TWI500999B - Touch panel - Google Patents

Description

Touch panel

The present invention relates to a touch panel, and more particularly to a touch signal that can be generated by recognizing a body contact or non-contact when the substrate is not bent, and capable of sensing multi-touch, and can be provided as A touch panel mounted on a single substrate of a display device.

Generally, the touch panel is an input device attached to a display panel, such as an LCD, a PDP, an OLED, or an AMOLED, and generates a position detection signal corresponding to the touch point by a finger or a pen. Touch panels are widely used in personal devices, industrial devices, and DIDs (Digital Information Devices).

Conventional touch panels are classified into a resistive type, an optical type, and the like, but the resistive touch panel is widely used because of its simple process and low cost. Figure 1 shows a resistive touch panel. In FIG. 1, the touch panel includes a first substrate 3 and a second substrate 5 that face each other on the display device 1. Transparent conductive layers 7 and 9 such as ITO (indium tin oxide) are applied to the upper surface of the first substrate 3 and the lower surface of the second substrate 5, respectively, and a plurality of resistance points 11 are provided on the upper surface of the first substrate 3. And although not shown, a plurality of resistance points are correspondingly provided on the lower surface of the second substrate 5.

If the pen 17 contacts the second substrate 5, the second substrate 5 is bent, and the conductive layer 9 of the second substrate 5 contacts the conductive layer 7 of the first substrate 3, and then the voltage values applied to the conductive layers 7, 9 are according to the corresponding resistance. The resistance value of the point 11 is lowered, and the detected voltage value is converted to a digital value by the AD converter 13, and the digital value is sent to the CPU 15 and the coordinate value of the touch point is obtained. This resistive touch panel is widely used because of its simple process and low cost.

However, the resistive touch panel has some disadvantages in that the deformation of the second substrate 5 is inevitable by detecting the contact using the curvature of the second substrate 5. Free. If the second substrate 5 is made of a film, the bending of the substrate causes scratches on the surface thereof. If the second substrate 5 is made of glass, the glass should be ground or etched to 0.2 to 0.3 mm to have sufficient elasticity, which causes structural weakening, and which may crack before becoming longer. And because the contact pressing of the curved substrate is rather weak, if the amount of bending is small, the contact cannot be recognized, and the contact signal may be lost.

Since the two substrates 3, 5 are used and the conductive layers 7, 9 of, for example, ITO are applied to all regions of the first substrate 3 and the second substrate 5, the resistive touch panel has a relatively low light transmittance. Low transmittance necessarily results in a low quality display device 1. And because it uses two substrates, it is inevitable that spacers must be provided to separate the two substrates, which results in complicated processes, high cost, and low yield.

A resistive touch panel cannot recognize multiple touches, which means multiple contacts that occur simultaneously. For example, if many people write an electronic blackboard at the same time and multiple touches occur, the conventional resistive touch panel cannot recognize multiple touches, or it may operate incorrectly.

And when the touch is detected by the analog signal, converting the analog signal to a digital signal will cause a time delay. Furthermore, the cost of a reliable AD converter cannot be ignored. In addition, the key problem of the resistive touch panel is that it needs to be corrected to fix the reference point of the resistance point. If the correction is not accurate, the error of detecting the position will increase. And this panel cannot be used for large display panels.

The present invention solves the above mentioned problems, and an object of the present invention is to provide a touch panel, wherein the touch chamber is composed of a three-way switching device (switching device with three terminals) and a conductive pad, and is multi-touch Control can be achieved by using a single The substrate is recognized by detecting soft contact or proximity of the body, so that the problem of reduced product life due to the bending of the substrate can be avoided, and the light transmittance can be increased, thereby improving the quality of the display device. Moreover, the mounting of the touch panel on the display device is simple.

SUMMARY OF THE INVENTION An object of the present invention is to provide a touch panel that can utilize established and proven display device manufacturing methods to achieve mass production and quality reliability and low cost.

The purpose of the present invention is to provide a diffusion sheet between the display device and the touch panel to prevent the Murray effect.

The object of the present invention is to provide a memory for storing a touch signal to prevent loss of a touch signal, which can call out and process a touch signal stored in the memory when the touch signal is lost.

The object of the present invention is to provide a touch panel in which the gate terminal of the switching device is floating, and the touch signal can be obtained by using static electricity of the body.

SUMMARY OF THE INVENTION An object of the present invention is to provide a touch panel in which contact pads are reliably electrically contacted to each other by a toothed conductive pad formed to be engaged with each other and by electrical conductivity of the body.

The object of the present invention is to provide a novel non-contact multi-touch identifiable touch panel by using the electrostatic capacitance of the body.

According to an aspect of the present invention, a touch panel is provided that can detect a contact or proximity of a contact mode including a human body to generate a corresponding position detection signal, the touch panel including: a substrate made of a light transmissive substance a plurality of first signal lines 32 and second signal lines 34 formed on a surface of the substrate 30, and the position detection signal is first through the plurality The signal line 32 and the second signal line 34 are input or output; the plurality of touch chambers 60 are formed on the divided active area of the substrate 30, and the plurality of touch chambers 60 include a three-way switching device 40 and are connected to the switching device 40. a conductive pad 50 of the gate terminal, in each divided region of the substrate 30, the three-way switching device 40 is placed between the first signal line 32 and the second signal line 34; a touch position detection When the contact pad 70 is in contact with or close to the conductive pad 50, the touch position detector 70 applies a position detection signal to the first signal line 32 according to the state change of the switching device 40, and The second signal line 34 receives a position detection signal to obtain a target value of the touch chamber 50 that is touched.

According to another aspect of the present invention, a diffusion sheet 90 is further provided under the substrate 30.

According to another aspect of the present invention, the touch position detector 70 further includes a memory 74 that stores an address corresponding to the coordinate value of the touch room 60, so if the position detection signal is from the second signal line 34 Receiving, the coordinate value of the corresponding touch chamber 60 is stored in a corresponding address of the memory 74.

According to another aspect of the present invention, a plurality of gate signal lines 36 are further disposed on one surface of the substrate 30, and each of the touch chambers 60 includes a capacitor 54 connected between the conductive pads 50 and the gate signal lines 36, and The touch position detector 70 applies a gate signal to the gate signal line 36.

