Patent Application
20100220078
Digital writing instruments (or styluses), interchangeably referred to herein as “digital pens” regardless of whether or not they write in ink, can be used to capture pen strokes and digitize them. Some digital writing systems including optical character recognition (OCR) software for converting recorded pen strokes to text data.
Typically, digital pens operate with and send data to a host device (any computerized platform device such as a “dedicated box”, a personal computer, a PDA, etc.). This may be directly or via one or more receiving stations which receive a signal from the digital pen. The location of the digital pen is tracked with a device tracking mechanism, and location data may be written into memory (volatile and/or non-volatile memory) of the host device. It is noted that systems including digital pens and host devices typically include a communications link (wired or wireless) between the digital pen and the host device.
Certain digital writing systems provide two modes of operations—“digital pen mode” for tracking pen strokes, and a “mouse mode” where the digital pen may serve as a mouse for the host device. In many applications, the pen or stylus (i.e. having a point) is used by the user to ‘write’ or perform strokes on a given surface. Thus, when the stylus or pen is “down” (i.e. contacting the surface), the location of the pen at any given moment may be tracked in order to perform pen strokes. When the pen is “up” (i.e. hovering over the surface) the location of the pen may be tracked in order to provide the “mouse mode,” or, alternatively, can be in “idle” status. Other applications of the “pen hovering” are also known. Typically, when the pen is ‘hovering’ the tip of the pen is less than 2-3 cm from the writing surface, though this is not a limitation, and there may be hovering at more than 2-3 cm. In many systems, the host device is associated with a display, and pen strokes and/or mouse movements may be displayed on the display.
A system for tracking the position of a digital pen including a (i) pen-fixed ultrasound device (i.e. transmitter or receiver) and (ii) a plurality of writing-surface fixed ultrasound devices (i.e. transmitters or receivers) is disclosed. In some embodiments, a measurement is made of the time that it takes for ultra-sound to travel between the pen-fixed ultrasound device and the writing-surface fixed ultrasound devices via a path that includes a writing surface sub-path between the ‘given point’ on the writing surface and the writing-surface fixed ultrasound devices. In some embodiments, the position of the digital pen or a component thereof may be determined in accordance with (i) the aforementioned measured times of ultra-sound travel; and (ii) the speed of sound within the writing surface. Related methods for tracking the position of the digital pen are disclosed. Related methods for manufacturing any presently-disclosed system are also provided. Furthermore, apparatus and methods for transmitting ultra-sound from a pen-fixed ultrasound transmitter, and for detecting ultra-sound that propagates in a board or writing surface are disclosed.
It is now disclosed for the first time a contact-mode measuring system comprising: a) a digital pen including a pen housing having a tip and a pen-fixed ultrasound device (i.e. whose position is fixed relative to the pen housing—for example, within the pen housing or attached to the pen house) selected from the group consisting of an ultrasound transmitter and an ultrasound receiver; b) a writing surface; c) a plurality of writing-surface-fixed ultrasound devices, each said ultrasound device selected from the group consisting of an ultrasound transmitter and an ultrasound receiver, each writing-surface-fixed ultrasound device having a respective position that is fixed relative to said writing surface; d) an ultra-sound propagation time measurement system operative, when said digital pen is located on said writing surface, to measure for said each writing-surface-fixed ultrasound device, a respective time that it takes for ultrasound to travel, through said writing surface, between: (i) said pen-fixed ultrasound device; and (ii) said each writing-surface-fixed ultrasound device, via a path that includes a respective writing subpath defined by a path between: (i) a location that is substantially a contact location between said tip and said writing surface within a tolerance that is less than 30% a distance between said contact location and a closest said writing-surface fixed ultrasound device; and (ii) said each writing-surface-fixed device; and e) an ultra-sound based position-determining system for determining a position of said pen-fixed ultrasound device n accordance with: i) said determined ultra-sound travel times; and ii) a speed of sound within said writing surface.
It is now disclosed for the first time a contact or hovering mode position measuring system comprising: a) a digital pen including a pen housing having a tip and a pen-fixed ultrasound device selected from the group consisting of an ultrasound transmitter and an ultrasound receiver; b) a writing surface; c) a plurality of writing-surface-fixed ultrasound devices, each said ultrasound device selected from the group consisting of an ultrasound transmitter and an ultrasound receiver, each writing-surface-fixed ultrasound device having a respective position that is fixed relative to said writing surface; d) an ultra-sound propagation time measurement system operative, when said digital pen is located on or over said writing surface, to measure for said each writing-surface-fixed ultrasound device, a respective time that it takes for ultrasound to travel, through said writing surface, between: (i) said pen-fixed ultrasound device; and (ii) said each writing-surface-fixed ultrasound device, via a path that includes a respective writing surface subpath defined by a path between: (i) an intersection point between elongate axis of said ultrasound device and said writing surface within a tolerance that is less than 30% a distance between said tip and a closest said writing-surface fixed ultrasound device; and (ii) said each writing-surface-fixed device; e) an ultra-sound based position-determining system for determining a position of said pen-fixed ultrasound device in accordance with: i) said determined ultra-sound travel times; and ii) a speed of sound within said writing surface.
