KR20100022746A - Switch type touch sensor and input device comprising the same, and input detection method thereof - Google Patents

Abstract

PURPOSE: A switch type touch sensor, an input device comprising the same, and an input detection method thereof are provided to conveniently produce accurate coordinate data. CONSTITUTION: A plurality of the first electrodes(111~118) are formed in parallel along with the first direction. A plurality of the second electrodes(121~128) are formed in parallel along with the second direction crossing the first direction. A spacer sheet(130) is installed between the first electrodes and the second electrodes. The spacer sheet isolates the first electrodes from the second electrodes.

Description

Switch-type touch sensor and input device including same, and input sensing method thereof {Switch type touch sensor and input device comprising the same, and input detection method}

The present invention relates to a touch sensor, and more particularly, to a switch type touch sensor that can acquire not only coordinate data of a position where a user touches, but also information on displacement and contact force.

Recently, as the trend toward miniaturization and integration of electronic devices has been accelerated, input means using touch sensors such as touch pads and touch screens, such as mobile phones, PDAs, PMPs, MP3 players, and notebook computers, have been in the spotlight.

The type of touch sensor varies greatly depending on the method of detecting the coordinate data of the contact position. For example, the touch screen attached to the surface of the display panel may be used as a resistive overlay, capacitive overlay, infrared beam, or surface acoustic wave according to the principle of operation. And the like.

Since the resistive touch screen is the most widely used among these, the touch screen of the resistive film type (particularly, the 4-wire resistive film type) will be briefly described with reference to the exploded perspective view of FIG. 1 and the cross-sectional view of FIG. 2. .

The 4-wire resistive touch screen has a structure in which the lower substrate 10 and the upper substrate 20 are joined by an adhesive sheet 30 interposed along the periphery thereof, and the upper and upper surfaces of the lower substrate 10. A first indium tin oxide (ITO) thin film 16 and a second ITO thin film 26 serving as a resistive film are formed on the bottom surface of the substrate 20, respectively.

On the surface of the first ITO thin film 16, the first electrode 11 and the second electrode 12, each of which elongate along the first direction (y-axis direction), are spaced apart from each other and arranged in parallel. In addition, the third electrode 21 and the fourth electrode 22 formed long in the second direction (x-axis direction) are disposed on the surface of the second ITO thin film 26 to be spaced apart from each other in parallel. The first and second electrodes 11 and 12 are connected to the first conductive line 13 and the second conductive line 14, respectively, and the third electrode 21 and the fourth electrode 22 are respectively connected to the third conductive line 23. ) And the fourth conductive line 24.

In addition, a transparent dot spacer 15 is formed on the surface of the first ITO thin film 16 of the lower substrate 10.

The operation principle of the 4-wire resistive touch screen is as follows. For example, when the common voltage Vcc is applied to the first electrode 11 of the lower substrate 10 and the base voltage V _GND is applied to the second electrode 12, the first electrode 11 and the second electrode are applied. An electric field in the x-axis direction is formed in the first ITO thin film 16 between the electrodes 12. In this state, when the user presses the surface of the upper substrate 10, the first ITO thin film 16 and the second ITO thin film 26 contact each other, so that the third or fourth electrodes 21 and 22 formed on the upper substrate 10 are in contact with each other. ) Can detect the voltage Vx of the contact point. The detection voltage Vx is input to a signal processing controller (not shown) via the AD converter, and the controller calculates the x coordinate of the contact point based on the detection voltage Vx.

In order to calculate the y-coordinate of the contact point, the third electrode is applied by applying the common voltage Vcc to the third electrode 21 of the upper substrate 20 and applying the _ground voltage V _GND to the fourth electrode 22. An electric field in the y-axis direction is formed in the second ITO thin film 26 between the 21 and fourth electrodes 22. In this state, the voltage Vy of the contact point is detected through the first electrode 11 or the second electrode 12 of the lower substrate 20. In the controller, the y coordinate of the contact point based on the detection voltage Vy. To calculate.

The controller includes coordinate data obtained by measuring the detection voltage at the predetermined coordinates in advance, and using the coordinate data to determine coordinates corresponding to the actual detection voltages Vx and Vy by interpolation or the like.

If the resistance of the first and second ITO thin films 16 and 26 serving as the resistive film is uniform, and the equipotential lines of the electric fields formed on the lower substrate 10 and the upper substrate 20 are parallel to each electrode, the above method is performed. You can get the exact coordinates with.

