TWI710932B - Active stylus and detection method thereof - Google Patents

Abstract

An active stylus and its detection method are provided. The active stylus includes a first light sensor, a second light sensor, and a signal processing circuit. The first light sensor and the second light sensor are respectively disposed on two opposite sides of the head of the active stylus. When the active stylus approaches and points to a touch display panel, the first light sensor and the second light sensor sense light emitted by the touch display panel to obtain a first illuminance and a second illuminance. The signal processing circuit obtains the tilt angle of the active stylus with respect to the touch display panel by using at least the first illuminance and the second illuminance.

Description

Active touch pen and its detecting method

The present invention relates to a touch pen, and more particularly to an active touch pen and a detection method thereof.

Touch electronic devices (for example: tablet computers, smart phones or other similar devices) have gradually become common devices in people's lives. The user can operate the touch screen of the electronic device with the touch pen. For example, the user can use the stylus to write text or record related data on the touch screen. A common active stylus forms an electric field on the tip of the pen. When the tip of the active stylus is hovered (or touched) on the touch screen, the touch screen can sense this electric field and calculate the position of the active stylus. The general active stylus can only provide the writing function of a single stroke. That is, the general active stylus cannot determine the tilt angle of itself (the active stylus) relative to the target surface (such as the touch screen).

It should be noted that the content of the "prior art" paragraph is used to help understand the present invention. Part of the content (or all of the content) disclosed in the "prior art" paragraph may not be the conventional technology known to those with ordinary knowledge in the technical field. The content disclosed in the "prior art" paragraph does not mean that the content has been known to those with ordinary knowledge in the technical field before the application of the present invention.

The invention provides an active stylus and a detection method thereof to detect the tilt angle of the active stylus.

The active stylus of the present invention includes a first light sensor, a second light sensor and a signal processing circuit. The first light sensor is arranged on the side of the head of the active stylus, and the second light sensor is arranged on the other side of the head of the active stylus. When the active stylus approaches and points to the touch display panel, the first light sensor senses the light emitted by the touch display panel to obtain the first illuminance, and the second light sensor senses the touch display panel The emitted light obtains the second illuminance. The signal processing circuit is coupled to the first light sensor and the second light sensor to receive the first illuminance and the second illuminance. The signal processing circuit uses at least the first illuminance and the second illuminance to obtain the tilt angle of the active stylus relative to the touch display panel.

The detection method of the present invention includes: arranging the first light sensor on the side of the head of the active stylus; arranging the second light sensor on the other side of the head of the active stylus; When the type stylus approaches and points to the touch display panel, the first light sensor senses the light emitted by the touch display panel to obtain the first illuminance, and the second light sensor senses the touch display panel The emitted light obtains the second illuminance; and the signal processing circuit uses at least the first illuminance and the second illuminance to obtain the tilt angle of the active stylus relative to the touch display panel.

Based on the above, when the active stylus approaches and points to the touch display panel, the active stylus can sense the same light of the touch display panel through multiple light sensors, and then Get multiple illuminances. The active stylus can use these illuminances to obtain the tilt angle of the active stylus relative to the touch display panel. Therefore, the tilt angle of the active stylus can be automatically detected.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

The term "coupling (or connection)" used in the full description of the case (including the scope of the patent application) can refer to any direct or indirect connection means. For example, if the text describes that the first device is coupled (or connected) to the second device, it should be interpreted as that the first device can be directly connected to the second device, or the first device can be connected through other devices or some This kind of connection means is indirectly connected to the second device. The terms "first" and "second" mentioned in the full text of the description of this case (including the scope of the patent application) are used to name the element (element), or to distinguish different embodiments or ranges, and are not used to limit the number of elements The upper or lower limit is not used to limit the order of components. In addition, wherever possible, elements/components/steps with the same reference numbers in the drawings and embodiments represent the same or similar parts. Elements/components/steps using the same reference numerals or using the same terms in different embodiments may refer to related descriptions.

FIG. 1 is a schematic side view of an active stylus 100 in different directions according to an embodiment of the present invention. The active stylus 100 shown in FIG. 1 includes a head 101 and a body 102. The head 101 has a pen tip Pt. Two opposite sides of the head 101 of the active stylus 100 are respectively configured with a first light sensor and a second light sensor. For example, two opposite sides of the head 101 of the active stylus 100 are respectively configured with a light sensor Sa and a light sensor Se, as shown in FIG. 1.

