CN103631460B - Signal processor, touch judgment device and touch judgment method - Google Patents

Abstract

A touch judgment device is suitable for judging whether a touch button arranged on a touch panel is touched, comprising: a judgment unit, analyzing a sensing data about the button at intervals, judging that the button is touched when the sensing data at the current time is ≧ a touch threshold, and judging that the button is not touched when the sensing data at the current time is < the touch threshold; and a correction unit, when the judgment unit judges that the button is not touched, not correcting the sensing data when the sensing data is between the touch threshold and a correction threshold, and correcting the sensing data when the sensing data is between the correction threshold and a steady-state value; wherein the touch threshold>the correction threshold>the steady-state value, and the steady-state value is the sensing data of the button when the touch panel is just powered on and is not touched.

Description

Signal processor, touch judging device and touch judging method

technical field

The present invention relates to a judging method and device, in particular to a signal processor for a touch application, a touch judging device and a touch judging method.

Background technique

In the circuit board of capacitive touch application, the sensor can charge and discharge the sensing capacitance of the touch button to obtain a sensing data proportional to the sensing capacitance. Generally speaking, factors affecting the inductive capacitance include the external force on the touch key, the parasitic capacitance effect of the overall circuit board on the touch key, and even the environment where the circuit board with the touch key is located. Among them, environmental factors such as: place the circuit board on an iron table, place the circuit board next to a power supply or other equipment that emits noise.

Referring to Figure 1, in the absence of environmental interference, the sensing data of the inductive capacitance will maintain a steady-state value when no external force is involved, and jump above the threshold during the period of external force intervention (such as time t=1~3), so In the prior art, it is easy to judge whether the touch button is touched or not.

Referring to FIG. 2 , if the touch key is disturbed by the environment at time t=1˜10, the sensing data of the sensing capacitor will increase. In order to prevent environmental interference from affecting the touch judgment result, the prior art corrects the sensing data when 0≦sensing data≦threshold, so as to approach the steady-state value. For example, the sensing data in FIG. 2 is continuously revised during time t=1˜7, and returns to a steady state value after t=7.

However, during the correction of the sensing data, if the touch key is touched by an external force, the change of the effective sensing capacitance may make the sensing data unable to exceed the threshold, resulting in a touch judgment error, as shown in time t=5-6 in Figure 3 . Therefore, how to adjust the sensing data correction method to maintain the accuracy of touch judgment is a major issue at present.

Contents of the invention

The purpose of the present invention is to provide a signal processor, a touch judging device and a touch judging method, which can accurately judge whether a key is touched or not even if there is environmental interference.

The touch judging method of the present invention is suitable for judging whether a button arranged on a touch panel is touched, comprising the following steps: (A) analyzing a sensing data about the button at regular intervals; (B) when When the sensing data at the current time≧a touch threshold, it is judged that the button is touched; and (C) when the sensing data at the current time<the touch threshold, it is judged that the button is not touched, and in The sensing data is not corrected when the sensing data is between the touch threshold and a correction threshold, and the sensing data is corrected when the sensing data is between the correction threshold and a steady-state value; wherein, the touch The touch threshold>the correction threshold>the steady state value, and the steady state value is the sensing data of the key when the touch panel is just powered on and not touched.

Step (C) is to use the sensing data and the steady-state value at the current time to correct according to the following formula; the corrected sensing data=A×current sensing data+B×steady-state value; wherein, a first Both parameter A and a second parameter B are related to the button material.

The touch judging device of the present invention is suitable for judging whether a touch button arranged on a touch panel is touched, and includes: a judging unit that analyzes a sensing data about the button every once in a while, when the current time When the sensing data ≧ a touch threshold, it is judged that the button is touched; when the sensing data at the current time is less than the touch threshold, it is judged that the button is not touched; and a correction unit, when the judgment The unit judges that the button is not touched, and does not correct the sensing data when the sensing data is between the touch threshold and a correction threshold, and does not correct the sensing data when the sensing data is between the correction threshold and a steady-state value Correcting the sensing data; wherein, the touch threshold>the correction threshold>the steady-state value, and the steady-state value is the sensing data of the key when the touchpad is just powered on and not touched.