According to another aspect of the present invention, a plurality of gate signal lines 36 and sub-signal lines 37 are further disposed on one surface of the substrate 30, and the touch chamber 60 includes a first switching device 42 whose input terminal is connected to the first signal line 32. Connected to the conductive pad 50 of the gate terminal of the first switching device 42, input a second switching device 44 connected to the output of the first switching device 42 and a capacitor 54 connected between the output of the first switching device 42 and the sub-signal line 37. The input of the second switching device 44 is connected to The second signal line 34 and its gate terminal are connected to the gate signal line 36, and the touch position detector 70 applies a gate signal to each of the gate signal lines 36.

According to another aspect of the present invention, a plurality of gate signal lines 36 are further disposed on one surface of the substrate 30. The conductive pads 50 of the touch chamber 60 include first conductive pads 50a connected to the gate terminals of the switching device 40 and A conductive pad 50a is spaced apart and connected to the second conductive pad 50b of the gate signal line 36, and the touch position detector 70 applies a gate signal to the gate signal line 36.

According to another aspect of the present invention, the first conductive pad 50a and the second conductive pad 50b of each touch chamber 60 have alternating recesses 51 and protrusions 53, and the recesses 52 and the protrusions 54 are engaged with each other.

According to another aspect of the present invention, a plurality of sub-signal lines 37 are further disposed on one surface of the substrate 30. Each of the touch chambers 60 includes a switching device and a conductive pad 50 connected to the gate terminal of the switching device 40, wherein the gate of the switching device The extremes are connected to the first signal line 32, and the input and output terminals thereof are connected to the sub-signal line 37 and the second signal line 34, respectively.

According to another aspect of the present invention, a plurality of gate signal lines 36 and sub-signal lines 37 are further disposed on one surface of the substrate 30, and the touch chamber 60 includes a first switching device 42 (the input end of which is connected to the first signal line) 32 and its gate terminal are connected to the gate signal line 36), the conductive pad 50 connected to the output end of the first switching device 42, and the second switching device 44 (the gate terminal of which is connected to the output of the first switching device 42 and The input end and the output end are respectively connected to the sub signal line 37 and the second signal line 34), and touch The position detector 70 applies a gate signal to each of the gate signal lines 36.

According to another aspect of the invention, capacitor 54 is coupled between the output of first switching device 42 and sub-signal line 37.

According to another aspect of the present invention, the sub-signal lines 37 are respectively provided by the first sub-signal line 37a and the second sub-signal line 37b, and the input terminal of the second switching device 44 is connected to the first sub-signal line 37a, and the capacitor One end of 54 is connected to the second sub-signal line 37b.

According to another aspect of the present invention, a transparent insulating layer is applied to one surface of the substrate 30 to protect the touch chamber 60.

According to the present invention, the signal line is placed on a single substrate, and the touch chamber includes a three-way switching device connected to the signal line of the divided active area of the substrate, and the conductive pad, and when the body or When other objects with conductive properties contact or approach the conductive pad, the coordinate value of the touch chamber can be changed according to the state of the switching device, so that the position detection signal can be generated without bending the substrate, and the slight touch on the substrate can be prevented. The signal loss caused by the pressing and the use of the touch panel of the present invention can be extended compared with the curved touch panel. Moreover, since only a single substrate is used, the light transmittance can be enhanced and the quality of the display device can be improved, and since the spacer is not used to separate the substrate, the panel can be made thin and simple, and the manufacturing process of the touch panel is also simple. of.

Moreover, according to the present invention, since the present invention independently recognizes a signal from a touch room by using a three-way switching device, multi-point touch can be detected. Furthermore, it can be manufactured via well-developed LCD or AMOLED manufacturing methods to achieve reliable mass production with low defect ratios. And because the position detection signal can be obtained in digital format, the response speed is very fast and can effectively prevent noise or Functional failure caused by other environmental factors. And it can be used in daylight without any malfunction. There is no need to fix any correction of the reference point, and it can be suitably used for a large-sized display panel.

According to the present invention, by providing a diffusion sheet under the substrate, the Murray effect due to signal line interference can be prevented.

Furthermore, according to the present invention, the position detection signal can be temporarily stored in the memory, so that when the amount of the touch signal is increased and the processing cannot be processed immediately, the detected position detection can be prevented by calling and processing the stored data. The loss of the signal.

According to the present invention, the gate terminal of the switching device is floating, and the switching device can be turned on or off by the static of the body, which can produce a very simple touch panel structure.

According to the present invention, the conductive pad pairs of the touch chamber are fabricated in the form of meshing teeth, and the conductive pads are electrically connected by the conductive properties of the body, so that the contact points can be recognized at any point of the active area of the touch panel.

According to the present invention, since the non-contact touch can be recognized by using the electrostatic capacitance of the body, the conductive pad can be protected by the protective coating or can be concealed by being placed on the lower surface of the substrate; it can prevent, for example, ITO. Peeling of the transparent conductive layer to achieve long product life.

In addition, since the driving IC of the present invention transmits and receives data only and does not operate the load, it is different from the gate IC or the source IC of the LCD display device, or the AD converter of the conventional touch panel, which requires a minimum of power. . In particular, the receiving driver IC receives only the high-impedance signal, so that almost no power is consumed. Therefore, if the touch panel of the present invention is used for a mobile device such as a mobile phone, the battery life can be greatly increased.

Hereinafter, preferred embodiments of the present invention are described. First of all, the present invention relates to a touch panel to be placed on top of a display panel such as an LCD, a PDP, an OLED, and an AMOLED, or to be used independently, which is different from a conventional touch panel. Two substrates are used in the conventional touch panel, and a touch signal is generated when the two substrates are in contact with each other due to the curved substrate. According to the present invention, a touch chamber including a three-way switching device such as a TFT and a conductive pad is formed on a single substrate, and if the body is in contact or close, it senses a change in the state of the TFT to obtain a touch signal.

The touch panel of the present invention has a structure in which a substrate is separated by a plurality of regions, and a touch chamber including a switching device and a conductive pad connected to the gate of the switching device is formed in each of the divided regions. The source terminal (hereinafter referred to as the input terminal) and the 汲 terminal (hereinafter referred to as the output terminal) of the switching device are connected to the signal line or the sub-signal line, and the gate terminal of the switching device is connected to the conductive pad. The gate is in a floating state, which is turned on or off by static or electrostatic capacitance of the body, or it can be turned on or off by receiving a gate signal from the gate signal line. When the state of the switching device changes according to the voltage applied to the gate terminal, the position detection signal is received via the signal line to obtain a touch signal.

