HK1183539B - Waterproof housing for digital devices having capacitive touch screen and its actuator mechanism - Google Patents

Abstract

An actuating mechanism for actuating a capacitive touch screen of a digital device inside a waterproof housing. The actuation mechanism comprises an actuation shaft extending through an opening formed on the housing, a button connected to the outer end of the shaft, a probe connected to the inner end of the shaft, and a bias member adapted to drive the probe away from the touch screen; In this way, pressing the button to counteract the bias force of the bias component will cause the probe to move towards the touch screen and make contact with it. A waterproof housing with an actuating mechanism was also disclosed.

Description

Waterproof housing of digital device with capacitive touch screen and actuating mechanism thereof

Technical Field

The present invention relates to a waterproof housing for a digital device, such as a smartphone (e.g., an apple phone), a tablet (e.g., an apple tablet), and a digital camera, having a capacitive touch screen. The invention also relates to an actuation mechanism for actuating a capacitive touch screen of a digital device housed within a waterproof housing.

Background

Many handheld digital devices, such as smartphones (e.g., apple cell phones), tablets (e.g., apple tablet computers), and digital cameras, are operated by touch screen input devices. Generally, a touch screen is a display screen that can identify the occurrence and location of a touch within a display area. The term "touch" generally refers to a touch of a finger or body part of a user. Which interacts with what is displayed on the screen, but not with other input devices that interact in an indirect manner, such as a keyboard, mouse, or touch pad. There are many different types of touch screens available today. The most commonly used types of handheld devices, such as smartphones, tablets, and digital cameras, are resistive and capacitive touch screens.

Resistive touch screens comprise a glass plate coated with a thin conductive layer and a metal layer. The two layers are separated by a spacer. When the user touches the touch screen, the two layers touch each other at the same location. The change in current is now identified and a set of coordinates on the touch screen display is calculated. Resistive touch screens can be operated by a finger or many types of objects as long as they can provide pin point type compression on the touch screen.

Another type of touch screen is a capacitive touch screen. Capacitive touch screens comprise a thin, visually transparent conductive layer, such as indium tin oxide. The conductive layer stores charge and is located on the glass layer of the display. When a user touches the touch screen, typically with a bare finger, a small amount of charge is transferred to or from the user's finger. The amount of charge at a specified location on the touch screen decreases. This change in charge is detected and calculated to give a set of coordinates on the display. Fingers and capacitive touch screens generally work well. The human body is a good charge transferor and charge transferee, because of the electromagnetic field around the human body all the time. Devices composed of compatible materials with good charge conductivity can perform this function. However, a pencil or stylus that is feasible on a resistive touch screen is not feasible on a capacitive touch screen.

As previously mentioned, these touch screens can be used in many handheld digital devices. These digital devices may not be waterproof and therefore may not be used in wet or underwater environments. If a user wants to operate those devices in the above-described environment, a waterproof enclosure or case must be used to enclose those digital devices, thereby avoiding water from entering the digital devices and damaging the internal electronic, mechanical, or optical components. These types of waterproof enclosures may be soft or hard. Which typically has an opening that allows a user to load a digital device into a waterproof housing. It typically has a locking mechanism that locks and seals the watertight housing.

With a soft, waterproof housing, a user may control some features of the digital device, such as a button, rocker switch, or rocker, from outside the housing with a finger. This type of bladder may also be used in devices having resistive touch screens. Some bladders are compatible with devices having capacitive touch screens. Under certain circumstances and conditions, this type of bladder can transfer charge back and forth between a human body and a capacitive touch screen. In some cases, for example, when a waterproof case containing a digital device is immersed in water to a certain water depth, the inner surface of the soft waterproof case is in close contact with the capacitive touch screen due to insufficient air inside the case or the air inside the case being compressed by the water pressure.

