TWI653570B - Electromagnetic touch-sensing device and method of operating the same - Google Patents

Abstract

The electromagnetic induction type touch device comprises a display panel, a digital board, a circuit control board and an electromagnetic stylus. The circuit board is used to detect changes in the magnetic flux in the tablet and the electromagnetic stylus to position the electromagnetic stylus. When the electromagnetic noise of the electromagnetic inductive touch device exceeds a threshold, the circuit board adjusts the settings of the display panel to obtain an optimal setting combination with one minimum electromagnetic noise, and combines the contents of the optimal setting. Lock to an existing setting for one of the display panels.

Description

Electromagnetic inductive touch device and related operation method

The present invention relates to an electromagnetic inductive touch device and related operation methods, and more particularly to an electromagnetic inductive touch device and related operation method capable of adaptively detecting electromagnetic interference during operation and timely adjusting system settings.

A stylus (stylus) is a small pen-shaped tool used to input commands to devices with touch screens such as computer screens, mobile devices, or graphics boards. Depending on the sensing technology, the stylus can be capacitive or electromagnetic. The electromagnetic stylus and the sensing line in the digitizer generate a magnetic field change to judge the action during operation, and have the advantages of fast response speed and accurate positioning, but the operating frequency is more susceptible to interference from the display panel. Although detailed evaluation will be carried out at the beginning of the system design to avoid interference, since the state of the display panel is also dynamically adjusted according to the environment or operation requirements, it is inevitable that it will encounter mutual interference in use.

Therefore, there is a need for an electromagnetic inductive touch device capable of adaptively detecting electromagnetic interference during operation of an electromagnetic stylus and adjusting system settings in a timely manner.

The invention provides a method for operating an electromagnetic inductive touch device. The electromagnetic inductive touch device comprises a display panel, a digital panel, a circuit control panel, and an electromagnetic stylus. The method includes the circuit board detecting a change of a magnetic flux in the digital board and the electromagnetic stylus to position the electromagnetic stylus, and the digital board detecting an electromagnetic noise of the electromagnetic induction type touch device, When the electromagnetic noise exceeds a threshold, the circuit board adjusts the settings of the display panel to obtain an optimal setting combination that causes a minimum electromagnetic noise, and the circuit board combines the optimal settings. The content is locked to one of the existing settings of the display panel.

The invention further provides an electromagnetic induction type touch device, comprising a display panel, a digital board, an electromagnetic stylus, and a circuit control board. The tablet includes a plurality of coils disposed on the back of the display panel. The electromagnetic stylus includes a resistance-inductor-capacitor circuit. The circuit board is configured to detect a change in magnetic flux in the digital board and the electromagnetic stylus to position the electromagnetic stylus, and when one of the electromagnetic induction touch devices exceeds a threshold value, Adjusting the settings of the display panel to obtain an optimal setting combination having one of the minimum electromagnetic noises, and locking the content of the optimal setting combination to one of the existing settings of the display panel.

FIG. 1 is a functional block diagram of an electromagnetic induction type touch device 100 according to an embodiment of the present invention. The electromagnetic inductive touch device 100 includes a display panel 10, a digital panel 20, a controller board 30, and an electromagnetic stylus 40. The display panel 10 can be a liquid crystal display panel or any type of touch panel. The tablet 20 includes a plurality of coils disposed on the back of the display panel 10. The electromagnetic stylus 40 includes a resistor-inductor-capacitor (RLC) circuit composed of a coil and a passive component.

When the circuit board 30 charges the digital board 20, the current in the inner coil changes, and the magnetic flux (ie, the magnetic field) in the coil also changes accordingly, thereby affecting the coil in the electromagnetic stylus 40. The magnetic flux, at this time, the RLC circuit in the electromagnetic stylus 40 charges and discharges the capacitance in the circuit. When the discharge is in progress, the change in the magnetic flux of the coil in the electromagnetic stylus 40 also affects the magnetic flux of the coil at the corresponding position on the tablet 20. Therefore, the circuit board 30 can position the electromagnetic stylus 40 by detecting the position of the coil whose magnetic flux is changed.

