Patent Application
20170115753
The present invention relates to a method for detecting an orientation of a stylus, and more particularly to a method for detecting an orientation of a stylus on a touch panel and a stylus with an orientation detection function.
Capacitive touch input technology is widely used in the touch panel, one of advantages is allowing user to proceed input operation via user's hand or a stylus so as to have a multi touch function which can generate a variety of applications according to specific corresponding operations by various gestures. A stylus allows user to perform exquisite input operations such as writing or to execute application programs on a touch panel via user interfaces. The coordinates of a stylus can be detected via capacitive coupling between detection electrodes of a touch panel and the stylus when the stylus approaches or contacts the touch panel. In order to establish capacitive coupling with detection electrodes of a touch panel, a stylus must receive driving signals from detection electrodes and output signals to detection electrodes so that coordinates of the stylus can be detected. Beside coordinates of the stylus, tilt angle, orientation, inclination or angular information of the stylus are also essential to the applications and functions of the stylus applied on the touch panel.
An object of the present invention is to provide a method for detecting an orientation of a stylus on a touch panel. One embodiment of the present invention uses a primary peak voltage signal and non-primary peak voltage signals on a first location and a second location of the touch panel generated from a tip of a nib of the stylus and a portion of the nib corresponding to a non-shielding portion of a shielding of the stylus respectively to determine the orientation of the stylus.
Another embodiment of the present invention utilizes capacitance variations on a first location and a second location of the touch panel generated from a tip of a nib of the stylus and a portion of the nib corresponding to a non-shielding portion of a shielding of the stylus to determine the orientation of the stylus.
Another embodiment of the present invention provides a stylus with an orientation detection function. The stylus comprises a conductive nib and a shielding comprising a non-shielding portion. The shielding surrounds the conductive nib, and a tip and a portion of the conductive nib corresponding to the non-shielding portion of the stylus are configured to generate capacitance variations on locations of a touch panel.
The accompanying drawings illustrate various embodiments of the present invention and are a part of the specification. The illustrated embodiments are merely examples of the present invention and do not limit the scope of the invention.
The detailed description of the present invention will be discussed in the following embodiments, which are not intended to limit the scope of the present invention, but can be adapted for other applications. While drawings are illustrated in details, it is appreciated that the scale of each component may not be expressly exactly.
In embodiments of the invention, some features related to a stylus which are not essential to the invention and are well known for any person skilled in the art to make and use the same will not be described in detail herein. For example, the following features relating to a stylus and a touch panel are well known for any person skilled in the art to make and use the same. A stylus includes a conductive tip while a touch panel has a capacitive detection array with a plurality of detection electrodes, wherein the detection electrodes comprise transmitting electrodes (Tx) and receiving electrodes (Rx). When a stylus is used upon a touch panel, the conductive tip approaches or contacts the capacitive detection array of the touch panel, and the conductive tip of the stylus will establish capacitive coupling with the detection electrodes under or adjacent the stylus. The stylus outputs a signal to the detection electrodes under or adjacent the stylus. The output signal allows the stylus to establish capacitive coupling with detection electrodes of the touch panel under or adjacent the stylus after scanning transmitting electrodes and receiving electrodes to generate a detection signal so as to calculate and determine coordinates of the stylus. Through capacitive coupling between the conductive tip and the detection electrodes, the signal from the stylus will be detected during scanning transmitting electrodes and receiving electrodes so that coordinates of the stylus can be calculated and determined. The capacitive detection array can use charge accumulation circuit, a capacitance modulation circuit, or other capacitance sensing methods known by those skilled in the art.
When stylus 10 touches or hovers over the touch panel 1, the stylus 10 establishes a capacitance with one or more electrodes 2 and 3, and the capacitances of the electrodes 2 and 3 are altered due to the capacitor between the stylus 10 and the electrodes 2 and 3. The sensing circuitry (not shown) of the touch panel 1 then detect signals generated from capacitance variations of the electrodes 2 and/or 3. The signals may be generated from capacitance variations of the electrodes 2 or 3 along conductive lines arranged in columns or rows. The signals may be generated from capacitance variations of the electrodes 2 and 3 along conductive lines arranged in columns and rows. Thus the sensing circuitry can obtain coordinate, orientation, inclination or angular information of the stylus via scanning the electrodes 2 and 3. The coordinate information of the stylus can be determined via detecting capacitance variations of a series of electrodes 2 or 3 along conductive lines arranged in columns or rows under the stylus 10 or capacitance variations of a single cross point of two series of electrodes 2 and 3 along conductive lines arranged in columns and rows under the stylus 10 respectively. Details of determination of orientation, inclination or angular information of the stylus will be further described in the following content.