In addition to a soft waterproof housing, there is also a hard waterproof case for handheld digital devices. The hard waterproof case may provide better protection of the digital device against impact and may go deeper in water than the soft waterproof case since the hard waterproof case can withstand a certain depth of water pressure without compressing the air inside the waterproof case. Due to its "hard" nature, it is not possible to use the digital device within the housing from the outside of the housing with only the user's fingers or body parts without any mechanism.

Accordingly, there is a need to provide a specifically designed actuation mechanism to actuate a capacitive touch screen of a digital device within a waterproof housing.

The above background description is provided to aid in understanding the watertight housing and its actuating mechanism and is not admitted to describe or constitute prior art to the watertight housing and its actuating mechanism disclosed in this application or to consider any cited text as patentable material for the claims of this application.

Disclosure of Invention

According to one aspect of the present invention, a waterproof case of a digital device having a capacitive touch screen is provided. The waterproof housing may include a housing body for receiving a digital device therein, an actuation shaft extending through an opening formed in the housing body, a button connected to an outer end of the shaft, a probe connected to an inner end of the shaft, and a biasing member adapted to urge the (urge) probe away from the touch screen; thus, pressing the button against the biasing force of the biasing member will move the probe toward and into contact with the touch screen. The button, shaft and probe may be made of a material capable of conducting an electrical charge.

According to one embodiment, the probe head may include a probe pad made of rubber in direct contact with the touch screen. The probe may comprise a sleeve mounted on the inner end of the shaft and the probe pad may be mounted on an enlarged free end of the sleeve.

The waterproof housing may further comprise an adapter having a first end and a second end, the first end being connected to the inner end of the shaft and the second end being connected to the probe; the probe is located off-center with respect to a central axis defined by the shaft. The adapter may include a through bore therein for receiving the inner end of the shaft. The through-hole of the adapter and the inner end of the shaft received therein may have a non-circular cross-section such that the adapter is rotatable about a central axis of the shaft and the probe is movable in a circular path over the touch screen to perform a "touch-and-wipe" action or a "touch-and-loop" action on the touch screen.

The waterproof housing may also include a retaining ring secured to the inner end of the shaft for holding the adapter in position against the inner surface of the housing body. The button, shaft, adapter and probe may be made of metal.

In one embodiment, the biasing member is a coil spring coiled around the outer end of the shaft between the button and a washer mounted on the base of a circular groove formed on the outer surface of the housing body. The waterproof case may further include an O-ring mounted on the shaft at the opening of the case body for sealing a gap between the shaft and the opening.

According to another aspect of the present invention, an actuation mechanism is provided for actuating a capacitive touch screen of a digital device housed within a waterproof housing. The actuation mechanism may include an actuation shaft extending through an opening formed in the housing, a button connected to an outer end of the shaft, a probe connected to an inner end of the shaft, and a biasing member adapted to urge the probe away from the touch screen; thus, pressing the button against the biasing force of the biasing member will move the probe toward and into contact with the touch screen. The button, shaft and probe may be made of a material capable of conducting an electrical charge.

In one embodiment, the probe may include a probe pad made of rubber that is in direct contact with the touch screen. The probe may comprise a sleeve mounted on the inner end of the shaft and the probe pad may be mounted on an enlarged free end of the sleeve.

The actuation mechanism may further include an adapter having a first end and a second end, the first end being connected to the inner end of the shaft, the second end being connected to the probe; the probe is located off-center with respect to a central axis defined by the shaft. The adapter may include a through bore therein for receiving the inner end of the shaft. The through bore of the adapter and the inner end of the shaft received therein may have a non-circular cross-section such that the adapter is rotatable about the central axis of the shaft and the probe is movable in a circular path over the touch screen to perform a "touch-and-dash" action or a "touch-and-loop" action on the touch screen.

The actuation mechanism may also include a retaining ring secured to the inner end of the shaft for holding the adapter in position against the inner surface of the housing. The button, shaft, adapter and probe may be made of metal.

In one embodiment, the biasing member is a coil spring coiled around the outer end of the shaft between the button and a washer mounted on the base of a circular groove formed on the outer surface of the housing. At the opening of the housing, the actuating mechanism may further comprise an O-ring mounted on the shaft for sealing a gap between the shaft and the opening.