FIG. 2 is a flow chart of the operation of the electromagnetic induction type touch device 100 in the embodiment of the present invention, which comprises the following steps.

Step 210: Turn on or wake up the tablet 20; perform step 220.

Step 220: Determine whether the electromagnetic noise of the electromagnetic inductive touch device 100 exceeds a threshold; if yes, execute step 230; if not, execute 240.

Step 230: Adjust each setting of the display panel 10 to obtain an optimal setting combination that causes one of the minimum electromagnetic noises; and perform step 240.

Step 240: Lock the content of the optimal setting combination to the existing setting of the display panel 10; perform step 250.

Step 250: Apply the existing settings of the display panel 10.

In step 210, the user can press the power button to turn on the tablet 20 that was previously in the off state, or press a preset or custom quick button or gesture to wake up the tablet that was previously in the standby/sleep state. 20. For example, the user can tap the display panel 10 with a finger or an electromagnetic stylus 40 to send a wake-up signal. However, the initial state or on/off mode of the tablet 20 does not limit the scope of the present invention.

In step 220, the tablet 20 can measure electromagnetic noise of the electromagnetic inductive touch device 100, and the circuit control panel 30 can determine whether the electromagnetic noise of the electromagnetic inductive touch device 100 is greater than a threshold value. In the embodiment of the present invention, different parts of the electromagnetic stylus 40 can correspond to different operating frequencies. For example, the operating frequency of the pen tip portion is F1, the operating frequency of the pen tail portion is F2, and the operating frequency of the pen body button is F3. In this way, the electromagnetic inductive touch device 100 can accurately recognize the pen tip operating frequency F1 related to the writing action, the pen tail operating frequency F2 of the simulated eraser, and the button operating frequency F3 of the right mouse button. If the operating frequency of the display panel 10 is directly opposite to the operating frequency of the upper electromagnetic stylus 40, or the operating frequency of the display panel 10 is an integer multiple (multiple frequency operation), the operating frequency of the upper electromagnetic stylus 40 is opposite, which may result in Generate electromagnetic interference. If it is determined that the electromagnetic noise of the electromagnetic inductive touch device 100 is greater than the threshold value, the display panel 10, the tablet 20 and the electromagnetic stylus 40 may not operate normally due to mutual interference, and the present invention may be in step 230. Adjust the settings of the display panel 10 to obtain the best combination of electromagnetic noise minimum settings.

FIG. 3 is a schematic view showing the operation of the display panel 10 in the embodiment of the present invention. DE represents the synchronization signal DE_H of the display panel 10, and the horizontal period tH and the effective horizontal period tHD represent the horizontal resolution and the horizontal motion pixel area (the horizontal resolution actually used) of the display panel 10, respectively, in units of resolution and vertical. The motion pixel area (the vertical resolution actually used), the unit is the horizontal period tH. Therefore, the horizontal front porch or horizontal blanking is the number of lines that are not displayed after the effective pixel data of one frame ends, and the value is tH-tHD; the vertical front porch or Also referred to as vertical blanking is the number of lines of valid pixel data that are not displayed after the end, and the value is tV-tVD.

For illustrative purposes, it is assumed that in the electromagnetic stylus 40 of the present invention, the pen tip operating frequency F1 is 562 KHz, the pen tail operating frequency F2 is 582 KHz, and the pen body button operating frequency F3 is 547 KHz. In the display panel 10, the picture update rate (1/tCLK) is 60 Hz, the ideal value of the horizontal period tH is 2416, the ideal value of the effective horizontal period tHD is 2256, and the ideal value of the vertical period tV is 1524, and the effective vertical period tVD The ideal value is 1504. In other words, the horizontal gap available for adjustment in the display panel 10 has a value of 160*tCLK, and the value of the vertical gap is 20*tH.

