TW201115156A - Capacitance touch contorl element - Google Patents

Abstract

The present invention provides a capacitance touch control element, which includes a variable capacitor, an integrator and a detector. The variable capacitor varies its capacitance according to a touch event on the capacitance touch control element. The integrator is coupled to the variable capacitor and a reference signal, and implemented for generating an output signal according to the capacitance of the variable capacitor and the reference signal. The detector is coupled to the integrator, and implemented for receiving the output signal and generating a touch event detection result according to the output signal.

Description

201115156 VI. Description of the Invention: [Technical Field] The present invention relates to a touch panel, in particular to a capacitive touch element using an integrator. [Prior Art] In a variety of electronic products, the touch panel provides a user interface that is simple and easy to operate. Traditional touch panels are often implemented with capacitors and op amps. Please refer to FIG. 1 , which is a schematic diagram of a conventional capacitive touch element 100 . The capacitive touch element 100 includes a current source I, a capacitor q' operational amplifier 110, a switch 120, and a control module 130. Under normal circumstances, the current source j continuously charges the capacitor G to form an input voltage Vx ' while an output voltage Vout of the output of the operational amplifier is fed back to a first input terminal (I) of the operational amplifier 110 via the switch 120. The input voltage Vx is equal to the output voltage Vout. When the input voltage Vx exceeds the input voltage vBG of a second input terminal (+) of the operational amplifier 110, the switch 12 turns off the first input terminal (I) and the output terminal of the operational amplifier 110. Connect, and ground the first input (1) to reset the input voltage vx. After the input voltage vx is reset, the switch 120 is coupled to the first input (1) and output of the operational amplifier 110, and the current source I charges the capacitor q again and repeats the above steps. In other words, the input voltage Vx 201115156 will rise with a fixed slope (^) until it is equal to the input voltage vBG, then it will be heavy

Cl sets the input voltage vx to zero, repeats the above steps to form a periodic triangular wave, and the output voltage VOUT keeps track of the value of the input voltage vx. Thereafter, the operational amplifier 110 transmits the output voltage V〇ut to the control module 130 to determine whether a condition for the occurrence of a touch event is reached.

In May, with reference to Figure 1, reference is made to Figure 2. Figure 2 shows the change in capacitance seen in the first-to-one input terminal of the capacitive touch element 1GG when a touch event occurs. schematic diagram. When the touch event occurs... the object (for example, the user's finger) touches the panel to form - parasitic capacitance & current source! Then charge the capacitor core plus the parasitic capacitance Cf 'to increase the input voltage % to the other - the mosquito is lower than the original low slope' until it is equal to the input voltage VBG, then reset to zero, repeat the above steps to form another cycle Long triangular waves. Please refer to Figure 3, when no touch event occurs, the input voltage Vx will be formed by the slope of the s) - three tests, and in the case of a coffee event, the slope of the input voltage V (7 X Å) will form. The period of the third period of the triangle period of the three __ collision events _ wave - the number of periodic calculations of the predetermined number or the calculation of the triangle control element ==: when the time is born, the generation of the triangular wave period of the electric butterfly temple Therefore, it requires a longer reaction time than 201115156' and the capacitor core requires a larger area in practice, which often results in an increase in manufacturing cost. Furthermore, in practice, one panel requires the use of multiple sensing elements. It is inevitable that each sensing element will cause a touch event due to the stray capacitance formed by the printed circuit board (PCB) circuit and the input/output 塾 (inpUt/〇utput pad) in the circuit. The error at the time of judgment and the crosstalk between the respective sensing elements. Please refer to Fig. 4, which is a partial circuit diagram of a conventional capacitive touch panel. Only four conventional capacitive touches are shown in Fig. 4. Control elements 100a~i00e, their structure and operation The capacitive touch element 100 shown in FIG. 1 is not described here. When the touch point is at the node A, the conventional capacitive touch element 1〇〇a will be due to the stray capacitance seen. Different from when the touch point is at the node B, so even if the two are on the same sensing axis & processed by the conventional capacitive touch element 10a, the result of the final output touch is It may also be different, and the larger the area of the panel, the longer the sensing axis will be, and the result of the judgment results obtained by different touch points becomes more and more serious, which affects the detection and determination of the touch component. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a capacitive touch element that improves the likelihood and speed of touch events and overcomes the effects of recording capacitance-jump event determinations. The utility model provides a capacitive touch component, comprising: a variable electric unit, an integrator and a detector, wherein the variable capacitor is based on a touch event of the capacitive touch on the 201115156 control element. Change its capacitance value. The integrator is connected to the variable The capacitor and the reference signal are used to generate an output signal according to the capacitance value of the Weirong and the reference signal. The _ _ is used in the integrator to receive the output signal and generate a touch event according to the output signal. The detection result is provided. According to another embodiment of the present invention, a capacitive touch element is provided, comprising: - signal detection such as - and - slope fine (3). The service inspection according to the capacitance

