Patent Publication Number: US-2015084921-A1

Title: Floating touch method and touch device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a nonprovisional application claiming benefit from a prior-filed provisional application bearing a Ser. No. 61/881,049 and filed Sep. 23, 2013, the entity of which is incorporated herein for reference. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates to a touch sensing method for a touch device, and particularly to a floating touch method and a touch device operated with the floating touch method. 
     BACKGROUND OF THE INVENTION 
     With rapid development of touch sensing technology, many electronic apparatuses such as mobile phones, notebook computers or tablet computers take advantage of touch devices to provide intuitive operation and easy human-machine interface. These electronic apparatuses hugely enter modern lives and great business opportunities are created. There are two known touch sensing technologies, i.e. capacitive sensing and resistive sensing. 
     For capacitive sensing, when the touch device is touched with a human finger or a conductive object, a capacitor is temporarily formed on the electrode corresponding to the touched position. Therefore, equivalent capacitance of the corresponding electrode changes. A sensor circuit can determine the touched position on the touch device according to the equivalent capacitance change of the corresponding electrode. 
     For resistive sensing, when an object such a human finger or a stylus presses down onto a surface of the touch device, the upper electrode and the lower electrode are electrically connected at the pressed position so that the electrodes behave as a voltage divider circuit. Therefore, the sensor circuit can determine the pressed position on the touch device according to the voltage change of the upper electrode and the lower electrode. 
     Since large-area flat-panel display gains popularity now and touch sensing technology is widely used as the most friendly human-machine interface, there is an increased demand for large-area touch screen these days. For a large-area flat-panel display, optimum viewing distance increases. It does not make sense to control the display by actually touch a surface of the display with a finger or a conductive object instead of remote control. Therefore, a novel touch sensing method and touch device are desired. 
     SUMMARY OF THE INVENTION 
     An aspect of the present disclosure provides a floating touch method used with a capacitive touch panel. At first, the capacitive touch panel is controlled to sense a control object within different sensing ranges at different time points to determine a distance value between the control object and the capacitive touch panel. Then, the capacitive touch panel is controlled to detect a floating touch action of the control object based on the distance value. Subsequently, a control signal corresponding to the floating touch action is issued. 
     In an embodiment, the capacitive touch panel includes many separate electrode units. To sense the control object, the electrode units are divided into first electrode unit groups which are detected individually to determine whether the control object is located within a first sensing range corresponding to the first electrode unit groups. Then, the electrode units are divided into second electrode unit groups which are detected individually to determine whether the control object is located within a second sensing range corresponding to the second electrode unit groups. The distance value is a distance threshold corresponding to a smaller sensing range of the first sensing range and the second sensing range if the control object is determined to be located within both the first sensing range and the second sensing range. 
     In an embodiment, each of the first electrode unit groups has a first number of the electrode units while each of the second electrode unit groups has a second number of the electrode units. The second number is greater than the first number, and the second sensing range is greater than the first sensing range. 
     In an embodiment, when the control object is determined to be located within the first sensing range, the distance value is the distance threshold corresponding to the first sensing range. 
     In an embodiment, an operation menu and a cursor are shown in response to a floating touch action of the control object. The floating touch action of the control object may be a hover action and the distance value determined during the hover action is recorded as a distance reference. 
     In an embodiment, the control signal is issued to make an icon of the operation menu deform when the cursor is controlled to stay on the icon and the control object moves toward the capacitive touch panel. If the determined distance value of the control object is smaller than a specific value or a specific proportion of the distance reference, a function corresponding to the icon is performed. 
     Another aspect of the present disclosure provides a touch device operated with a floating touch method. The touch device includes a capacitive touch panel and a sensor circuit electrically connected to the capacitive touch panel. The sensor circuit controls the capacitive touch panel to sense a control object within different sensing ranges at different time points to determine a distance value between the control object and the capacitive touch panel, controls the capacitive touch panel to detect a floating touch action of the control object based on the distance value, and issues a control signal corresponding to the floating touch action. 
     In an embodiment, the capacitive touch panel includes many separate electrode units and corresponding connecting traces. The capacitive touch panel further includes fractal electrode units disposed around edges of the separate electrode units. 