Tables 1 and 2 below show the electromagnetic noise caused by the display panel 10 of the present invention under different horizontal/vertical gap conditions. On the premise of the same vertical gap, Table 1 shows the electromagnetic noise generated when the horizontal gap is set to 0, 5, 100, and 160. When the display panel 10 operates at a single frequency, the single frequency operating frequency under the conditions 1 to 4 falls between 135 KHz and 145 KHz, and does not interfere with the operating frequency of the electromagnetic stylus 40 between 531 KHz and 582 KHz. However, when the display panel 10 operates at quadruple frequency, the operating frequency of the quadruple frequency under conditions 1 to 4 falls between 541 kHz and 580 kHz, wherein the operating frequency of 565 KHz under condition 3 and 562 kHz in the electromagnetic stylus 40 The tip operating frequency F1 is quite close, so there is a possibility of interference.  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> horizontal gap</td><td> effective horizontal period </ Td><td> single frequency operating frequency</td><td> quadruple frequency operating frequency</td></tr><tr><td> condition 1 </td><td> 0 </td>< Td> 2256 </td><td> 135360 </td><td> 541440 </td></tr><tr><td> Condition 2 </td><td> 5 </td><td> 2261 </td><td> 135660 </td><td> 542640 </td></tr><tr><td> Condition 3 </td><td> 100 </td><td> 2356 < /td><td> 141360 </td><td> 565440 </td></tr><tr><td> Condition 4 </td><td> 160 </td><td> 2416 </td ><td> 144960 </td><td> 579840 </td></tr></TBODY></TABLE> Table 1  

On the premise of the same horizontal gap, Table 2 shows the electromagnetic noise generated when the vertical gap is set to 0, 5, 10 and 20. When the display panel 10 operates at a single frequency, the single frequency operating frequency under the conditions 5 to 8 falls between 90 KHz and 92 KHz, and does not interfere with the operating frequency of the electromagnetic stylus 40 between 531 KHz and 582 KHz. However, when the display panel 10 operates at six times the frequency, the six-frequency operating frequency under the conditions 5 to 8 falls between 541 kHz and 548 kHz, wherein the 548 KHz operating frequency under the condition 8 and the 547 kHz button in the electromagnetic stylus 40 The operating frequency F3 is quite close and therefore may cause interference.  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> Vertical gap</td><td> Effective vertical period </ Td><td> single frequency operating frequency </td><td> six frequency operating frequency </td></tr><tr><td> condition 5 </td><td> 0 </td>< Td> 1504 </td><td> 90240 </td><td> 541440 </td></tr><tr><td> Condition 6 </td><td> 5 </td><td> 1509 </td><td> 90540 </td><td> 543240 </td></tr><tr><td> Condition 7 </td><td> 10 </td><td> 1514 < /td><td> 90840 </td><td> 545040 </td></tr><tr><td> Condition 8 </td><td> 20 </td><td> 1524 </td ><td> 91440 </td><td> 548640 </td></tr></TBODY></TABLE> Table 2  

Since the electromagnetic noise received by the tablet 20 is a collective effect provided by a plurality of components in the entire system, although the set values of the parameters of the display panel 10 may theoretically have an infinite number of combinations, in practice, Only a specific number of combinations of settings are available. Therefore, the present invention can use the approximation method in step 230 to perform electromagnetic noise measurement on all component combinations step by step to find the optimal combination setting. In the embodiment shown in FIGS. 3A-3B, Table 1 and Table 2, the present invention provides 16 combinations for the conditions 1 to 4 for setting the horizontal gap and the conditions 5 to 8 for setting the vertical gap in step 230. And determining, for each combination, which is the best combination that causes the least interference, then locking the content of the optimal setting combination to the existing settings of the display panel 10 in step 240, and finally applying the existing display panel 10 in step 250. set up.

For example, if the present invention determines the lowest electromagnetic noise in the combination of the condition 2 of the horizontal gap and the condition 5 of the set vertical gap in the measurement results of the 16 combinations in step 230, the step is The horizontal gap of the display panel 10 is set to 5 in 240 and 250, and the vertical gap of the display panel 10 is set to zero. However, the horizontal/vertical gap of the display panel 10 is only an embodiment of the setting of the display panel 10, and does not limit the scope of the present invention.

