Automated hair cutting system and method of operation thereof

Methods and devices for automatically cutting hair are disclosed herein. In one embodiment, an automated system for cutting hair on a subject comprises a hair cutting device, configured for manual manipulation, the hair cutting device comprising a cutting mechanism and configured to engage the cutting mechanism to cut said hair. The automated system also comprises a positioning device coupled to the subject, the positioning device configured to interact with the cutting device for determining a position of the hair cutting device relative to the subject.

TECHNICAL FIELD

This application is directed, in general, to hair-cutting systems and, more specifically, to an automated hair-cutting system.

BACKGROUND

A very large number of professional barbers, hair stylists, and other professionals provide hair cutting services in most countries of the world. The importance in society of having well-groomed hair is highlighted by significant sums of money and time spent for these services. The substantial cost of a haircut and the time and inconvenience associated with getting one makes the idea of automated hair cutting systems attractive. Today, there are a number of systems available that provide guides, cutters, training materials, and other approaches to make it somewhat easier to cut hair without the need for extensive training. Regrettably, these systems are difficult to use for most people and often strictly limit the number of hair styles possible. Simple hair length guides, mechanical combs mounted on cutter heads, hair cutters mounted on vacuum hoses, and other common approaches do not allow people to generate most of the stylish and well-groomed results they seek. It is therefore desirable to have a system allowing a person without extensive training to accurately cut hair.

In light of the benefits an automated hair cutting system provides, several attempts at such a system have been made. In U.S. Pat. No. 3,054,183, Zucker teaches a mechanical guide that adjusts a cutter head as it is moved across a person's scalp. The simple, mechanical design Zucker offers does not allow a wide variety of hair styles, and its rolling wheels or sliding mechanical guides may tend to smash some hair down, making it harder to access and cut properly. In U.S. Pat. No. 3,413,985, Dlouhy teaches a helmet fitted over a person's head and aligned with ear retractors that insert into the person's ears. Multiple cutter heads are used inside the helmet to cut hair. Dlouhy teaches a rigid helmet, many cutter heads and a large, heavy mechanism that would necessarily be expensive, bulky, and uncomfortable to use.

In U.S. Pat. No. 4,602,542, Natrasevschi teaches a frame rigidly holding a person's head and a robotic arm that cuts hair. Hair length is controlled with an adjustable vacuum stretcher tube and rotary cutter tube. Such a system would be necessarily expensive, bulky, and uncomfortable. In addition, the end of Natrasevschi's hair cutter always touches the person's head so it may smash hair down and the maximum length that hair may be cut is physically limited by the length of the cutter tube and stretcher tube. Employment of longer tubes would make the hair cutter unwieldy and interchangeable tubes, while perhaps possible, would be inconvenient. In U.S. Patent Application 2004/0004559, Rast teaches a hair cutter with some features similar to Natrasevschi. Rast also suffers from limitations on hair length and the need to make physical contact with a person's head to position his hair cutter. Rast explains how position of his hair cutter may be determined using electronic sensors, but depends on his mechanical separator sleeve (similar in some sense to Natrasevschi's stretcher tube) to determine position above the scalp. Hence, hair is always potentially mashed down, and there are clear limitations on possible styles and hair length.

It is also noteworthy that the hair cutting devices of Natrasevschi and Rast, like many available on the market today, operate by continuously operating their cutter heads such that any hair that contacts the cutter heads is cut once engaged. Such approaches lead to a noisy environment as the hair cutting device will normally buzz or at least hum through the course of a haircut and the continuous operation of the cutter head leads to additional wear on moving parts and unnecessary consumption of power.

SUMMARY

One aspect provides an automated hair cutting system. In one embodiment, the system includes: (1) a hair cutting device configured to engage a cutting mechanism to cut the hair on a subject and (2) a positioning structure operable to interact with the hair cutting device to determine a position of the hair cutting device relative to a reference point.

Another aspect provides an automated system for cutting hair on a subject. In one embodiment, the system includes: (1) a hair cutting device having a plurality of engagable blades proximate comb teeth and controlled to to allow the hair to be combed through the comb teeth and cut by the engagable blades after extension of the hair and (2) a positioning structure operable to interact with the hair cutting device to determine a position of the hair cutting device.

Yet another aspect provides a method of employing a hair cutting device to cut hair on a subject to conform to a specified style. In one embodiment, the method includes: (1) associating a positioning structure with the subject, the associating detecting but not impeding movement of the subject, (2) sensing a position of the hair cutting device and (3) engaging a cutting mechanism of the hair cutting device if the position correlates with the specified style.

DETAILED DESCRIPTION

Before describing various embodiments of the automated hair cutting system and method, techniques for controlling and monitoring a position of a hair cutting device will be generally described.

It is realized herein that the position of a hair cutting device may be monitored relative to a subject such that it cuts hair at specified locations and times yielding a desired haircut. It is further realized herein that a positioning structure may be used in monitoring the position of a hair cutting device relative to a subject and that various embodiments of a positioning structure are possible. It is further realized herein that such a positioning structure may include a positioning device having positioning interfaces that is coupled to a subject. It is further realized herein that such a positioning structure may include a camera for monitoring a subject, or for monitoring a positioning device, or for monitoring both a subject and a positioning device. It is realized herein that reference points on the subject's face may be employed to provide greater flexibility in the shape of the positioning device and the precision with which it is coupled to the subject. It is further realized herein the positioning device need only be stable relative to the subject during operation.

It is realized herein the positioning structure may interact with the hair cutting device to determine the position and orientation of the hair cutting device relative to the subject. It is realized herein scalp outlines and tables may be employed to provide hair cut information. Hair cut information may include: hair length per region, scalp irregularities, color, presence of thinning hair, or many other hair characteristics. It is further realized herein that an electronic computing device may be employed to carry out computations associated with control of the automated hair cutting system, interact with sensors, and to provide a user interface. It is realized herein the electronic computing device may be a computer, cell phone, computerized tablet or a variety of other devices.

It is realized herein a person receiving a haircut may operate the system or have another person operate it. A person operating the system cuts hair by responding to guidance from the system that may be provided through the positioning device, the hair cutting device, the electronic computing device or possibly other devices of the system.

It is also realized herein that the automated hair cutting system may be applied to cutting hair on the subject's scalp and face (moustache and beard hair in addition to scalp hair) and may also be applied to other fields where precise relative alignment of a tool or other device to another object provides benefit. It is realized herein medical surgery systems, drug delivery systems, robotic systems, machine tools, cutting systems, and many other systems may benefit from the teaching of the system and method.

FIG. 1shows an embodiment of an automated hair cutting system100including a user102, a positioning device108, a hair cutting device200, and an electronic computing device106. Electronic computing device106may be embodied as a cell phone, tablet computer, notebook computer, desktop computer, or other computing device. Electronic computing device106may include a display screen, touchscreen, buttons, cursor controls, joysticks, cameras107, speakers, buzzers, microphones, haptics, indicator lights, software, electronic interfaces, and other elements that may allow electronic computing device106to interface to user102, positioning device108, and hair cutting device200. Cameras107may be used to provide useful information to other elements of automated hair cutting system100and additional cameras may be provided on positioning device108, on hair cutting device200, or additional stand-alone cameras or cameras mounted on other elements of some embodiments. Electronic computing device106may also include wired or wireless electronic interfaces to positioning device108, hair cutting device200, and possibly to elements not shown inFIG. 1such as the Internet, Internet servers, cloud computing elements, or other devices. No wires are shown inFIG. 1to avoid clutter; however, wired interfaces between electronic computing device106, positioning device108, and hair cutting device200may provide power and communications. Wired interfaces such as Universal Serial Bus (USB), P1394, Thunderbolt and many other wired interfaces that provide communications or power to the devices inFIG. 1are possible. Wireless interfaces between electronic computing device106, positioning device108, and hair cutting device200are also possible and may provide power or communications. Wireless interfaces such as Bluetooth, Bluetooth Low Energy, WiFi (IEEE 802.11), Zigbee, and other wireless interfaces are also possible. Electronic computing device106, positioning device108, and hair cutting device200may receive power over wired or wireless connections, and may also receive power from batteries that may be disposable batteries or rechargeable batteries.

InFIG. 1, positioning device108is secured to the face of user102through forehead support118, nose support120, and mouth support122. Certain embodiments of the automated hair cutting system100may not include a positioning device108. Such embodiments may use cameras observing user102or may use other embodiments of positioning structures suitable for monitoring position and/or orientation of hair cutting device200relative to user102. Forehead support118and nose support120may employ suction cups, vacuum, textured surfaces, non-slip surfaces, adhesive, tape, two-sided tape (i.e., tape having adhesive on both sides), springs, mechanical structures, or other techniques to secure positioning device108temporarily to the face of user102so that it remains substantially in place during some operations of automated hair cutting system100. Mouth support122may be embodied as a tab or other feature that may be contoured or formed to fit comfortably to the teeth of user102or other features of the mouth of user102. Mouth support122may be bitten on by user102such that it remains securely aligned to the head of user102during some operations of automated hair cutting system100. Additional embodiments of positioning device108may be secured to the face of user102through additional elements contacting the eye sockets, cheeks, temples, ears, or other features of the face of user102. Certain embodiments of positioning device108may use any combination of forehead support118, nose support120, or mouth support122to secure positioning device108to the face of user102. Embodiments are also possible in which positioning device108is secured to the shoulders, neck, arms, or other parts of the body of user102. However, embodiments of positioning device108that primarily contact the head of user102and maintain alignment and position substantially constant relative to the head, and consequently, the hair and scalp, are also useful.

Positioning device108as embodied inFIG. 1also includes positioning interfaces: a first positioning interface110, a second positioning interface112, a third positioning interface114, and a fourth positioning interface116. The positioning interfaces may transmit signals that are received by sensors on hair cutting device200so that the position and orientation of hair cutting device200may be determined relative to positioning device108. The signals transmitted from the positioning interfaces may be radio signals or other electromagnetic signals, acoustic sound signals, audible sound signals, ultrasonic signals, optical signals, light signals, infrared signals, or other possible signals that may be transmitted from the positioning interfaces and received by sensors on hair cutting device200such that distances from the positioning interfaces to sensors on hair cutting device200may be determined. Analysis of signal propagation time (sometimes referred to as time-of-flight analysis), analysis of signal propagation angles (as is sometimes done in radar, lidar, and sonar systems), or any other method or technique of signal analysis may be used. It is noted that in some cases, the distances determined from, for example, first positioning interface110to a sensor on hair cutting device200may be a direct line-of-sight distance, or may represent the distance of the path taken by the signal from first positioning interface110to the noted sensor on hair cutting device200. If acoustic sound signals are used, for example, they will travel around the head of user102and may not always provide a line-of-sight distance. Optical signals, light signals, infrared signals, and some other signals, on the other hand, would normally provide a line-of-sight distance, but suffer the disadvantage that they may be blocked by the hands, arms, hair, or head of user102or by other possible obstructions to the signal's path.

Likewise, in the embodiment ofFIG. 1, signals may also be transmitted from transmitters on hair cutting device200and received by sensors located at the positioning interfaces. Since computation of the position or orientation of hair cutting device200relative to positioning device108is desired, the system and method may be served by signals propagating in either direction. Certain embodiments employ some signals transmitted from the positioning interfaces and other signals transmitted from hair cutting device200. Other embodiments employ a combination of signals: radio and acoustic sound, audible sound and ultrasonic, optical and light, ultrasonic and infrared, etc.