The present invention provides various modifications of the basic structure described above, and includes the following modifications: adding a switching device to each of the touch chambers, providing a pair of conductive pads, or adding a capacitor. The specific embodiments described below include a specific embodiment in which the state of the switching device is changed by the static electricity of the body, and the state of the switching device is changed by electrically connecting a pair of conductive pads spaced apart from each other due to physical contact. The specific embodiment and the state of the switching device are specific embodiments in which the electrostatic capacitance of the body is changed. Although not described, the present invention covers that the position detection signal is transmitted or received by two signal lines, or that the switching device and the conductive pad are provided in each of the touch chambers, so that when the body is connected A specific embodiment of the touch signal can be obtained according to the state change of the switching device when the conductive pad is touched or approached.

Also, the touch panel of the present invention can be mounted separately from the display panel, but it can be fabricated by a developed and reliable TFT manufacturing method using a method similar to LCD or AMOLED display panel manufacturing. Thereafter, the switching means can be replaced by 'TFT' and the same number can be applied to the switching means and the TFT.

Referring to Figure 2, a single substrate 30 is placed on top of the display device 20, which is fabricated from glass, film or other suitable light transmissive material. The driver ICs 71 are mounted on the edge of the substrate 30, as described below, applying a position detection signal or a gate signal to the signal line. The driver ICs 71 can be distributed at the edges, or they can be concentrated or integrated into portions of the edges. Further, the driver ICs 71 may be mounted on the edge of the substrate 30 in the form of a COF (Crystalline Film) or COG (Crystal Overlay).

Although the touch panel of the present invention is placed on the top of the display device 20 in FIG. 2, the touch panel of the present invention includes a single substrate, so that it can be embedded in the display device 20 without damaging the slim and small size of the display device. . For example, in the case of an LCD panel, the single touch panel of the present invention can be assembled on a liquid crystal panel in which a TFT substrate and a color filter are combined, and then a polarizing plate is placed thereon, and the combined panel can be installed in the BLU chamber. .

FIG. 3 is a schematic view showing a touch panel according to an embodiment of the present invention. A plurality of first signal lines 32 and second signal lines 34 are placed on one surface of the substrate 30. The first signal line 32 is to transmit the position detection signal, and the second signal line 34 is to receive the position detection signal. In the third figure, the signal lines 32, 34 are crossed to each other, but they may be arranged in parallel or they may be tilted. Place.

The three-way switching device 40 is connected to the first signal line 32 and the second signal The gate terminals 34 and the gate terminals of the three-way switching device 40 are connected to the conductive pads 50 to form the touch chamber 60. Preferably, the three-way switching device 40 is a TFT. As shown, the input of TFT 40 is coupled to first signal line 32, and the output of TFT 40 is coupled to second signal line 34. Therefore, if the Off voltage is applied to the gate terminal, the first signal line 32 and the second signal line 34 are not connected to each other. If the On voltage is applied to the gate terminal, the first signal line 32 and the second signal line 34 are connected to each other, so that the position detection signal can be transmitted from the first signal line 32 to the second signal line 34.

The conductive pad 50 is formed on the top of the substrate 30 by applying a transparent conductive material such as ITO. The conductive pad 50 may be placed to cover all areas of the touch chamber 60, but preferably, it may be placed on a partial area of the touch room 60. For example, the width of the finger end of the touch substrate 30 is about several millimeters, if the touch chamber 60 is The width is smaller than the width of the end of the finger, and even if the conductive pad 50 covers only a part of the area of the touch chamber 60, the touch room can still contact the finger. Preferably, the conductive pads 50 are placed to align with one of the signal lines 32, 34. If the conductive pad 50 covers only a portion of the touch chamber 60 or is placed to align with the signal lines 32, 34, the light transmittance of the touch panel can be greatly increased.

The touch chamber 60 is formed by the active area of the split panel, where the actual contact is made, and the touch chamber 60 is arranged in a matrix format similar to the pixel array of the LCD panel. The touch chamber 60 of the present invention preferably has a display device 20 The resolution is reduced to an integer ratio reduction because the size of the conductive pad 50 is preferably larger than the pixel size of the display device 20 to ensure a reliable contact signal. However, the resolution of the touch chamber 60 may be the same as or larger than the resolution of the pixels of the display device 20.

If the resolution of the touch chamber 60 is the same as the resolution of the display device 20 or decreases in an integer ratio, the first signal line 32 and the second signal of the touch panel The line type of the line 34 can be aligned with the line pattern of the gate line and the data line of the display device, which enhances the transmittance of the touch panel and the quality of the display device 20, and prevents the waveform from being displayed due to interference between the signal lines. The Murray effect.

FIG. 4 shows another method of preventing the Murray effect. In this method, the diffusion sheet 90 is additionally placed under the substrate 30, and even if the line pattern of the touch panel is not aligned with the line pattern of the display panel 20, it can prevent Mo. Rui phenomenon. Returning to Figure 3, the touch panel has a 3*3 resolution example for illustration only, and the following examples are also described with 3*3 resolution.

FIG. 5 shows a system of the present invention including a touch position detector 70. The touch position detector 70 includes a drive IC 71, a clock controller 72, a signal processor 73, and a memory 74. The touch signal obtained by the touch position detector 70 is transmitted to the CPU 75 to generate an input signal corresponding to the touch position coordinate value.

The driving ICs 71 apply a position detection signal to the first signal line 32 and receive signals from the second signal line 34. The driving IC 71 is mounted on the edge of the substrate 30 in the form of COG or COF. In the specific embodiments described below, the driver ICs 71 can apply gate signals and sub-signals to the gate signal line 36 and the sub-signal line 37, respectively.

Preferably, the driving IC 71 sequentially applies the scan pulse to each of the first signal lines 32. To do this, the clock controller 72 generates a time division signal of several tens of milliseconds or less, and the signal processor 73 is based on the slave clock controller. The clock of 72 provides the pulse of Fig. 6 to the driver IC 71. Referring to FIG. 6, the drive IC 71 applies time division position detecting signals D1, D2, and D3 to each of the first signal lines 32, respectively. The period of each pulse is T.

