Abstract:
The present application is directed to a pointing device and a method for interacting with touch-sensitive devices. The pointing device includes a base; a housing configured to cover a portion of the base; a cavity formed between the housing and the portion of the base; a sliding member; a supporting member; a biasing member situated between the sliding member and the supporting member; a first contact point provided on the sliding member and configured to contact a screen of the touch-sensitive device when the pointing device is placed on the screen; and a second contact point provided on the supporting member and configured to contact the screen when the pointing device is placed on the screen; wherein the first contact point slides on the screen relative to the second contact point via the engagement of the housing and the sliding member when the housing moves towards the screen.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This present application claims the benefit of Hong Kong Short-term Patent Application No. 13106809.3 filed on Jun. 7, 2013; the contents of which are hereby incorporated by reference. 
     FIELD OF INVENTION 
     The present application refers to a pointing device to be used on touch screens, more particularly, to a pointing device and a method for interacting with touch-sensitive devices. 
     BACKGROUND OF INVENTION 
     Touch-sensitive devices are gaining tremendous popularity in today&#39;s consumer electronics market. Such devices are playing important roles in people&#39;s daily lives. In the past, pointing devices such as mice and trackballs are commonly used for navigating on the user interface of computers. The buttons of these traditional pointing devices only acknowledge on/off input from the user and are incorporated with complex mechanical/electronic constructions which incurred substantial costs in manufacturing. Moreover, these pointing devices require the user to learn and to get used with the controls through some period of practice. All in all, these pointing devices fail to provide an intuitive way for the user to interact with electronic devices. The present application provides a pointing device to be used on most touch-sensitive devices such as the Apple iPad® which mitigates the inconsistencies and inaccuracies caused by using bare fingers on touch-sensitive devices and allows the control of a range of values by varying the pressure by the user. Further, the present application provides an intuitive way for the user to interact with the touch-sensitive devices. 
     SUMMARY OF INVENTION 
     The present patent application is directed to a pointing device for interacting with a touch-sensitive device, includes a base; a housing configured to cover a portion of the base; a cavity formed between the housing and the portion of the base; a sliding member provided inside the cavity, wherein a first side of the sliding member is engaged with the housing and a second side of the sliding member is supported on the base; a supporting member provided inside the cavity and supported on the base; a biasing member situated between the sliding member and the supporting member; a first contact point provided on the sliding member and configured to contact a screen of the touch-sensitive device when the pointing device is placed on the screen; and a second contact point provided on the supporting member and configured to contact the screen when the pointing device is placed on the screen; wherein the first contact point slides on the screen relative to the second contact point via the engagement of the housing and the sliding member when the housing moves towards the screen. 
     The pointing device for interacting with the touch-sensitive may further include an actuating member provided in the cavity and engaged with the housing; wherein the first side of the sliding member is engaged with the housing via the actuating member. 
     The actuating member may have a slanted surface; and the first side of the sliding member may be a corresponding slanted surface to the slanted surface of the actuating member. 
     The supporting member may be fixedly mounted on the base. 
     The biasing member may be a helical spring; and when a pressure which causes the housing to move towards the screen is released, the housing may return to a default position in which the pressure is not applied on the housing via an elastic force of the spring. 
     When the pressure is released, the first contact point may slide on the screen away from the second contact point. 
     The first contact point may slide on the screen towards the second contact point when the housing moves towards the screen. 
     The base may be non-conductive. 
     The first contact point may include at least two points. 
     An opening may be formed on a bottom of the housing; and the base may be coupled with the opening of the housing when the portion of the base is inserted into the housing. 
     The base may include a plurality of apertures; and the first contact point and the second contact point may be inserted into and through the apertures in order to contact the screen of the touch-sensitive device during use. 
     The base may include a protruded peripheral edge; and the first contact point and the second contact point may protrude downwardly and be at the same height with a bottom of the protruded peripheral edge in order to contact the screen during use. 
     A change in displacement of the first contact point relative to the second contact point may depend on a pressure applying on the housing and may be record by the touch-sensitive device. 
     The change in displacement of the first contact point relative to the second contact point may include a variety of patterns of movements which are detected and recognized by the touch-sensitive device. 
     Data values of a list of the patterns may be stored in a data file which is accessible by executable applications on the touch-sensitive device. 
     A device identification may be determined by the touch-sensitive device by comparing and matching a total displacement value of the first contact point and the second contact point before the housing is fully depressed and a displacement value of the first contact point and the second contact point after the housing is fully depressed with a maximum displacement value and a minimum displacement value of each of the patterns stored in the data file. 
     Once the device identification is determined by the touch-sensitive device, the touch-sensitive device may trigger a predetermined command. 
     The touch-sensitive device may be an iPad, an iPhone, or any Android equipped touch-sensitive devices. 
     There is also provided in the present application a method for interacting with the touch-sensitive device using the pointing device of claim  1  includes the steps of:
         a) detecting and recording positions of the first contact point and the second point of the pointing device on the screen of the touch-sensitive device in its default state;   b) detecting and recording positions of the first contact point and the second point of the pointing device on the screen of the touch-sensitive device in its fully depressed state;   c) determining a change in displacement of the first contact point;   d) determining a distance between the first contact point and the second point in its default state;   e) determining a distance between the first contact point and the second point in its fully depressed state;   f) comparing values of the distances of the step d) and the step e) with preset values stored in a data file; and   g) triggering a command if the values of the step d) and the step e) match with the preset values.       