Some embodiments of positioning device108may allow the distances between some or all of the positioning interfaces to be determined electronically using signal propagation techniques or other techniques explained in this patent applications, or other techniques available in the prior art. Some embodiments of positioning device108may be sufficiently rigid that the distances between some or all of the positioning interfaces are known due to the construction of positioning device108(or they could be measured and recorded after positioning device108is manufactured). In any case, if the distances between positioning interfaces are known, they may be used in support of computations to determine the position and/or orientation of hair cutting device200. For example, inFIG. 1, if the distance between first positioning interface110and third positioning interface114is known, it may be used directly in position and/or orientation calculations. Hair cutting device200may contain multiple sensors and the distances between those sensors may be used in position and orientation calculations.

Additional signals may also pass between positioning device108and hair cutting device200. These additional signals may pass through the positioning interfaces to and from hair cutting device200or through other wired or wireless interfaces between positioning device108and hair cutting device200. These additional signals may also pass through or be coordinated by electronic computing device106. These additional signals may relate to timing synchronization, system control, system security, system safety, device authentication, device capability, device model numbers, or many other aspects of the operation of automated hair cutting system100.

Embodiments of automated hair cutting system100may employ a wide variety of signals and techniques to compute positions and orientation. These signals and techniques include: orthogonal signals, CDMA (code division multiple access), TDMA (time division multiple access), FDMA (frequency division multiple access), OFDMA (orthogonal frequency division multiple access), ultra-wide band signals, chirp signals, radar signals, sonar signals, lidar signal, and many others. Signals passing to or from the positioning interfaces from or to hair cutting device200may be modulated (AM, FM, PSK, FSK, MSK, QAM, or any other possible modulations may be used) or otherwise coded or configured to contain timing, synchronization, control, data, identification of multipath signal components, security codes, information to ensure proper operation, and redundancy. Signals passing to or from the positioning interfaces from or to hair cutting device200may include Gold codes, PN codes, M-Sequence codes, Walsh codes, Walsh-Hadamard codes, or any other coding. In certain embodiments, signals passing to or from the positioning interfaces to electronic hair cutting device200may include multipath components, Doppler errors due to motion, signal fades, and may at times be blocked or modified by the arms of user102, other people, or other objects, making it difficult to accurately determine distance from the positioning interfaces to sensors on electronic hair cutting device200. For such embodiments, signal processing techniques and signals may be applied that assist in dealing with multipath, Doppler errors, fading, obstructions, and other non-ideal situations. CDMA signals, for example, may benefit some embodiments regarding multipath, fades, or blocked signal paths. Additionally, signal processing algorithms such as optimal estimators, Kalman filters, and other techniques may be helpful in some embodiments to accurately determine position or orientation of hair cutting device200.

Power control techniques similar to those used in communications systems may also be employed in an automated hair cutting system100. Weak or redundant transmitters (such as transmitters operating in signal paths experiencing fading, or transmitters that are not needed as other transmitters are providing enough signals to substantially ensure accurate information) in positioning interfaces or hair cutting device200may be temporarily powered off to reduce interference and also to save power. As hair cutting device200may contain multiple sensors, power control signals from hair cutting device200to positioning device108to control the power levels of the positioning interfaces on positioning device108may be employed to provide acceptable signal power at the multiple sensors on hair cutting device200.

As some embodiments of positioning device108may include speakers, acoustic drivers, or other elements that may cause physical motion or vibration, such embodiments may employ techniques to reduce the effect of vibration. Vibration may be uncomfortable to users and physical motion of positioning device108may cause errors or loss of precision in position measurements. Positioning interfaces containing audible sound or ultrasound speakers, for example, may employ signaling that randomizes signals, such as CDMA signals or other signal processing techniques. Differential signals may be employed to cancel vibration. Certain embodiments may employ ballast on positioning device108to increase its mass to reduce vibration or power control signal processing schemes that minimize the drive level to the positioning interfaces. Positioning interfaces out of range, blocked by the head of user102, or otherwise occluded may be powered off to save power and minimize vibration.

Automated hair cutting system100may also compensate automatically for changes in environmental parameters that may affect signal propagation, and hence, give rise to positioning errors if not accounted for. For example, if ultrasound, audible sound, or other sound signals are used, the propagation speed of sound will change with temperature, air pressure, and humidity. Automated hair cutting system100may include temperature, air pressure, and humidity sensors so that the effect of these environmental parameters on positioning accuracy may be compensated to achieve substantially accurate results. Alternatively, positioning device108may be constructed so that at least two of the positioning interfaces it contains are substantially rigidly fixed apart from each other at a substantially fixed distance; and for such an embodiment, positioning device108may have the ability to directly measure the distance from one positioning interface to the other that is substantially rigidly fixed a known distance from it. In such a case, the distance between the substantially rigidly spaced positioning interfaces can be measured directly by signal propagation and compared to the known rigidly fixed distance. In this way, the effect of environmental parameters may be directly assessed so that appropriate compensations may be determined. Some embodiments of an automated hair cutting system100may provide positioning interfaces a known substantially rigidly fixed distance apart on some other structure, besides positioning device108as explained here, and determine compensation for environmental parameters in an otherwise similar way.

Positioning device108may be battery powered with disposable or rechargeable batteries or may be powered through a wired or wireless connection. The positioning interfaces are shown inFIG. 1as spheres, but may also be embodied in a wide variety of other shapes and sizes. Special shapes and/or sizes for the positioning interfaces may provide benefit in some embodiments in allowing improvement of transmitted or received signal propagation and to allow easy identification of them if computer vision systems or other image processing is used. For example, if radio signals are used, the positioning interfaces may benefit if they are sized to provide room to allow effective radio antennas to be incorporated inside them or if they are formed to directly provide antenna functions. Positioning interfaces and the circuits and elements they contain may also be configured to enhance signal propagation in specific directions of interest so that reduced power levels, enhanced signal levels, or other benefits may be obtained. It is also noted that while the embodiment ofFIG. 1makes use of four positioning interfaces, embodiments with more or less positioning interfaces are possible. While it may seem necessary to have at least four positioning interfaces to establish a position in space, it is noted that since operation of some embodiments of automated hair cutting system100may be limited to determining position on and/or above a user's102head, embodiments may be possible that use only one or two positioning interfaces, especially if the range of hair styles is limited to simple styles or only some parts of a user's hair are to be cut (for example, if such an embodiment was intended only as a beard or moustache trimmer). Of course, additional positioning interfaces may provide benefit in more accurately and consistently determining position and orientation. As noted above regarding blocked signal paths and multipath, the incorporation of additional positioning interfaces may provide redundancy that may allow more robust system operation in the face of detrimental conditions.

It is also possible to use a camera107on electronic computing device106or another camera or cameras in automated hair cutting system100as elements of a positioning structure to determine the position and/or orientation of hair cutting device200relative to the head of user102. In such an embodiment, position and/or orientation information from such a camera or cameras may be used separately or in conjunction with positioning information from positioning device108for operation of automated hair cutting system100. Cameras, in such embodiments, may be incorporated into electronic computing device106, positioning device108, hair cutting device200, or into additional devices not shown in the embodiment ofFIG. 1. Cameras incorporated in automated hair cutting system100may determine position and/or orientation information of the head of user102and/or hair cutting device200through observation and computational analysis of the head and/or facial features of user102, features of positioning device108, and possibly through observation of other elements such as features of a room or other features not shown inFIG. 1. Special features such as targets, special shapes, symbols, or other features may be incorporated to make the determination of positions and orientations easier and more reliable. For example, the incorporation of easily recognized shapes on positioning device108may be helpful (this will be further explained with regard toFIG. 7EandFIG. 7F). Structured light or other special illumination techniques may also be applied to benefit the determination of features, distances, and other elements that may be helpful in determining positions and orientations. It is noted that use of structured light may be used for illumination of positioning interfaces and other possible features of a positioning device108, or structured light may be used to directly illuminate the face or head of a user102so that positioning information may be determined directly from analysis of images or video of a user102under illumination of structured light.

Images and video generated from cameras incorporated into automated hair cutting system100may also be displayed on electronic computing device106or other electronic displays that may be available (but are not shown inFIG. 1) to assist user102in positioning hair cutting device200beneficially so that the hair of user102may be successfully cut.

Some embodiments of positioning device108may further include accelerometers or gyroscopes or other sensors that allow automated hair cutting system100to monitor motion, orientation, or position of positioning device108. Such embodiments may allow automated hair cutting system100to pause operation if it is determined through monitoring the accelerometers or gyroscopes or other sensors that positioning device is being moved so rapidly that significant positioning errors may occur. For example, if user102shakes their head rapidly, positioning device108may bend or flex so that the positioning interfaces move relative to each other and no longer provide correct or consistent information. Rapid motion of the head of user102may also cause positioning device108to shift in position on the face of user102. If such conditions occur, embodiments of positioning device108including accelerometers and/or gyroscopes or other sensors may provide benefit in pausing operation, guiding user102to move more slowly and/or smoothly, and possibly in guiding user102to re-position positioning device108if it may have moved from its proper location relative to the head of user102.

The embodiment of positioning device108inFIG. 1may provide benefit in that positioning device108is formed primarily in the front and sides of the face of user102. Such a design may allow user102to access their head and hair with their arms and minimizes the degree to which positioning device108obstructs access. As will be shown subsequently, many additional embodiments of positioning devices are also possible that offer benefit for some embodiments of automated hair cutting systems100. It is also noted that electronic computing device106may be placed on a counter, a stand, or affixed to a mirror or wall in front of user102so that user102has both hands substantially free and may operate hair cutting device200with one hand while positioning hair, possibly with a comb or other device, with his or her other hand. Automated hair cutting system100may also be configured to provide audible prompts, visible signals, and respond to voice commands and signals from user102so that it operates substantially in a hands-free fashion. The structure of positioning device108may be provided using metals, tubing, plastics, wood, or other materials and the electronics, switches, buttons, batteries, antennas, microphones, speakers, and other elements needed for various embodiments may be positioned within or on the structure of positioning device108.

Hair cutting device200will be described later and multiple embodiments and features will be shown. In the embodiment ofFIG. 1, hair cutting device200is held by user102or another person and is manually positioned to collect and cut the hair of user102. As illustrated inFIG. 1, hair cutting device200may collect a region of hair160and extend it so that automated hair cutting system100may actuate the cutter head of hair cutting device200at a substantially precise point of time when the region of hair160is at a substantially correct length. Through repeated operation of selecting and extending regions of hair so that they may be cut, user102or another person manually positioning hair cutting device200may substantially cut the hair of user102to create a desired hair style. It is noted with regard toFIG. 1that hair cutting device200may operate to cut the hair of user102responsive to signals and/or information from a positioning device108, from inputs from a user102, and possibly also from an electronic computing device106. With this basic understanding of hair cutting device200, operation of automated hair cutting system100may be further described.