If physical contact occurs in the right lower touch chamber 60 of Figure 3, The On voltage of the body static electricity is applied to the TFT 40 in the corresponding touch chamber 60, and the TFT 40 will be electrically connected. Accordingly, the position detection signal can be obtained from the corresponding second signal line 34 of the touch chamber 60 when the position detection signal is applied to the first signal line 32. Referring to FIG. 6, the position detection signal S3 is obtained through the rightmost second signal line 34 at time t3~t4, the obtained touch signal is transmitted to the signal processor 73, and the touch position detector 70 is obtained. Touch signals corresponding to coordinate values D3, S3. That is, if the pulse signal D3 is generated and the signal S3 is obtained, it indicates that the contact occurs at the coordinates D3, S3.

However, during data processing, the touch position detector 70 may be "busy" and cannot capture the position detection signal, and then the lost signal cannot be recovered and the reliability of the touch panel is reduced. To avoid this, the touch position detector 70 has a memory 74 having a larger number of bits than the touch chamber 60. As shown in FIG. 7, the memory 75 has an absolute address corresponding to the coordinate value of the touch room 60. In this embodiment, the memory 74 has a capacity of at least 9 bits, and the position detection signal received by the touch position detector 70 can be stored in the address "m9" with the coordinate value "D3, S3". The stored signal data can be called and used by the signal processor 73. For example, each time the touch position detector 70 scans all of the position detection signals applied to the first signal line 32, it reads the memory 74 to check for the presence of the missing signal. If the resolution of the touch chamber 60 is 1366*768, the capacity of the memory 74 needs to be at least 1049088 bits, so about 132 kilobytes are to be scanned.

In accordance with the present invention, a three-way switching device such as TFT 40 is mounted in each of the touch chambers 60. The TFT 40 has a number of advantages in that it is an established and certified device in the field of LCD or AMOLED. For example, the touch panel of the present invention can be manufactured by using a conventional LCD process, which makes reliable quality And low-cost mass production is feasible.

The main advantage of providing a three-way switching device such as TFT 40 to each of the touch chambers 60 is that multi-point contact can be identified by using the TFT 40 to separate the signals in each of the touch chambers 60.

Figures 8 and 9 show another embodiment in which the state of the TFT 40 is varied by using body static electricity. Different from FIG. 3, the first signal line 32 and the second signal line 34 are placed in parallel, but they may be placed in a crossed or oblique array. In general, the impedance of the TFT40 gate terminal is very high, such as tens of millions of ohms, so if the gate terminal is floating, when the finger 25 or other parts of the body contact the gate terminal, the TFT 40 can be opened by using the static electricity of the body. Or off. This embodiment provides a new touch panel to change the state of the TFT 40 by using body static electricity.

Referring to FIG. 8, in addition to the basic structure of FIG. 3, a plurality of gate signal lines 36 are further provided on the substrate 30, and the touch chamber 60 further includes a capacitor connected between the conductive pad 50 and the gate signal line 36. 54. The touch position detector 70 sequentially applies a scan pulse to each of the gate signal lines 36. Unlike the wave of FIG. 6, the position detection signal applied to the first signal line 32 does not need to be a time division signal, but when applied The gate signal should only remain in the On state. That is, if one of the gate signals G1, G2, and G3 is On, Dn is On, and Dn also has a sleep period during the sleep period between G1, G2, and G3. Dn can also be administered continuously. In this particular embodiment, the gate Off voltage of the gate signal is negative, and the gate On voltage is zero or positive, and the gate voltage can be determined in accordance with the voltage applied to the first signal line 32.

In FIG. 8, if the contact occurs in one of the touch chambers 60, the capacitor stores the electric charge generated by the static electricity of the body, and then, if corresponding to the touch chamber The gate terminal of 60 is in a state in which the gate off voltage is applied. Even if the capacitor 54 is in the charging step or in the fully charged state, the base voltage of the capacitor 54 is low, so that the TFT 40 cannot be electrically connected. If the gate On voltage is applied to the gate terminal of the corresponding touch chamber 60, the gate voltage rises to a higher gate voltage than the uncharged touch chamber, so that the TFT 40 can be electrically connected. Therefore, the signal received from the second signal line 34 is detected and the touch signal is obtained.

In order to achieve electrical connection by the charging capacitor 54, the gate On voltage should be selected to be zero or a positive voltage, and the voltage of the position detecting signal Dn is preferably 3 volts or more lower than the gate voltage. It is known that the voltage generated by the body is about 3 volts, so if the voltage of the capacitor is 3 or 4 volts, and this voltage is all applied to the gate terminal, the TFT 40 is not electrically connected when a voltage of 5 volts Dn is applied. If the Dn voltage is 1 volt, a reliable electrical connection of the TFT 40 can be ensured by a relatively low voltage of 3 volts generated by the body.

Referring to FIG. 9, in addition to the basic structure of FIG. 3, a plurality of gate signal lines 36 and sub-signal lines 37 are further disposed on the substrate 30, and the touch chamber 60 further includes a first switching device 42 connected to the first The conductive pad 50 of the gate terminal of the switching device 42, the second switching device 44, and the capacitor 54 connected between the output of the first switching device 42 and the sub-signal line 37. The input of the first switching device 42 is connected to the first signal line 32. The input of the second switching device 44 is connected to the output of the first switching device 42, the output of which is connected to the second signal line 34, and its gate terminal is connected to the gate signal line 36.

In this embodiment, the touch position detector 70 sequentially applies scan pulses to each of the gate signal lines 36, applies a signal synchronized with the gate signal Gn to the sub-signal line 37, or continuously applies the ground voltage. . The position detection signal Dn is applied by a fixed Hi pulse, or it can be Pulsed application of Gn synchronization.

In this embodiment, the gate Off voltage is -7 volts and the On voltage is 15 volts. The sub-signal applied via the sub-signal line is synchronized with the gate signal, so if the gate signal is Hi, the Hi level signal is applied, and if the gate signal is low, the Low level signal is applied. Preferably, the Hi level signal is 0 volts and the Low level signal is -15 volts.

If the body contacts any of the touch chambers 60, the first TFTs 42 are electrically connected by static electricity applied to the body of the conductive pads 50 corresponding to the touch chamber 60, and then the capacitors 54 are charged. If the gate signal is applied via the gate signal line 36, the Hi level signal is applied synchronously to the other end of the capacitor 54 via the sub-signal line 37. Therefore, the voltage charged in the capacitor 54 is electrically connected by the second switching device 44, so that the position detection signal can be obtained via the second signal line 34, and the touch position detector 70 reads the input position detection signal to obtain the touch. Control signal.