The active stylus 100 shown in FIG. 1 is configured with a sensor ring 103 and a plurality of light sensors Sa, Sb, Sc, Sd, Se, Sf, Sg, and Sh. The light sensors Sa to Sh are arranged on the sensor ring 103, as shown in FIG. 1. The sensor ring 103 is disposed on the head 101 of the active stylus 100 and surrounds the head 101. In any case, the number of light sensors of the active stylus 100 can be determined according to design requirements.

When the active stylus 100 approaches and points to the touch display panel (not shown), the light sensors Sa to Sh can sense the light emitted by the touch display panel. The illuminance sensed by the light sensors Sa~Sh is proportional to the brightness of the light emitted by the touch display panel, and the illuminance sensed by the light sensors Sa~Sh is the same as the light sensor Sa~Sh to touch The square of the distance between the display panels is inversely proportional. For example, E = I/r ² , where E is the illuminance sensed by the light sensor, I is the brightness of the light emitted by the touch display panel, and r is the light sensor Sa～Sh to the touch display panel the distance between. When the brightness I of the touch display panel is known, the active stylus 100 can obtain the distance r according to the illuminance E.

2 is a schematic diagram illustrating a situation in which the active stylus 100 approaches and points to the touch display panel 210 of the host (touch display device) 200 according to an embodiment. The active stylus 100 and the sensor ring 103 shown in FIG. 2 can refer to the related description of FIG. 1, so they will not be repeated. FIG. 3 shows a schematic diagram of the illuminance obtained by each of the light sensors Sa to Sh by sensing the light emitted by the touch display panel 210 in the scenario shown in FIG. 2. The horizontal axis shown in FIG. 3 represents the light sensors Sa to Sh, and the vertical axis represents the illuminance sensed by the light sensors Sa to Sh. Please refer to Figure 2 and Figure 3. When the inclination angle of the active stylus 100 relative to the touch display panel 210 is 90 degrees, that is, when the active stylus 100 is perpendicular to the touch display panel 210, because the light sensors Sa to Sh reach the touch The distances between the control display panels 210 are approximately equal to each other, so the illuminances sensed by the light sensors Sa to Sh are approximately equal to each other.

4 is a schematic diagram illustrating another situation in which the active stylus 100 approaches and points to the touch display panel 210 of the host 200 according to an embodiment. The active stylus 100 and the sensor ring 103 shown in FIG. 4 can refer to the related description of FIG. 1, so they will not be repeated. FIG. 5 shows a schematic diagram of the illuminance obtained by the light sensors Sa to Sh respectively sensing the light emitted by the touch display panel 210 in the scenario shown in FIG. 4. The horizontal axis shown in FIG. 5 represents the light sensors Sa to Sh, and the vertical axis represents the illuminance sensed by the light sensors Sa to Sh. Please refer to Figure 4 and Figure 5. When the inclination angle of the active stylus 100 with respect to the touch display panel 210 is less than 90 degrees, because the distances from the light sensors Sa to Sh to the touch display panel 210 are not equal to each other, the light sensor Sa ~ The illuminance sensed by Sh is also not equal to each other. Taking FIG. 5 as an example, because the light sensor Se is the one closest to the touch display panel 210 among the light sensors Sa to Sh, the illuminance sensed by the light sensor Se is greater than other light sensors. The illuminance sensed by the sensor.

6 is a schematic diagram of a circuit block of an active stylus 100 and a host (touch display device) 200 according to an embodiment of the invention. The host 200 (touch display panel 210) shown in FIGS. 2 and 4 can refer to the related description of the host 200 (touch display panel 210) shown in FIG. 6. The host 200 shown in FIG. 6 includes a touch display panel 210, a touch controller 220, a display controller 230, and a backlight controller 240. The touch controller 220 can drive (control) the touch display panel 210 to detect a touch event of an object (such as the active stylus 100, a finger, or other objects). The display controller 230 can drive (control) the touch display panel 210 to display images. The backlight controller 215 can drive (control) the touch display panel 210 to adjust the brightness of the backlight.

The active stylus 100 shown in FIG. 6 includes a light sensor 110, a light sensor 120, a signal processing circuit 130 and a transmission electrode 140. According to design requirements, the active stylus 100 can also be optionally configured with receiving electrodes 150. The signal processing circuit 130 is coupled to the light sensor 110, the light sensor 120, the transmitting electrode 140 and the receiving electrode 150. The transmitting electrode 140 and the receiving electrode 150 are disposed on the head 101 of the active stylus 100. The transmitting electrode 140 and the receiving electrode 150 are coupled to the signal processing circuit 130. The signal processing circuit 130 can send electrical signals to the touch display panel 210 via the transmitting electrodes 223, and the signal processing circuit 130 can receive electrical signals from the touch display panel 210 via the receiving electrodes 150. According to design requirements, the electrical signal can be an electric field signal, an electromagnetic signal, a radio frequency signal, or other wireless signals. When the active stylus 100 approaches and points to the touch display panel 210, the touch display panel 210 receives the signal of the transmitting electrode 140 of the active stylus 100 for positioning.