In summary, the electromagnetic inductive touch device of the present invention has the advantages of high speed and accurate positioning, and can automatically detect electromagnetic interference during operation and adjust system settings in time to avoid interference of operating frequencies of components. And affect the normal operation. The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

10‧‧‧ display panel

20‧‧‧ digital tablet

30‧‧‧Circuit Control Board

40‧‧‧Electromagnetic stylus

100‧‧‧Electromagnetic Inductive Touch Device

210~250‧‧‧Steps

DE‧‧‧sync signal

tH‧‧‧ horizontal period

tHD‧‧‧effective horizontal period

tV‧‧‧ vertical period

tVD‧‧‧effective vertical period

FIG. 1 is a functional block diagram of an electromagnetic induction type touch device according to an embodiment of the present invention. 2 is a flow chart of the operation of the electromagnetic induction type touch device in the embodiment of the present invention. FIG. 3 is a schematic view showing the operation of the display panel in the embodiment of the present invention.

Claims (10)

A method of operating an electromagnetic inductive touch device, comprising: a display panel, a digital panel, a circuit control panel, and an electromagnetic stylus, the method comprising: the circuit control panel detecting Locating the electromagnetic stylus by the change of magnetic flux in the digital tablet and the electromagnetic stylus; the digital board detects electromagnetic noise of the electromagnetic induction type touch device; when the electromagnetic noise exceeds a threshold value The circuit board adjusts the settings of the display panel to obtain an optimal setting combination that causes a minimum electromagnetic noise; and the circuit board locks the content of the optimal setting combination to one of the display panels. set up. The method of claim 1, further comprising: when the electromagnetic noise exceeds a threshold, the circuit board adjusts one of the horizontal blanking of the display panel to obtain one of the minimum electromagnetic noises. An optimal horizontal gap; and the circuit board locks the optimal horizontal gap to the existing setting of the display panel. The method of claim 1, further comprising: when the electromagnetic noise exceeds a threshold, the circuit board adjusts one vertical blanking of the display panel to obtain one of the minimum electromagnetic noises An optimal vertical gap; and the circuit control board locks the optimal vertical gap to the existing setting of the display panel. The method of claim 1, further comprising: When the electromagnetic noise exceeds a threshold, the circuit board adjusts one horizontal gap and one vertical gap of the display panel to obtain an optimal setting combination for causing the minimum electromagnetic noise; and the circuit board will One of the best horizontal gaps and one optimal vertical gap lock included in the preferred setting combination is the existing setting of the display panel. The method of claim 1, further comprising: when the electromagnetic noise exceeds the threshold value, the display panel directly operates with the existing setting. An electromagnetic inductive touch device comprising: a display panel; a digital panel comprising a plurality of coils disposed on the back of the display panel; and an electromagnetic stylus comprising a resistor-inductor-capacitor (RLC) a circuit control board for: detecting a change in magnetic flux in the digital board and the electromagnetic stylus to position the electromagnetic stylus; and one electromagnetic noise of the electromagnetic induction type touch device exceeds one When the threshold is thresholded, the settings of the display panel are adjusted to obtain an optimal setting combination having one of the minimum electromagnetic noises; and the content of the optimal setting combination is locked to an existing setting of the display panel. The electromagnetic inductive touch device of claim 6, wherein the circuit control board is further configured to: when the electromagnetic noise exceeds the threshold, adjust a horizontal gap of the display panel to obtain the minimum electromagnetic impurity One of the best horizontal gaps; The optimal horizontal gap is locked to the existing setting of the display panel. The electromagnetic inductive touch device of claim 6, wherein the circuit control board is further configured to: when the electromagnetic noise exceeds the threshold, adjust a vertical gap of the display panel to obtain the minimum electromagnetic impurity One of the best vertical gaps; and locking the optimal vertical gap to the existing setting of the display panel. The electromagnetic inductive touch device of claim 6, wherein the circuit control board is further configured to: adjust a horizontal gap and a vertical gap of the display panel when the electromagnetic noise exceeds the threshold value to obtain One of the minimum electromagnetic noise optimal combination combinations; and locking one of the optimal horizontal gaps and an optimal vertical gap included in the optimal setting combination to the existing setting of the display panel. The electromagnetic inductive touch device of claim 6, wherein the circuit control panel is further configured to: when the electromagnetic noise exceeds the threshold value, control the display panel to directly apply the existing setting to operate.