Operation of automated hair cutting system100may embody many different sequences and approaches that may provide benefit depending on the nature of user's102hair and the style and hair length he or she is seeking. In order to illustrate some possible embodiments, an embodiment of operation of automated hair cutting system100is now explained. User102may first clean their hair and comb it to avoid tangles. For some individuals or hair styles, wetting hair with water, gel, or other solutions may be beneficial. Electronic computing device106may then be enabled and consulted for potential styles that may be applied. A camera107on electronic computing device106may collect images of user102and assess their present hair length and style and determine what styles and lengths are possible with user's102hair. User102may also measure their hair and input that information into electronic computing device106. Automated hair cutting system100may be used to aid or automate measurement of user's102hair. User102may also input information about the type or shape of scalp or skull they have. Electronic computing device106may show user102examples of how she might look after their haircut is complete. User102may also receive options for modifications or combinations of styles and may select these through electronic computing device106. Once user102determines a style and hair length using the interfaces on electronic computing device106, electronic computing device106may prompt user102to secure positioning device108to their face and turn it on. Electronic computing device106may then prompt user to turn on hair cutting device200. Electronic computing device106may then temporarily disable the cutting action of hair cutting device200and direct user102to touch the idle cutter head of hair cutting device200to reference points on the user's102head. Reference points may be used to determine the location of first positioning interface110, second positioning interface112, third positioning interface114and fourth positioning interface116relative to the head and hair of user102. These reference points may include the tops of user's ears152, the back of user's neck at a collar line154, the tops of user's eyebrows150, and other reference points that are of specific interest in properly fitting a given hairstyle to a user's102head and facial features. Other reference points might include the front or back of a user's ears, the sides of a user's102eye sockets, the user's102hair line (the point at which the user's102hair scalp ends and skin without thick hair begins) at various points around the user's102scalp, desired locations for hair parts (the common meaning of a hair part is used here, that is, where the hair is combed apart in different directions to create a line-like feature in the hair), where hair jewelry is worn, where hair dye is present, or other features of specific hair styles, and other reference points. Additional reference points may be touched by user102at direction from electronic computing device106to help electronic computing device106determine the size and shape of user's102head and determine the location of first positioning interface110, second positioning interface112, third positioning interface114and fourth positioning interface116relative to the head and hair of user102. It is noted that for the purpose of determining the location of positioning interfaces, use of reference points such as the tops of the user's ears152, the tops of the user's eyebrows150, and other reference points that are substantially consistent may be favored over use of reference points like the location of hair dye, hair parts, and other reference points that may vary depending on hair growth, combing, or other variable factors. Alternatively, instead of using hair cutting device200for mapping the reference points as noted, a stylus1302(an embodiment of such a stylus1302is shown inFIG. 13), different hair cutting device, or other reference device may be used to provide reference point positions. Reference points may be established through a user touching a hair cutting device200, stylus1302, or other suitable device to the predefined reference point on their head or face and acknowledging (through a button press, audible sound, or other suitable signal—or alternatively, automated hair cutting system100may observe the user and determine from computer vision analysis when a reference point has been touched) to automated hair cutting system100that the reference point is being touched. The use of reference points allows precise information regarding the location of a specific region of hair on user102to be determined relative to reference point features of user102without the need for positioning device108to be precisely positioned relative to the face of user102(positioning device108need only be stable relative to the face of user102through the course of a haircut). Consequently, embodiments of automated hair cutting system100including the use of reference points as described, may provide convenience to people using them (since positioning device108need not be precisely aligned to their face, but only needs to be stable for the duration of a haircut) and also allow for a wide range of shapes, sizes, and other configurations of positioning device108. With the information of the reference points determined, electronic computing device106may then map the chosen hair style to specific locations on the head of user102so that the hair length needed to create the chosen hair style is now defined based on location on user's102head. Electronic computing device106may now direct user102to engage hair cutting device200to specific locations on user's102head, to engage the cutter head of hair cutting device200into user's102hair, and to pull hair cutting device200substantially away from user's102head so that hair is extended from the specific location.

Alternatively, electronic computing device106may allow user102to select any location on their scalp to begin, measure that position, and determine the length of hair needed specific to that location for subsequent cutting. While user102extends their hair for cutting, positioning device108may continue to monitor the position and orientation of hair cutting device200to ensure that user102is extending their hair sufficiently so that accurate cutting may take place. In the event that user102is not suitably extending the hair in the cutter head of hair cutting device properly, automated hair cutting system100may perform computations to correct for errors that would otherwise occur, or automated hair cutting system100may alert user102to try again. As user102extends their hair engaged in hair cutting device200, electronic computing device106may monitor the distance of the cutter head202of hair cutting device200from the head of user102and enable cutting action when the hair of user102specific to that location is at a substantially correct length for a specific chosen hair style and length that was previously selected so that hair in the cutter head202of hair cutting device200is cut substantially to a correct length. Once the hair specific to that location has been cut, electronic computing device106again disables cutting action of hair cutting device200and directs user102to engage hair in another location. Through repeated selection, engagement, extension, and cutting of hair, user's102hair is cut to fit the chosen style and length. It is noted that electronic computing device106may also direct user102to roll their head and use their free hand (the one not being used to hold hair cutting device200) to most conveniently keep loose hair away from the cutting operation and avoid inadvertently cutting hair that should be kept longer for the desired style and hair length. Since positioning device108is affixed to the face of user108, a key benefit of the system and method is that user102is free to move their head in the course of a haircut without compromising positioning or orientation information of hair cutting device200relative to positioning device108.

The process of repeated selection, engagement, extension, and cutting of hair, as described above, offers benefit that hair cutting device200need not continuously operate its cutter head. That is, the cutter head may be kept idle during the selection, engagement, and extension of hair and the cutter head need only be actuated to cut hair at times when the position of hair cutting device200is beneficial for cutting specific hair at substantially desired lengths. The ability to only operate the cutter head of hair cutting device200at times when hair cutting device200is properly positioned to cut specific hair allows energy consumption, noise levels, and cutter head wear to all be reduced.

It is very common for hair cutting professionals to measure hair length with their fingers or using a comb or scissors handle as a reference. As a hair cutting professional works across the head of a person, they alter the length of cut to create the style they plan to achieve. Automated hair cutting system100works in a way very similar to how human barbers have cut hair for a very long time. It is also possible for automated hair cutting system100to operate in different ways. For example, if a user102is shaving the back of their neck with hair cutting device200, automated hair cutting system100may prompt them on how to position hair cutting device200and what direction to move it. From there, automated hair cutting system100may enable the cutter head of hair cutting device200as user102properly moves hair cutting device200and may disable the cutter head of hair cutting device200if user102moves it incorrectly. In this way, automated hair cutting system100ensures that user102cuts their hair properly while allowing hair cutting device200to be moved smoothly across the back of their neck or other regions of their scalp where a shaving or other hair cutting technique benefits from smooth motion of hair cutting device200. Still other modes of operation of automated hair cutting system100are possible. As an additional example, consider the well-known “flat top” men's hair style. In this style, hair across the top of a man's head is cut to be as flat as possible, without regard to the specific length of hair for each specific region of the man's scalp. For such a hair style, automated hair cutting system100may actuate the cutter head of hair cutting device200to cut hair when it has been collected and extended to the right point to substantially create a flat top instead of with regard to the precise length of hair for each scalp region.

Since hair cutting device200has a cutter head of a significant width, it is possible for hair cutting device200to have hair in the cutter head that should be cut at different lengths for any given operation (the operation as noted above of selecting a location, engaging some hair, extending the hair, and cutting it to a substantially correct length). In such cases, electronic computing device106may direct hair cutting device200to cut the hair in the cutter head only when all hair in the cutter head has been extended so that it is all at either a correct length for cutting or at a longer than needed length. In this way, additional cycles of selecting, engaging, extending, and cutting may be used to further reduce the length of hair that was previously cut longer than desired, but no hair is substantially ever cut too short. This form of operation is important especially for locations on the head of a user102where the surface of the user's102scalp curves rapidly, or for hair styles in which hair length changes rapidly from one location to another. InFIG. 5C, an embodiment of a cutter head capable of cutting subsets of hair contained in it at different times is shown. Such a cutter head allows embodiments of automated hair cutting system100to cut specific hair collected in hair cutting device200at specific times, providing benefit in dealing with the situation as described in this paragraph. It is also possible for automated hair cutting system100to provide additional guidance or instructions to user102to control hair cutting device200so that most of the hair contained in cutter head of hair cutting device200for a specific operation may be suitably cut at the same time to the length needed. In this way, a user102who may operate automated hair cutting system100more skillfully may be able to produce an accurate haircut in fewer operations than a user102who uses automated hair cutting system100substantially without such additional guidance or instructions or who disregards such additional guidance or instructions.

Once user102has completed cutting their hair in the fashion described and possibly combed it to exhibit the desired style, a camera on electronic computing device106or other camera may be used to collect images of user's102hair. These may be shown to user102and user102may direct electronic computing device106that they desire some modification to their hair. For example, user102may desire slightly shorter hair above their eyebrows (shorter bangs), a slightly higher collar line in back, or other features. Once user102has selected modifications, electronic computing device106may again direct user102to cut their hair in a manner similar to that previously described to achieve the desired effect. A camera on electronic computing device106or other camera may also monitor user102through the course of their haircut to ensure that user102is operating automated hair cutting system100properly and is achieving acceptable results. In such a case, electronic computing device106may process images from such a camera or cameras and determine if user102should be provided with additional guidance as they cut their hair.

Before the hair cutting process is completed, electronic computing device106may ask user102if they would like to store some or all of the information about the size and shape of their head, reference point information regarding the location of their ears, eyebrows, etc., their preferred styles, the specific style they chose for this just-completed haircut and perhaps the modifications to that style that were ultimately selected, or other information. If user102so desires, this and other information may be stored for future use either directly in electronic computing device106, or possibly in a network server, cloud computing element, or other device or computing element.

It is noted that each time a user102makes use of automated hair cutting system100, positioning device108may be positioned to a slightly different position on their face. Additionally, positioning device108may be of a slightly different shape if it was folded (see the embodiments ofFIG. 6BandFIG. 7Dfor reference) for storage or was slightly deformed, bent, or modified since its prior use. In such cases, automated hair cutting system100may need to ask user102to re-enter the reference point information noted above so that it may properly fit a desired hair style to the head of user102. Also, prior to cutting features in a user's102hair that demand very precise alignment, such as cutting around the ears or ensuring a feature is precisely aligned to a part of a user's102face, automated hair cutting system100may prompt user102to touch and reestablish some reference points specific to the operation about to be undertaken, ensuring substantially precise alignment. In some cases and with some embodiments, if automated hair cutting device100has stored information regarding reference points, the size and shape of a user's head, and possibly other information for user102from prior use of automated hair cutting system100, automated hair cutting system100may be able to account for changes in precise positioning and shape of positioning device108with fewer reference points entered than may otherwise be required.

The display function and computational functions of electronic computing device106may be embodied into positioning device108or even into hair cutting device200. Alternate embodiments of automated hair cutting system100may also include electronic displays, touchscreens, keyboards, or similar human interface functions. In certain embodiments, instructions, queues, information, and directions to the user102from electronic computing device106(or as noted other devices in the system whether electronic computing device106is present or not) may be delivered visually on electronic displays, with audible signals, with indicator lights, with haptic signaling, or through other techniques.