The correction unit uses the sensing data and the steady-state value at the current time for correction according to the following formula; the corrected sensing data=A×current sensing data+B×steady-state value; wherein, a first parameter Both A and a second parameter B are related to the button material.

The signal processor of the present invention is suitable for coupling a touch panel provided with a button, including: a transmission interface for receiving a sensing data from the touch panel, wherein the sensing data is related to the button The size of a sensing capacitance; a judging unit, which analyzes the sensing data at regular intervals, when the sensing data at the current time ≧ a touch threshold, it is judged that the button is touched, when the sensing data at the current time <When the threshold is touched, it is judged that the button is not touched; and a correction unit, when the judgment unit judges that the button is not touched, when the sensing data is between the touch threshold and a correction threshold, no Correcting the sensing data, correcting the sensing data when the sensing data is between the correction threshold and a steady-state value; wherein, the touch threshold>the correction threshold>the steady-state value, and the steady-state value It is the sensing data of the button when the touchpad is just powered on and not touched.

The correction unit uses the sensing data and the steady-state value at the current time for correction according to the following formula; the corrected sensing data=A×current sensing data+B×steady-state value; wherein, a first parameter Both A and a second parameter B are related to the button material.

The transmission interface is an I2C (Inter-Integrated Circuit, inter-integrated circuit) interface.

The signal processor also includes: an output unit, when the judging unit judges that the button is touched, the output unit emits light matching the sensing data.

The beneficial effect of the present invention is that the correction unit performs correction only when the sensing data < correction threshold, so even if there is environmental interference and the correction threshold ≦ sensing data < touch threshold, the judging unit can still accurately judge that the key P is touched situation.

Description of drawings

FIG. 1 is a timing diagram illustrating changes in sensing data when there is no environmental interference;

FIG. 2 is a timing diagram illustrating changes in sensing data when there is environmental interference;

FIG. 3 is a timing diagram illustrating changes in sensing data when there is environmental interference;

Fig. 4 is a block diagram illustrating the touch control system of this preferred embodiment;

FIG. 5 is a circuit diagram illustrating an embodiment of a charging converter;

FIG. 6 is a flowchart illustrating a first preferred embodiment of a touch determination method;

FIG. 7 is a timing diagram illustrating changes in sensing data when there is no environmental interference;

FIG. 8 is a timing diagram illustrating changes in sensing data when there is environmental interference;

FIG. 9 is a flowchart illustrating a second preferred embodiment of the touch determination method.

detailed description

Below in conjunction with accompanying drawing and embodiment the present invention is described in detail:

Referring to FIG. 4 , a preferred embodiment of the touch determination device 22 of the present invention is applicable to a touch control system 100 , and the touch control system 100 includes a touch panel 1 and a signal processor 2 . The touch panel 1 includes an input unit 11 , a sensor 12 , and a transmission interface 13 . The signal processor 2 includes a transmission interface 21 , the touch determination device 22 and an output unit 23 .

Preferably, the input unit 11 has a key P and an inductive capacitor C, which is sensed by a copper foil conductor of a printed circuit board, which can be solid copper or grid copper. But other ways can also use indium tin oxide (ITO) technology to realize capacitive sensing, such as multimedia buttons of mobile phones, but not limited to the above. In addition, factors affecting the size of the inductive capacitance C include the parasitic capacitance effect of the entire touch panel 1 on the key P, the external force on the key P, and the environment where the touch panel 1 is located. Therefore, when the touch panel 1 is powered on and there is no external force or environmental interference, the sensing capacitance C has a non-zero value, so the initial value of the sensing data is non-zero, and the initial value is referred to as a steady-state value hereinafter.

Generally speaking, in the touch panel 1 , the sensor 12 obtains a sensing data according to the magnitude of the sensing capacitance C, and then transmits it through the transmission interface 13 . The signal processor 2 receives the sensing data through the transmission interface 21 , judges the sensing data through the touch judging device 22 to understand the situation of the key P being touched, and presents the judging result through the output unit 23 .