It is now disclosed for the first time a contact or hovering mode position measuring system comprising: a) a digital pen including a pen housing having a tip and a pen-fixed ultrasound device selected from the group consisting of an ultrasound transmitter and an ultrasound receiver; b) a writing surface; c) a plurality of writing-surface-fixed ultrasound devices, each said ultrasound device selected from the group consisting of an ultrasound transmitter and an ultrasound receiver, each writing-surface-fixed ultrasound device having a respective position that is fixed relative to said writing surface; d) an ultra-sound propagation time measurement system operative, when said digital pen is located on or over said writing surface, to measure for said each writing-surface-fixed ultrasound device, a respective time that it takes for ultrasound to travel, through said writing surface, between: (i) said pen-fixed ultrasound device; and (ii) said each writing-surface-fixed ultrasound device, via a path that includes a respective writing surface subpath defined by a path between: (i) a given point on said writing surface; and (ii) said each writing-surface-fixed device; e) an ultra-sound based position-determining system for determining a position of said pen-fixed ultrasound device in accordance with: i) said determined ultra-sound travel times; and ii) a speed of sound within said writing surface, wherein, for each said writing surface subpath a ratio between a length of an above-surface sub-path between: (i) said pen-fixed ultrasound device; and (ii) said given point, and a length of said each writing surface subpath is at least 0.1 and at most 10.
It is now disclosed for the first time a comprising: a) a digital pen including a pen housing having a tip and a pen-fixed ultrasound device selected from the group consisting of an ultrasound transmitter and an ultrasound receiver; b) a writing surface; c) a plurality of writing-surface-fixed ultrasound devices, each said ultrasound device selected from the group consisting of an ultrasound transmitter and an ultrasound receiver, each writing-surface-fixed ultrasound device having a respective position that is fixed relative to said writing surface; d) an ultra-sound propagation time measurement system operative, when said digital pen is located on or over said writing surface, to measure for said each writing-surface-fixed ultrasound device, a respective time that it takes for ultrasound to travel, through said writing surface, between: (i) said pen-fixed ultrasound device; and (ii) said each writing-surface-fixed ultrasound device, via a path that includes a respective writing surface subpath selected from the group consisting of: A) a first respective writing surface subpath defined by a path between: I) a given point whose distance from, an intersection point between elongate axis of said ultrasound receiver and said writing surface, is less than 30% a distance between said tip and a closest said writing-surface fixed ultrasound device; and II) said each writing-surface-fixed device; B) a second respective writing surface subpath defined by a path between: I) a location that is substantially a contact location between said tip and said writing surface within a tolerance that is less than 30% a distance between said contact location and a closest said writing-surface fixed ultrasound device; and II) said each writing-surface-fixed device; and e) an ultra-sound based position-determining system for determining a position of pen-fixed ultrasound device in accordance with: i) said determined ultra-sound travel times; and ii) a speed of sound within said writing surface.
In some preferred embodiments, any aforementioned “30% tolerance” for either the contact point between the pen tip and the writing surface or the “intersection point” between the elongate axis of the pen-fixed ultrasound device and the surface is another tolerance—for example, 50% tolerance, 10% tolerance, 5% tolerance and 1% tolerance.
According to some embodiments, each said writing surface subpath a ratio between a length of an above-surface sub-path between: i) said pen-fixed ultrasound device; and (ii) said given point, and a length of said each writing surface subpath is at least 0.1 and at most 10.
According to some embodiments, in said writing surface is transparent.
According to some embodiments, said writing surface is flexible.
According to some embodiments, said writing surface is flexible.
According to some embodiments, said writing surface is constructed of at least one of wood, metal and transparent plastic.
According to some embodiments, the system further comprises: e) a hover-detection element operative to determine if said digital pen is in contact with said writing surface or hovering above said writing surface in accordance with a magnitude of detected sound signals between said pen-fixed ultrasound transceiver and at least one said writing-surface-fixed ultrasound transceiver.
According to some embodiments, the system further comprises: f) a pen-stroke-capturing element operative to capture pen strokes in accordance with changes of position of said digital pen as determined by said ultra-sound based position-determining system; and g) a pen-stroke-processing element operative to handle said captured pen strokes in a manner that is contingent on said digital pen being in said contact with said writing surface, as determined by said hover-detection element.
According to some embodiments, said pen-stroke-processing element is operative to provide a digital writing only for pen-strokes detected when, according to said hover-detection element, said digital pen is in contact with said writing surface.
According to some embodiments, said pen-fixed ultrasound device is an ultrasound transmitter.
According to some embodiments, for a sub-section that is at least 20% of a length of said writing surface subpath, said writing surface subpath is substantially parallel to a local upper surface of said writing surface within a tolerance that is at most 20 degrees.
According to some embodiments, said sub-section is at least 50% of a length of said writing surface subpath.