FIG. 7 is a schematic flowchart of a detection method of the active stylus 100 according to an embodiment of the invention. Please refer to Figure 6 and Figure 7. In step S710, the light sensor 110 and the light sensor 120 are respectively arranged on two opposite sides of the head 101 of the active stylus 100. For any one of the light sensors Sa to Sh shown in FIGS. 1 to 5, reference may be made to the related description of the light sensor 110 or the light sensor 120. For example, the light sensor Sa shown in FIGS. 1 to 5 may refer to the related description of the light sensor 110, and the light sensor Se shown in FIGS. 1 to 5 may refer to the related description of the light sensor 120. .

When the active stylus 100 approaches and points to the touch display panel 210 (the result of step S720 is “close to the touch display panel”), the light sensor 110 may proceed to step S730. In step S730, the light emitted by the touch display panel 210 is sensed to obtain an illuminance 111 (first illuminance), and the light sensor 120 can sense the light emitted by the touch display panel 210 to obtain an illuminance 121 (No. Two illuminance). The signal processing circuit 130 is coupled to the light sensor 110 and the light sensor 120 to receive the illuminance 111 and the illuminance 121.

As illustrated in FIGS. 4 and 5, when the inclination angle of the active stylus 100 relative to the touch display panel 210 is less than 90 degrees, the illuminance sensed by the multiple light sensors at different positions will be different. The difference between the illuminances sensed by the light sensors is related to the tilt angle of the active stylus 100 relative to the touch display panel 210. Therefore, the signal processing circuit 130 can use at least the illuminance 111 and the illuminance 121 to obtain the tilt angle of the active stylus 100 with respect to the touch display panel 210 (step S740). For example, a lookup table (not shown) can be prepared in the active stylus 100 in advance. According to the illuminance 111 and the illuminance 121 (or even more illuminance), the signal processing circuit 130 can find the corresponding tilt angle from the look-up table.

Although the embodiment shown in FIG. 6 shows two light sensors, the number of light sensors of the active stylus 100 should not be limited thereto. In the case that the active stylus 100 is configured with three (or more) light sensors, the signal processing circuit 130 can use the three (or more) illuminances sensed by these light sensors to obtain The tilt angle of the active stylus 100 relative to the touch display panel 210 is shown.

FIG. 8 is a schematic flowchart of a detection method of an active stylus 100 according to another embodiment of the present invention. In step S810, the touch display panel 210 can detect the electrical signal sent by the transmission electrode 140 of the active stylus 100 for positioning. In step S820, the signal processing circuit 130 can sense the touch via multiple light sensors (such as the light sensors 110 and 120 shown in FIG. 6, or the light sensors Sa~Sh shown in FIG. 1) The light emitted by the display panel 210 obtains multiple illuminances.

In step S830, the signal processing circuit 130 can obtain the first distance from the light sensor 110 to the touch display panel 210 according to the illuminance 111, and the signal processing circuit 130 can obtain the light sensor 120 to the touch display panel according to the illuminance 121 The second distance of 210. There is a third distance between the light sensor 110 and the light sensor 120. In step S840, the signal processing circuit 130 can obtain the tilt angle of the active stylus 100 relative to the touch display panel 210 according to at least the first distance, the second distance, and the third distance. Then in step S850, the signal processing circuit 130 may report the tilt angle to the host (touch display device) 200 via the transmission electrode 140 (or other communication channel).

FIG. 9 is a schematic diagram illustrating another situation in which the active stylus 100 approaches and points to the touch display panel 210 of the host 200 according to an embodiment. In the embodiment shown in FIG. 9, the light sensors 110 and 120 are arranged on the sensor ring 103. When the active stylus 100 is inclined to the touch display panel 210, the distance from the light sensor 110 to the touch display panel 210 is R, and the distance from the light sensor 120 to the touch display panel 210 is mR. It is assumed here that the brightness of the touch display panel 210 is 1. The light sensor 110 can sense the light emitted by the touch display panel 210 to obtain the illuminance E1=I/R ² . The light sensor 120 can sense the light emitted by the touch display panel 210 to obtain the illuminance E2=I/(mR) ² . When the brightness I of the touch display panel 210 is known, the signal processing circuit 130 can obtain the distance R according to the illuminance E1 and obtain the distance mR according to the illuminance E2.