- Touch event on the touch device to generate - output signal. The slope detector is connected to the signal detection H' for generating a touch event detection result according to the slope of one of the round signals. [Embodiment] Please refer to Fig. 5, which is a schematic view showing an embodiment of a capacitive touch element of the present invention. The capacitive touch element 500 includes, but is not limited to, a variable capacitance 仏, a 10 minute H 510, and a detector 52 〇. The variable capacitance Cr represents the equivalent capacitance seen by the integrator 51 at an input terminal, including the line parasitic capacitance of the printed circuit board, the stray capacitance formed by the input/output 塾 in the circuit, and the like. When the capacitive touch element 5〇〇 touches a event, the variable capacitor 改变^ changes its power according to the touch event, for example. When the object is like the user's finger, the paste panel is formed to form a parasitic capacitance cf, which increases the equivalent capacitance seen at the input. The integrator 51 is connected to the variable. The power CR and a periodic reference signal v are used to generate an output signal ν〇υτ according to the capacitance value of the variable capacitor CR and the reference Vref. _ 〇 52〇 is connected to the 201115156 t output signal W, and according to the received round-trip signal v. -, Touch the event price measurement result TR. In this embodiment, the reference signal #v is a periodic square wave, which is used to move the REF ” ” 駆 駆 駆 510 510 ' ' ' ' ' ' 积分 积分 510 510 510 510 101 101 101 101 101 101 101 101 101 101 101 101 101 5 101 5 5 5 The amplifier 51〇1 has a first terminal (you connect the variable capacitor Cr and a second input terminal (1) to the reference signal coffee, and generate an output signal V0UT at the output terminal V-0UT to the detector 520. And the feedback Cfb is connected between the first input end (1) and the output end v-〇, and the output signal νουτ' is fed back to the first input end (-) of the operational amplifier pass. The operation can be explained by the following equation: = = a) such as cj·-) (1) - where 11 $ flows through the variable capacitor CR and the parasitic capacitance cf, and 12 is the current flowing through the feedback capacitor Cfb due to The operational amplifier is an ideal operational amplifier. The first input (1) does not pass any current, so 1 "12. During the predetermined time dT, the amount of charge charged to the Wei SCr and the parasitic capacitance Cf is (Cff cR ) *(v_) ' and the amount of charge charged by the current L to the feedback capacitor Cfb is c Ί, -V-). Another equation is obtained ⑴ formula _ ⑺: OUT 'c

V

Jb

And by equation (2), step-by-step (3): (2) (3) 201115156 d

Vout' d It cr K) In equation (3), d vo^t\ represents the slope of the output cue V〇ut' on the time axis.

Because of the wide slope, c is Cf=G when no touch event occurs, so V· will rise with a small oblique S j(~); and when a touch event occurs, ν〇υτ , with a big rise. Compared with the prior art, the output signal νουτ of the capacitive touch element of FIG. 1 is increased according to the presence or absence of the touch event by the positive J c_ + C; The touch ratio of the touch element 5〇〇 is (-