According to some embodiments, said writing surface includes an edge having a jagged section wherein: i) the length of said jagged section is at least 0.2 times the longest dimension of said writing surface; ii) said jagged edge includes at least n peaks and n−1 troughs, n being defined as an integer that is at least 5; iii) for adjacent peaks over said edge, a distance between adjacent peaks is between at least 0.01 and at most 0.1 times said longest dimension of said writing surface; and iv) for each peak, a peak-to-adjacent trough distance is at least 0.001 and at most 0.03 times said longest dimension of said writing surface.
According to some embodiments, said writing surface includes an edge having a jagged section wherein: i) the length of said jagged section is at least 0.2 times the longest dimension of said writing surface; ii) said jagged edge includes at least n peaks and n−1 troughs, n being defined as an integer that is at least 5; iii) for adjacent peaks over said edge, a distance between adjacent peaks is between at 0.5 and 5 times an ultrasound wavelength of ultrasound produced by an ultrasound transmitter of one of said pen-fixed ultrasound device and said writing-surface fixed ultrasound device; iv) for each peak, a peak-to-adjacent trough distance is at 0.5 and 5 time said ultrasound wavelength.
According to some embodiments, wherein: i) said writing surface is configured such that, when ultrasound propagates over a distance of 5 times, an ultrasound wavelength of ultrasound produced by an ultrasound transmitter of one of said pen-fixed ultrasound device and said writing-surface fixed ultrasound device, an amplitude of said propagating ultrasound is reduced by at most 30% (in some preferred embodiments, at most 20% or at most 10%); and ii) said writing surface includes an edge having a jagged section such that at a distance of (or in some preferred embodiments, a distance of 7 times or 10 times) times said ultrasound wavelength from said jagged section, an amplitude of ultrasound waves reflected from said jagged section is at most 50% of an amplitude of ultrasound wave incident to said jagged section.
This may be due, for example, to damping and/or phase cancellation of ultrasound waves.
In some embodiments, the system further comprises: f) a wired connection between said pen-fixed ultrasound transceiver and each said writing-surface-fixed ultrasound transceiver for ultra-sound signal synchronization, wherein said ultra-sound propagation time measurement system is operative to measure said sound travel times in accordance with said wired-connection-provided signal synchronization.
In some embodiments, said ultra-sound based position-determining is operative when there is no line of site between said pen-fixed ultrasound transceiver and at least one said writing-surface-fixed ultrasound transceiver.
In some embodiments, i) said digital pen further includes an optical transmitter operative to transmit light downwards; ii) the system further includes a writing surface fixed optical receiver; and iii) said writing surface is configured as a waveguide to substantially control a direction of propagation of light such that said propagating light is forced to follow a path that is substantially, within a tolerance of at most 10 degrees, parallel to a plane defined by an upper surface of writing surface for a distance that is at least 20% a distance between optical transmitter and optical receiver.
It is now disclosed for the first time an electronic pen device comprising: a) an elongated housing including an elongated inner cavity and a tip; and b) an ultrasound transmitter for generating ultrasound waves, comprising a piezoelectric film cylinder deployed within said elongated inner cavity such that an elongate axis of said piezoelectric film cylinder is substantially parallel to an elongate axis of said elongated inner cavity within a tolerance that is at most 45 degrees (or at most 22.5 degrees or at most 10 degrees in some preferred embodiments).
According to some embodiments, said elongated housing and said ultrasound transmitter are configured such that, for a transmission axis defined by a line parallel to said elongate axis of said piezoelectric film cylinder through said tip, at least one quarter of power of said generated ultrasound waves crosses a base circle defined by an intersection between: i) a plane perpendicular to said transmission axis; and ii) a body-fixed cone whose apex is said tip, whose theta angle is at most 45 degrees, whose axis is said transmission axis, and whose height is given by 5 times a wavelength of said generated ultrasound.
According to some embodiments, at least a majority of said power of said generated ultrasound waves crosses said base circle.
According to some embodiments, said theta angle is at most 22.5 degrees.
According to some embodiments, said theta angle is at most 10 degrees.
According to some embodiments, said elongated housing and said ultrasound transmitter are configured such that, for a transmission axis defined by a line parallel to said elongate axis of said piezoelectric film cylinder through said tip, at least one majority of power of said generated ultrasound waves crosses a base circle defined by an intersection between: i) a plane perpendicular to said transmission axis; and ii) a body-fixed cone whose apex is said tip, whose theta angle is at most 45 degrees, whose axis is said transmission axis, and whose height is given by 5 times a wavelength of said generated ultrasound.
According to some embodiments, at least a majority of said power of said generated ultrasound waves crosses said base circle.
According to some embodiments, said theta angle is at most 22.5 degrees (or at most 10 degrees in some preferred embodiments).
In some embodiments, the system further comprises: c) at least one ultrasound reflector deployed above said piezoelectric film cylinder within said elongated inner cavity for reflecting upwardly propagating sound generated by said ultrasound transmitter relative to a body-fixed axis of the pen device in a downwards direction, said at least one ultrasound reflector operative to downwardly reflect at least a 25% by ultrasound power upwardly propagating, relative to said body-fixed axis, said ultrasound generated by ultrasound transmitter.
In some embodiments, said at least one ultrasound reflector is configured to downwardly reflect at least a majority by ultrasound power of said upwardly propagating ultrasound.
In some embodiments, said at least one ultrasound reflector is configured to downwardly reflect at least a significant majority by ultrasound power of said upwardly propagating ultrasound comprising at least 75% of said upwardly propagating ultrasound.
In some embodiments, the pen further comprises: c) an ultrasound resonator deployed below, relative to a body fixed axis of the pen device, said piezoelectric film cylinder such that at least 50% of said generated (i.e. by power) ultrasound enters said ultrasound resonator, said ultrasound resonator operative to provide at least a 25% amplitude boost for said generated ultrasound that enters said ultrasound resonator.
In some embodiments, said ultrasound resonator is operative to provide at least a 50% said amplitude boost.
In some embodiments, said ultrasound resonator is operative to provide at least a % said amplitude boost.
In some embodiments, said piezoelectric film cylinder of said ultrasound transmitter comprises at least 5 turns of piezoelectric film.
It is now disclosed for the first time a system for handling ultrasound signals, the system comprising: a) a thin writing surface having a thickness that is at most 0.05 times a longest dimension of said writing surface; and b) an ultrasound receiver comprising a piezoelectric film cylinder fixed relative to said writing surface, at least a contacting portion of said piezoelectric film cylinder deployed in contact with said side surface of said thin writing surface, at least an upper portion of said piezoelectric film cylinder deployed above an upper surface of said writing surface, at least a lower portion of said piezoelectric film deployed below a lower surface of said writing surface, said ultrasound receiver configured to receive ultrasound signals that propagate within said writing surface.
In some embodiments, said ultrasound receiver is configured to receive ultrasound signals that propagate within said writing surface substantially parallely to said upper surface at a contact region: within a tolerance of 22.5 degrees.
In some embodiments, said ultrasound receiver is configured to receive ultrasound signals that propagate within said writing surface substantially parallely to said upper surface at a contact region: within a tolerance of 5 degrees.
In some embodiments, said thickness that is at most 0.01 times a longest dimension of said writing surface.
In some embodiments, said thickness that is at most 0.005 times a longest dimension of said writing surface.
In some embodiments, at least one of (or both of): i) a height of said upper portion above said upper surface; ii) a negative height of said lower portion below said lower surface, is at most 5 times said thickness.
Different embodiments of the invention provide methods for carrying out any technique (for example, for determining a location of a pen-fixed ultrasound device, for measuring the time of propagation of ultrasound signals between a pen-fixed ultra-sound device and a writing surface-fixed ultrasound device, for transmitting ultrasound from a pen-fixed ultra-sound device to a writing surface-fixed ultrasound device, for detecting ultrasound signals that propagate within a writing surface or board).
Related methods for manufacturing any presently-disclosed system are also provided.
These and further embodiments will be apparent from the detailed description and examples that follow.
While the invention is described herein by way of example for several embodiments and illustrative drawings, those skilled in the art will recognize that the invention is not limited to the embodiments or drawings described. It should be understood that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning “having the potential to’), rather than the mandatory sense (i.e. meaning “must”).
The present invention will now be described in terms of specific, example embodiments. It is to be understood that the invention is not limited to the example embodiments disclosed. It should also be understood that not every feature of the apparatus and methods for determining a location of a digital pen and/or sending ultrasound signals from a digital pen and/or detecting ultrasound signals that propagate (for example, horizontally) within a “writing surface” is necessary to implement the invention as claimed in any particular one of the appended claims. Various elements and features of devices are described to fully enable the invention. It should also be understood that throughout this disclosure, where a process or method is shown or described, the steps of the method may be performed in any order or simultaneously, unless it is clear from the context that one step depends on another being performed first.
The location of the stylus may be tracked when the stylus 100 contacts the writing surface 140 (i.e. pen down—see
The term writing surface 140 relates to an object on which the user writes (typically planar), and may have a “thickness” (for example, a “portable” writing surface such as paper) and may also be referred to herein as a board 140. In
In this application, the term board 140 and writing surface 140 are used interchangeably and may refer to a computer screen, a transparent overlay, a piece of paper, or any other object on which one may write or to which one may point. Thus, as shown in
Although the stylus 100 in
There is no limitation on the size of the stylus. In exemplary embodiments, the length is between 8 and 12 cm, and the diameter is between 6 and 10 mm.
As depicted in
In order to track the location of the stylus 100, the stylus 100 includes at least one of an ultra-sound transmitter and/or receiver system and an optical (i.e. using light, for example, IR light) transmitter and/or receiver system. Determining the location of the stylus 100 at any given moment may be carried out, for example, by triangulation, for example, using electronic circuitry. As used herein, the ‘electronic circuitry’ refers to any combination of electronic hardware, software or firmware. Furthermore, some or all of the electronic circuitry may be located at any location within the presently disclosed system 5, including at the stylus, at a location associated with an ultrasound 150 or optical 152 receiver, in the host device 20, or any other location. As is known in the art, triangulation may be carried out by measuring the time of flight of the ultra-sound signal between the ultra-sound transmitter 210 (which produces ultra-sound waves) and each of the plurality of ultra-sound receivers 150, using the optical signal sent from the stylus 100 to the optical (i.e. IR) receivers 152 for signal synchronization.