Although the disclosed watertight housing and its actuating mechanism have been shown and described with respect to certain embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present application includes all such equivalents and modifications, and is limited only by the scope of the claims.

Drawings

Specific embodiments of the watertight housing and its actuation mechanism disclosed herein will now be described, by way of example, with reference to the accompanying drawings. Wherein:

FIG. 1 is a front perspective view of a waterproof housing for receiving a smart phone therein according to an embodiment of the present invention;

FIG. 2 is a rear perspective view of a waterproof housing (showing an actuation mechanism) for receiving a smartphone in accordance with an embodiment of the present invention;

FIG. 3 is a schematic view of the actuating mechanism in a rest position;

FIG. 4 is a schematic view of the actuating mechanism in an actuated position when the button is pressed;

FIG. 5 is a cross-sectional view of an actuation mechanism according to a first embodiment of the present invention;

FIG. 6 is an exploded view of the actuation mechanism of FIG. 5;

FIG. 7a is a cross-sectional view of an actuation mechanism according to a second embodiment of the present invention;

FIG. 7b is a schematic view of the downward movement of the actuation mechanism of FIG. 7 a;

FIG. 8 is an exploded view of the actuation mechanism of FIG. 7 a;

FIG. 9a is a cross-sectional view of an actuation mechanism according to a third embodiment of the present invention;

FIG. 9b is a schematic view of the actuation mechanism of FIG. 9a in a downward/stroking motion (swipingmovement); and

fig. 10 is an exploded view of the actuation mechanism of fig. 9 a.

Detailed Description

Reference will now be made in detail to the preferred embodiments of the disclosed watertight housing and its actuating mechanism, examples of which are also provided in the following description. It will be apparent to those skilled in the art that the exemplary embodiments of the disclosed watertight housing and its actuating mechanism are described in detail, although some features that are not particularly important to understanding the watertight housing and its actuating mechanism are not shown for the sake of brevity.

Furthermore, it should be understood that the disclosed watertight housing and its actuating mechanism are not limited to the precise embodiments described below, and that various changes and modifications may be effected therein by one skilled in the art without departing from the spirit or scope of the appended claims. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims.

It should be noted that throughout the description and claims herein, when an element is described as being "coupled" or "connected" to another element, this does not necessarily mean that one element is secured, fastened, or otherwise attached to the other element. Conversely, the terms "coupled" or "connected" mean that one element is directly or indirectly connected to another element, or that it is in mechanical or electrical communication with another element.

Fig. 1 is a front perspective view of a waterproof case 10 for housing a smartphone in accordance with an embodiment of the present invention. When the smartphone is housed in the waterproof case 10, the lens of the camera of the smartphone is located behind the transparent glass 8. The camera can thus take pictures or take video underwater. Fig. 2 is a rear perspective view of a waterproof case 10 for accommodating a smartphone according to an embodiment of the present invention. In this embodiment, the actuation mechanism 12 is provided at the rear of the waterproof housing 10 and is capable of actuating a capacitive touch screen of a smartphone within the waterproof housing 10. The camera can thus be controlled by the actuating mechanism 12.

As will be described in fig. 3-10, the actuation mechanism 12, 12', 12 "may be disposed on a side of the housing 10 facing the capacitive touch screen. The actuation mechanism 12, 12', 12 "is adapted to actuate a capacitive touch screen within the housing 10. The actuating mechanism 12, 12', 12 ″ will be described in detail later. It should be understood that the waterproof housing 10 may be sized and shaped to accommodate different digital devices of different shapes and models (e.g., smart phones, tablets, digital cameras, etc.). The waterproof housing 10 may be made of a transparent material so that a user may view the movement of the actuation mechanism 12, 12', 12 "and view the touch screen from the exterior of the housing 10.

Fig. 3 is a schematic view of the actuation mechanism 12 in the rest position. The actuation mechanism 12 may include an actuation shaft 14, a button 16, and a probe 18. In this rest position, the probe 18 does not touch the capacitive touch screen 20.

FIG. 4 is a schematic view of the actuation mechanism 12 in an actuated position when the user's finger pushes the button 16 down/inward and the probe 18 touches the capacitive touch screen 20. In this actuated position, as indicated by the arrows, an electrical charge E may be transferred between the user's finger and the capacitive touch screen 20 via the button 16, the actuation shaft 14, and the probe 18.

Fig. 5 and 6 are schematic views of an actuating mechanism 12 according to a first embodiment of the present application. The actuation shaft 14 of the actuation mechanism 12 may extend through an opening 22 formed in the body of the housing 10 and define a central axis X. The diameter of the actuating shaft 14 may be slightly smaller than the diameter of the opening 22 so that the actuating shaft 14 may move in and out smoothly through the opening 22. The actuating shaft 14 may have an outer end and an inner end. The actuation shaft 14 may be long enough to allow the outer end of the actuation shaft 14 to extend outwardly from the housing 10 and the inner end of the actuation shaft 14 to extend inwardly into the housing 10. The actuation shaft 14 may be made of metal, metalized material, or a material capable of conducting an electrical charge.

A button 16 may be connected to the outer end of the actuating shaft 14. Button 16 may be a top portion of actuation mechanism 12. The button 16 may be mushroom-shaped or flat-headed, which is comfortable for a user to press with a finger or hand. The button 16 may be made of metal, metalized material, or a material capable of conducting an electrical charge. Alternatively, a thin layer of non-metallic plating may be used. This type of surface finish can produce good contact with the user's finger or hand, allowing the charge on the touch screen 20 of the digital device to be transferred to and from the user's hand.

The biasing member 40 may be used to urge the probe 18 away from the touch screen 20. When the button 16 is pressed against the biasing force, the probe 18 may be moved toward the touch screen 20 and into contact with the touch screen 20.

According to the illustrated embodiment, the biasing member 40 is a coil spring coiled around the actuating shaft 14 and between the button 16 and a washer 42 mounted on the base of a circular groove 44 formed on the outer surface of the housing 10. The biasing member 24 provides a biasing force to urge the button 16 to its uppermost position, which is the initial position when the button 16 is not depressed by the user. The biasing member 40 may also urge and support the washer 42 within the circular recess 44. The gasket 42 may be made of metal or plastic.

Although a coil spring is shown, it will be appreciated by those skilled in the art that other suitable types of biasing members may be used, such as a leaf spring.

At the opening 22 of the watertight housing 10, an O-ring 50 may be mounted on the actuation shaft 14 and used to seal the gap between the actuation shaft 14 and the opening 22. An O-ring 50 may be disposed below the washer 42 and mounted on the base in a circular groove 52. The O-ring 50 may be made of an elastic material, such as rubber or synthetic rubber. The inner diameter of the O-ring 50 may be slightly smaller than the diameter of the actuation shaft 14 so that the O-ring 50 may be tightly fitted (fit) around the actuation shaft 14. Further, the diameter of the circular groove 5 may be slightly smaller than the outer diameter of the O-ring 50 so that the O-ring 50 fits closely within the circular groove 52. Due to the application of the O-ring 50, the actuating shaft 14 may move outwardly and inwardly while maintaining the housing 10 in a tightly sealed condition. Additionally, a water-sealing compound may be used between the O-ring 50, the circular groove 52, and the actuation shaft 14 to enhance water-sealing performance while lubricating the actuation shaft 14 to smooth its motion and minimize friction generated by the O-ring 50.

According to the embodiment illustrated in fig. 5 and 6, the probe head 18 may include an adapter in the form of a sleeve 28 and a probe pad 30 for direct contact with the touch screen 20. A sleeve 28 may be mounted at the inner end of the actuating shaft 14 and a probe pad 30 may be mounted at the enlarged free end of the sleeve 28. The sleeve 28 may be formed with internal threads for threaded engagement with complementary external threads formed on the inner end of the actuating shaft 14.

