments. Each shell segment is free to move relative to an adjacent shell segment, and the faces are free to rotate about axes extending from a core toward the faces.

The first step is to obtain an initial pattern of the shell segments on the faces. ) Non-limiting examples of obtaining the initial pattern are provided above in the discussion of the last embodiment.

The next step is to sense the rotation of the faces. ) Rotation sensors of the types discussed above may be used for this sensing.

The following step is to provide data to processing circuitry based on the rotation of the faces. ) The processing circuitry determines from the face rotation data the movement of the shell segments to determine a new shell segment pattern.

An exemplary use of this method is on a three-dimensional puzzle in which the shell has six faces, which collectively form a cube. The shell segments are six central cubelets, eight vertex cubelets, and twelve central edge cubelets. The central cubelets each are on a different face of the shell and each contact a separate post extending from the core along the axis of rotation of the face.

Another aspect of the invention is engaging the multiple player's use of the puzzle for online competitions worldwide. A central server may send unique sets of moves for the players, such as a different sequence of rotations for each user, as handicaps to make them all reach the same cube pattern as a "fair match" with similar initial conditions. The information from the users may be collected and ranking statistics provided. The statistics may include bout duration, number of moves, rotation speed, and personal records.

Claim 1:
A three-dimensional puzzle comprising:
a shell comprising at least four faces (76u, 76r, 76d, <NUM>) and formed by multiple shell segments, each shell segment being free to move relative to an adjacent shell segment;
a core (<NUM>) within the shell, the faces being free to rotate relative to the core about axes extending from the core toward the faces;
for each face, a rotation sensor (<NUM>, <NUM>) operative to sense rotation degree and direction of the face relative to the core and provide data to a processing circuitry based on the rotation of the faces;
a processing circuitry (<NUM>) located within the three-dimensional puzzle and configured to determine shell segment pattern based on (i) an obtained initial pattern, and (ii) said data; and
communication circuitry to transmit shell segment pattern data to an external client; and
wherein the initial pattern is obtained by any one of the following methods: retrieving the pattern from the puzzle's memory; using a given value that results from a factory reset; manual data entry from a peripheral device; photographing the puzzle; and using the initialization of the puzzle.