Wherein, the inductor 12 has a charge converter (Charge Transfer) 14 and a counter 15 . The implementation of the charging converter 14 can refer to FIG. 5 , which uses the power signal VDD to charge and discharge the sensing capacitor C to output a comparison signal with multiple pulses. The counter 15 uses a clock signal with multiple pulses to count the interval between two adjacent pulses of the comparison signal as the sensing data about the inductive capacitance C. More specifically, the sensing data refers to "two comparison signals". Adjacent pulse interval" covers "how many pulses of the clock signal".

The presentation mode of the output unit 23, for example: if it is determined that the key P is touched, the seven-segment display as the output unit 23 will emit light matching the sensing data, and for example: if it is determined that the key P is touched, do The speaker of the output unit 23 will beep.

More specifically, in view of the fact that in the prior art, erroneous touch judgments are often caused by the environment of the touch panel 1, the touch judgment device 22 specifically implements the first preferred embodiment of the touch judgment method of the present invention to improve the accuracy of judgment. Spend. The touch judging device 22 in FIG. 4 has a judging unit 24 and a correcting unit 25 to analyze the sensing data at intervals of sampling time. The main steps include the following process as shown in FIG. 6 .

Step 71: The judging unit 24 judges whether the sensing data at the current sampling time point≧correction threshold, wherein the correction threshold>steady-state value. If yes, continue to step 72; if not, it means that the current sensing data is between the correction threshold and the steady state value, so it is determined that the button P is not touched and skip to step 73.

Step 72: The judging unit 24 judges whether the sensing data at the current sampling time point≧touch threshold, wherein the touch threshold>correction threshold. If yes, it is determined that the button P is touched and the process goes to step 74 , otherwise it is determined that the button P is not touched and the process goes to step 74 .

Step 73: The correction unit 25 uses the steady state value to correct the sensing data so as to approach the steady state value.

Step 74: The judging unit 24 returns to step 71 when a period of sampling time has passed since the previous sampling time point.

Preferably, in this example, the steady state value=0, the correction threshold=360, and the touch threshold=1600, but other applications are not limited thereto. In practice, when the key P is actually touched and the sensing data = Ds, then the touch threshold is set to = Ds × 0.8, and the correction threshold is set to = Ds × G, where 0.1<gain G<0.5. In addition, the correction unit 25 corrects the sensing data according to the current sensing data and the steady-state value, that is, the corrected sensing data=A×current sensing data+B×steady-state value, preferably the first parameter A=0.6 And the second parameter B=0.4, these two parameters are related to the material of the button P (such as real copper or mesh copper). The setting of the above parameters is a preferred embodiment, but other applications should not be limited thereto.

Two examples are given below to illustrate, where the steady state value=0, the correction threshold=360, and the touch threshold=1600.

Referring to FIG. 7 , in the absence of environmental interference, the sensing data only presents a value = 2000 when the button P is pressed externally (ie time t = 1-3), and maintains a value = 0 at other times. Therefore, the touch determination device 22 of this embodiment determines that the key P is touched at time t=1˜3.

Referring to FIG. 8 , in the case of environmental interference, the sensing data is increased to 1500 by the environmental interference at time t=1-8, because 1500 is between the correction threshold and the touch threshold, so the sensing data is not corrected. The sensing data increases to 2000 at time t=5-6 due to the external force pressing the key P, so the touch determination device 22 of this embodiment can correctly determine whether the key P is touched.

Moreover, the touch judging device 22 can also implement the second preferred embodiment of the touch judging method of the present invention to achieve the purpose of improving the judgment accuracy, as shown in FIG. 9 .

Step 81: The judging unit 24 judges whether the sensing data at the current sampling time point≧the touch threshold. If yes, it is determined that the button P is touched and skip to step 84 . If not, it is determined that the key P is not touched and the process continues to step 82 .

Step 82: The judging unit 24 judges whether the sensing data at the current sampling time point≧the correction threshold. If yes, the process skips to step 84 ; if not, it means that the current sensing data is between the correction threshold and the steady-state value, and proceeds to step 83 .

Step 83: The correction unit 25 uses the steady state value to correct the sensing data so as to approach the steady state value.

Step 84: The judging unit 24 returns to step 81 when a period of sampling time has passed since the previous sampling time point.