The sfl number V0UT’ is proportional to I C.fb J

It applies the characteristics of the integrator, so that the slope of the output signal V is only related to the ratio of the capacitance value. In practice, the ratio between the capacitances of the 敎_ can be reduced, thus saving the manufacturing cost. . In addition, since the integrator Μ0 is driven by the reference signal ¥559 of the job, the shame member of the present invention is made on the same panel (for example, the capacitive touch element 5GG shown in FIG. 5) When the 'each time is simultaneously driven by the reference signal V·, the stray capacitance seen by the different touch points of each capacitive touch element is equivalently the same, so There is not much difference in the final touch point judgment result' and the interference between the various sensing elements is lower than that of the prior art. 9 201115156 The controller 520 receives the output signal generated by the integrator 510. Bribe, and according to the slope of the output signal V〇UT', the touch event detection result TR is generated. For example, the detector 52G can output the signal V() UT, the amplitude variation within the predetermined time Τι Whether Δv becomes larger to determine the touch event detection result TRe, please refer to FIG. 6 , which is the waveform of one of the capacitive touch elements 5 第 of the capacitive touch element 5 in FIG. 5 and an output signal. Figure. When the amplitude variation Δν does not change much or is zero, the _ 520 will determine that the touch event has not occurred; however, when the amount of amplitude change exceeds a threshold, the detector 520 determines that a touch event has occurred. In another embodiment - the detector 520 The output signal ν〇υτ can be detected to determine whether the touch event detection result TR is exceeded by a predetermined threshold value Vth within a predetermined time L. When the output signal v0UT fails to exceed the predetermined threshold value Vth, the detector 汹The f-touch event does not occur; when the trace is like the signal vGUT, __槛V:H, the detector 520 determines that the touch event has occurred. Compared to the prior art, the present invention applies the slope to generate the touch. The point of the event price measurement is that it only needs a very short anti-correction, and (4) it needs to wait for the output signal to pass through multiple cycles as judged in the prior art. In addition, the circuit of the printed circuit is in 2 circuits. The stray capacitance formed by the input/output 会 will increase the slope of the signal due to the characteristics of the integrator, thereby accelerating the determination of the touch event. Please note that all the above implementations are only used to describe the present invention, and Limit this 201115156 - the invention of the invention For example, the side H 520 in Figure 5 does not have to be matched with the product divider 510, and can be used alone with a conventional capacitive touch element to detect the rate of an output signal to generate A change in design is also within the scope of the present invention. Please refer to FIG. 7 , which is a schematic diagram of another embodiment of the capacitive touch element of the present invention. 〇〇 includes, but is not limited to, a signal detector 702 and a slope detector 704. The signal detector 7〇2 can be implemented by any conventional capacitive touch element for capacitive touch control. The φ-touch event on the component produces an output signal 10(10)", and the slope controller 7〇4 is connected to the signal detector 702' for receiving the output signal v. And, according to the slope of one of the output signals ^" to generate a - touch event detection result TR'. For example, as the operation of the detector 520 described above (see Fig. 6), the slope side device 7〇4 can Detecting the output signal It, whether the amplitude change amount in a predetermined time period becomes larger to determine the touch event detection result TR, or whether the detection output signal V〇ut exceeds the gate broadcast within a predetermined time The value determines the touch event detection result JR. In summary, the present invention provides a capacitive touch element that uses the characteristics of an integrator to obtain an output signal, and then determines the touch through the slope of the output signal: whether an event occurs. The use of the integrator can reduce the unnecessary capacitance area, thereby reducing the manufacturing cost. In addition, applying the slope to determine the touch event can increase the reaction speed of the capacitive touch element. The present invention applies the job signal to drive the integrator. It can also effectively overcome the influence of stray capacitance on the determination of touch events. The preferred embodiment of the invention is only described in the U.S. Patent Application Serial No. 201115156, and the scope of the present invention is covered by the present invention. [Fig. 1] A schematic diagram of a touch element. Fig. 2 is a view showing the change of the capacitance value of the input terminal of the operational amplifier II in Fig. 1. Seen when the touch event occurred

Fig. 3 is a waveform diagram of the output signals of the conventional capacitive touch elements in Fig. 1 in the presence of a touch event and a non-touch event. FIG. 4 is a schematic diagram of a part of a circuit of a conventional capacitive touch panel. Figure 5 is a schematic view of an embodiment of a capacitive touch element of the present invention. Figure 6 is a waveform diagram of a reference signal and an output signal of a capacitive touch element in Figure 5. FIG. 7 is a schematic view of another embodiment of the capacitive touch element of the present invention. [Main component symbol description] Call 100, 100a~100e, 500, 700 Capacitive touch elements 110, 5101 Operational amplifier 120 Switch 130 Control module 510 Integrator 520 Detector 12 201115156 702 Signal detector 704 Slope detector C! Capacitor Cr Variable Capacitor Cf Parasitic Capacitance Cft Feedback Capacitor I Current Source 13

Claims (1)

201115156 VII. Application for patents: 1. A capacitive touch element comprising a variable capacitor that changes its capacitance according to a touch event on the capacitive touch element. An integrator coupled to the variable capacitor and a reference signal for generating an output signal according to the electric valley of the variable electric valley and the reference signal; and - the debt measurement 0' is connected to the integral The device is configured to receive the round-trip signal and generate a touch event detection result according to the round-trip signal. 2. The capacitive touch element of claim 7, wherein the reference signal is a periodic signal. 3. The capacitive touch element described in the patent application, wherein the integrator comprises an operational amplifier having a first input terminal coupled to the variable capacitor to be coupled to the reference The signal, and the J-feedback capacitor is generated at the output terminal, and is connected between the first input terminal and the wheel output terminal. 4. If the capacitive touch described in the scope of the patent application is a slope detector, the result of the detection of the helmet is a cobalt-capped sleeve. m ..... each one... 6 sea detector system slope The capacitive touch element of claim 4, wherein the slope detection device detects an amplitude variation of the output signal for a predetermined time to generate The touch event detection result. 6. The capacitive touch element of claim 4, wherein the slope detector detects whether the round signal exceeds a predetermined threshold within a predetermined time to generate the touch event detection. result. 7. The electric valley type touch component comprises: a signal detector 'for generating an output signal according to a touch event on the capacitive touch element; and a slope detector, light The signal detector is connected to generate a touch event detection result according to the slope of the round signal. 8. For example, U (4) 7-fold capacitive-type financial system detects the amplitude change of the input heart and the slanting sheep to detect the touch event. Eight, 囷 type: