Patent Application
20190155408
The present invention relates to a stylus tip and, in particular, to a replaceable electrical stylus tip which enables precise detection of stylus contact with a touch control screen and to a stylus using the electrical stylus tip.
With the development of technology, 3C (computer, communication, consumer electronics) products have gained increasing popularity. 3C products having a touch control interface, such as tablet computers and smart phones, have become mainstream electronic products. The touch control interface typically utilizes a touch screen collaborating with an operation system to provide a graphical operation interface. There are different types of touch screens available in the market, including resistive touch screens, capacitive touch screens, and inductive touch screens.
When a stylus is used with the touch screen, the position of the stylus is detected for performing operations on the touch control operation interface. However, when the stylus obliquely taps the touch screen, the touch position is often not precisely detected. This results in errors in the determined stylus position, and reduces accuracy of positioning, so that operation of the stylus is inconvenient to users. Besides, a stylus tip may be worn out, bent or broken after used in a long time.
In view of this, the inventor studied various technologies and created an effective solution in the present disclosure.
It is an objective of the present invention to provide an electrical stylus tip and a stylus using the same for enabling precise detection of the position of the stylus.
It is another objective of the present invention to provide a replaceable electrical stylus tip and a stylus using the same.
Accordingly, the present invention provides an electrical stylus tip, assembled to a barrel, for operating a capacitive touch sensitive device. The electrical stylus tip includes a metal rod and a plastic covering member. The metal rod includes a head portion, an end portion and a body portion connected to the head portion and the end portion. A connection rod is connected between the head portion and the body portion. The plastic covering member includes a conductive element covering the head portion and includes a non-conductive element covering the body portion. The connection rod is enclosed within the conductive element and the non-conductive element, and the end portion protrudes out of the non-conductive element.
Accordingly, the present invention also provides a stylus which includes a barrel and the electrical stylus tip. The electrical stylus tip is assembled to the barrel and is replaceable. The barrel can be conductive or non-conductive, and depending on requirement.
The present invention further has the following functions. In one embodiment, the plastic covering member and the metal rod are integrally formed by insert molding. In other words, the conductive element, the non-conductive element and the metal rod are integrally formed by insert molding. A recess of the metal rod enhances a joining effect between the metal rod and the plastic covering member which are of different materials. A connection rod is disposed passing through the head portion and the body portion. The recess is formed on the connection rod by, for example, lathe cutting the connection rod, so that the plastic covering member can be stably connected and fixed to the metal rod.
A cross-sectional area of the head portion is two times or more the cross-sectional area of the connection rod, so it is more difficult for the connection rod to cause capacitive coupling with a touch screen. In addition to that, a distance from the connection rod to the touch screen is longer than a distance from the electrical stylus tip to the touch screen, so the position of the electrical stylus tip is very close to the coordinates determined by a capacitive touch sensitive device (or a capacitive touch sensitive system). In other words, errors in the determined stylus position are reduced, thus achieving precise coordinate detection and thereby improving user experience.
If the conductive element of the electrical stylus tip has been worn out after being used in a long time or is broken accidentally, a user can detach the old electrical stylus tip from an insertion hole of the barrel, and then connect a new electrical stylus tip to the barrel by threadedly connecting an external threaded portion of the new electrical stylus tip to an internal threaded portion of the barrel. In alternative embodiments, the replaceable electrical stylus tip is detachably joined to the barrel by interference fit or by using a flange engaged with a groove or by other fastening method. The electrical stylus tip is reliable and can be replaced easily, so there is no need to buy a new stylus, which results in considerable cost savings.
The disclosure will become more fully understood from the detailed description, and the drawings given herein below is for illustration only, and thus does not limit the disclosure, wherein:
Detailed descriptions and technical contents of the present invention are illustrated below in conjunction with the accompanying drawings. However, it is to be understood that the descriptions and the accompanying drawings disclosed herein are merely illustrative and exemplary and not intended to limit the scope of the present invention.
Referring to
In the embodiment shown in
Referring to
The plastic covering member 3 and the metal rod 2 are integrally formed by insert molding, so that the stylus 6 has a wear resistant and elastic contact surface for tapping the capacitive touch sensitive device (not illustrated). The plastic covering member 3 includes a conductive element 31 covering the head portion 21 and includes a non-conductive element 32 covering the body portion 22, the connection rod 25 is disposed inside the conductive element 31 and the non-conductive element 32, the conductive element 31 is connected to the non-conductive element 32, and the end portion 23 protrudes out of the non-conductive element 32.
A recess 24 is formed on the connection rod 25. The recess 24 is an annular recess on the exterior of the connection rod 25. In the present embodiment, the conductive element 31 and the non-conductive element 32 are integrally formed with the metal rod 2 by, preferably, bi-injection molding (insert molding). The recess 24 of the metal rod 2 increases the joining effect between the two different materials of the conductive element 31 and the non-conductive element 32. In the embodiment of
In detail, the head portion 21 is of disc shape, and the connection rod 25 is of cylindrical shape. A cross-sectional area of the head portion 21 is two times or more a cross-sectional area of the connection rod 25. The connection rod 25 partially protrudes from the conductive element 31, i.e. the non-conductive element 32 partially covers the connection rod 25, so that an input signal is generated due to capacitive coupling between the capacitive touch sensitive device and both the head portion 21 and a portion of the connection rod 25 inside the conductive element 31. By contrast, no capacitive coupling/signals occurs between the capacitive touch sensitive device and both the body portion 22 and a portion of the connection rod 25 inside the non-conductive element 32 since the body portion 22 and the portion of the connection rod 25 are enclosed inside the non-conductive element 32 made of a non-conductive material.
Although both the head portion 21 and the portion of the connection rod 25 inside the conductive element 31 cause capacitive coupling with the touch screen, the cross-sectional area of the head portion 21 is two times or more the cross-sectional area of the connection rod 25, so it is more difficult for the connection rod 25 to cause capacitive coupling with the touch screen. In addition, a distance from the connection rod 25 to the touch screen is longer than a distance from an electrical stylus tip 21 to the touch screen, so the position of the electrical stylus tip 1 is very close to the coordinates determined by the capacitive touch sensitive device (i.e. a capacitive touch sensitive system), thereby achieving precise detection of stylus position, thus improving user experience.
Furthermore, the description below with reference to
The conductive element 31 can be constituted by POM, i.e. the same plastic material that constitutes the non-conductive element 32. Therefore, the conductive element 31 and the non-conductive element 32 after solidified have proper electrical impedance, hardness, elasticity, and wear resistance on their surface, and also have stable shapes. However, in alternative embodiments, the conductive element 31 and the non-conductive element 32 can consist of polyurethane (PU) or other suitable thermoplastic material, wherein metal powders are mixed into the conductive element 31 consisting of PU.
Furthermore, the conductive element 31 has a length L′ preferably shorter than a length L″ of the non-conductive element 32 along a longitudinal direction of the metal rod 2, so that when the electrical stylus tip 1 obliquely contacts the capacitive touch sensitive device, the head portion 21 inside the conductive element 31 even more effectively causes capacitive coupling with the capacitive touch sensitive device.
In the embodiment shown in
An exterior surface of the end portion 23 includes an external threaded portion 231, and the external threaded portion 231 is threadedly connected to the barrel 5, so that the electrical stylus tip 1 is replaceable. Referring to
Please refer to
Furthermore, the configuration of the metal rod 2 also reduces the noise (see
It is to be understood that the above descriptions are merely the preferable embodiments of the present invention and are not intended to limit the scope of the present invention. Equivalent changes and modifications made in the spirit of the present invention are regarded as falling within the scope of the present invention.