     In an embodiment, the sensor circuit divides the electrode units into first electrode unit groups which are detected individually to determine whether the control object is located within a first sensing range corresponding to the first electrode unit groups, divides the electrode units into a plurality of second electrode unit groups which are detected individually to determine whether the control object is located within a second sensing range corresponding to the second electrode unit groups, and determines the distance value to be a distance threshold corresponding to a smaller sensing range of the first sensing range and the second sensing range if the control object is determined to be located within both the first sensing range and the second sensing range. 
     In an embodiment, the sensor circuit shows an operation menu and a cursor on a display device. 
     In an embodiment, the floating touch action of the control object is a hover action and the distance value determined during the hover action is recorded as a distance reference. 
     In an embodiment, the sensor circuit issues the control signal to make an icon of the operation menu deform when the cursor is controlled to stay on the icon and the control object moves toward the capacitive touch panel, and the sensor circuit enables the touch device to perform a function corresponding to the icon if the determined distance value of the control object is smaller than a specific value or a specific proportion of the distance reference. 
     Another aspect of the present disclosure provides a floating touch device. The floating touch device includes a capacitive touch panel and a sensor circuit electrically connected to the capacitive touch panel. The sensor circuit controls the capacitive touch panel to sense a control object within different sensing ranges at different time points to detect a press action, and issue a control signal corresponding to the press action. 
     In an embodiment, the sensor circuit issues the control signal when the control object moves toward the capacitive touch panel and a distance value between the control object and the capacitive touch panel is smaller than a specific value or a specific proportion of a distance reference. 
     In an embodiment, the floating touch device includes an elastic cover disposed on the capacitive touch panel. A distance value between a touch area of the elastic cover and the capacitive touch panel before the press action is recorded as the distance reference. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages of the present disclosure will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: 
         FIG. 1  is a schematic diagram illustrating a touch device according to an embodiment of the present invention; 
         FIGS. 2A-2C  are schematic diagrams illustrating relations between sensing ranges and grouping electrode units; 
         FIG. 3  is a flowchart illustrating a floating touch method according to an embodiment of the present invention; 
         FIG. 4  is a flowchart illustrating a floating touch method according to another embodiment of the present invention; 
         FIG. 5A  is a schematic diagram illustrating a floating touch action; 
         FIG. 5B  is a schematic diagram illustrating an icon change in response to a press action; 
         FIG. 5C  is a schematic diagram illustrating another floating touch action; and 
         FIG. 6  is a flowchart illustrating a floating touch method according to a further embodiment of the present invention; and 
         FIG. 7  is a schematic diagram illustrating a portion of a keyboard device operated with the float touching method according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present disclosure will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed. 
     Please refer to  FIG. 1 , a schematic diagram illustrating a touch device according to an embodiment of the present invention. The touch device  1  includes a capacitive touch panel  11  and a sensor circuit  13 . The capacitive touch panel  11  includes separate electrode units  111  and connecting traces  112 . Each of the connecting traces  112  is electrically connected to a corresponding electrode unit  111  in one-to-one manner. In this embodiment, the electrode units  11  are (regular) hexagonal electrode units  11  but are not limited to this shape. The connecting traces  112  are electrically connected to respective electrode units  111 , and the sensor circuit  13  is electrically connected to the connecting traces  112  so as to control the capacitive touch panel  11 . The sensor circuit  13  controls the capacitive touch panel  11  to determine a distance value between a control object (e.g. a human finger, palm or conductive member) and the capacitive touch panel  11 . The sensor circuit  13  controls the capacitive touch panel  11  to detect a floating touch action of the control object based on the distance value, and issues a control signal to enable the touch device  1  or the capacitive touch panel  11  to perform a specific function in response to the floating touch action of the control object. 