The probe pad 30 may be made of a soft material such as rubber. Additives may be added to the rubber to enhance its charge transfer properties. The soft material is used because it minimizes possible scratches or damage on the touch screen 20.

Fig. 7a, 7b and 8 are schematic views of a second embodiment of the actuation mechanism 12 of the watertight housing 10. According to this embodiment, the actuation mechanism 12 'may include an adapter 28'. The adapter 28 ' may be formed with a through bore 58 ' through which the inner end of the adjusted actuating shaft 14 ' may pass. The diameter of the through bore 58 'may be the same as the diameter of the inner end of the actuating shaft 14', so that the inner end of the actuating shaft 14 'may fit snugly within the through bore 58'.

The adapter 28 'may be in the form of an arm having a first end connected to the inner end of the actuation shaft 14' and a second end connected to the probe 18 ', wherein the probe is disposed at an off-center position away from the central axis X of the actuation shaft 14'. The probe pad 30 can be mounted on the probe head 18'. A retaining C-ring or retaining E-ring 60 or other type of fastener may be used to hold the adapter 28' in place against the inner surface of the housing 10.

The adapter 28' may be made of metal, metalized material, or a material capable of conducting an electrical charge. The adapter 28' may have a relatively large flat surface or mushroom-shaped head to improve charge transfer to or from the touch screen 20.

As shown in FIG. 3, in the initial state, when the button 16 is released and the button 16 is urged upward by the biasing member 40, the button 16 is in its uppermost position. The biasing member 40 presses down on the gasket 42 to support the O-ring 50 in a circular groove 52 formed in the watertight housing 10. With the button 16 in its uppermost position, the probe 18 connected to the shaft is also in its uppermost position. Thus, the probe 18 does not touch the capacitive touch screen 20 of the digital device within the waterproof housing 10. The charge E on the capacitive touch screen 20 does not change.

When the user's finger or body part comes into contact with the button 16 and presses down, the user's finger or body part comes into close contact with the button 16 and the area in contact with the button 16 increases. Since the button 16 is metallic or metalized, a user's finger or body part is connected with an electrical charge.

The electrical conductivity between the button 16 and the user's finger or body part is further enhanced as the user's finger or body part continues to be depressed downward. The button 16 and the actuating shaft 14 together begin to move downward. The biasing member 40 supporting the button 16 is thus compressed. Since the O-ring 50 is mounted on the actuating shaft 14 with a water sealing compound, it prevents water outside the watertight housing 10, 10 from entering the watertight housing 10, 10 and from damaging the digital devices contained therein. The probe 18 actuated by the actuation shaft 14 begins to touch the touch screen 20. When the probe pad 30 is further pressed against the touch screen 20, the probe pad 30 begins to deform and forms a larger contact area with the touch screen 20 (as shown in fig. 4), thereby enhancing the electrical charge conductivity. By virtue of the large flat surface or mushroom-type surface of the button 16, by virtue of the actuation shaft 14 and the probe 18, it begins to transfer charge to or receive charge from the body. This results in a change in the charge on the touch screen 20. The digital device may then calculate a set of coordinates on the touch screen display.

When the button 16 is released, the biasing member 40 then pushes the button 16 upward. The actuation shaft 14 and the probe 18 also move upward, thereby separating the probe 18 from the touch screen 20 and ceasing interaction with the touch screen 20. Operation of the actuating mechanism 12 is then complete.

In some cases where the location designated by the button 16 does not match the sensed location of the touch screen 20 due to design limitations, it is then necessary to mount the probe 18 in an off-center location that is away from the central axis X of the actuation shaft 14. Therefore, another embodiment slightly modified from the foregoing embodiment is required.