In particular, the sensor 12 and transmission interface 13 of FIG. 4 can be integrated into one touch chip 10, and the transmission interface 13 of the touch panel 1 and the transmission interface 21 of the signal processor 2 are the I2C (I2C) proposed by Philips. Inter-Integrated Circuit, inter-integrated circuit) interface, but other applications are not limited to this.

To sum up, in the aforementioned preferred embodiment, the correction unit 25 performs correction only when the sensing data<the correction threshold, so even if there is environmental interference and the correction threshold≦sensing data<the touch threshold, the judging unit 24 still It can accurately determine the touch situation of the button P, unlike the prior art, which is prone to misjudgment due to downsizing the sensing data, so the purpose of the present invention can indeed be achieved.

But the above-mentioned person is only preferred embodiment of the present invention, when can not limit the scope of the present invention implementation with this, promptly all the simple equivalent changes and modifications that are done according to the patent scope of the present invention and the content of the description of the invention, All still belong to the scope that the patent of the present invention covers.

Claims (5)

1. A touch judging method, suitable for judging whether a button on a touch panel is touched, it is characterized in that, comprising the following steps: (A) analyzing a sensing data about the button at regular intervals; (B) When the sensing data at the current time≧a touch threshold, it is judged that the key is touched; and (C) When the sensing data at the current time is less than the touch threshold, it is judged that the button is not touched, and the sensing data is not corrected when the sensing data is between the touch threshold and a correction threshold , correcting the sensing data when the sensing data is between the correction threshold and a steady-state value; Wherein, the touch threshold>the correction threshold>the steady-state value, and the steady-state value is the sensing data of the key when the touch panel is just powered on and not touched; Step (C) is to use the sensing data and the steady-state value at the current time to correct according to the following formula; Corrected sensing data = A × current sensing data + B × steady state value; Wherein, a first parameter A and a second parameter B are both related to the button material. 2. A touch judging device, which is suitable for judging whether a touch button arranged on a touch panel is touched, it is characterized in that, comprising: A judging unit, which analyzes a sensing data about the button at regular intervals, and judges that the button is touched when the sensing data at the current time is greater than or equal to a touch threshold, and when the sensing data at the current time < the When the threshold is touched, it is judged that the button has not been touched; and A correction unit, when the judging unit judges that the button is not touched, the sensing data is not corrected when the sensing data is between the touch threshold and a correction threshold, and the sensing data is between the correction threshold Correct the sensing data when between and a steady-state value; Wherein, the touch threshold>the correction threshold>the steady-state value, and the steady-state value is the sensing data of the key when the touch panel is just powered on and not touched; The correction unit uses the sensing data and the steady-state value at the current time to perform correction according to the following formula; Corrected sensing data = A × current sensing data + B × steady state value; Wherein, a first parameter A and a second parameter B are both related to the button material. 3. A signal processor suitable for coupling a touch panel provided with an input unit, the input unit comprising a button and an inductive capacitor, characterized in that it comprises: a transmission interface for receiving a sensing data from the touch panel, wherein the sensing data is related to the size of the sensing capacitance, and the sensing capacitance corresponds to the button; A judging unit, which analyzes the sensing data at regular intervals. When the sensing data at the current time is ≧ a touch threshold, it is judged that the button is touched. When the sensing data at the current time is < the touch threshold , judging that the button has not been touched; and A correction unit, when the judging unit judges that the button is not touched, the sensing data is not corrected when the sensing data is between the touch threshold and a correction threshold, and the sensing data is between the correction threshold Correct the sensing data when between and a steady-state value; Wherein, the touch threshold>the correction threshold>the steady-state value, and the steady-state value is the sensing data of the key when the touch panel is just powered on and not touched; The correction unit uses the sensing data and the steady-state value at the current time to perform correction according to the following formula; Corrected sensing data = A × current sensing data + B × steady state value; Wherein, a first parameter A and a second parameter B are both related to the button material. 4. The signal processor as claimed in claim 3, wherein the transmission interface is an interface between integrated circuits. 5. signal processor as claimed in claim 3, is characterized in that, also comprises: An output unit, when the judging unit judges that the button is touched, the output unit emits light matching the sensing data.