After a cyclic read is completed, the particular embodiment of Figure 9 must discharge capacitor 54 for the next cycle of reading. To this end, 15 volts are applied to all of the gate signal lines 36 to electrically connect all of the second TFTs 44 and apply zero voltage to the second signal line 34. This discharge can be performed during the short waiting time of the next cycle read.

Figure 10 shows a specific embodiment in which the state of the TFT 40 is changed by using body conductivity. Because the body has conductive properties, if the body contacts two conductive pads with different voltage levels, the conductive pads can be electrically connected. Because the impedance of the body is high, it is difficult to electrically connect the two conductive pads when the signal interval is large, but if the signal interval is about several microseconds, the conductive pads can be electrically connected by body contact.

Referring to Figure 10, in addition to the basic structure of Figure 3, a plurality of gates The pole signal line 36 is further disposed on the substrate 30, and the conductive pad 50 of the touch chamber 60 includes a first conductive pad 50a connected to the gate terminal of the TFT 40 and a portion separated from the first conductive pad 50a and connected to the gate signal line 36. Two conductive pads 50b. The touch position detector 70 sequentially applies a scan pulse to each of the gate signal lines 36, and the position detection signal applied to the first signal line 32 is a fixed Hi pulse, or it may be a gate signal Gn. One of them is a signal that remains in the On state when On.

11 is a configuration diagram of a specific embodiment of FIG. 10, showing the formation of the touch chamber 60 on the substrate 30, the first signal line 32 is placed longitudinally, and the second signal line 34 and the gate signal line 36 are Place it horizontally. The first conductive pad 50a and the second conductive pad 50b are in a tooth shape alternately having a recess 51 and a protrusion 53, and the recess 51 and the protrusion 53 are engaged with each other with a gap. According to this configuration, the first conductive pad 50a and the second conductive pad 50b maintain a very small gap, and the two conductive pads 50a, 50b can be electrically connected even if the body contacts any portion of the touch chamber 60. And any other electrically conductive object such as a pen can electrically connect the conductive pads 50a, 50b.

As shown in Fig. 11, the gate terminal 56 of the TFT 40 is connected to the first conductive pad 50a, the source terminal 57 of the TFT 40 is connected to the first signal line 32, and the 汲 terminal 52 is connected to the second signal line 34. The signal line includes an insulated gate metal and a source metal disposed on the substrate 30, and the terminals of the TFT 40 include an insulated gate metal, a source metal, and an amorphous germanium of a multilayer structure. To connect the conductive pad 50 and the TFT 40 to the signal line, a contact 59 formed by the ITO contact method is used.

If the body contacts any of the touch chambers 60, the pairs of conductive pads 50a, 50b are electrically connected to each other, and when the gate signals are applied via the gate signal lines 36, the TFTs 40 are electrically connected. Then, the touch position detector 70 can be from the second signal. Line 34 receives the position detection signal and obtains a touch signal. If, in FIG. 10, the signal G3 and the received signal S3 are applied, the touch position detector 70 can obtain the coordinate values D3, S3.

Figures 12 through 18 show a specific embodiment in which the state of the TFT 40 is altered by the use of capacitance between the conductive pad 50 and the body in accordance with the body's contact or proximity to the conductive pad 50. Referring to Fig. 12, the finger 25 approaches the conductive pad 50 at an interval 'd', as shown in the phase effect circuit diagram, the capacitance C may be present between the finger 25 and the conductive pad 50. The earth is used as a virtual ground. For example, when the body touches the conductive pad and the earth is used as a virtual ground, the capacitance is 10-20 pF, and the electrostatic capacitance is about 2~5 pF when the body approaches the conductive layer without contact. The invention utilizes the capacitive characteristics between the conductive pad 50 and the body to obtain a touch panel with contact or non-contact identifiable multi-point contact.

This particular embodiment can identify touch signals by a non-contact method, which has many advantages. The specific embodiment mentioned above is a structure that senses soft contact, so the conductive pad 50 should be placed outside the substrate 30, but the conductive pad 50 should be coated with a transparent substance (for example, TNO) to prevent the conductive pad 50 from being scratched. It will increase the cost of the process. However, in this embodiment, the touch chamber 60 including the conductive pad 50 may be coated with a transparent insulating layer such as a film, a plastic, an organic insulating layer, and a transmissive adhesive, or a conductive pad 50 may be placed behind the substrate 30. No coating may be applied to the touch chamber 60. Thereby, the high cost of the process of protecting the conductive pad 50 can be avoided, and the conductive pad 50 can be placed more stably to increase the durability of the display panel.

Referring to FIG. 13, in addition to the basic structure of FIG. 3, a plurality of sub-signal lines 37 are further placed on the substrate 30, and the touch chamber 60 includes the TFT 40 and the conductive pads 50. The gate terminal of the TFT 40 is connected to the first signal line 32, the input end thereof is connected to the sub-signal line 37, and its output terminal is connected Connected to the second signal line 34. The conductive pad 50 is connected to the gate terminal of the TFT 40. The touch position detector 70 sequentially applies scan pulses to the sub-signal lines 37 to obtain touch signals by electrical connection of the TFTs 40. In this particular embodiment, the signal applied to the first signal line 32 should be such that the TFT 40 is at a high impedance. For example, the driver IC 71 outputs the necessary signal to the first signal line 32, and then maintains the first signal line 32 in a high impedance state.

Figure 14 shows a specific embodiment in which two switching devices 42, 44 are used to detect the contact position. When the touch chamber 60 of the specific embodiment of FIG. 14 includes two switching devices 42, 44, even if the output from the driving IC 71 to the first signal line 32 is not high impedance, the signal on the conductive pad 50 can be held by the first TFT 42. At high impedance. Therefore, this embodiment will have a lower transmittance than that of Fig. 13, but it can provide a very reliable touch detection method in which each signal is processed.

Referring to FIG. 14, in addition to the basic structure of FIG. 3, a plurality of gate signal lines 36 and sub-signal lines 37 are further disposed on the substrate 30, and the touch chamber 60 includes a first TFT 42, a conductive pad 50, and a second TFT 44. . The output of the first TFT 42 is connected to the first signal line 32, and its gate terminal is connected to the gate signal line 36. The conductive pad 50 is connected to the output end of the first TFT 42. The gate terminal of the second TFT 44 is connected to the output terminal of the first TFT 42, the input terminal thereof is connected to the sub-signal line 37, and the output terminal thereof is connected to the second signal line 34. The touch position detector 70 sequentially applies scan pulses to each of the gate signal lines 36 to sequentially electrically connect the first TFTs 42, or simultaneously turns on the gate signals Gn, and induces charges by the body, and then sequentially connects the sub-signals. Line 37, which detects the contact position.

Figure 15 is a plan view of the touch chamber unit 60 of the embodiment of Figure 14. The first signal line 32 and the second signal line 34 are placed longitudinally Placed on the substrate 30, and the gate signal line 36 and the sub-signal line 37 are placed laterally. The conductive pad 50 is formed on the touch chamber 60 with a sufficiently large area. The conductive pads 50 may overlap the signal lines 32, 34 or may extend through regions separated by signal lines 32, 34. The gate terminal 56 of the first TFT 42 is connected to the gate signal line 36, and the source terminal 57 of the first TFT 42 is connected to the first signal line 32, and the drain terminal 58 of the first TFT 42 is connected to the conductive pad 50. The gate terminal 56 of the second TFT 44 is connected to the 汲 terminal 58 of the first TFT 42, the source terminal 57 is connected to the sub signal line 37, and the 汲 terminal 58 is connected to the second signal line 34. The signal lines are formed on the substrate 30 in a plurality of layers by source metal or gate metal. The terminals of the TFTs 42 and 44 are formed of a gate metal, a source metal, and an amorphous germanium of a multilayer structure insulated by an insulating layer. To connect the conductive pad 50 or the TFT 40 to the signal line, a contact 59 formed by the ITO contact method is used. A light blocking layer can be placed on the uppermost surface of each of the TFTs 42, 44 to prevent malfunction of the TFT due to the outermost light.

Figure 16 is a pulse diagram of a specific embodiment of Figure 14. The touch position detector 70 sequentially applies a scan pulse to each of the gate signal lines 36, and the gate signal Gn applied by the touch position detector 70 has a sufficient voltage sufficient to make the gate terminal of the first TFT 42 active. Level. For example, the voltage level of the gate signal Gn is set to be 3 volts higher than the position detection signal Dn from the first signal line 32. Preferably, the Hi level voltage of Dn is 13 volts, and the Hi level voltage of Gn is 18 volts. The gate Off voltage for stably turning off the first TFT 43 is -5 to -7 volts.

The gate signal Gn has a sufficient period of monitoring between each signal to obtain sufficient charging time for the dummy capacitor formed between the finger 25 and the conductive pad 50. As shown in the figure, sufficient monitoring time 1 sleep period For between G1 and G2. The position detecting signal Dn from the first signal line 32 is applied in such a manner that if any one of Gn is in the Hi state, the Hi level signal should be kept necessary, and preferably if Gn has an off state , Dn can also have a slight off state.

The touch position detector 70 applies the monitor voltage via the sub-signal line 37, and the signal Auxn from the sub-signal line 37 is provided in such a manner that if the Gn is in the Hi level period, it should be the Hi level, or It can be provided by a fixed Hi level. At the Hi level, the sub-signal Auxn provides a monitored voltage of 13 volts lower than the 13 volts of the charging voltage between the finger 25 and the conductive pad 50 via Dn. Here, 3 volts is the threshold voltage of the second TFT 44. For example, if the monitored voltage is 5 volts, it will be sufficient.

The waveform of the second signal line 34 and the method by which the touch signal is obtained will be described with reference to FIG. As in the case of applying the gate signals G1 and G2, if the gate signal is applied and the monitoring time is passed, but the body is not close, the signal Sn obtained via the second signal line 34 has a waveform as shown. This is because the body is not close to the capacitor and is not formed between the conductive pad 50 and the body. Specifically, when the gate signal G1 is applied, the first TFT 42 is electrically turned on, and the voltage level applied to the gate terminal of the second TFT 44 is higher than the voltage level applied to the input terminal of the second TFT 44 via the sub-signal line 37. The second TFT44 is also electrically turned on. However, because of the line impedance of the second signal line and the parasitic capacitor, as shown, the obtained signal Sn has a curve in the rising interval to the Hi level and the falling interval to the Low level. As shown in Fig. 16, it is assumed that T1 is the time from when the first TFT 42 is turned off by G1 and the monitoring time to when the gate voltage of the second TFT 44 is rapidly lowered and the obtained signal Sn falls to the full Low level. Interval, but ignores the time delay produced by the output signal Sn.

If the body approaches the touch chamber 60 at the lower right of FIG. 14 at any time, a capacitor can be formed between the conductive pad 50 and the body finger 25 in the corresponding touch chamber 60. As shown in Fig. 16, if the touch is generated at an interval when G3 is Hi level, the virtual capacitor is formed once the finger 25 is close to each other, and then, as shown in Fig. 16, when the waveform of Sn is in contact The resulting momentary distortion, the charging voltage can fluctuate during the initial charging phase, but charging will complete quickly and Sn will rise to the Hi level.

If the signal G3 changes to the watch time mode, that is, G3 is off, the charged voltage in the dummy capacitor is discharged, and the gate voltage of the second TFT 44 is slowly lowered, and the output waveform of the second TFT 44 is displayed as For the characteristic properties shown by the S3 waveform, it is assumed that T2 is a range in which Sn is reduced to less than 50%.

Referring to FIG. 16, T1 and T2 are extremely different, and the touch position detector 70 reads the time from when the Gn is turned off to when the signal Sn from the second signal line 34 falls, or is read at a predetermined time. When the voltage drops, the touch signal is obtained. In this embodiment, when S3 is obtained after the gate signal G3 is turned off, the touch signal is the coordinate value 'D3, S3'.

Figure 16 is an example of obtaining a touch signal, but other methods can also obtain a touch signal. For example, all of the gate signals Gn can be turned on at the same time to induce charging of the dummy capacitor between the body and the conductive pad 50, followed by applying a sequence signal to the sub-signal line 37, and monitoring the output waveform.

Figure 14 is a specific embodiment in which the touch signal is obtained by the body approaching the generated capacitor. The assumed body finger 25 contacts the conductive pad 50. In this case, a capacitor of several pF is generated, and the touch signal can be obtained therefrom. However, if the actual capacitor is additionally connected to the conductive pad 50, The body is close to the formed virtual capacitor for charge sharing, so the voltage level of the gate of the second TFT 44 is lowered, or the charging time is lengthened, so that a more reliable touch signal can be obtained by body contact.