However, in practice, since the thicknesses of the first and second ITO thin films 16 and 26 are not uniform, the resistance values are not uniform, and the resistance values vary depending on the temperature, humidity, and degree of deterioration. It must be big. Therefore, in order to solve such a problem, the controller needs to perform an appropriate compensation process, which causes a problem in that the configuration of the product is complicated and the processing speed is delayed. In addition, there is a problem in that the user inconvenience because it has to initialize the stored coordinate data periodically.

Meanwhile, the first to fourth electrodes 11, 12, 21 and 22 made of silver (Ag) and copper (Cu) and the first to fourth conductive lines 13, 14, 23, and 24 connected to the electrodes are also used. A voltage drop occurs, and in order to reduce the error, the resistance value of the ITO thin films 16 and 26 connected to the electrodes 11, 12, 21 and 22 must be increased. However, in order to increase the resistance values of the ITO thin films 16 and 26, the thickness of the thin film must be reduced, and if the thin film thickness is reduced, the durability is reduced and the uniformity of the resistance is deteriorated.

In addition, the 4-wire resistive touch screen should alternately form an electric field on the lower substrate 10 and the upper substrate 20. In order to reduce an error due to capacitance formed between both substrates 10 and 20, the lower substrate There is a problem in that a sufficient gap is provided between the time point at which the common voltage Vcc is applied to (10) and the time point at which the common voltage Vcc is applied to the upper substrate 20, which causes a long overall sampling time.

In addition, the conventional resistive touch screen has a problem in that it is impossible to realize the so-called multi-touch function because it is impossible to simultaneously recognize the coordinates of two points when the user presses two places at the same time.

In addition, the conventional touch screen simply recognizes only the coordinates pressed by the user and cannot identify information about the z-axis direction, that is, information about the force pressed by the user. In order to check the information on the z-axis direction, a separate pressure sensor must be installed, which causes a complicated structure and increases manufacturing costs.

On the other hand, in the case of the touch pad, there is a similar problem because a separate pressure sensor must be installed in order to obtain information on the z-axis direction.

An object of the present invention is to provide a touch sensor that can easily calculate more accurate coordinate data than conventional touch sensors.

It is also an object of the present invention to provide a touch sensor that can determine not only x-y coordinate data but also information on the z-axis direction, that is, the degree of contact force.

It is also an object of the present invention to provide a touch sensor that can implement a multi-touch function that can simultaneously recognize a plurality of contact points.

The present invention, in order to achieve the above object, a plurality of first electrodes formed in parallel to each other in a first direction, a plurality of second electrodes formed in parallel to each other along a second direction crossing the first direction, A touch sensor comprising a space keeping means for separating the plurality of first electrodes and the plurality of second electrodes, wherein the maximum resistance of the first electrode selected from the plurality of first electrodes and the plurality of second electrodes When the maximum resistances of the selected one of the second electrodes are R1max and R2max, respectively, when the first voltage is applied to the first electrode through the fixed resistor R, and the second voltage is applied to the second electrode. When the first electrode and the second electrode are in contact with each other, the maximum output voltage Vout (max) output from the node between the fixed resistor R and the first electrode is equal to or less than a first reference voltage. If the first electrode and the second electrode is not in contact Group maximum output voltage provides the touch sensor, characterized in that not less than a second reference voltage larger than the first reference voltage.

In the touch sensor, the first reference voltage may be a reference voltage recognized as low in the digital logic circuit, and the second reference voltage may be a reference voltage recognized as high in the digital logic circuit. .

In addition, the present invention, a plurality of first electrodes formed in parallel to each other along a first direction, a plurality of second electrodes formed in parallel to each other along a second direction crossing the first direction, and the plurality of first electrodes And a touch sensor including a space keeping means disposed between the plurality of first electrodes and the plurality of second electrodes to space the plurality of second electrodes. An analog mux sequentially inputting electrical signals for scanning to the plurality of first electrodes and having a plurality of switching circuits; A decoder for selecting a switching circuit to input the electrical signal among the plurality of switching circuits of the analog mux; A latch unit including a latch circuit for converting signals output from the plurality of second electrodes into binary data signals; The present invention provides an input device of an electronic device including a controller for transmitting a selection signal for selecting a switching circuit of the analog mux to the decoder and determining coordinates of a touched point by using an output signal of the latch unit.