     Please refer to  FIGS. 2A-2C , schematic diagrams illustrating relations between sensing ranges and grouping electrode units. As shown in  FIG. 2A , when the sensor circuit  13  simultaneously measures capacitances (or capacitance changes) of two electrode units  1111  and  1112 , namely an electrode unit group, the control object  2  such as a finger located within the sensing range r 1  can be sensed according to floating touch technology. For many electrode unit groups each of which includes two electrode units  111 , a combined sensing range with a “thickness” h 1  forms in front of the capacitive touch panel  11 . In other words, if the control object  2  is located at a distance no more than a distance threshold h 1 , the control object  2  can be sensed by the capacitive touch panel  11  when every two electrode units  111  are grouped to perform the sensing function. As shown in  FIG. 2B , when the capacitances (or capacitance changes) of the electrode unit group including four electrode units  1111 ,  1112 ,  1113  and  1114  are measured, the control object  2  located within the sensing range r 2  which is greater than the sensing range r 1  can be sensed. Under this condition, a combined sensing range with a distance threshold h 2  is obtained. As shown in  FIG. 2C , when the sensor circuits  13  simultaneously detects seven electrode units  1111 ,  1112 ,  1113 ,  1114 ,  1115 ,  1116  and  1117  which means that an electrode unit group includes seven electrode units, a further greater sensing range r 3  is achieved. Under this condition, the distance threshold is h 3 . 
     Referring to  FIGS. 2A-2C , the sensing range for floating touch can be adjusted by changing the number of the electrode units  111  in one electrode unit group, i.e. the number of the electrode units  111  simultaneously detected by the sensor circuit  13 . In other words, the greater distance between the control object  2  and the capacitive touch panel  11  is, the larger virtual projected region covering the electrode units  111  is. The electrode units  111  included in the projected region are required for sensing the control object  2  at the specific distance. Thus, more electrode units  111  included in a greater projected region corresponds to a greater sensing range. Therefore, an effective area of the electrode units  111  included in the projected region results in an increased sensible distance between the control object  2  and the capacitive touch panel  11 , and the effective area may be viewed as a parameter of sensing strength. It is possible to fine-tune or balance the effective area of the electrode units  111  included in an electrode unit group (projected region). As shown in  FIG. 2C , the electrode units  1111 ,  1112 ,  1113 ,  1114 ,  1115 ,  1116  are full electrode units  111   a , and the electrode unit  1117  is a fractal electrode unit  111   b  with a smaller electrode area. The fractal electrode units  111   b  may be arranged at specific regions of the capacitive touch panel  11 , for example, around edges of the full electrode units  111   a  to adjust, balance or fine-tune the effective areas of the electrode unit groups. The quantities and the positions of the fractal electrode units  111   b  and the full electrode units  111   a  are not limited to this example and may be modified in different embodiments to meet various requirements. 
     Please refer to  FIG. 3 , a flowchart illustrating a floating touch method according to an embodiment of the present invention. The floating touch method is used with a touch device  1  including a capacitive touch panel  11  and a sensor circuit  13 . At first, the sensor circuit  13  controls the capacitive touch panel  11  to sense a control object  2  within different sensing ranges at different time points to determine a distance value between the control object  2  and the capacitive touch panel  11  (step S 31 ). Then, the sensor circuit  13  controls the capacitive touch panel  11  to detect a floating touch action of the control object  2  based on the distance value, and issues a control signal to enable the touch device  1  or the capacitive touch panel  11  to perform a specific function in response to the floating touch action of the control object  2  (step S 32 ). The distance value between the control object  2  and the capacitive touch panel  11  may be determined through different ways which are described in detail later. 
     Please refer to  FIG. 4 , a flowchart illustrating a floating touch method according to another embodiment of the present invention. At first, the sensor circuit  13  divides the electrode units  111  into first electrode unit groups and detects the first electrode unit groups individually, and determines whether the control object  2  is located within a first sensing range corresponding to the first electrode unit groups (step S 41 ). Each of the first electrode unit groups includes a first number of the electrode units  111 . The sensor circuit  13  detects the electrode units  111  (i.e. measuring capacitances or capacitance changes of the electrode units  111 ) of the same first electrode unit group simultaneously in response to a first driving signal from the sensor circuit  13 . Thus, the sensor circuit  13  can determine whether the control object  2  is located within the first sensing range according to the capacitance changes. 