In other embodiments, a robotic arm under automated control could either grip hair cutting device200or be otherwise fitted with a cutter head so that it may directly cut the hair of user102. Further robotic arms could also be applied to comb hair or position it for cutting. In such a fashion, a robotic system could provide automated hair cutting services.

In alternate embodiments automated hair cutting system100may have multiple modes of operation and may provide different commands, guidance or information depending on whether user102is using automated hair cutting system100to cut their own hair, if another person is using automated hair cutting system100to cut a user's102hair, or whether automated hair cutting system includes other elements such as Internet access (which would allow additional modes of operation, instructions, etc. to be downloaded). The information provided by automated hair cutting system100in the course of a haircut may also be varied depending on the skill level of the person operating it and the type of haircut being provided. For example, novice users of automated hair cutting system100may desire more complete guidance especially if they are attempting a complex or challenging hair style.

Those skilled in the art will recognize that the teachings of the system and method may be applied to create robotic or otherwise automated systems for a wide variety of uses where a wide variety of tools (such as cutting devices, grinders, polishers, material dispensing devices, imagers, video cameras, and other possible tools) may be beneficially tracked or monitored relative to another structure, such as a positioning device, so that those tools may be applied to objects with known position and/or orientation relative to such a structure to achieve desired results. A key benefit of the system and method is the ability to accommodate changes in such objects so that they do not need to be substantially identical (as is normally the case for many modern manufacturing or other such systems). As an example, such an automated system may allow a person holding a device or tool to substantially precisely locate it by hand for the application of makeup, hair dye, hair tints, hair highlights, cosmetic surgery, and many other possible functions. And those skilled in the art will further recognize that the teachings of the system and method may be applied to fabrication of mechanical devices, formation of sculpture, fabrication of physical models with modeling clay or other materials, operations such as cutting, grinding, ablating, polishing, clamping, hammering, puncturing, drilling, mixing, painting, coating, imaging, illuminating, robotic micro-surgery, eye surgery, drug delivery, dental work, dental surgery, cutting tools, machine tools, and in wide variety of other applications.

FIG. 2is an illustration of an embodiment of hair cutting device200including handle206, body204, cutter head202, sensors208, accelerometer210, indicator lights212, recessed region214, camera216and illumination source218. Body204and handle206may contain operation and control electronics, batteries, power electronics, a motor to drive cutter head202, and other functions. Cutter head202may be typical of hair cutter heads found on commonly available hair clippers, trimmers, shavers, or other devices, or may be of special construction for beneficial use in an automated hair cutting system100. Cutter head202may be configured so that it is removable from hair cutting device200for cleaning or replacement. Certain embodiments may employ interchangeable cutter heads such that one cutter head may be designed to cut longer hair and it could be interchanged with a trimming cutter head that could be used for detailed trimming, shaving or other functions. Indicator lights212may be of various colors, sizes, and locations and may be visible to user102in the course of a haircut especially if viewed into a mirror in front of user102in the course of a haircut. Indicator lights may help to signal a user on how best to orient, position, and move hair cutting device200for substantially better or faster results. Hair cutting device200may also contain audible speakers, buzzers, bells, chimes, haptic devices, displays, and other devices to help guide, signal, or provide information to user102. Indicator lights212and audible speakers, buzzers, bells, chimes, haptic devices, displays, and other devices to help guide, signal, or provide information to user102on hair cutting device200may operate in conjunction with information that user102may receive from electronic computing device106or from positioning device108.

Accelerometer210may be monitored by hair cutting device200to determine its position and orientation and to ensure that it has not been suddenly jerked or rapidly moved before cutter head202is enabled to cut the hair it contains. In this way, hair may not be incorrectly cut if sudden user102motions exceed the ability of automated hair cutting system100to sufficiently determine position and orientation. Hair cutting device200may also contain a gyroscope or other position or orientation monitoring sensors and electronics to ensure hair is only cut when it should be and to determine the position and orientation of hair cutting device200. Accelerometer210is shown on the surface of hair cutting device200for clarity, but accelerometer210, gyroscopes, and other possible sensors may be contained inside body204and may not be visible on the outside of hair cutting device200.

The embodiment of hair cutting device200shown inFIG. 2includes three sensors208that are operable, as shown inFIG. 1, with the first positioning interface110, second positioning interface112, third positioning interface114, and fourth positioning interface116to determine the position and orientation of hair cutting device200relative to positioning device108as already described. These three sensors208as embodied inFIG. 2are shown at the end of handle206and in body204near each end of cutter head202. Such placement of sensors208as far from each other as reasonably possible on hair cutting device200may be beneficial in providing accurate information about the precise location and orientation of hair cutting device200. Alternate embodiments may employ alternative placement of sensors208, for example, placing sensors208to avoid obstruction by arms or hands of a user102or other people. Other embodiments may place sensors208in still other locations and may even place sensors208on posts, supports, or other features that adjoin body204, handle206, or other elements of hair cutting device200and allow sensors208to be located beneficially. Having accurate information regarding the orientation of hair cutting device200and the location of sensors208, an accurate determination of the position of cutter head202is possible.

Depending on the types of signals used for first positioning interface110, second positioning interface112, third positioning interface114, and fourth positioning interface116shown inFIG. 1, sensors208may include antennas, microphones, light sensors, infrared sensors, or other types of sensors. Certain embodiments may use transmitters in place of sensors208on hair cutting device200and sensors on positioning device108with similar effect and with signals simply propagating from hair cutting device200to positioning device108instead of in the other direction. While three sensors208are shown in the embodiment ofFIG. 2, any number of sensors208may be applied in various embodiments. A single sensor208, for example, may be used in conjunction with accelerometer210and possibly with additional gyroscopes or other sensors to achieve good results. And embodiments with two, three, four, or more sensors208may provide benefit in offering robust results and accurate positioning and orientation information potentially in the face of blocked signals, multipath or other detrimental aspects of signal interfaces as described above.

Some embodiments of hair cutting device200may include a recessed region214, as shown inFIG. 2, containing a camera216and possibly also an illumination source218. Alternative embodiments may include other physical features to house camera216or illumination source218such as additional housings or fittings. In certain embodiments employing a recessed camera216or illumination source218, the surface of hair cutting device200is kept substantially free of obstructions. Camera216may be employed to observe features of the head, face, and hair of a user including reference points that may especially be used to determine locations on a user's scalp or face, to observe features of a positioning device, or to observe other things of benefit in the operation of automated hair cutting system100. An illumination source218, may provide illumination to augment operation of camera216and may also provide colored light or structured light to augment the ability of automated hair cutting system100to analyze images provided by camera216. Structured light is a well-known concept and will not be discussed in detail here. For purposes of this disclosure, “structured light” is defined as one or more beams of light (incoherent or coherent) that are shaped or arranged relative to one another to form a defined pattern (such as a grid, lines, dots or geometric primitives) and projected so as to illuminate one or more objects to allow distances to specific points on the one or more objects to be ascertained by analyzing images of the one or more objects taken (typically by one or more cameras) under the illumination of the predefined pattern of light. Embodiments of hair cutting device200that contain multiple cameras216, and/or multiple illumination sources218, and/or multiple sources of structured light, are possible.

Hair cutting device200may also include a manual operation mode in which its position is not tracked, but in which it operates as a conventional hair cutter or trimmer such as those commonly available prior to the teaching herein. Such a manual operation mode may be entered through actuation of a switch, button, voice command, or any other type of control. When operating in such a manual operation mode, hair cutting device200may continuously actuate cutter head202or cutter head202may be actuated when a button is pressed, a voice command is given, or through any other type of control.

FIG. 3shows an additional embodiment of a hair cutting device. InFIG. 3, a hair cutting device with side handle300is shown. Hair cutting device with side handle300includes sensors208, indicator lights212, accelerometer210, and cutter head202that all perform functions substantially equivalent to those described for hair cutting device200already described. Hair cutting device with side handle300also includes a side handle306and body304that are shaped in a way that some people may find beneficial or more comfortable for cutting hair. The embodiment of hair cutting device with side handle300inFIG. 3is shown primarily to call attention to the ability to incorporate the system and method into a very wide variety of shapes and styles of hair cutting devices. In addition to the embodiments of hair cutting device200and hair cutting device with side handle300, the system and method may be applied to a very wide variety of hair cutters, clippers, trimmers, shavers, and other devices and may also be applied to devices that shave or trim beards, eyebrows, facial hair, and other hair in addition to hair on a user's102scalp as shown inFIG. 1.

In addition to the straight handle206of hair cutting device200and side handle306of hair cutting device with side handle300, many other embodiments of handles, knobs, levers, supports, and other possible structures may be used so that a person may position a hair cutting device. Handles including pivots so they may be rotated, hinges so they may be tilted, flexible members, telescoping members, adjustable features, rubber grips (or grips made from other materials), contours, or any other enhancements may be applied to embodiments of handles for hair cutting devices.

Hair cutting device with side handle300as shown inFIG. 3may also include touch sensor308on the portion of body304that may contact user's102scalp when hair cutting device with side handle300is operated. Touch sensor308may be a simple switch, electronic touch sensor, or other contact sensor that signals to hair cutting device with side handle300that it has contacted user's102scalp, so that hair cutting device with side handle300may determine and record its position and orientation. In this way, hair cutting device with side handle300may substantially precisely determine the location of user's102scalp and compare that on an ongoing basis to where computation from previously determined reference points as described with regard toFIG. 1indicated user's102scalp is expected to be. In this way, automated hair cutting system100may monitor its operation and determine if it is sufficiently accurately determining position and orientation of hair cutting device with side handle300. If user102, for example, inadvertently bumps, moves, or otherwise disturbs positioning device108so that the relative position of positioning device108is changed with regard to user's102hair, hair cutting device with side handle300may detect this as described, stop cutting hair, and request the user102to reestablish reference points so that automated hair cutting system100may ensure accurate hair cutting. Of course, minor errors in scalp position determined when touch sensor308signals that it has contacted user's102scalp may be ignored or used to calibrate or otherwise improve automated hair cutting system's100estimates of the shape and size of user's102scalp. Only one touch sensor308is shown in the embodiment ofFIG. 3, but two or more are possible and they may be positioned along the length of body304near cutter head202for beneficial effect, or in other beneficial locations. Embodiments where no touch sensor308is employed but where accelerometer210or positioning information determined from sensors208are monitored to determine when user's102scalp has been contacted are also possible.

In certain embodiments of automated hair cutting systems100, touch sensor308includes radar, sonar, or other electronic or electro-mechanical system to determine the distance from the bottom surface of cutter head202to the scalp of user102. The distance from the bottom surface of cutter head202to the scalp of user102may be employed in some embodiments to determine the location or orientation of hair cutting device with side handle300and may also be employed to determine when cutter head202should be activated to cut hair it contains. Use of a touch sensor308is not limited to a hair cutting device with side handle300, but may be applied to hair cutting device200, or other possible embodiments of hair cutting devices.