In this embodiment, the tip of the nib 12 of the tilted stylus 10 is on Xn coordinate along x axial direction, a plurality of electrodes 2 and/or 3 under the nib 12 of the tilted stylus 10 will establish capacitive coupling with the tilted stylus 10. Particularly, capacitance variations of the electrodes 2 and/or 3 under the tip of the nib 12 and the non-shielding portion 141 would generate a primary peak voltage signal on Xn coordinate and a secondary peak voltage signal on Xn+5 coordinate after the sensing circuitry scans the electrodes 2 and 3 along conductive lines arranged in columns and rows. Auxiliary primary peak voltage signals on Xn−2, Xn−1, Xn+1 and Xn+2 coordinates aside Xn coordinate and auxiliary secondary peak voltage signals on Xn+4 and Xn+6 coordinates aside Xn+5 coordinate may also detected. The peak voltage signals on Xn−2, Xn−1, Xn Xn+1 and Xn+2 coordinates constitute a primary peak voltage signal group, while the peak voltage signals on Xn+4, Xn+5 and Xn+6 coordinates constitute a non-primary/secondary peak voltage signal group. Since voltage signals will mainly be generated on coordinates under the nib 12 of the tilted stylus 10, the orientation, inclination or angular information of the tilted stylus 10 can be obtained through the voltage signals generated from capacitance variations of the electrodes 2 and/or 3 under the tip of the nib 12 and the non-shielding portion 141.
In one embodiment, the tilt degree of the stylus 10 can be calculated by the following equations:
Tilt degree={(VXn+4+VXn+5+VXn+6)/(VXn−1+VXn+VXn+1)}*90 degree
or
Tilt degree={(VXn+4+VXn+5+VXn+6)*K/(VXn−2+VXn−1+VXn+VXn+1+VXn+2)}*90 degree
(K is an adjusting parameter for tilt ratio.)
or
Tilt ratio={(secondary peak voltage signal)/(primary peak voltage signal)}
or
Tilt ratio={(sum of secondary peak group)/(sum of primary peak group)}
However, the orientation, inclination or angular information of the tilted stylus 10 can be obtained via other ways. It is easily expected that the ratio between the primary peak voltage signal and the secondary peak voltage signal generated from capacitance variations of the electrodes 2 and/or 3 under the tip of the nib 12 and the non-shielding portion 141 respectively is a function of the inclination amount of the stylus 10. For example, the larger the stylus 10 tilts, the more the ratio approaches 1. Conversely, the lesser the stylus 10 tilts, the more the ratio approaches zero.
Moreover, the distance between the primary peak voltage signal and the secondary peak voltage signal generated from capacitance variations of the electrodes 2 and/or 3 under the tip of the nib 12 and the non-shielding portion 141 respectively is also a function of the inclination amount of the stylus 10. For example, the larger the stylus 10 tilts, the larger the distance is. Conversely, the lesser the stylus 10 tilts, the smaller the distance is. Moreover, the distance between the locations of the electrodes 2 and/or 3 under the tip of the nib 12 and the non-shielding portion 141 is also a function of the inclination amount of the stylus 10.
The rotation of the stylus 10 can also be determined by the primary peak voltage signal and the secondary peak voltage signal generated from capacitance variations of the electrodes 2 and/or 3 under the tip of the nib 12 and the non-shielding portion 141 respectively. For example, various designs of shape or configuration or arrangement of the non-shielding portion 141 of the shielding 14 can induce various and different secondary or non-primary peak voltage signals on the electrodes 2 and/or 3 under or close to the non-shielding portion 141. For example, the non-shielding portion 141 comprises three openings or non-conductive parts without shielding function arranged in a circular manner around the shielding 14 which can induce non-primary peak voltage signals on the electrodes 2 and/or 3 under or close to the non-shielding portion 141. Through determining the relative location changes of non-primary peak voltage signals, the rotation of the stylus 10 can be determined. For example, as the stylus 10 rotates, the non-primary peak voltage signals correspondingly rotate as their magnitudes change. Accordingly, a determination can be made regarding how much the stylus 10 rotated between the orientations.
Although specific embodiments have been illustrated and described, it will be appreciated by those skilled in the art that various modifications may be made without departing from the scope of the present invention, which is intended to be limited solely by the appended claims.