Fig. 7a, 7b and 8 are schematic views of an actuation mechanism 12' according to another embodiment of the present invention. In this embodiment, the actuation mechanism 12 may include an adapter in the form of an extension arm 28'. The extension arms 28' may be made of a metallic material or other charge conducting material. One end of extension arm 28 'may be attached to the adjusted actuation shaft 14' by an E-ring 60 or other suitable fastening technique. The E-ring 60 may be used to hold the extension arm 28' in position against the inner surface of the watertight housing 10. At the other end of the extension arm 28 'may be provided a probe 18' of similar design to the previous embodiment.

One or more posts or guides (not shown) may be provided along the sides of extension arm 28 'to prevent probe 18 from detecting the wrong position on touch screen 20 as extension arm 28' swings or rotates about actuation axis 14. This allows the probe 18' to be moved only vertically up or down as shown in figure 7 b. The button 16, actuation shaft 14 ', extension arm 28 ' and probe 18 ' form a complete charge conduction path. When the user presses the button 16, the probe 18 ' moves downward along with the button 16, the actuation shaft 14 ' and the extension arm 28 '. The probe 18' is then brought into contact with the touch screen 20. This results in a change in the charge on the touch screen 20. The digital device can then detect the occurrence of a touch and calculate a set of coordinates on the touch screen display.

In some cases where the touch screen 20 of the digital device requires a "touch-and-swipe" or "touch-and-loop" action, rather than just a "touch" action, the probe 18' may need to move in a swiping action or a circular action after touching the touch screen 20. This requires other embodiments that are slightly modified from the previous embodiments.

Fig. 9a, 9b and 10 are schematic views of an actuation mechanism 12 "according to another embodiment of the present invention. In this embodiment, the inner end of the actuating shaft 14 "is formed in a non-circular shape, for example, a rectangular shape. Which matches the actuation shaft 14 "with the same shaped through hole 58". The adapter 28 "has one end connected to the actuation shaft 14" and another end merging with the probe 18 ". Similarly, a retaining ring such as an E-ring 60 or other securing technique may be used to hold the adapter 28 "in place against the inner surface of the watertight housing 10. The button 16, actuation shaft 14 ", adapter 28" and probe 18 "form a complete electrical charge conduction path.

When the user presses the button 16, the probe 18 "moves downward along with the button 16, the actuation shaft 14" and the adapter 28 ". The probe 18 "moves upward and makes contact with the touch screen 20. This results in a change in the charge on the touch screen 20. The digital device can then detect the occurrence of a touch and calculate a set of coordinates on the touch screen display. When the user turns the button 16 while pressing the button 16, the actuation shaft 14 "rotates about the central axis X of the actuation shaft 14". As illustrated in FIG. 9b, the probe 18 "of the adapter 28" may be moved in a circular path about the actuation axis 14 "while the probe 18" touches the touch screen 20. The touch screen 20 may then detect a change in charge along the path, and the touch screen 20 may calculate a new set of coordinates on the touch screen display. Thus, the detent mechanism 12 of the present embodiment "may perform a" touch-and-swipe "action or a" touch-and-loop "action, thereby activating a function on the touch screen 20.

While the watertight housing and its actuating mechanism disclosed herein have been shown and described in connection with a number of embodiments thereof, it should be noted that various other changes and modifications may be made without departing from the scope of the appended claims.

Claims (18)

1. A waterproof case for a digital device having a capacitive touch screen, the waterproof case comprising:

a housing body for accommodating the digital device therein;

an actuation shaft extending through an opening formed in the housing body;

a button connected to an outer end of the actuating shaft;

a probe connected to an inner end of the actuation shaft; and

a biasing spring adapted to urge the probe away from the touch screen; wherein pressing the button to oppose the biasing force of the biasing spring will move the probe toward and into contact with the touch screen; wherein the button, actuation shaft and probe are made of a material capable of conducting an electrical charge;

the probe comprises a probe pad directly contacting the touch screen, the probe pad is made of soft rubber, the rubber is added with additives to enhance the charge transfer performance of the probe pad, and when the probe pad is further pressed on the touch screen, the probe pad begins to deform and forms a larger contact area with the touch screen, so that the charge conductivity is enhanced.