FIG. 4is an illustration of an embodiment of a manually driven hair cutter400that includes sensors208, accelerometer210, indicator lights212, and cutter head202that perform similar functions to those of hair cutting device200. Manually driven hair cutter400also includes fixed handle402, pivot408, body404, and movable handle406. Fixed handle402and movable handle406are similar to handles on a pair of scissors, and motion from moving the moveable handle406could be transferred to cutter head202to actuate cutter head202and cut hair it may contain. Since some embodiments of the system and method involve cutting hair at substantially precise times so that hair is cut to substantially precise lengths, it is also possible to store energy from motion of movable handle406in a spring or other energy storage device and to release that energy through electronic controls to actuate cutter head202at substantially precise points in time. In this way, moveable handle406may cock a spring or other mechanism or device and the associated energy may be released under control from electronics inside manually driven hair cutter400or from signals received from electronic computing device106, positioning device108, or from other elements that may be present in some embodiments. It is noted that while moveable handle406may be used to provide some of the energy needed to operate manually driven hair cutter400, that manually driven hair cutter400may also receive energy from wired connections, batteries, or other or combinations of energy supplying or energy storage elements. One possible embodiment would be for the cutter head202on manually driven hair cutter400to be driven with energy from motion of moveable handle406and for other elements of manually driven hair cutter400to be powered from batteries or a wired or wireless power connection.

In addition to storing energy from motion of moveable handle406in a cocked spring or other element, it is also possible for moveable handle406to directly actuate cutter head202so that cutter head202cuts the hair in it directly when handle406is moved (much as a scissors cuts items in its blades when the handles are moved). In such an embodiment, the user102may be signaled by automated hair cutting system100as to when moveable handle406should be moved. Such a signal may be audible, haptic, visual, or through other techniques. Several alternative embodiments for a manually driven hair cutter400are possible including a very wide variety of handles, levers, knobs, etc. for how a user may manually drive a hair cutter.

FIG. 5Ashows a cutter head500that may be employed for cutter head202shown inFIGS. 2-4. Front edge of cutter head502is formed from cutter head comb teeth504, and cutter head500operates when blade506is actuated back and forth through the openings shown in cutter head comb teeth504. Blade506may be actuated with a linear actuator, rotary motor, piezo motor, magnetic motor, or other types of motors or actuators. When blade506actuates back and forth any hair sufficiently inside cutter head comb teeth504that it contacts blade506may be cut. Cutter heads formed from adjoining cutting blades that move back and forth, rotary cutters, laser cutting devices, and other types of cutters may be adapted to work with the system and method. Cutter head500may be employed such that contact with a person's hands, a comb, or with other tools for positioning hair does not cause injury or damage. Spacing of comb teeth504and other possible design considerations may be taken into account in providing a substantially safe design for cutter head500that substantially avoids injury or damage if inadvertent contact is made with it.

FIG. 5Bshows a cutter head having an auxiliary comb550. Cutter head with auxiliary comb550includes front edge of cutter head502, cutter head comb teeth504, and blade506. These elements perform the same functions as the cutter head500shown inFIG. 5A. Cutter head with auxiliary comb550also includes auxiliary comb teeth552that may be spaced over and above cutter head comb teeth504so that auxiliary comb teeth552also engage and substantially contact hair collected in cutter head with auxiliary comb550. Some embodiments of the system and method may employ auxiliary comb teeth552to provide additional friction making it easier to control hair in cutter head with auxiliary comb550versus other possible types of cutter heads. A user102, for example, that has curly hair or other types of hair may find that their hair springs free from the cutter head before it can be cut unless auxiliary comb teeth552or some other means is used to provide additional friction. Auxiliary comb teeth552may be formed from plastics, metals, or other materials and may be textured, serrated, coated, or otherwise finished so that they provide a desirable level of friction to hair collected in cutter head with auxiliary comb550. In addition, auxiliary comb teeth552may be fixed in place above cutter head comb teeth504, or may be actuated and may serve to grab or latch hair into cutter head with auxiliary comb550. If auxiliary comb teeth552are actuated, they may move together or individually in response to electrical or mechanical mechanisms and may move sideways, up and down, or in other directions. Embodiments in which auxiliary comb teeth552may be adjusted to achieve a desired level of friction, interchanged with other embodiments of auxiliary comb teeth to adjust friction, or retracted or removed if no additional friction is desired are also possible. It is also possible that cutter head teeth504be specially formed, coated, textured, serrated, or otherwise finished so that they also provide the function of providing sufficient friction for convenient control of hair. Embodiments in which cutter head teeth504may be specially formed, coated, textured, serrated, or otherwise finished to provide sufficient friction may be applied whether or not auxiliary comb teeth552are present in those embodiments.

The embodiment of cutter head with auxiliary comb550shown inFIG. 5Bmay also offer benefit in gripping hair after it has been cut so that it may be moved to a place suitable for disposal and released. If auxiliary comb teeth552are actuated under control from a user102, under automatic electronic control, or through another control method, some embodiments may allow user102to manually (or through voice commands, etc.) signal when to release auxiliary comb teeth552so that cut hair is released. Alternative embodiments of hair cutting devices such as hair cutting device200shown inFIG. 2may include the ability to connect a vacuum such that cut hair may be suctioned away. Other embodiments contain features to allow cut hair to be temporarily stored (possibly after grinding it for more compact storage) before it is discarded.

FIG. 5Cshows an embodiment of a cutter head with bottom comb560. Bottom teeth562are spaced to allow hair to enter and to be combed in a conventional way (that is, like a common comb is used). Cutter knives564are positioned on top of bottom teeth562so that they do not interfere with the function of the bottom comb, allowing regions of hair to be engaged and extended. Cutter knives564may then be actuated so that they slide over the regions between bottom teeth562and cut hair that may be present. Cutter knives564may be actuated together as a single element, or some embodiments may allow them to be actuated in groups or to be actuated individually. If cutter knives564can be actuated in groups or individually, it is possible for automated hair cutting system100to actuate them so that the hair collected between individual bottom teeth562is optimally cut, potentially providing improved accuracy versus a cutter head that cuts all the hair collected in it at once. Cutter knives564are not shown present on top of end bottom teeth566, but some embodiments may include them. Putting cutter knives564on top of end bottom teeth566may not be necessary as cutter knives564above adjacent bottom teeth562may cut the hair collected near them. It is also possible to eliminate cutter knives564from alternate bottom teeth562across the entire cutter head with bottom comb560if the cutter knives564present can actuate in both directions and cut hair in both the adjacent gaps between bottom teeth562they adjoin.

FIG. 6Ashows an embodiment of a foldable positioning device600. Foldable positioning device600operates similarly to the embodiment of positioning device108shown inFIG. 1and includes a forehead support610, a nose support618, connecting members608, and four positioning interfaces616. Foldable positioning device600also includes two body housings612and four hinges614. Foldable positioning device600is shown affixed to the face of a user602. Communications and control electronics, batteries, buttons, speakers, microphones, wireless interfaces, wired interfaces, and other functions may be incorporated in body housings612. Hinges614allow foldable positioning device600to be folded so that it can be compactly stored or transported. Foldable positioning device may be fabricated from metals, plastics, woods, other suitable materials and combinations of materials.

FIG. 6Bshows foldable positioning device600fromFIG. 6Aafter it has been folded at hinges614for compact storage. It is noted that in addition to hinges614as shown, foldable positioning device600may include flexible members, telescoping shafts, and other elements to allow it to be compactly folded. In addition to folding for storage, a positioning device108or foldable positioning device600may include elements allowing it to be adjusted to fit a range of faces of different possible users. For example, one embodiment of a positioning device108or foldable positioning device600allows adjustment to properly fit a small face of a child and also a relatively large face of an adult. A positioning device108or foldable positioning device600may also be configured for specific hair styles (i.e., such that positioning device108or foldable positioning device600provides sufficient positioning information for a specific hair style and having less weight, material, space, or is more convenient or cost effective, or provides other additional benefits than it would if it were intended for other hair styles).

FIG. 7Ais an illustration of an embodiment of a positioning device with tubular construction700. Ear supports714and a head band708support a main tube704of positioning device with tubular construction700around the face and head of user702. Band connectors706may allow head band708to be adjusted in length and in position along main tube704. Main tube704supports positioning interfaces712that may operate and function in a fashion similar to those shown inFIG. 1. The embodiment ofFIG. 7Ahas six positioning interfaces712visible and a seventh positioning interface blocked from view by the neck of user702(end positioning interfaces710are also considered positioning interfaces712for this count, indeed, end positioning interfaces710are only separately numbered to call attention to their specific location). Additional embodiments of positioning device with tubular construction700may support larger or smaller numbers of positioning interfaces712. While positioning interfaces712inFIG. 7Aare shown as enlarged regions of main tube704, some embodiments may make use of a main tube704large enough that positioning interfaces712are fully contained inside it and are not externally visible. In such embodiments, main tube704may appear to be smooth and may not show external features where positioning interfaces712are present. Ear supports714and head band708may be adjustable in position along main tube704, in length, in orientation relative to main tube704, and in other aspects. Hinges716are shown that allow main tube704to be folded for storage (this will be explained further with regard toFIG. 7D). Certain embodiments may employ hinges, flexible tubing, telescoping tubing, adjustable screws, springs, elastic materials, fasteners, and other techniques to allow positioning device with tubular construction700to be folded or otherwise made compact for storage or adjusted to better fit user702. End positioning interface710and end housing718are shown at one end of main tube704and a similar end positioning interface and end housing on the other end of main tube704are blocked from view by the neck of user702. End housing718and main tube704may contain batteries, electronics, computing devices, signal processing devices, and other functions to enable operation of positioning device with tubular construction700as a positioning device as described with regard to positioning device108ofFIG. 1and other embodiments shown in this patent application. Positioning device with tubular construction704may receive power and interface signals from batteries and/or wired or wireless interfaces. End housing718may allow some of the heavier elements of positioning interface with tubular construction700to be positioned below and behind the ears of user702so that they provide balance to positioning interface with tubular construction700and provide leverage from ear supports714to help keep head band708in place against the forehead of user702. The embodiment of end housing718shown inFIG. 7Ais shown as a conical structure, but many other shapes and sizes are possible including cubic structures and cylindrical structures. Some embodiments of positioning device with tubular construction704may lack end housings718as their electronics and other needed elements may be contained entirely inside main tube704or in other areas inside or upon positioning device with tubular construction700.

Positioning device with tubular construction700has regions of narrow tubing705in which main tube704is substantially reduced in diameter. Certain embodiments may employ regions of narrow tubing705to allow hair cutting devices to be more easily applied and operated in regions of the face and head of user702. InFIG. 7A, regions of narrow tubing705are shown in areas where positioning device with tubular construction700passes in front of the ears of user702. Other embodiments may employ regions of narrow tubing705to allow more precise trimming of sideburns and other features of haircuts just above and in front of the ears of a user702. Certain embodiments may also include regions of narrow tubing or other features to allow improved convenience in or on other parts of positioning device with tubular construction700.

Positioning device with tubular construction700as embodied inFIG. 7Amay be employed to provide a simple and attractive design that is easy to store, clean, and maintain. Positioning device with tubular construction704may be constructed from plastics, metals, wood, ceramics, rubber or other materials and may be constructed to be easy to clean and may employ materials that resist the formation of bacteria and germs. Positioning device with tubular construction700may be designed to be submersible in water so that it may be easily rinsed clean.