It is assumed here that the distance between the light sensor 110 and the light sensor 120 is D. At least the distance R, the distance mR and the distance D, the signal processing circuit 130 can obtain the tilt angle of the active stylus 100 relative to the touch display panel 210. For example, a lookup table (not shown) can be prepared in the active stylus 100 in advance. According to the distance R and the distance mR (or even more distances), the signal processing circuit 130 can find the corresponding tilt angle from the look-up table (ie, "90-θ" as shown in FIG. 9). According to different definitions, sometimes the "θ" shown in Figure 9 will be understood as the "tilt angle". In any case, when the "θ" shown in FIG. 9 is defined as the "inclination angle", the contents of the above-mentioned embodiments can be analogized and referred to.

According to different design requirements, the implementation of the blocks of the signal processing circuit 130 touching the controller 220, the display controller 230, and/or the backlight controller 240 can be hardware, firmware, or software. (Software, program) or a combination of more of the above three.

In terms of hardware, the blocks of the signal processing circuit 130 touching the controller 220, the display controller 230, and/or the backlight controller 240 can be implemented in a logic circuit on an integrated circuit. The related functions of the signal processing circuit 130 touch controller 220, display controller 230, and/or backlight controller 240 can use hardware description languages (such as Verilog HDL or VHDL) or other suitable programming languages. To be implemented as hardware. For example, the related functions of the signal processing circuit 130 touch controller 220, display controller 230, and/or backlight controller 240 can be implemented in one or more controllers, microcontrollers, microprocessors, Special application integrated circuit (Application-specific integrated circuit, ASIC), digital signal processor (digital signal processor, DSP), field programmable logic gate array (Field Programmable Gate Array, FPGA) and/or various other processing units Logic blocks, modules and circuits.

In terms of software and/or firmware, the related functions of the signal processing circuit 130 touching the controller 220, the display controller 230, and/or the backlight controller 240 can be implemented as programming codes. For example, general programming languages (such as C, C++ or assembly languages) or other suitable programming languages are used to implement the signal processing circuit 130 touch controller 220, display controller 230, and/or backlight controller 240. The programming code may be recorded/stored in a recording medium, which includes, for example, a read-only memory (Read Only Memory, ROM), a storage device, and/or a random access memory (Random Access Memory, RAM). . A computer, a central processing unit (CPU), a controller, a microcontroller, or a microprocessor can read and execute the programming code from the recording medium, thereby achieving related functions. As the recording medium, a "non-transitory computer readable medium" can be used, for example, tape, disk, card, semiconductor memory, and Programming logic circuits, etc. Furthermore, the program can also be provided to the computer (or CPU) via any transmission medium (communication network, broadcast wave, etc.). The communication network is, for example, the Internet, wired communication, wireless communication, or other communication media.

In summary, multiple light sensors are respectively arranged at different positions of the head 101 of the active stylus 100 according to the embodiments of the present invention. When the active stylus 100 approaches and points to the touch display panel 210, the active stylus 100 can sense the same light of the touch display panel 210 through a plurality of light sensors, In turn, multiple illuminances are obtained. The active stylus 100 can use these illuminances to obtain the tilt angle of the active stylus 100 relative to the touch display panel 210. Therefore, the tilt angle of the active stylus 100 can be automatically detected.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be determined by the scope of the attached patent application.

100: Active stylus 101: head 102: body 103: sensor ring 110, 120, Sa, Sb, Sc, Sd, Se, Sf, Sg, Sh: light sensor 111, 121: Illumination 130: signal processing circuit 140: transfer electrode 150: receiving electrode 200: host 210: Touch display panel 220: Touch the controller 230: display controller 240: backlight controller D, mR, R: distance Pt: nib S710～S740, S810～S850: steps

FIG. 1 is a schematic side view of an active stylus in different directions according to an embodiment of the present invention. 2 is a schematic diagram illustrating a situation in which the active stylus approaches and points to the touch display panel of the host according to the embodiment. FIG. 3 shows a schematic diagram of the illuminance obtained by sensing the light emitted by the touch display panel by a plurality of light sensors in the scenario shown in FIG. 2. 4 is a schematic diagram illustrating another situation in which the active stylus approaches and points to the touch display panel of the host according to the embodiment. FIG. 5 shows a schematic diagram of the illuminance obtained by sensing the light emitted by the touch display panel by multiple light sensors in the scenario shown in FIG. 4. FIG. 6 is a schematic diagram of a circuit block of an active stylus and a host according to an embodiment of the present invention. FIG. 7 is a schematic flowchart of an active stylus detection method according to an embodiment of the invention. FIG. 8 is a schematic flowchart of an active stylus detection method according to another embodiment of the present invention. FIG. 9 is a schematic diagram illustrating another situation in which the active stylus approaches and points to the touch display panel of the host according to an embodiment.