Figures 17 and 18 show a specific embodiment in which a more reliable touch signal can be obtained in the case of physical contact, but these embodiments can also obtain a reliable touch signal in the case where the body is not in contact. Referring to Fig. 17, in addition to the structure of the embodiment of Fig. 14, the capacitor 54 is additionally connected between the output of the first TFT 42 and the sub-signal line 37. In this embodiment, the touch position detector 70 sequentially applies scan pulses to each of the gate signal lines 36, or it can apply the same gate signal to all of the gate signal lines 36. In this particular embodiment, the gate signal Gn and the sub-signal Auxn for monitoring are not necessarily accompanied by each other and they can be applied independently. However, if the capacitor 54 is charged by Gn for a long time, the capacitor 54 is freely discharged, so that it may not be monitored. Therefore, the sub-signal Auxn is preferably applied immediately after the capacitor 54 is charged by Gn.

For example, the Gn On voltage is 15 volts. When Gn is applied, Dn is also applied and charged to the capacitor 54 of the gate terminal of the second TFT 44. The Dn Hi level voltage will turn on the second TFT 44, which is preferably 10 volts considering Gn. Dn is supplied with a charging capacitor 54 for a sufficient period of time.

The voltage at the gate terminal of the second TFT 44 is 3 volts or more higher than the voltage at the input terminal Auxn, so the second TFT 44 is always in an on state. If the body simultaneously contacts the lower right touch chamber 60 while the sub-signal Auxn is being administered, the charge stored in the capacitor 54 is discharged and moved to the virtual capacitor 54 formed by the body until the voltage levels of the two capacitors become Equal to each other. If the charging capacity of the capacitor 54 is sufficiently smaller than the charging capacity of the virtual capacitor formed by the body, the above-described charge sharing is generated and applied to the second The voltage at the gate terminal of the TFT 44 may not turn on the second TFT 44 or the output signal Sn associated with the sub-signal Auxn may be lowered, and it may be detected and a touch signal may be obtained. The touch signals obtained in this embodiment are coordinate values D3, S3.

Referring to FIG. 18, the sub-signal line 37 includes a first sub-signal line 37a and a second sub-signal line 37b, and one end of the capacitor 54 is connected to the first sub-signal line 37a and the second TFT 44 is connected to the second end. Sub-signal line 37b. This embodiment is identical to Fig. 17 except that the sub-signals for monitoring and the sub-signals for monitoring the state are separate. The sub-signals Aux1-n are applied to the first sub-signal line 37a for monitoring, and the sub-signals Aux2-n are applied to the second sub-signal line 37b for monitoring.

In this embodiment, the Gn On voltage is 18 volts. The Dn Hi level voltage will turn on the second TFT 44, and suitably 12 volts. The sub-signal Aux1-n for monitoring can be -18 volts at the low level and 0 volts at the Hi level. For example, when the sub-signal Aux1-n is low and the capacitor 54 is charged, the gate voltage of the second TFT 44 is -6 volts, and for the second sub-signal line 37b of higher voltage, the second TFT 44 is not electrically connected. When Aux1-n is Hi level (zero volt), the Dn Hi level voltage is 12 volts, and for the sub-signal Aux2-n which is 3 volts lower, it is determined that the second TFT 44 is electrically connected. Preferably, the sub-signal Aux2-n is synchronized with the sub-signal Aux1-n, and the Hi level voltage and the Low level voltage of Aux2-n are preferably equal to the Hi level voltage and the Low level voltage of Aux1-n.

The specific embodiments of Figures 17 and 18 can select capacitors 54 of various capacitances such that the voltage applied to the gate of the second TFT 44 after charge sharing is adjusted, which is a determining factor for the downward tilt angle of the Sn signal wave upon contact. . That is, by adding a capacitor 54, the voltage level of each signal is expanded. The range of selection, and the downward tilt of the Sn signal can be more gradual, so it is more sure that the touch signal can be obtained.

As described above, the specific embodiments of FIGS. 12 to 18 show a method of detecting a touch position by using a capacitor formed between the body and the conductive pad 50, and the conductive pads 50 of these embodiments are not required to be exposed. . Therefore, a transparent insulating layer can be coated on one side of the substrate 30 to protect elements (not shown) of the touch chamber 60. The coating method of such a transparent insulating layer is easier than the coating method of the conductive layer, and the durability of the panel can be enhanced. With the transparent insulating layer, the body can approach the conductive pad 50 closer, and when the virtual capacitor is formed by the body approaching, it increases the virtual capacitance by reducing the distance value which constitutes the denominator of the capacitance equation.

The above specific embodiments describe that the touch signal is obtained by physical contact or proximity, but it is obvious that other methods, such as a high-voltage radiation stylus or the like, may be used to contact or approach the touch panel to obtain a touch signal.

The present invention has been described in connection with the preferred embodiments thereof. However, the invention is not limited to the specific embodiments described above, and various modifications and changes can be made without departing from the scope of the invention as defined by the appended claims.