Certain embodiments of positioning device with tubular construction700employ an enlarged open region in front of the eyes of user702so that user702may wear eyeglasses while operating automated hair cutting system100. While eyeglasses may interfere with cutting hair on some parts of the head of a user702, some users may prefer to cut some or most of their hair with their eyeglasses on and only remove their eyeglasses to cut those portions of their hair obstructed by their eyeglasses. Alternate embodiments employ a positioning device that allows a user702to wear their eyeglasses and also to remove and replace their eyeglasses without disrupting operation of the positioning device. While certain embodiments of positioning devices may be configured to allow operation with eyeglasses in place, positioning device with tubular construction700, as shown embodied inFIG. 7A, allow for easier access because of the large opening it provides in front of the eyes of user702.

Main tube704and regions of narrow tubing705may be composed of flexible materials that may be bent and formed such that positioning device with tubular construction700may be properly and comfortably fit to the head of user702. Alternatively, main tube704and regions of narrow tubing705may be composed of rigid or semi-rigid materials and may be formed to include smooth curves. Main tube704and regions of narrow tubing705may also be composed of materials that provide tension or spring function so that positioning device with tubular construction700applies an acceptable level of compression against the face of user702through ear supports714and head band708so that they more easily grip the face of user702. Ear supports714and head band708may employ coatings, adhesives, paste, tape, texturing, or other techniques to improve their grip to the face of user702or improve comfort. Ear supports714may also be coated, textured, or otherwise finished so that eyeglasses resting over the top of ear supports714may more easily grip ear supports714. Main tube704and regions of narrow tubing705may have a circular, square, triangular, hexagonal, or other cross-section. Normally, main tube704and regions of narrow tubing705will include a hollow center so that wiring, circuitry, electronics, and other elements may be formed or placed inside them. However, embodiments in which main tube704and regions of narrow tubing705have solid cross-sections without a hollow center are also possible.

FIG. 7Bshows a top view of an embodiment of a positioning device with tubular construction700. Ear supports714, end housings718, end positioning interfaces710, positioning interfaces712, and main tube704are shown around the head of user702. The end of the nose703of user702is also shown inFIG. 7Bto avoid any possible confusion regarding the orientation of this top view of user702. Distance711from head702to main tube704inFIG. 7Bis shown to call attention that keeping a gap between the main tube704of positioning device with tubular construction700and the head of user702provides a substantially less obstructed path between positioning interfaces712and sensors208on hair cutting device200(or other embodiments of hair cutting devices) than may be possible if main tube704were in close proximity to the head of user702. Maintaining a distance711from head702to main tube704may also be beneficial as it allows positioning device with tubular construction to be applied and fit to users702of different ages and with different sized and shaped heads. Distance711may be selected for different embodiments based on multiple factors including size, weight, comfort, and other factors but may generally be in the range of one to several inches. It is also noted that inFIG. 7B, the sections of positioning device with tubular construction700behind the ears of user702including end housings718and end positioning interfaces710are oriented slightly outward, away from the back of the head of user702. In some embodiments, sections of positioning device700may be oriented outward behind the ears of user702, as shown, providing easier access to the back portions of user's702head and scalp. Other embodiments employ positioning devices kept partially or fully in close contact with the face and head of user702.

FIG. 7Cshows positioning device with tubular construction700fromFIG. 1in which user702is omitted such that an unobstructed view of positioning device with tubular construction700is possible. The elements ofFIG. 7Care identically numbered to those inFIG. 7Awith the addition of ear hooks715(ear hooks715are not numbered inFIG. 1as view of them is almost entirely obstructed by the ears of user702). Ear hooks715as shown in the embodiment ofFIG. 7Cprovide support by hooking over the tops of the ears of a user wearing positioning device with tubular construction700and also allow some tension to be developed between the back of the ears of a user to the head band708. In this way, head band708may fit the forehead of a user with some tension so that it is less likely to slip. Head band708may be formed from or include rubber, plastics, springs, or other elastic materials so that it may maintain tension against the forehead of a user. Head band708may also be adjusted in length and in position along main tube704using band connectors706. Ear supports714may also be formed from materials that are able to be flexed so that some pressure may be maintained against the back of the ears of a user wearing positioning device with tubular construction700. Additional embodiments of positioning device with tubular construction700are possible in which other support features or techniques are incorporated instead of or in addition to head band708and ear supports714. For example, positioning device with tubular construction may be supported with features that contact the temples, checks, ear lobes, inside the ears, in front of the ears, below the ears, behind the ears, above the ears, eye sockets, nose, mouth, and other regions of the face and head of a user. Ear hooks715may be fabricated from metals, plastics, wire, or other materials. Flexible ear hooks715made from loops of string, wire, or other materials that partially or fully encircle the ear of a user are also possible.

FIG. 7Dshows an embodiment of positioning device with tubular construction700fromFIG. 1folded at hinges716for compact storage. The regions of positioning device with tubular construction700near ear supports714have been folded across each other and the region of positioning device with tubular construction700near head band708has been folded downwards. Hinges716in the embodiment shown include special construction to allow for both pivoting and folding for the embodiment as shown inFIG. 7Dto be possible. Alternate embodiments of positioning device with tubular construction700or other possible positioning devices may contain many combinations of hinges, pivots, telescoping elements, ball joints, flexible materials, elastic materials, actuators, and other possible elements to fold or otherwise be re-configured conveniently.

Before describingFIGS. 7E and 7F, it should be noted that, in addition to observing a positioning device through a camera (with or without structured light), embodiments of positioning structures are possible in which the user may also be “directly” observed. Direct observation of the face or head of a user may be used in conjunction with a positioning device (and in conjunction with accelerometers, gyroscopes, etc.) to compute position and/or orientation of a hair cutting device. It is also possible to have embodiments of positioning structures that do not use a positioning device (as noted in the Detailed Description with reference toFIG. 1) and that determine position and/or orientation only through direct observation of the user (again, with or without structured light and potentially in conjunction with use of accelerometers, gyroscopes, etc.). Cameras may also be used to ensure substantially proper placement of a positioning device on a user's face, and to detect if a positioning device has moved from correct placement. Cameras may be the camera107ofFIG. 1, a camera or cameras mounted on hair cutting devices such as camera216mounted on hair cutting device200ofFIG. 2, or could be cameras in sensor hubs904(FIG. 9), or other cameras.

FIG. 7Eis an illustration of an embodiment of a positioning device with easily visible features701. Ear supports714, head band708, band connectors706, main tube704, regions of narrow tubing705, and user702are all visible and provide similar functions to like numbered elements inFIG. 7A. However, unlike the embodiment ofFIG. 7A, the embodiment of positioning device with easily visible features701ofFIG. 7Ehas first visible positioning interface720, second visible positioning interface722, third visible positioning interface724, and end visible positioning interface726that are larger and of various shapes versus the smaller spherical positioning interfaces712ofFIG. 7A. First visible positioning interfaces720are cubical, second visible positioning interface722is pyramidal, third visible positioning interfaces are spherical, and end visible positioning interfaces726are hexagonal. Certain embodiments of positioning devices employ easily visible and distinguishable positioning interfaces (such as first visible positioning interface720, second visible positioning interface722, third visible positioning interface724and end visible positioning interface726) and cameras (such as camera216on hair cutting device200, or camera107on electronic computing device106). By observing first visible positioning interface720, second visible positioning interface722, third visible positioning interface724, and end visible positioning interface726through a camera and performing analysis with computer vision algorithms, the relative positions of first visible positioning interface720, second visible positioning interface722, third visible positioning interface724, and end visible positioning interface726may be easily distinguished and used to make a determination of the position and orientation of the camera relative to positioning device with easily visible features701. Embodiments employing such a camera allow the calculation of position and orientation of hair cutting device200relative to positioning device with easily visible features701. In alternate embodiments, first visible positioning interface720, second visible positioning interface722, third visible positioning interface724, and end visible positioning interface726may also provide the function of positioning interfaces as described inFIG. 1, where signals and propagation delay computations for are employed for determining position or orientation. Certain embodiments employ positioning interfaces as visible features that may be observed by cameras, video cameras, imagers, or other elements capable of generating video or images from which position or orientation may be computed. Other embodiments employ positioning interfaces as signal transmission or reception functions from which propagation delay computations may be used to determine position or orientation. Yet other embodiments employ a combination.

InFIG. 7E, bearing721and handle717are also shown. Bearing721may be a simple bearing consisting of an axle and cylindrical sleeve, a roller bearing, a ball bearing or other types of bearing. Certain embodiments couple ear support714to main tube704, end housing718, and other elements of a positioning device through a bearing721to allow the positioning device to pivot at the bearing721. Consequently, ballast or weight from batteries, electronics, and other elements within end housing718act as a lever force over bearing721to keep head band708against the forehead of user702, improving the stability of head band708on the forehead of user702. Rotary springs, springs, elastic, rubber bands, or other elements could further be used to pull ear supports714against the back of the ears of user702by pulling against ear support714relative (in a forward direction so as to create pressure on the back of the ears of user702) to other portions of a positioning device. Handle717is shown attached to ear support714and configured to allow user702or another person to rotate ear support714in bearing721. Handle717or other embodiments of handles, tabs, knobs, levers, extensions, or other features allowing a person to easily rotate ear support714may benefit some embodiments as they may allow user702or another person to more easily put on and position positioning device with easily visible features701or other possible positioning devices more easily.

InFIG. 7F, an embodiment of a positioning device with easily visible features703is shown in which like numbered elements perform substantially identical functions to those of positioning device with easily visible features701, shown inFIG. 7E. Positioning device with easily visible features703as shown inFIG. 7Edoes not include bearing721or handle717(although some embodiments of it do), but employs ear support714as was shown for positioning device with tubular construction700. Additionally, positioning device with easily visible features703includes dots730, stripes732, and stripes734. Dots730, stripes732, and stripes734are the result of illumination with structured light from a light source such as illumination device218on hair cutting device200as shown inFIG. 2. Visible features from structured light such as dots730, stripes732, and stripes734offer additional information as the application of structured light may allow distance and orientation to be determined from analysis of the dots730, stripes732, stripes734, or other features resulting from structured light. For example, the center-to-center distance between dots730may provide an indication of how far they are away from the structured light illumination source (and, hence, how far away they are from hair cutting device200if the illumination source is mounted on hair cutting device200).

A positioning interface may be a visible or invisible feature, specifically, the positioning interface may be any possible feature or element that could be observed or interacted with to generate position information. The positioning interface may be a physical marking, a decal, an image, a paint mark, an indentation, a recognizable physical feature, a recognizable physical structure, an electronic transmitter, an electronic receiver, an antenna, a speaker, a microphone, a transducer, a sensor, a sensing point, or any other possible feature or structure or combination of features or structures that may be detected in some fashion, whether visible or not, so that position information may be determined.

FIG. 7Falso includes auxiliary positioning device740around the neck of user702. Auxiliary positioning device740includes positioning interfaces742and may include all types of positioning interfaces that have been described. Auxiliary positioning device740provides an example and shows that positioning devices may be broken into multiple parts that interact with each other, with hair cutting devices and other possible elements of an automated hair cutting system100through wired or wireless interfaces. It is noted that auxiliary positioning device740is around the neck of user702, so it would not normally move with the movement of the head and face of user702. However, through interaction with positioning device with easily visible features703, the position and orientation of auxiliary positioning device740may be computed allowing positioning interfaces742to provide beneficial information to automated hair cutting system100. Many different types of auxiliary positioning devices are possible that may be affixed to a user702in a wide variety of positions and orientations so that a wide range of benefits may be delivered.