     Then, the sensor circuit  13  divides the electrode units  111  into second electrode unit groups and detects the second electrode unit groups individually, and determines whether the control object  2  is located within a second sensing range corresponding to the second electrode unit groups (step S 42 ). Each of the second electrode unit groups includes a second number of the electrode units  111 , while the second number is greater than the first number. For example, one of the first electrode unit groups includes two electrode units  1111  and  1112  ( FIG. 2A ) and one of the second electrode unit groups includes four electrode units  1111 ,  1112 ,  1113  and  1114  ( FIG. 2B ). The second sensing range r 2  is greater than the first sensing range r 1 . In a similar manner, the sensor circuit  13  detects the electrode units  111  (i.e. measuring capacitances or capacitance changes of the electrode units  111 ) of the same second electrode unit group simultaneously in response to a second driving signal from the sensor circuit  13 . Thus, the sensor circuit  13  can determine whether the control object  2  is located within the second sensing range according to the capacitance changes. In this embodiment, the sensor circuit  13  controls the capacitive touch panel  11  to scan from a smaller sensing range to a larger sensing range, i.e. in a direction away from the touch device  1  like an outward scanning. 
     According to the determination in steps S 41  and S 42 , the distance value between the control object  2  and the capacitive touch panel  11  is determined according to the following steps. If the control object  2  is determined to be located within both the first sensing range and the second sensing range, the distance value is a first distance threshold corresponding to the first sensing range (step S 43 ). If the control object  2  is determined to be located within the second sensing range but not located within the first sensing range, the distance value is a second distance threshold corresponding to the second sensing range (step S 44 ). If the control object  2  is determined to be not located within any of the first sensing range and the second sensing range (step S 45 ), there is no sensible control object, and the method returns to step S 41  to start another dividing and determining step. 
     Please be noted that the number of the sensing ranges may be adjusted according to the total quantity of the electrode units  111 , dimension of the capacitive touch panel  11  or other factors. Therefore, the electrode units  111  are grouped in different sizes at different time points. On condition that the control object  2  is determined to be located within multiple sensing ranges, the distance value is the distance threshold corresponding to the smallest sensing range among the multiple sensing ranges. 
     The steps for determining the distance value are not limited to the examples as described above. For example, once the control object  2  is found to be located in a specific sensing range, it is not necessary for the sensor circuit  13  to control the capacitive touch panel  11  to scan farther. Therefore, the step for determining the distance value may be modified as follows. At first, the sensor circuit  13  divides the electrode units  111  into electrode unit groups and detects the electrode unit groups individually, and determines whether the control object  2  is located within a sensing range corresponding to the electrode unit groups. If the control object  2  is determined to be located within the sensing range, the distance value of the control object  2  is a distance threshold corresponding to the sensing range. If the control object  2  is determined to be not located within the sensing range, the sensor circuit  13  repeats the previous steps wherein the next electrode unit groups include more electrode units than the previous electrode unit groups. In this embodiment, the sensor circuit  13  does not control the capacitive touch panel  11  to complete a full scanning in a direction away from the touch device  1  every time to determine the distance value. 
     Alternatively, the sensor circuit  13  may control the capacitive touch panel to complete a full scanning in a direction away from the touch device  1  every time to determine the distance value. This approach can avoid unpredictable disturbance during the scanning. 
     As described above, the sensor circuit  13  controls the capacitive touch panel  11  to sense the control object  2  within different sensing ranges at different time points. The whole procedure may be considered as a three dimensional scanning action (i.e. x-axis and y-axis representing orthogonal directions along the surface of the capacitive touch panel  11  and z-axis representing a direction perpendicular to the surface). In addition to the position of the control object  2 , the sensor circuit  13  can obtain more information such as motion or contours of the control object  2  in front of the touch device  1 . 
     After the sensor circuit  13  determines the distance value between the control object  2  and the capacitive touch panel  11 , the sensor circuit  13  controls the capacitive touch panel  11  to detect whether the control object  2  performs a floating touch action based on the determined distance value (step S 46 ). For example, the floating touch action is a hover action, i.e. moving along a direction substantially parallel to the xy plane of the capacitive touch panel  11 . As shown in  FIG. 5A , the control object  2  moves from a position A to a position B at a distance h 4  from the capacitive touch panel  11 , and the hover action can be detected by the sensor circuit  13  through sensing different electrode unit groups corresponding to the positions A and B. 