     A device identification may be determined by the touch-sensitive device by comparing and matching a total displacement value of the first contact point and the second point before the housing is fully depressed and a displacement value of the first contact point and the second point after the housing is fully depressed with a maximum displacement value and a minimum displacement value of each unique pattern stored in the data file. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1 a    shows an exploded sectional view of the pointing device of an embodiment of the present application; 
         FIG. 1 b    shows a bottom view of the pointing device of an embodiment of the present application in its default state; 
         FIG. 1 c    shows a bottom view of the pointing device of an embodiment of the present application with the housing is fully depressed; 
         FIG. 1 d    shows a side view of the pointing device of an embodiment of the present application in its default state; 
         FIG. 1 e    shows a side view of the pointing device of an embodiment of the present application with the housing is fully depressed; 
         FIG. 2 a -2 f    show examples of embodiment of the present application with different patterns of movement of contact points; 
         FIG. 3  shows an example of three pointing devices of different patterns being used on a touch-sensitive device; 
         FIG. 4 a    shows the touch points detected on the screen by the touch-sensitive device where the pointing device is in its default state; 
         FIG. 4 b    shows the touch points detected on the screen by the touch-sensitive device where the pointing device&#39;s housing is fully depressed; 
         FIG. 5  shows the change of pointing direction of the device; 
         FIGS. 6 a  and 6 b    show an elevation view and a cutaway view of the pointing device and the default positions of the contact points before the housing is pressed down; 
         FIGS. 7 a  and 7 b    show an elevation view and a cutaway view of the pointing device and the positions of the contact points when the housing is pressed down by a user. 
     
    
    