It is noted that the optical transmitter 160 and receivers 152 are just one way (in this case, ‘wireless’) to provide ‘signal synchronization.’ Alternatively or additionally, signal synchronization may be provided in a ‘wired manner’ as is known in the art, using wires to ultrasound transmitter 210 and ultrasound receiver 150.
Although one of the ultrasound 150A and the optical 152 receivers are depicted in
Towards this end, in the example of the figures, the stylus 100 is also associated with a light or electromagnetic radiation transmitter 160 for producing light (i.e. 171), for example, IR light.
It is noted that although only two ultrasound 150 receivers and only one optical receiver 152 are depicted in
Furthermore, it is noted that in
Thus, the system provides at least one optical transmitter and at least one optical receiver. Furthermore, the system provides at least one of: A) at least one ultra-sound transmitter and at least two ultra-sound receivers and/or B) at least two ultra-sound transmitters and at least one ultra-sound receiver.
Various possible configurations are illustrated in
Although the ultrasound transmitter 210 is depicted in
Although the optical transmitter 160 is depicted in
Although in
A Comment about Space-Fixed Vertical Axis 999 and Body-Fixed Vertical Axis 130
It is noted that in the example of
In the present disclosure, “downward” and “upward” refer to relative to either (i) space-fixed vertical axis 999 or to (ii) body-fixed axis 130 (or another body-fixed axis that runs from the proximal end to the distal end, depending on the context as explained in the figures. This also refers to terms such as “up” and “down,” “upper” and “lower,” and the like.
It is noted that in exemplary embodiments, one or both of the ultra ultra-sound signal and the optical signal (i.e. IR) propagates through the board 140 when traveling from the stylus 100 (or a location associated with the stylus) to the ultra-sound 150 and/or optical 152 receiver. It is noted that
Not wishing to be bound by theory, it is noted that when the light and/or the ultra-sound travels from any point(s) associated with the stylus to the receiver(s) (i.e. 150 and/or 152) through the board 140 (as opposed to directly from the pen to the receiver) this may obviate the need to provide a “line of site” between the location(s) of transmission (i.e. the points transmitting at least one of ultra-sound and light) and the receivers.
Not wishing to be bound by theory, it is noted that transmission of the ultra-sound through the board 140 may allow the detection of pen up/pen down events, as explained below.
A Discussion of “Above-Surface” Propagation Subpath 177 and ‘Writing Surface Subpath 170” with Reference to
As is illustrated in
In general, a “given point” 175 is any point on writing surface 140. In the example of
It is noted that in some embodiments, ultrasound transmitter 210 (or alternatively an ultrasound receiver) includes an elongate structure (for example, a piezzo film cylinder such as actuator 230 illustrated in
In the example of
In the example of
In the example of
Depending on where the pen 110 is located (i.e. how far the pen is above writing surface 140), in different embodiments, the ratio between the length of above-surface sub-path 177 and any given writing sub-path 170 may vary. In different example, this ratio may be less than 10, less than 5, or less than 1. In different embodiments, this ratio may be at least 0.5, at least 1, or at least 2.
In some preferred embodiments (i.e. where the ‘given point’ is any point on writing surface 140), a length ratio between the “above-surface” sub-path 177 and the writing surface sub-path 170 is at least 0.1 and at most 10.
In some embodiments in accordance with the example of
The Board 140
Propagation of Light Parallel to the Surface of the Board
There is no limitation of the material from which the board or writing surface 140 may be fashioned. Exemplary materials include but are not limited to glass, plastic, wood and metal. In exemplary embodiments, for example, where the board 140 is used as a transparent overlay for a computer screen, the board may be transparent.
In some embodiments, the board 140 may be laminated, for example, with a layer of anti-scratch protective material and/or a layer of glass. For example, for embodiments where light waves (e.g. IR) are propagated through the board 140 or a layer of the board 140 or on a surface 141 of the board 140, the board includes (for example, the upper surface 141) a material operative to propagate light such as glass or a transparent or semi-transparent plastic. In some particular embodiments, the surface of the board 140 may be rough or not smooth (for example, including micro-scratches) to facilitate the penetration of light into the board 140 (i.e. to avoid reflection) and/or to facilitate the propagation of light (e.g. IR) along the surface of the board 140 (i.e. to function as a ‘wave guide’) and/or in a direction that is substantially parallel to the local surface of the board 140.
As used herein, a “waveguide” is a device that substantially controls the propagation of an electromagnetic wave so that the wave is forced to substantially follow a path defined by the physical structure of the guide. In the present example, board or writing surface 140 may be configured to force light to follow a path that is substantially (i.e. within a tolerance of at most 10 degrees, or at most 5 degrees, or at most 1 degree) parallel to a plane defined by an upper surface of writing surface 140 or board for a distance that is at least 20% (or at least 50% or at least 75%) a distance between optical transmitter 160 and optical receiver 152.