     If no floating touch action is detected in step S 46 , the method returns to step S 41 . Otherwise, if the sensor circuit  13  detects a floating touch action based on the distance value, the distance value h 4  is recorded as a distance reference. In addition, the sensor circuit  13  enables a display device (not shown) to show an operation menu and a cursor (step S 47 ). The cursor moves or changes in response to subsequent movement of the control object  2 . 
     Sometimes, the distance values determined during the hover action are not a constant value and slightly vary. Under this condition, the distance reference may be an average value of the determined distance values. 
     When the control object  2  stops moving and makes the cursor stay on an option or an icon  50  ( FIG. 5B ) of the operation menu, the control object  2  may be controlled to move toward the capacitive touch panel  11  to simulate a press action. Under this condition, the determined distance value between the control object  2  and the capacitive touch panel  11  becomes smaller and smaller ( FIG. 5C ). The press action can be detected by the sensor circuit  13  because smaller and smaller distance values are obtained during the press action. When the sensor circuit  13  finds the phenomenon during continuous scanning along the z-axis with respect to the capacitive touch panel  11 , it is determined that a press action occurs. In response to the press action, the sensor circuit  13  issues a control signal to make the icon  50  deform. For example, the icon  51  curves inward continuously as shown in  FIG. 5B , but it is not limited to such effect. During the press action, after the determined distance value is smaller than a specific value or a specific proportion (e.g. 50%) of the distance reference h 4 , animation effects to the icon  51 , e.g. rupture may be provided. Then, the touch device  1  performs a specific function represented by the icon  50  (step S 48 ). 
     Please refer to  FIG. 6 , a flowchart illustrating a floating touch method according to a further embodiment of the present invention. Compared to the floating touch method with reference to  FIG. 4 , the floating touch method in this embodiment performs an inward scanning. At first, the sensor circuit  13  divides the electrode units  111  into first electrode unit groups and detects the first electrode unit groups individually, and determines whether the control object  2  is located within a first sensing range corresponding to the first electrode unit groups (step S 61 ). Each of the first electrode unit groups includes a first number of the electrode units  111 . The sensor circuit  13  detects the electrode units  111  (i.e. measuring capacitances or capacitance changes of the electrode units  111 ) of the same first electrode unit group simultaneously in response to a first driving signal from the sensor circuit  13 . Thus, the sensor circuit  13  can determine whether the control object  2  is located within the first sensing range according to the capacitance changes. 
     Then, the sensor circuit  13  divides the electrode units  111  into second electrode unit groups and detects the second electrode unit groups individually, and determines whether the control object  2  is located within a second sensing range corresponding to the second electrode unit groups (step S 62 ). Each of the second electrode unit groups includes a second number of the electrode units  111 , while the first number is greater than the second number. For example, one of the first electrode unit groups includes four electrode units  1111 ,  1112 ,  1113  and  1114  ( FIG. 2B ) and one of the second electrode unit groups includes two electrode units  1111  and  1112  ( FIG. 2A ). The first sensing range r 1  is greater than the second sensing range r 2 . In a similar manner, the sensor circuit  13  detects the electrode units  111  (i.e. measuring capacitances or capacitance changes of the electrode units  111 ) of the same second electrode unit group simultaneously in response to a second driving signal from the sensor circuit  13 . Thus, the sensor circuit  13  can determine whether the control object  2  is located within the second sensing range according to the capacitance changes. In this embodiment, the sensor circuit  13  controls the capacitive touch panel  11  to scan from a larger sensing range to a smaller sensing range, i.e. in a direction toward the touch device  1  like an inward scanning. 
     According to the determination in steps S 61  and S 62 , the distance value between the control object  2  and the capacitive touch panel  11  is determined according to the following steps. If the control object  2  is determined to be located within both the first sensing range and the second sensing range, the distance value is a second distance threshold corresponding to the second sensing range (step S 63 ). If the control object  2  is determined to be located within the first sensing range but not located within the second sensing range, the distance value is a first distance threshold corresponding to the first sensing range (step S 64 ). Furthermore, the sensor circuit  13  may control the capacitive touch panel  11  to finish a full inward scanning to accurately determine the distance value. 