1, 20‧‧‧ display devices

3‧‧‧First substrate

5‧‧‧second substrate

7, 9‧‧‧ transparent conductive layer

11‧‧‧Resistance point

13‧‧‧ converter

17‧‧‧ pen

25‧‧‧ fingers

30‧‧‧Substrate

D1, D2, D3‧‧‧ time division position detection signal

32‧‧‧ plural first signal line

34‧‧‧ plural second signal line

36‧‧‧gate signal line

37‧‧‧Sub Signal Line

37a‧‧‧First sub-signal line

37b‧‧‧Second sub-signal line

40‧‧‧Switching device

42‧‧‧First switching device

44‧‧‧Second switching device

50‧‧‧Electrical mat

50a‧‧‧First conductive pad

50b‧‧‧Second conductive pad

51‧‧‧ recess

53‧‧‧ protruding

54‧‧‧ capacitor

56‧‧‧ gate extreme

57‧‧‧ source extreme

58‧‧‧汲 Extreme

59‧‧‧Contacts

60‧‧‧Multiple touch room

70‧‧‧Touch position detector

71‧‧‧Drive ICs

72‧‧‧clock controller

73‧‧‧Signal Processor

74‧‧‧ memory

90‧‧‧Diffuser

G1, G2, G3‧‧‧ gate signal

Aux1-n, Aux2-n, Auxn‧‧‧ sub-signals

Dn‧‧‧ position detection signal

The above and other objects and advantages of the present invention will become more apparent from the detailed description of the preferred embodiments of the invention. FIG. 1 is a cross-sectional view of a conventional resistive touch panel; 3 is an exploded perspective view of a touch panel according to an embodiment of the present invention; FIG. 3 is a schematic view of a touch panel according to an embodiment of the present invention; and FIG. 4 is a perspective exploded perspective view of a specific embodiment with a diffusion sheet. Figure 5 is a block diagram of a system in accordance with the present invention; Figure 6 is a pulse diagram in accordance with an embodiment of the present invention; Figure 7 is a schematic diagram of a memory according to the present invention; and Figure 8 is a diagram showing the use of bulk static electricity. FIG. 9 is a block diagram of another embodiment using bulk static electricity; FIG. 10 is a block diagram of a specific embodiment using bulk conductivity; and FIG. 11 is a view of a specific embodiment of FIG. FIG. 12 is a block diagram showing a specific embodiment using a bulk electrostatic capacitance; FIG. 13 is a block diagram showing a specific embodiment using a bulk electrostatic capacitance; and FIG. 14 is another specific implementation using a bulk electrostatic capacitance. FIG. 15 is a configuration diagram of a touch chamber unit of a specific embodiment of FIG. 14; FIG. 16 is a pulse wave diagram of a specific embodiment of FIG. 14; and FIG. 17 is another specific example of using a bulk electrostatic capacitance. A block diagram of an embodiment; and an 18th block is a block diagram of another embodiment using bulk electrostatic capacitance.

D1, D2, D3‧‧‧ time division position detection signal

30‧‧‧Substrate

32‧‧‧ plural first signal line

34‧‧‧ plural second signal line

40‧‧‧Switching device

50‧‧‧Electrical mat

60‧‧‧Multiple touch room

Claims (12)

A touch panel capable of detecting a contact or proximity of a contact manner of a human body to generate a corresponding position detection signal, the touch panel comprising: a substrate 30 made of a light transmissive substance; formed on the a plurality of first signal lines 32 and second signal lines 34 on a surface of the substrate 30, and the position detection signals are input or output through the plurality of first signal lines 32 and second signal lines 34; the plurality of touch chambers 60, Formed on the divided active area of the substrate 30, and the plurality of touch chambers 60 include a three-way switching device 40 and a conductive pad 50 connected to the gate terminal of the switching device 40, in each divided region of the substrate 30. The three-way switching device 40 is disposed between the first signal line 32 and the second signal line 34; a touch position detector 70, when contacting or approaching the conductive pad 50 in the contact manner, The touch position detector 70 applies a position detection signal to the first signal line 32, and receives a position detection signal from the second signal line 34 according to the state change of the switching device 40 to obtain the contact Control room 50 A nominal value of the switching device 40 is based on the capacitive characteristics between the conductive pad 50 and the contact mode. The touch panel of claim 1, wherein a diffusion sheet 90 is further provided under the substrate 30. The touch panel of claim 1, wherein the touch position detector 70 further includes a memory 74 that stores an address corresponding to the coordinate value of the touch room 60, so if the location The detection signal is received from the second signal line 34. The coordinate value of the corresponding touch chamber 60 is stored in a corresponding address of the memory 74. The touch panel of claim 1, wherein the plurality of gate signal lines 36 are further disposed on a surface of the substrate 30, and each of the touch chambers 60 includes a conductive pad 50 and the gate signal line 36. A capacitor 54 is disposed therebetween, and the touch position detector 70 applies a gate signal to the gate signal line 36. The touch panel of claim 1, wherein the plurality of gate signal lines 36 and the sub-signal lines 37 are further disposed on a surface of the substrate 30. The touch chamber 60 includes a first switching device 42 and is connected to a conductive pad 50, a second switching device 44 and a capacitor 54 of the gate terminal of the first switching device 42. The input end of the first switching device 42 is connected to the first signal line 32. The second switching device 44 The input end is connected to the output end of the first switching device 42, the output end of the second switching device 44 is connected to the second signal line 34, and the gate terminal of the second switching device 44 is connected to the gate signal line 36, the capacitor 54 is connected between the output end of the first switching device 42 and the sub-signal line 37, and the touch position detector 70 applies a gate signal to each of the gate signal lines 36. The touch panel of claim 1, wherein the plurality of gate signal lines 36 are further disposed on a surface of the substrate 30, and the conductive pad 50 of the touch chamber 60 includes a gate terminal connected to the switching device 40. a first conductive pad 50a and a second conductive pad 50b spaced apart from the first conductive pad 50a and connected to the gate signal line 36, and the touch position detector 70 applies a gate signal to the gate Pole signal line 36. The touch panel of claim 6, wherein the first conductive pad 50a and the second conductive pad 50b of each touch chamber 60 have alternating recesses 51 and protrusions 53, the recesses 52 and The projections 54 mesh with each other. The touch panel of claim 1, wherein the plurality of sub-letters The line 37 is further disposed on a surface of the substrate 30. Each of the touch chambers 60 includes a switching device and a conductive pad 50. The gate terminal of the switching device is connected to the first signal line 32. The input end of the switching device and The output terminals are respectively connected to the sub-signal line 37 and the second signal line 34, and the conductive pad 50 is connected to the gate terminal of the switching device 40. The touch panel of claim 1, wherein the plurality of gate signal lines 36 and the sub-signal lines 37 are further disposed on a surface of the substrate 30. The touch chamber 60 includes a first switching device 42 and a conductive pad. 50 and a second switching device 44, the input end of the first switching device 42 is connected to the first signal line 32 and its gate terminal is connected to the gate signal line 36, and the conductive pad 50 is connected to the first switching device 42. The output terminal of the second switching device 44 is connected to the output end of the first switching device 42 and its input end and output end are respectively connected to the sub-signal line 37 and the second signal line 34, and the touch The position detector 70 applies a gate signal to each of the gate signal lines 36. The touch panel of claim 9, wherein a capacitor 54 is connected between the output of the first switching device 42 and the sub-signal line 37. The touch panel of claim 10, wherein the sub-signal line 37 is provided by the first sub-signal line 37a and the second sub-signal line 37b, respectively, and the input end of the second switching device 44 Connected to the first sub-signal line 37a, one end of the capacitor 54 is connected to the second sub-signal line 37b. The touch panel of claim 8 to 11, wherein a transparent insulating layer is applied to a surface of the substrate 30 to protect the touch chamber 60.