Thus, in exemplary embodiments, the light may penetrate into the material of the board 140 (for example, through the not-smooth surface) and then propagate within this material of the board.
There are no limitations on the dimension of the board. Typically, the dimensions of the board are on the same order of magnitude as a typical piece of paper (i.e. A4 or 8½ by 11), though this is not a limitation. In exemplary embodiments, the length and/or width of board is between 15 cm and 60 cm.
It is noted that in
For example, one or more edges 180 of the board 140 may not be a “straight edge” (not a straight line) as shown in
In some embodiments, the exact curvature may be selected in accordance with the wavelength of the ultra-sound used in the system.
Alternatively or additionally, the edge of the board includes a material (for example, a coating) operative to damp the amplitude of reflected ultra-sound waves. In some specific non-limiting examples, this ultra-sound damping material may include one or more of an adhesive material (for example, a material that adheres to glass), a resin material (including but not limited to synthetic resin and turpentine resin), any amorphous and/or soft material (for example, wax), a material that is poorly soluble or insoluble in water but soluble in nonpolar organic solvents (for example, wax), and polyamide EVA, ethylene, a copolymer such as vinyl acetate copolymer, wax. The exact amounts of materials provided, types of materials provided, and ratio of components of materials provided may vary in accordance with the structure of the board 140, and the skilled artisan will be able to select appropriate materials for given boards 140.
In one particular example, the ultra-sound damping material includes one or more of (or all of) polyamide EVA, synthetic resin (for example, 5% synthetic resin), ethylene, vinyl acetate resin copolymer, turpentine resin (for example, 40% turpentine resin), and wax (for example, 5%).
Although the board 140 in
Although the writing surface 140 is referred to as a board 140, this does not imply that the writing surface 140 (board) is rigid. In some embodiments, the board 140 is transparent, and/or flexible or semi-flexible. In one exemplary application, the board 140 may be provided as a transparent screen overlay, to be layered over the display 30 screen (including but not limited to CRT screen or an LCD screen). This may allow a user to “write on the screen” and to record pen strokes.
As shown in
Furthermore, it is noted that in some embodiments, the ultra-sound waves propagate through at a portion of the stylus towards the board or writing surface 140, before subsequently propagating through the board or writing surface 140.
A Discussion of Accuracies of Determining Pen Locations with Reference to
In some embodiments, the time of flight between the ultra-sound transmitter 210 and each ultra-sound receiver 150 may be determined. Time of flight data may be useful, for example, for determining the location of the stylus by triangulation.
Thus, it is noted that it is possible to determine (to a certain degree of accuracy) the location of digital pen 110 by measuring respective ultrasound travel times between ultrasound device 210 (i.e. a pen-fixed transmitter or receiver) and each particular writing-surface 140-fixed (or board 140-fixed) ultrasound receiver The principle of “triangulation” of digital pens is based on determining multiple times of flight (at least, possible more) of ultrasound traveling between: (i) a pen-fixed ultrasound device (i.e. transmitter or receiver); (ii) each of a plurality of writing board fixed ultrasound devices (i.e. transmitter or receiver). In the event that the ultrasound travels along a straight line between the pen-fixed ultrasound device and the writing-surface fixed ultrasound devices, then the location determined is a “unique location.” In certain embodiments of the present invention, however, the measured ultrasound does not travel on a “straight line” between the pen-fixed ultrasound device and the writing-surface fixed ultrasound devices. Rather, the ultrasound travels (either from the pen-fixed ultrasound devices to the writing-surface fixed ultrasound devices or vice versa) along a path that includes (i) an ‘above-surface’ or air sub-path 177 (ii) a writing surface subpath 170. Thus, in some embodiments, the determined location may not be unique, but rather there may be multiple locations associated with a given set of ultra-sound propagation time measurements.
This is illustrated in
Nevertheless, all locations that provide the given measured ultra-sound propagation times are typically “close” to each other. Thus, when the “location of the digital pen” (i.e. either the digital pen or a component thereof—for example, the pen-fixed ultrasound transmitter or receiver) is determined, there may be certain degree of “inaccuracies” in this determination. The present inventors are disclosing that this is acceptable to certain applications—for example, systems for recording pen strokes.
Also, it is noted that “determining the location” of the pen does not require determining the location in three dimensions. For example, it may be difficult to determine the “height” of the digital pen in this manner, and when “determining the location” it may be sufficient to determine the location in two dimensions—for example, ‘horizontal dimensions” defined according to writing surface 140.
Thus, in some embodiments, the location of the stylus 100 is determined (for example, using triangulation based on time of flight to the receivers) not exactly, but approximately, within a given tolerance. Not wishing to be bound by theory, it is noted that in some embodiments, the margin of error associated with a determined location (i.e. along the x-y plane defined by the writing surface 140) may be greater when the pen is not contacting the writing surface 140 and ultra-sound waver propagate through the air before reaching the board or writing surface 140 (i.e. greater than the margin of error with a determined location when the pen or stylus 100 contacts the writing surface 140, i.e. in ‘pen down’ mode).