100: Active stylus

103: sensor ring

Sa, Se: light sensor

200: host

210: Touch display panel

Claims (10)

An active stylus, including: A first light sensor is arranged on one side of a head of the active stylus, wherein when the active stylus is close to and pointed at a touch display panel, the first light sensor is Measuring the light emitted by the touch display panel to obtain a first illuminance; A second light sensor is arranged on the other side of the head of the active stylus, wherein when the active stylus is close to and points to the touch display panel, the second light sensor Sensing the light emitted by the touch display panel to obtain a second illuminance; and A signal processing circuit is coupled to the first light sensor and the second light sensor to receive the first illuminance and the second illuminance, so as to obtain at least the first illuminance and the second illuminance An inclination angle of the active stylus relative to the touch display panel. The active stylus as described in item 1 of the scope of patent application further includes: A sensor ring is arranged on the head of the active stylus and surrounds the head, wherein the first light sensor and the second light sensor are respectively arranged on the sensor ring The two opposite sides. The active stylus as described in item 2 of the scope of patent application further includes: At least one third light sensor is disposed on the sensor ring, wherein when the active stylus approaches and points to the touch display panel, the at least one third light sensor senses the touch display The light emitted by the panel obtains at least a third illuminance, The signal processing circuit uses the first illuminance, the second illuminance and the at least one third illuminance to obtain an inclination angle of the active stylus relative to the touch display panel. According to the active stylus described in claim 1, wherein the signal processing circuit obtains a first distance from the first light sensor to the touch display panel according to the first illuminance, and the signal processing circuit A second distance from the second light sensor to the touch display panel is obtained according to the second illuminance, there is a third distance between the first light sensor and the second light sensor, and the The signal processing circuit obtains the tilt angle of the active stylus relative to the touch display panel at least according to the first distance, the second distance, and the third distance. The active stylus as described in item 1 of the scope of patent application further includes: A transmission electrode is disposed on the head, wherein the signal processing circuit is coupled to the transmission electrode, and the signal processing circuit sends an electrical signal to the touch display panel through the transmission electrode. The active stylus as described in item 1 of the scope of patent application further includes: A receiving electrode is disposed on the head, wherein the signal processing circuit is coupled to the receiving electrode, and the signal processing circuit receives an electrical signal from the touch display panel through the receiving electrode. An active stylus detection method includes: Disposing a first light sensor on one side of a head of the active stylus; Disposing a second light sensor on the other side of the head of the active stylus; When the active stylus approaches and points to a touch display panel, the first light sensor senses the light emitted by the touch display panel to obtain a first illuminance, and the second light sensor The sensor senses the light emitted by the touch display panel to obtain a second illuminance; and A signal processing circuit uses at least the first illuminance and the second illuminance to obtain an inclination angle of the active stylus relative to the touch display panel. The detection method described in item 7 of the scope of patent application further includes: A sensor ring is arranged on the head of the active stylus, wherein the sensor ring surrounds the head, and the first light sensor and the second light sensor are respectively arranged on the Two opposite sides of the sensor ring. The detection method described in item 8 of the scope of patent application further includes: At least one third light sensor is arranged on the sensor ring; When the active stylus approaches and points to the touch display panel, the at least one third light sensor senses the light emitted by the touch display panel to obtain at least a third illuminance; and The signal processing circuit uses the first illuminance, the second illuminance and the at least one third illuminance to obtain the tilt angle of the active stylus relative to the touch display panel. According to the detection method described in claim 7, wherein the step of obtaining the tilt angle of the active stylus relative to the touch display panel includes: Obtaining a first distance from the first light sensor to the touch display panel by the signal processing circuit according to the first illuminance; The signal processing circuit obtains a second distance from the second light sensor to the touch display panel according to the second illuminance, wherein there is a distance between the first light sensor and the second light sensor Third distance; and The signal processing circuit obtains the tilt angle of the active stylus relative to the touch display panel at least according to the first distance, the second distance, and the third distance.

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