In addition, the present invention, a plurality of first electrodes parallel to each other in a first direction and a plurality of second electrodes parallel to each other in a second direction crossing the first direction intersect in a state spaced apart from each other, A method of sensing a user's input using a touch sensor in which a switch is defined for each intersection area where the first electrode and the plurality of second electrodes cross each other, the method comprising: (a) at each end of each of the plurality of first electrodes; Applying a first voltage through a fixed resistor (R) and applying a second voltage to only one second electrode selected from the plurality of second electrodes; (b) Detecting an output voltage Vout at a node between the one end of the plurality of first electrodes and the fixed resistor R, and defining each crossing region of the selected second electrode and the plurality of first electrodes. Determining whether the plurality of switches are turned on or off; (c) selecting second electrodes other than the selected second electrode one by one to apply the second voltage and repeating the step (b); (d) it provides an input sensing method of the touch sensor comprising the step of confirming the coordinates of the switch in the ON state of the switch.

The touch sensor according to the present invention can obtain coordinate data very simply because the touch sensor can accurately determine the coordinates of the contact point by determining whether the switch defined for each intersection area is turned on or off by crossing the electrodes. There is an advantage that no error correction procedure is required.

In addition, even if the resistance value of the electrode is slightly changed by temperature or humidity, it is possible to accurately determine whether the contact and the contact position without being affected. In addition, there is no inconvenience in storing coordinate data measured in advance like a resistive film and initializing it periodically.

In addition, since not only the coordinate data of the contact position but also the strength of the contact force can be determined, various user interfaces can be provided.

In addition, since a method of determining whether a plurality of switches are on or off, there is an advantage in that the multi-touch function can be easily implemented.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1. Structure of touch sensor

3 and 4 are exploded perspective views and coupling cross-sectional views of the touch sensor 100 according to the embodiment of the present invention, respectively.

The touch sensor 100 according to the embodiment of the present invention is a switch method for checking the coordinates of the contact point through the contact of the upper and lower electrodes. The lower substrate 110, the spacer sheet 130, and the upper substrate 120 sequentially It has a laminated structure. Although not shown, a protective film may be attached to the outer side of the upper substrate 120.

On the surface of the lower substrate 110 (upper surface in the drawing), a plurality of first electrodes 111 to 118 having a stripe shape extending in a first direction (eg, y-axis direction) are disposed substantially parallel to each other. On the surface of the upper substrate 120 (the lower surface of the drawing), a plurality of strip-shaped second electrodes 121 to 128 extending in the second direction (eg, the x-axis direction) are disposed substantially parallel to each other.

Therefore, when the lower substrate 110 and the upper substrate 120 are coupled to each other, the first electrodes 111 to 118 and the second electrodes 121 to 128 cross each other by being spaced apart from each other by the spacer sheet 130. Although the first electrodes 111 to 118 and the second electrodes 121 to 128 preferably cross at right angles to each other, the crossing angles may not necessarily be right angles.

The lower substrate 110 and the upper substrate 120 on which the first and second electrodes 111 to 118 and 121 to 128 are formed are an insulating material, and the spacer sheet 130 should also be an insulating material.

If the touch sensor 100 of the present invention is attached to the surface of the display panel and used, the lower substrate 110, the upper substrate 120 and the spacer sheet 130 may be made of transparent glass, transparent plastic, transparent film, or the like. Should be And since the upper substrate 120 can be bent down and restored again as the user presses, as shown in Figure 5 should be made of a transparent plastic or a transparent film having a suitable elasticity.

The first and second electrodes 111 to 118 and 121 to 128 are preferably made of metal having excellent conductivity. If the touch sensor 100 of the present invention is used as a touch screen, the first and second electrodes 111 to 118 and 121 to 128 may be indium tin oxide (ITO), indium zinc oxide (IZO), or tao (tin). It is made of a material containing transparent conductive oxide (TCO: Transparent Oxide) such as Antinomy Oxide), TO (Tin Oxide), ZnO (Zinc Oxide).

Although the widths of the first and second electrodes 111 to 118 and 121 to 128 are preferably within 0.5 mm when formed with, for example, ITO, the widths of the first and second electrodes 111 to 118 and 121 to 128 may vary depending on materials and resistance values. have. In addition, the length of each electrode and the distance between the adjacent electrodes may vary according to the size or shape of the device on which the touch sensor 100 is mounted, and the desired recognition resolution.

If the first or second electrodes 111 to 118 and 121 to 128 are formed of a metal material, the first or second electrodes 111 to 118 and 121 to 128 may be formed by plating or etching. It can also be combined. If the electrode is formed of a transparent conductive oxide (TCO), it can be formed by sputtering, CVD, or the like. Of course, it can also be formed by other methods.