2. The watertight housing of claim 1, wherein the probe comprises a sleeve mounted on an inner end of the actuating shaft, the probe pad being mounted on an enlarged free end of the sleeve.

3. The waterproof housing of claim 1 further comprising an adapter having a first end and a second end, said first end connected to an inner end of said actuation shaft and said second end connected to said probe; the probe is located off-center with respect to a central axis defined by the actuation shaft.

4. The watertight housing of claim 3 wherein the adapter includes a through hole therein for receiving the inner end of the actuating shaft.

5. The watertight housing of claim 4 wherein the through-hole of the adapter and the inner end of the actuation shaft received therein have a non-circular cross-section such that the adapter rotates about the central axis of the actuation shaft and the probe moves in a circular path on the touch screen to perform a "touch-and-dash" motion or a "touch-and-loop" motion on the touch screen.

6. The watertight housing of claim 3, further comprising a retaining ring secured to an inner end of the actuation shaft for holding the adapter in position against an inner surface of the housing body.

7. The watertight housing of claim 3, wherein the button, the actuation shaft, the adapter and the probe are made of metal.

8. The watertight housing of claim 1, wherein the biasing spring is a coil spring coiled around the outer end of the actuating shaft between the button and a washer mounted on a seat of a circular groove formed on the outer surface of the housing body.

9. The watertight housing of claim 1, further comprising an O-ring mounted on the actuating shaft at the opening of the housing body for sealing a gap between the actuating shaft and the opening.

10. An actuation mechanism for actuating a capacitive touch screen of a digital device housed within a waterproof housing, the actuation mechanism comprising:

an actuating shaft extending through an opening formed in the housing;

a button connected to an outer end of the actuating shaft;

a probe connected to an inner end of the actuation shaft; and

a biasing spring adapted to urge the probe away from the touch screen; thus, pressing the button to oppose the biasing force of the biasing spring will move the probe toward and into contact with the touch screen; wherein the button, actuation shaft and probe are made of a material capable of conducting an electrical charge;

the probe comprises a probe pad directly contacting the touch screen, the probe pad is made of soft rubber, the rubber is added with additives to enhance the charge transfer performance of the probe pad, and when the probe pad is further pressed on the touch screen, the probe pad begins to deform and forms a larger contact area with the touch screen, so that the charge conductivity is enhanced.

11. The actuation mechanism of claim 10, wherein the probe comprises a sleeve mounted on an inner end of the actuation shaft, the probe pad being mounted on an enlarged free end of the sleeve.

12. The actuation mechanism of claim 10, further comprising an adapter having a first end and a second end, the first end being connected to the inner end of the actuation shaft, the second end being connected to the probe; the probe is located off-center with respect to a central axis defined by the actuation shaft.

13. The actuating mechanism of claim 12, wherein said adapter includes a through-hole therein for receiving an inner end of said actuating shaft.

14. The actuation mechanism of claim 13, wherein the through-hole of the adapter and the inner end of the actuation shaft received therein have a non-circular cross-section such that the adapter rotates about the central axis of the actuation shaft and the probe is movable in a circular path on the touch screen to perform a "touch-and-dash" motion or a "touch-and-loop" motion on the touch screen.

15. The actuation mechanism of claim 12, further comprising a retaining ring secured to an inner end of the actuation shaft for holding the adapter in position against an inner surface of the housing.

16. The actuation mechanism of claim 12, wherein the button, actuation shaft, adapter and probe are made of metal.

17. The actuator mechanism of claim 10, wherein the biasing spring is a coil spring coiled around the outer end of the actuating shaft between the button and a washer mounted on a seat of a circular groove formed on an outer surface of the housing.

18. The actuator mechanism of claim 10, wherein the watertight housing further comprises an O-ring mounted on the actuator shaft at the opening of the housing for sealing a gap between the actuator shaft and the opening.