FIG. 8Ashows an embodiment of a positioning device with tubular construction in which some positioning interfaces extend above a user's head802or extend behind. InFIG. 8A, upper positioning interface812is shown above top reference line806that extends over the top of user's head802so that substantially all regions of the top user's head802have a line of sight connection possible to upper positioning interface812. Lower positioning interface810is shown behind back reference line804that extends behind user's head802so that substantially all regions of the back of user's head802have a line of sight connection possible to lower positioning interface810. Embodiments such as the one ofFIG. 8Ain which some regions of user's head802have line of sight connections possible to some positioning interfaces may offer benefit of additional accuracy. This may be especially true if light, optical, infrared or other signals that propagate in straight lines are used as positioning signals in an automated hair cutting system100.

FIG. 8Bshows the embodiment ofFIG. 8Aof a positioning device with tubular construction in which some positioning interfaces either extend above user's head802or extend behind; and further illustrates how sensors824may be placed on a hair cutting device820so that obstruction from the hands and arms of a person operating the hair cutting device820may be minimized. InFIG. 8B, sensors824are placed substantially near the cutter head of hair cutting device820and an extended handle822is provided so that hands and arms may be kept substantially away from the path between sensors824and at least some of the positioning interfaces shown in the embodiment. As is visible inFIG. 8B, the hand or arm of a person on handle822of hair cutting device820may be easily kept away from a line of sight from the sensors824shown on hair cutting device820to upper positioning interface812. Similarly, sensors824may benefit from reduced obstruction due to hands and arms of a person on the handle822of hair cutting device820to lower positioning interface810when hair cutting device820is positioned behind user's head802. While the embodiment of a hair cutting device200shown inFIG. 2included a sensor208on handle206for the benefit of maximum spacing of the sensors208,FIG. 8Billustrates that certain embodiments minimize obstruction from the hands and arms of people operating automated hair cutting system100if sensors824are kept substantially away from handle822of hair cutting device820as shown.

FIG. 9shows an embodiment of an automated hair cutting system in which sensor hubs904contribute to operation of the automated hair cutting system and in which sensor hubs904are affixed to a wall, mirror902, or are otherwise mounted near a user102. Certain embodiments employing sensor hubs904offer improved accuracy of automated hair cutting system100, or may reduce size, weight, or complexity of a positioning device108. Positioning device108may communicate with sensor hubs904through wired or wireless interfaces. Sensor hubs904may be battery operated or receive power through wires. Sensor hubs904may be affixed to mirror902or other surfaces with adhesive, tape, suction cups, or other techniques. Sensor hubs904may contain positioning interfaces712(as previously described), cameras, imagers, radar, sonar, lidar, structured light illumination sources, scanning lasers, or other electronic elements that allow sensor hubs904to monitor the position, orientation, hand position, arm position, head position, hair position, hair style, and/or other aspects of user102. Sensor hubs904may also contain indicator lights, buzzers, chimes, speakers, microphones, gesture recognition devices, time-of-flight monitors, or other elements that allow sensor hubs904to communicate with user102. Information may be exchanged between multiple sensor hubs904, user102, positioning device108, electronic computing device106(not shown inFIG. 9), hair cutting device200(not shown inFIG. 9), and other possible elements of automated hair cutting system100to provide guidance, control and other information that may be beneficial in the operation of automated hair cutting system100. The embodiment ofFIG. 9shows three sensor hubs904, but embodiments with other numbers of sensor hubs904are also possible.

FIG. 10Ais an illustration of one embodiment of an outline1002of a first type of human scalp. Human scalp outline1002may be formed by flattening a three-dimensional model of a human scalp to form a two-dimensional outline as shown inFIG. 10A. Flattening a three-dimensional model of a human scalp to form a two-dimensional human scalp outline may involve some stretching and/or compression of some parts of the model and such an operation may mean that the distances between points on outline1002may not correspond precisely with distances between the same represented points on a corresponding three-dimensional model (much as two dimensional maps of the earth include some stretching or expansion versus distances on an earth globe). For many hair styles a substantially smooth translation of hair length from one region of a person's scalp to another is employed and so, such distortions in the modeling process may not cause problems in achieving an acceptable haircut. Different human beings have different scalps. Certain aspects of outline1002shown inFIG. 10Ainclude a front peak1010, a side burn1004, an ear opening1008, and a flat back1006. Outlines such as outline1002inFIG. 10Amay be employed in some embodiments of automated hair cutting systems100as a user102of such a system may provide information about the type of scalp they have or through use of automated hair cutting system100, information about the type of scalp user102has may be determined directly by measurements, camera images, and other techniques. The information may be employed to determine possible hair styles, modifying or adjusting styles for beneficial results, fitting particular hair styles to a specific user102, or for other purposes.

FIG. 10Bis an illustration of another embodiment of a human scalp outline1022. Outline1022is an example of a human scalp having a flat front1024, a side peak1028, a side burn1004, an ear opening1008, and a back peak1026. Various embodiments of an automated hair cutting system100provide many different human scalp outlines that may be associated to specific users. Some of these human scalp outlines may be specific to males and females, while others may be applicable to people of either sex.

FIG. 10Cis an illustration of how the location of positioning interfaces on a positioning device may be determined relative to reference points on the head of a user1130. The embodiment ofFIG. 10Cis based on signal propagation times from positioning interfaces to sensors on a hair cutting device or stylus. Additional embodiments are possible that include position or orientation measurements based on camera images, radar, sonar, lidar, images taken under illumination by structured light, and by other techniques. First positioning interface1134, second positioning interface1136, third positioning interface1138, and fourth positioning interface1140are mounted on main tube1132. Additional positioning interfaces, head bands, ear supports, hinges, other supports and other possible features of some embodiments of a positioning device are not shown inFIG. 10Cto avoid cluttering the figure. InFIG. 10C, main tube1132and the positioning interfaces as shown are part of an embodiment of a positioning device. First reference point1150at front center of user's1130scalp, second reference point1152at top center of user's1130scalp, third reference point1154at lower end of side burn of user's1130scalp, fourth reference point1156at top of user's1130ear, and fifth reference point1158at back center of user's1130scalp are shown inFIG. 10Cas circles with cross hairs inscribed. Positioning interface locations may be established relative to reference points by prompting a user1130or other person operating automated hair cutting system100to position hair cutting device200, stylus1302, or other suitable device to a desired reference point and provide an acknowledgement to automated hair cutting system100that the hair cutting device200, stylus1302, or other suitable device is properly positioned at the reference point, so that the distances from each sensor208, located on such a stylus1302, hair cutting device200, or other suitable device to each positioning interface, may be determined. Distance ranges1160from the positioning interfaces to the reference points inFIG. 10Cmay be substantially precisely measured as explained previously from signal propagation measurements or other described techniques. As shown inFIG. 10C, multiple distance ranges1160are shown from each reference point to each positioning interface. In certain embodiments it is not possible to measure the distance range1160from every reference point to every positioning interface as the head of user1130, or other obstructions may block some signal paths. However, certain embodiments will allow a sufficiently large number of distance ranges1160to be measured so that automated hair cutting system100may operate.FIG. 10Calso shows positioning interface distance ranges1162that represent the distance from one positioning interface to another. Depending on the design of a specific positioning device, the distance from various positioning interfaces to other positioning interfaces may or may not be precisely known. A specific embodiment of a positioning device may contain hinges, flexible members, telescoping members, or other features that allow the dimensions between various positioning interfaces to vary from one use to a next. Some embodiments of positioning devices may allow the distance between various positioning interfaces to be determined electronically. As shown inFIG. 10C, the distance between some of the positioning interfaces may be known and those known positioning interface distance ranges1162may also be used in computations to determine positioning device locations based on reference points. Multiple distance ranges1160or positioning interface distance ranges1162from each reference point to each positioning interface, or between positioning interfaces, allow substantially precise locations of positioning interfaces to be computed relative to the reference points as shown inFIG. 10C. If reference point locations are known, then the locations of positioning interfaces may be determined from them as described. If the reference points of the embodiment ofFIG. 10Care established on a scalp outline such as human scalp outline1002, human scalp outline1022, or other possible human scalp outlines, then the location of first positioning interface1134, second positioning interface1136, third positioning interface1138, and fourth positioning interface1140may also be substantially projected on the scalp outline. Reference point locations may also be determined with reference to solid models such as three-dimensional model1102shown inFIG. 11. In certain embodiments three or more distance ranges1160or positioning interface distance ranges1162are needed to determine the location in three dimensional space of a positioning interface relative to the locations of the reference points from which those distance ranges1160were determined. Embodiments of automated hair cutting systems100may employ multiple sensors208on hair cutting devices200or on stylus1302, so several distance ranges1160between the various sensors and positioning interfaces may be measured. Embodiments employing such an over-determined system may mitigate sensors or positioning interfaces being blocked at various times by the hands or arms of user1130, other people or covered with hair or other items (such as combs, brushes, etc.). Such an over-determined system may also allow embodiments of the system and method to accommodate a range of users with various sized and shaped heads. In embodiments employing three-dimensional models, three-dimensional mathematics may be applied and substantially precise locations of the various sensor interfaces relative to the reference points of the scalp of a user1130may be determined. In embodiments employing two-dimensional scalp outlines, various distortions and approximations are involved to transform a three-dimensional human scalp to a flat plane human scalp outline. With regard to the positioning interfaces shown inFIG. 10C, for example, their positions may be projected to a human scalp outline by determining their perpendicular projection to a plane tangential to the scalp or head of user1130.

If all users1130of an automated hair cutting system100had the same size and shape of head then reference point locations could be measured and used for all possible users of automated hair cutting system100, and the embodiment ofFIG. 10Cwould then be closely analogous to GPS (Global Positioning System) (since there is only one Earth inside the GPS satellite constellation). Certain embodiments accommodate many different users1130with a large range of head sizes and shapes, ear locations, and scalp sizes. Certain embodiments assume a standard head model, such as three-dimensional model1102with reference point locations that are substantially precisely known in three-dimensional space. It is then possible to vary the assumptions of the size, shape, and other features of the standard head model so that the distance ranges1160measured result in self-consistent computations for the locations of the positioning interfaces, regardless of which distance ranges are used to compute the location of a specific positioning interface. For example, if a specific user1130has a smaller head than an assumed standard head model, then the distance range1160measured from first reference point1150to first positioning interface1134may be inconsistently long relative to the measured distance range1160from fourth reference point1156to first positioning interface1134. This concept applies to many distance ranges1160that may be inconsistent if an assumed standard head model does not sufficiently match the shape and size of the head of the specific user1130using the automated hair cutting system100. Alternate embodiments are possible where adjustment of the size assumptions of the standard head model will allow the many distance ranges1160measured to become sufficiently self-consistent; and once this is accomplished, the locations of each positioning interface may be sufficiently computed. Recursive algorithms, analytic algorithms, search algorithms, and other types of algorithms may be employed to determine a correct head model with reference point locations that match those of the specific user1130to acceptable tolerances.