Nevertheless, there are certain applications where it is nevertheless useful to compute the location of the pen or stylus 100 during ‘hovering,’ even though the computed x-y location may only be approximate, and may not be completely accurate. For example, when the ‘hovering pen’ is being operated with the host device 10 in ‘mouse mode,’ the user typically may views the screen, and move the pen in order to solicit a motion of the ‘mouse pointer’ displayed on the display 20 screen, and typically, there may not be a need for capturing pen strokes in ‘hovering mode’. Thus, according to these examples (i.e. associated with using a hovering pen in mouse mode) if the tracked location of the pen has a certain degree of error, it is assumed in many applications, that the user will adjust the position of the pen accordingly (user hand-eye feedback).
In accordance with the determine propagation times, digital pen position determining system 155 determines the position of digital pen 110. Digital pen position determining system 155 may be implemented in any combination of hardware or software, and may be deployed in part or in whole at any location(s).
In the example of
In the example of
As illustrated in
As mentioned above, when the pen ‘hovers’ above the writing surface 140 or board, the ultra-sound waves may first prorogate through the air before propagating through the writing surface 140 or board. In some embodiments, the amplitude of the ultra-sound waves received at the receivers is determined, and it may be determined whether or not the pen or stylus is hovering or contacting the writing surface 140 or board (or alternatively, a distance between a fixed point on the stylus 100 and the writing surface 140) in accordance with a determined amplitude of the received ultra-sound wavers (i.e. received at the receiver 150).
More specifically, the amplitude of ultra-sound signals (i.e. transmitted by the stylus and/or pen and received by ultra-sound receivers 150 at the board, or transmitted at the board and received by an ultra-sound receiver in the stylus and/or pen) may increase by an order of magnitude (i.e. at least a factor of 3, or at least a factor of 7) when the stylus, previously hovering, is broad into contact with the writing surface of board 140. Similarly, the amplitude of ultra-sound signals decrease by an order of magnitude (i.e. at least a factor of 3, or at least a factor of 7) when the stylus, previously in contact with the writing surface of board 140, is made to ‘hover’ over the surface of the writing board 140.
Thus,
In the event that the pen is “above” writing surface 140 and is “hovering,” pen strokes may be handled differently from the case where the pen 100 is in contact with writing surface 140. In one non-limiting case, when the pen is in contact or “down” pen strokes are handled as “writing” and recorded as such. When the pen is “up” or “hovering,” pen strokes are operative to “move the cursor” of digital pen 100 without recording digital writing.
This is shown in
For the purposes of “synchronization” of ultrasound signals, in the specific example of
As illustrated in
An exemplary ultra-sound transmitter 210 that is embedded within an external housing 220 of the stylus 100 is illustrated in
Furthermore, although the present inventors are disclosing the ultrasound transmitter 210 in the context of the system of
In the example of
Thus, in exemplary embodiments, a majority of power associated with the ultra-sound waves that leave the uni-directional ultra-sound transmitter/transmitter/actuator 210 and/or the pen tip 120 is substantially in the direction (i.e. within 10 degrees of a given vector (the vector of transmission), for example, the vector defined by pen axis 130, and/or within 25 degrees of this transmission vector, and/or within 45 degrees of this transmission vector, and/or within 70 degrees of this transmission vector, and/or within 90 degrees of this transmission vector. Related examples of the ‘substantially uni-directional transmission feature” are discussed below with reference to
This anisotropic ultra-sound transmission profile may (i.e. ultra-sound broadcast or transmission in a substantially un-directional manner) may be provided in a number of ways. According to the example of
One example of such a “vibrating object” is piezzo film 230 such as coiled piezzo film—in this case, rolled to have a ‘cylindrical’ shape. As shown in
In
There is no limitation on this electrical power source (not shown). It may include a battery (such as a rechargeable battery) or may include a rechargeable “capacitor.” It is recognized that the latter may be rechargeable over a shorter time scale, and thus, in some embodiments, an electronic “ink well” is provided, which a user may engage to recharge the capacitor.
Although certainly not a limitation of the present invention, in exemplary non-limiting embodiments between about 10 to 20 turns of piezzo film 230 are provided. In exemplary non-limiting embodiments, the radius of the piezzo film is about 2-3 mm and the length of the piezzo film is between 2 and 5 mm.
As mentioned earlier, the ultra-sound transmitter or transducer 210 may be operative to provide ultra-sound with an anisotropic ultra-sound transmission profile (for example, a substantially ‘uni-directionally’ transmitted ultra-sound). This may be provided in a number of ways. According to the exemplary embodiment of
This ultra-sound reflector 222 may be held in place, for example, with a compressible object such as a spring 224 (a ‘centering’ spring).
Thus, the piezzo film-reflector assembly may be held in place (i.e. relative to the proximal end of the stylus 100) with the compressible object. Furthermore, on the distal end of the style (i.e. toward the tip 120) the piezzo film may be attached to a support element between the ultrasound transmitter 210 or actuator (i.e. including piezzo film 230) bearing flange 212 using an adhesive, such as a double-sided adhesive film 214.