     DETAILED DESCRIPTION 
     The present application refers to a pointing device for interacting with touch-sensitive devices and a method for interacting with touch-sensitive devices. 
     The pointing device may be used for navigating on a touch-sensitive device, or as a component of an entertaining system used with touch-sensitive devices. The pointing device provides up to four types of inputs to the touch-sensitive device, namely, (1) positioning of the device with reference to the screen coordinates; (2) pointing direction of the device; (3) a command actuated by depressing the housing; (4) a continuous range of values when the button is being gradually depressed. 
     Identification of the pointing device is based on the patterns and the displacements of touch points before-and-after the housing is fully pressed by the user. The structure and components of the pointing device will be discussed in the following. 
     An exploded view of the device  100  is shown in  FIG. 1 a   . A housing  101  houses all the components and covers a portion of a base  105 . The base  105  may be non-conductive. An opening is formed on the bottom of the housing  101  to receive the base  105 . The base  105  is formed in a way so that it is coupled with the opening of housing  101  while a portion of the base  105  is inserted into the housing  101 . 
     As shown in  FIGS. 1 b  and 1 c   , a plurality of apertures is provided on the base  105  in accordance with the designated pattern associated with a particular pointing device. A sliding member  102  and a supporting member  104  are provided with contact points  106  and  107  respectively. The contact points  106  and  107  are inserted into and through the apertures provided on the base  105  such that the contact points can be in contact with the surface of the screen of a touch-sensitive device during use. It is appreciated that first contact point  106  is provided on the sliding member  102  and second contact point  107  is provided on the supporting member  104 . Moreover, a protruded peripheral edge  108  is provided on the base  105 . The contact points  106  and  107  protrude downwardly and are substantially flush (i.e. at the same height) with the bottom of the protruded peripheral edge  108  in order to be in contact with the screen during use. 
     In  FIG. 1 a   , an actuating member  109  is provided in the housing  101  and has a slanted surface  1091  for engaging with the sliding member  102 . The sliding member  102  is provided with a corresponding slanted surface  1021 . A biasing member  103  in form of a helical spring, as a non-limiting example, is situated between the sliding member  102  and the supporting member  104 .  FIG. 1 a    shows an unassembled view of the pointing device  100  indicating the arrangement of the above mentioned components. As a downward pressure is applied on the housing  101  by the user, actuating member  109  pushes downward and the slanted surface  1091  forces the sliding member  102  to move in the direction as shown in  FIGS. 1 b -1 c   . The supporting member  104  is fixedly mounted on the base  105  and causes the biasing member  103  in between to be compressed. Once the user releases the pressure on the housing  101 , the biasing member  103  decompresses and pushes the sliding member  102  back to its default position. Further, the slanted surface  1021  of the sliding member  102  forces the housing  101  to rise to its default position. As the sliding member  102  moves, the first contact point  106  displaces relative to the second contact point  107  which is formed with the supporting member  104 .  FIG. 1 d    and  FIG. 1 e    illustrate the device  100  when pressure is applied. 
     When the pointing device  100  is placed on a screen of a touch-sensitive device and pressure is applied on the housing  101 , i.e., the housing is being fully pressed downward, the contact points  106 ,  107  are pressed against and in contact with the surface of the screen and causes first contact point  106  to slide relative to second contact point  107 . The sliding movement of first contact point  106  relative to second contact point  107  forms a pattern which is detected and recognized by the touch-sensitive device. Once the movement pattern is detected by the touch-sensitive device, subsequent actions may be executed to indicate the system acknowledged the input, for a non-limiting example, an image corresponds to that particular device  100  may be displayed on the screen  21  as shown in  FIG. 3 . It is appreciated that data values of a list of patterns are stored in the data file which is accessible by executable applications on the touch-sensitive device  20 . 
       FIGS. 2 a -2 f    show a variety of patterns of movements of the first contact point  106  relative to second contact point  107 . These unique patterns are individually recognized by the touch-sensitive device according to the data values in a predetermined list of patterns as mentioned. Details of how the patterns are interpreted by the touch-sensitive device will be discussed in the following. 
     Reference is made to  FIG. 4 a   . For a non-limiting example, the two contact points  106  and  107  of the pointing device  100  are in contact with the screen  21 , positions in terms of X and Y coordinates of the two touch points  200   a  and  200   b  on the screen  21  are detected and registered by the touch-sensitive device  20 . 
     When housing  101  is depressed, the movable first contact point  106  slides to a direction relative to second contact point  107 . In the example, first contact point  106  moves closer to second contact point  107  in a horizontal direction as shown in  FIG. 4 b   . It is appreciated that the touch points  200   a  and  200   b  correspond to the movements of contact points  106  and  107 .  FIGS. 6 a  and 6 b    show a elevation view and a cutaway view of the device and the default positions of the contact points  106  and  107  before the housing  101  is pressed down, while  FIGS. 7 a  and 7 b    show an elevation view and a cutaway view of the device and the positions of the contact points  106  and  107  when the housing  101  is pressed down by a user. An image example  32  is displayed on the screen  21  indicating the pointing device  100  is identified by the touch-sensitive device based on the list of patterns stored in the data file. 
     Referring to  FIG. 5 , assume the movable contact point is being recognized and the corresponding finger IDs are matched and recorded. Regardless of the state of the pointing device, the pointing direction of the device is determined by vector s generated by the current positions of the two contact points with reference to vector r generated by the last recorded positions of the two contact points. The degree of rotation of the pointing device depends on angle θ in-between vector r and vector s. For example, if there is an image attached with the position of the device, the orientation changes depending on angle θ in-between vector r and vector s, indicating the change of pointing direction of the device. 
     The two individual touch points  200   a  and  200   b  are differentiated by the absolute delta change in displacement of each touch point with reference to its previous position recorded, i.e., before any change of displacement takes place. 
     Let x1, y1 and x2, y2 be the x and y coordinates of touch points  200   a  and  200   b  of their previous positions respectively (the housing is not pressed down), and 
     Let x1′, y1′ and x2′, y2′ be the x and y coordinates of touch points  200   a  and  200   b  of their current positions respectively (the housing is fully pressed down). 
     Accordingly, the absolute change in displacement of touch point  200   a , ΔD1, may be determined by:
 