     Please be noted that the number of the sensing ranges may be adjusted according to the total quantity of the electrode units  111 , dimension of the capacitive touch panel  11  or other factors. Therefore, the electrode units  111  are grouped in different sizes at different time points. On condition that the control object  2  is determined to be located within multiple sensing ranges, the distance value is the distance threshold corresponding to the smallest sensing range among the multiple sensing ranges. 
     After the sensor circuit  13  determines the distance value between the control object  2  and the capacitive touch panel  11 , steps S 46 -S 48  are performed as described in the previous embodiment with reference to  FIG. 4 , and the redundant detail is not repeated here. 
     In conclusion, the floating touch method and the touch device operated with this method allow the capacitive touch panel  11  to sense a control object  2  within different sensing ranges at different time points. The major step is to divide the electrode units  111  into electrode unit groups to enlarge the sensible distance. The electrode units  111  in the same group are detected simultaneously in response to a driving signal. The driving signal may be sent to the electrode unit groups individually or simultaneously. Changing grouping size of the electrode units can adjust the sensing range to obtain a distance value. The sensor circuit  13  issues a control signal in response to a floating touch action of the control object  2  which is detected based on the distance value. The touch device  1  or the capacitive touch panel  11  performs the specific function in response to the control signal. Although the user may use the control object  2 , i.e. his finger at different positions or different distances in front of the touch device  1 , the distance values are obtained in real time to adapt the floating touch method for the user habit. It is not necessary for the user to stand at a fixed position to remotely control the touch device  1 , so convenience and flexibility of the touch sensing operation is greatly improved. 
     Further, the floating touch method and the touch device can be applied to an input device or other floating touch device, e.g. a keyboard device or a virtual keyboard. Please refer to  FIG. 7 , a schematic diagram illustrating a portion of a keyboard device operated with the float touching method according to the present disclosure. The keyboard device  7  includes a capacitive touch panel  11  and a sensor circuit (not shown), which are similar to the elements as described in the previous embodiments and the redundant detail is not repeated here. An elastic cover  72  is disposed on the capacitive touch panel  11 . For example, the elastic cover  72  includes many arched or convex resilient member made of flexible or rubber material. Each convex resilient member may correspond to one key of the keyboard device  7 . No electronic circuit is required to be connected to the elastic cover  72  because the elastic cover  72  mainly provides “touch and press feeling” assisting the user in accurate typing to reduce discomforts due to unfamiliar floating touch manner. The elastic cover  72  may be or may be not in contact with the capacitance touch panel  11 . Before the user presses the elastic cover  72  with any control object such as a finger or palm, a distance h between a touch area  721  of the convex resilient member and the capacitive touch panel  11  may be considered as a distance reference as described above, but the distance reference is not limited to this definition. 
     When the user touches and presses the touch area  721  of a convex resilient member corresponding to a specific key, the sensor circuit can detect the press action by continuous scanning which includes the step of sensing the control object within different sensing ranges at different time points to determine distance values between the user finger and the capacitive touch panel  11 . If the sensor circuit finds that the distance values are getting smaller and smaller, a press action may occur and the convex resilient member curves inward. After the distance value is smaller than a specific value or a specific proportion of the distance reference, e.g. 50%, the sensor circuit issues a keystroke signal (control signal) corresponding to the specific key of the keyboard device  7 . After the pressure is removed from the touch area  721 , the convex resilient member restores to its original shape. The elastic cover  72  may be fixed in the keyboard device  7 , or be detachably coupled to the capacitive touch panel  11 , especially for a virtual keyboard which is hidden for some cases. Alternatively, no elastic cover  72  is provided, and the user operates the keyboard device  7  in a floating manner. 
     In an embodiment, different distance references may be set for different regions on the touch device. For example, a display region and a keyboard region may have different distance references so as to adjust touch sensitivities for different regions. For another example, since the user may virtual-press the touch device with a non-constant pressure, e.g. greater pressure at the central region and weaker pressure at the sides, the sensing ranges and distance references may be adjusted at different regions to fit individual habit. Therefore, the present disclosure provides a more convenient and user friendly floating touch method and device. 
     While the disclosure has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.