In some embodiments, the generated pressure wave of the ultra-sound is transmitted through the bearing flange 212 (for example, having a thickness of about 0.6 mm, for example, made of plastic) into a resonator 208. This resonator (and in particular, the length of the resonator) may be dimensioned in accordance with the resonant frequency for a wavelength of ultra-sound being used to allow for transfer of a maximum (or near-maximum) energy from the actuator to the tip of the stylus or pen (and no to the ultrasound receiver 250). This may be useful for transmitting a narrow band of ultra-sound. According to one non-limiting example, a value of l3 is between 3 and 4 mm.
Another view of the actuator or ultra-sound transmitter 210 is provided in
In some embodiments one or more optical receivers are provided, for example, the optical receiver is located at or near the edge 180 (this may be easier to use or manufacture, especially for the case of a computer screen overlay where an optical receiver in the middle may obstruct the user's view of the computer screen) of the board 140, though this is not a requirement of the present invention
In some embodiments, an ultra-sound receiver 150 is provided, for example, fastened or attached to the writing board 140.
There is no limitation on where the ultra-sound receivers may be located relative to the writing board 140-the receivers 150 may, for example, be located near or at an edge 180 of the board 140, at or near the center of the board 140, or anywhere in between.
In exemplary embodiments, one or more ultra-sound receivers 150 may be located at or near an edge 180 of the board 140.
The piezzo film is fastened to the board by a fastener 310 (for example, a plastic fastener, or a fastener made from a material other than a conducting material such as an insulator) such that at least a portion of the piezzo film 320 is substantially below the plane and/or coplanar with the upper surface 141 of the writing board 140, though this is not a limitation. Within the rolled piezzo film 320, is an inner core 312 or cylinder (for example, for mechanical support and/or for improving the receiver's electrical performance). This core 312 may be made of any material, including but not limited to conducting materials (such as metals), semi-conductor materials, and insulators. In the case where a conducting material is selected, it may be recommended or necessary to provide an insulating layer 314 between the piezzo film 320 and the conducting core 312.
As illustrated in the
As shown in
As shown in
As shown in
At least an “upper portion” 393 of piezoelectric film 320 is “above” upper surface 135; at least a “lower portion” 395 of piezoelectric film 320 is “below” lower surface 137.
According to the specific example of
Although the illustrations refer to a PCB 330, it is noted that any ‘housing’ for electrical circuitry (chips in a single chip or multi-chip package) may be used.
Thus, referring to
The upper surface 364 of the terminal 380 of the piezzo film 320 in electrical contact with (for example, attached to) a conductor (for example, elongated conductor 372). This elongated conducting piece 372 is typically not in electrical contact with the lower surface 362 of the terminal 380.
This elongated conducting piece 372 may be in electrical contact with a second printed conducting region 368 of the PCB. Thus, it evident that 366 and 368 may serve, effectively, as a pair of terminals for the piezzo film 320 (and as part of an “interface” between the piezzo film 320 which generates an electrical signal and external electrical circuitry, for example, on PCB 330, which handles the generated electrical signal) and that an electrical potential between these two terminal (i.e. 366 and 368) on the PCB (i.e. generated by the piezzo film 320) is therefore determined in accordance with acoustic or ultra-sound signals detected by the piezzo film 320. The signal is subsequently handled (for example, processed and used in triangulation to determine the location of stylus 100.
As shown in
The distances illustrated in
As shown in
It is noted that on one side of the piezzo film, the shaded regions are not contiguous to define specific regions which are each at a different voltage (relative to the other side of the piezzo film) when detecting ultra-sound signals.
It is note that in some embodiments, the inner 412 and outer surfaces 414 of the piezzo film 320 are structure according to one or more teachings disclosed in international patent application publication WO 03/022156 of the present inventors (for example, see
It is noted that in some embodiments, one or more teachings disclosed in international patent application publication WO 03/022156 (incorporated herein by reference) (i.e. which discloses an ultrasound transceiver and cylindrical ultrasound transducer structure) may be applied to any presently-disclosed ultra-sound receiver assembly, and any system or method disclosed
In the description and claims of the present application, each of the verbs, “comprise” “include” and “have”, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements or parts of the subject or subjects of the verb.
All references cited herein are incorporated by reference in their entirety. Citation of a reference does not constitute an admission that the reference is prior art.
The articles “a” and “an” are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, “an element” means one element or more than one element.
The term “including” is used herein to mean, and is used interchangeably with, the phrase “including but not limited” to.
The term “or” is used herein to mean, and is used interchangeably with, the term “and/or,” unless context clearly indicates otherwise.
The term “such as” is used herein to mean, and is used interchangeably, with the phrase “such as but not limited to”.
The present invention has been described using detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. The described embodiments comprise different features, not all of which are required in all embodiments of the invention. Some embodiments of the present invention utilize only some of the features or possible combinations of the features. Variations of embodiments of the present invention that are described and embodiments of the present invention comprising different combinations of features noted in the described embodiments will occur to persons of the art.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IL07/01205 | 10/7/2007 | WO | 00 | 4/5/2009 |
| Number | Date | Country | |
|---|---|---|---|
| 60828240 | Oct 2006 | US |