Other embodiments employ alternate approaches to determine and fit reference points of a specific user to a model so that consistent positioning interface locations may be computed and hair styles may be fitted to those models. These approaches include direct measurement to determine the size and shape of the head of a specific user1130, analysis of camera images of a specific user1130, analysis of camera images of a specific user1130taken under illumination with structured light, precision measurement of the locations of reference points of a specific user1130using a substantially precise three-dimensional measurement system, solid modeling techniques, or Lidar scanning.

Since embodiments may exist in which positioning interface locations are substantially over-determined by reference point locations and measured distance ranges1160, as previously explained, it is also possible to favor certain reference point locations and measured distance ranges1160for the determination of a specific positioning interface location. For example, third positioning interface1138is near the ear of user1130inFIG. 10C, so some embodiments may favor signals from third positioning interface1138in determining the position and orientation of hair cutting device200for hair cutting operations near the ear of user1130. Certain embodiments may favor reference points near the ear of user1130in determining the location of third positioning interface1138, so that more precise hair cutting may be substantially achieved. In other words, use of third reference point1154, fourth reference point1156and fifth reference point1158may be favored for the determination of the location of third positioning interface1138, as shown inFIG. 10C, versus other possible reference points.

Some hair cutting operations may benefit if certain positioning interface locations are substantially more precise relative to certain reference points, and that other hair cutting operations may benefit if those same positioning interface locations are substantially more precise relative to other reference points. Consequently, certain embodiments are possible in which positioning interface locations are recomputed from more favorable reference points specific to hair cutting operations about to be undertaken. In this fashion, positioning interface locations may be recomputed multiple times during a haircut to improve precision.

In certain embodiments, a mathematical correction may be employed in orientation measurements using the stylus1302, hair cutting device200or other device. Such corrections may include use of accelerometers or other orientation, tilt, or gravity sensing devices.

Signal propagation times from a positioning device to multiple sensors on a stylus1302, hair cutting device200, or other device may be used to measure reference points in some embodiments. Errors in orientation using signal propagation measurements, arising before reference points and positioning interfaces have been substantially determined, may be managed by using sensors and positioning interfaces for orientation measurement that are normally positioned to be insensitive to precise sensor or positioning interface location. Alternatively, relatively minor errors may be accommodated without compensation.

FIG. 10Dshows the outline of a first type of human scalp fromFIG. 10Awhere positions on the human scalp outline1002may be designated by coordinates relative to an embodiment of an x-axis1040and a y-axis1042. Incorporation of an x-axis1040and a y-axis1042may allow any point on the scalp of a user of an automated hair cutting system100to be referenced relative to the x-axis1040and/or the y-axis1042with numerical coordinates. These numerical coordinates may provide distances in quantified measures such as millimeters, centimeters, inches, etc., or in relative distance as a percentage of the size of human scalp outline (for example, as a percentage of the total dimension of human scalp outline1002along the y-axis1042). The location of the positioning interfaces shown inFIG. 10Care shown projected onto the coordinate system shown inFIG. 10D. As noted in the description ofFIG. 10C, such a projection may be computed as a perpendicular projection from a positioning interface to the surface of the scalp or head of a user, but other projections are also possible. AsFIG. 10Cwas a side view of the head of user1130, only four positioning interfaces were visible; whereas the scalp outline ofFIG. 10Dincludes the additional four positioning interfaces around the head of user1130that were not visible inFIG. 10C. The positioning interfaces ofFIG. 10Care shown like numbered for the left and right sides ofFIG. 10D(that is, left and right of the y-axis1042) and first positioning interface1134, second positioning interface1136, third positioning interface1138, and fourth positioning interface1140are shown. Many alternate systems of coordinates and axes are possible in addition to the rectangular coordinates shown inFIG. 10D. For example, a polar coordinate system based on angles from a reference vector and distance from a center point may also be used. A very wide range of coordinate systems are possible and may be applied.

FIG. 10Eshows the outline of a first type of human scalp fromFIG. 10Ain which a region of thinned hair1052and a region of a skull irregularity1050are designated relative to an embodiment of an x-axis1040and a y-axis1042. Human's may have regions of their scalp with especially thick or thin hair, regions of coarse hair, bald spots, regions with gray or graying hair, or other irregularities in their hair. Humans may have regions of their skull that are normally shaped, but have depressions, ridges, or other irregularities. By noting these regions as shown by example inFIG. 10E, certain embodiments of automated hair cutting system100may account for them and make adjustments to hair styles and recommendations to users of the system so that they achieve potentially beneficial results. The region of thinned hair1052and the region of a skull irregularity1050inFIG. 10Emay be encoded with coordinates relative to the x-axis1040and the y-axis1042.

FIG. 10Fshows an embodiment of a table1060that provides information specific to hair in specific regions of a first type of human scalp outline1002where the specific regions are designated by coordinates relative to an embodiment of an x-axis1040and a y-axis1042. Title row1061of table1060provides representative column headings that are optional and may not be present in all embodiments. Each row of table1060below the title row1061includes a coordinate in a first column1062that references x-axis1040, and a coordinate in a second column1064that references y-axis1042. For each row in table1060, the remaining columns provide information about the hair in the region referenced by the coordinates in the first column1062and second column1064as follows: a third column1066provides a present length (designated P-L in table1060), a fourth column1068provides a desired length (designated D-L in table1060), a fifth column1070specifies an accuracy tolerance to which hair should be cut (designated Tol in table1060), and a sixth column1072provides an indicator of the thickness of hair (designated Typ and denoted: TH for thin, M for medium in table1060). First reference line1074shows how a specific region on human scalp outline1002is mapped to the first row of table1060. Second reference line1076shows how a specific region on human scalp outline1002is mapped to the second row of table1060. Third reference line1078shows how a specific region on human scalp outline1002is mapped to the third row of table1060. Fourth reference line1080shows how a specific region on human scalp outline1002is mapped to the fourth row of table1060.

Mapping from human scalp outline1002to table1060as shown inFIG. 10Fallows all regions of human scalp outline1002to be mapped such that a substantially complete tabular record of human scalp outline1002may be created in table1060through the addition of rows to table1060. It is clear that each row of table1060contains specific information regarding how hair is to be cut in that specific region and that with other aspects of the system and method, specific hair styles may be represented for specific people so that acceptable results may be achieved. Table1060may also include other or additional columns to provide information regarding hair types (bristly, curly, straight, etc.), hair color (gray, white, blond, brown, etc.), skull irregularities (may be noted as higher or lower regions with deviations from nominal provided as quantified measurements), or any other features of hair relative to specific regions of human scalp outline1002. In certain embodiments, table1060may be represented in a computer as an array of numbers, as a spreadsheet, or through other electronic computing techniques. It is noted that the numerical values presented in table1060are for example purposes only and, apart from the first column1062and second column1064that correspond to locations of human scalp outline1002as already shown and explained, the numerical values in table1060do not convey numerical information of specific interest.

Human scalp outline1002and table1060as presented inFIG. 10F, may substantially contain the information needed by automated hair cutting system100to determine the length hair should be cut to for a user102. It was explained in the description ofFIG. 1that user102may be asked to place hair cutting device200or a stylus1302on reference points so that positions on the head and scalp of user102may be accurately referenced by positioning device108. Referring again toFIG. 1, these reference points may include the tops of user's ears152, the back of user's neck at a collar line154, the tops of user's eyebrows150, and other reference points that are of specific interest in properly fitting a given hairstyle to a user's102head and facial features. Other reference points might include the front and back of a user's ears, the sides of a user's102eye sockets, the user's102hair line (the point at which the user's102hair scalp ends and skin without thick hair begins) at various points around the user's102scalp, and other reference points. Those skilled in the art will recognize that by determining reference points as described, the human scalp outline1002and table1060ofFIG. 10Fmay be referenced to specific locations on the head of a user102for a specific placement of positioning device108on the head of user102. And in this way, table1060may be used to provide substantially precise information for how long to cut the hair at each region of a user's102scalp so that automated hair cutting system100may achieve acceptable results.

FIG. 11is an illustration of an embodiment of a three-dimensional model1102of a human head. Three-dimensional model1102partitions the surface of a human head into specific regions1104. Three such specific regions1104are numbered for reference inFIG. 11, but all the rectilinearly defined regions may be specifically referenced. Since certain regions of the human head may not be of interest in the operation of an automated hair cutting system100, no rectilinearly defined regions are defined for the eye socket area1108and the ear area1106. Certain embodiments of automated hair cutting system100may employ a three-dimensional model1102of a human head instead of the two-dimensional scalp outlines that were explained inFIGS. 10A-10F. Other embodiments employ coordinate axes and tabular information as was explained inFIGS. 10A-10Fextended to a three-dimensional model1102such as the one shown inFIG. 11and may be used in a similar fashion in support of operation of automated hair cutting system100.

FIG. 12is an illustration of one embodiment of a hair dye dispensing device1202including sensors208, indicator lights212, accelerometer210, body1206, handle1204, comb1208, and dispensing slot1210. Hair dye dispensing device1202provides an example of an alternative device to a hair cutting device200that may be used in conjunction with an automated hair cutting system100to provide a function besides cutting hair. Sensors208, indicator lights212, and accelerometer210provide analogous functions to those described with regard toFIG. 2regarding hair cutting device200. Handle1204allows a user102to grip and position hair dye dispensing device1202. Body1206may contain a container of hair dye; motors, valves, piping, and other elements to dispense hair dye; electronics and computing elements to control hair dye dispensing device1202; and other functions. Comb1208allows specific hair to be gathered so that it may receive application of dye at the precise locations desired. And dispensing slot1210may spray, squeeze, or otherwise dispense hair dye at precise times and locations under control of automated hair cutting system100. Embodiments of hair dye dispensing device1202may include the ability to dispense multiple dye types or colors of dye so that specific hair in specific locations on a user's102head may be dyed to create interesting styles.

FIG. 13shows an embodiment of a stylus1302that may be used for providing reference point information. As previously described, reference points such as those shown inFIG. 1(top of ear152, back of user's102neck at a collar line154, etc.) may be used to allow automated hair cutting system100to accurately determine precise locations on a user's102head even if position device108(or other embodiments of positioning devices) is not precisely located on user's102head. While hair cutting device200may be used for determining reference points with its cutter head202disabled, a light weight stylus1302such as the one shown inFIG. 13may be easier to use. Sensors208shown on stylus1302allow precise location of tip1306to be determined while a user102holds it by handle1304and positions it to specific reference points as desired. Additional sensors208may be incorporated into stylus1302on the side not visible inFIG. 13. Stylus1302may contain a button, switch, or other element (these are not shown inFIG. 13) to allow a user to acknowledge to stylus1302that a reference point is being properly touched. Stylus1302may be battery operated or powered from a wired connection. It may also include wireless or wired interfaces to allow it to communicate to other elements of automated hair cutting system100. Stylus body1304may be constructed from wood, metal, plastics, or other materials. Some embodiments of hair cutting device200or other hair cutting devices shown in this patent application may employ a stylus1302built into their structure. That is, a physical element, stylus tip1306, or other feature suitable for the purpose of touching reference points may be present on such a hair cutting device or may extend through electronic control or manual extension from the structure of such a hair cutting device so that the benefit of higher precision in using a stylus for determining reference points may be achieved without the need for a separate stylus.