Δ D   1 =√{square root over (|( x   1   ′−x   1 ) 2 +( y   1   ′−y   1 ) 2 |)}
 
     While the absolute change in displacement of touch point  200   b , ΔD2, may be determined by:
 
Δ D   2 =√{square root over (|( x   2   ′−x   2 ) 2 +( y   2   ′−y   2 ) 2 |)}
 
     As second contact point  107  (touch point  200   b ) in the above example is a fixed contact point, ΔD2 is theoretically 0. 
     The value of ΔD1 reflects the pressure act on the housing  101  on the screen  21 . The more pressure is act on the housing, the farther the sliding member  102  travels and higher the value of ΔD1 is resulted. The change of the pressure level acting on the housing  101  is transformed to numerical values for controlling a range of values on the touch-sensitive device. For examples, the change of the pressure level may be used for controlling sliders or scrolling pages. 
     In order for the touch-sensitive device to identify and distinguish a specific pointing device, the direct distance between the touch points is determined. L signifies the initial direct distance between the two touch points, i.e.,  200   a  and  200   b , and L′ represents the direct distance between  200   a  and  200   b  after the housing  101  is fully depressed. 
     The values L and L′ are then stored in the memory of the touch-sensitive device and routines are executed to compare these values with the preset values of L max  and L min  in the list of patterns in a data file. L max  is the variable of the maximum allowed distance between the two touch points, and L min  is the variable of the minimum allowed distance between the two touch points. The values of L max  and L min  of each pattern are unique and are accessible by executable applications. Upon comparison of these values and a match is found, a specific command may be executed. For a non-limiting example, a corresponding image of the particular device will be displayed to acknowledge the identification of the device as shown in  FIG. 3 . 
     Both L and L′ allow maximum absolute error S by default 0.1 cm but not limited to this value. 
     To be validated, both L and L′ must also satisfy the following equation:
 
| L   measured   −L   data   |≦S  
 
     L measured  represents either L or L′. L data  represents either L max  or L min . 
     The abovementioned pointing device and method of the present application utilize at least one movable touch point rather than two fixed touch points so that a L max  and L min  between the two touch points may be determined to serve the purpose of increasing the matching requirement of the recorded values with the preset values in the data file. Assuming only two fixed touch points are used, the recognition of patterns would merely base on the distance L between the two touch points. As a result, a user may easily imitate the touch point pattern by placing fingers on the screen. This is of particular significance when the pointing device is to be used in games and applications where the strict use of the device is essential. 
     The pointing device and method of the present application allow the determination of the position and orientation of the device on a touch-sensitive device with least number of touch points required. The same also allow interactive inputs by the user such as clicking, double clicking, sliding and scrolling, dragging and dropping of objects displayed on the screen of the touch-sensitive device. Furthermore, it is another advantage of the present application that multi-touch gestures can be simulated for interacting with designated applications on the touch-sensitive devices. 
     It may be appreciated that various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the above described features.