One end of each of the first and second electrodes 111 to 118 and 121 to 128 is connected to an external conductor, and in particular, when the first and second electrodes are transparent electrodes, an external conductor is connected to an end surface of the transparent electrode. It is preferable to form the electrode terminal 150 for. At this time, the electrode terminal 150 is preferably made of a metal material such as silver (Ag), copper (Cu) excellent in conductivity.

The spacer sheet 130 is provided to separate the first electrodes 111 to 118 from the second electrodes 121 to 128 and includes a plurality of openings 132. The opening 132 may be a switch area in which the first electrodes 111 to 118 and the second electrodes 121 to 128 spaced apart from each other when the user presses the same contact with each other.

The opening 132 may be formed in one-to-one correspondence with each crossing area of the first electrodes 111 to 118 and the second electrodes 121 to 128, and two or more crossing areas may be formed in one opening 132. It may be formed to correspond.

If you respond one-on-one. As shown in FIG. 3, when the first electrodes 111 to 118 and the second electrodes 121 to 128 are eight, a total of 64 cross regions exist, so that the openings 132 of the spacer sheet 130 are similar to each other. It is formed in the same number.

When the touch sensor 100 of the present invention is used as a touch screen, the thickness of the spacer sheet 130 is preferably 1 to 500 μm. In addition, it is preferable that the width of each opening 132 is 0.1-500 micrometers, and the space | interval with the adjacent opening 132 is 0.1-500 micrometers.

Bonding between the lower substrate 110 and the spacer sheet 130 and between the upper substrate 120 and the spacer sheet 130 to join the lower substrate 110, the upper substrate 120 and the spacer sheet 130. The sheet 140 may be interposed. At this time, the adhesive sheet 140 should be opened in the center portion corresponding to the touch sensing area.

In addition, the lower substrate 110, the upper substrate 120 and the spacer sheet 130 may be combined with a screw.

In FIG. 3, the openings 132 of the spacer sheet 130 are regularly arranged, but the openings 132 are not necessarily the same shape or regularly arranged. In addition, although it is preferable that all the intersecting regions of the upper and lower electrodes and the openings 132 correspond one-to-one, in some cases, the openings 132 may not necessarily correspond one-to-one to all the intersecting regions.

According to this aspect, the spacer sheet 130 may be replaced with a porous polymer thin film in which a plurality of openings 132 are formed randomly or uniformly.

Meanwhile, as shown in the exploded perspective view of FIG. 6 and the combined cross-sectional view of FIG. 7 instead of the spacer sheet 130, a plurality of hemispherical shapes are formed between the plurality of first electrodes 111 to 118 on the surface of the lower substrate 110. Dot spacer 160 may be formed.

The dot spacer 160 is preferably an insulating material, and may be formed by a dry or wet etching method using a CVD method or a mask. When applied to the touch screen, of course, the dot spacer 160 should be a transparent material. In addition, the diameter and height of the dot spacer 160 are preferably in the range of 10 to 50 µm, respectively, and the elastic modulus is preferably about 500 MPa. In addition, if the interval between adjacent dot spacers 160 is too narrow, an excessively high compressive force is required for contact between the upper and lower electrodes, so that the interval between the dot spacers 160 is preferably 1 mm or more, and the maximum interval of the first electrodes 111 to 118 is increased. It can be adjusted according to the interval or design criteria.

As shown in FIG. 6, the dot spacers 160 may be arranged in one column or two or more columns may be disposed between two adjacent electrodes. In addition, two or more electrodes 111 to 118 may be disposed between adjacent dot spacers 160 in consideration of widths or intervals of the electrodes 111 to 118.

On the other hand, when the first and second electrodes 111 to 118 and 121 to 128 are transparent conductive oxides, the resistance values vary slightly depending on temperature and humidity compared to metal materials such as copper and silver, and also depending on the deposition thickness. This is a very different feature.

Therefore, it is important to be able to accurately detect whether the first and second electrodes are in contact despite the change in the resistance value, which will be described below.

First, the first and second electrodes 111 to 118 and 121 to 128 are made of ITO, the length of the first electrodes 111 to 118 is 435 mm, and the length of the second electrodes 121 to 128 is 275 mm (20 inch monitor). Size) and the thickness and width of the first and second electrodes are assumed to be 500 nm and 0.5 mm, respectively.

As shown in FIG. 8, a common voltage Vcc is applied to an arbitrary first electrode 111 through a fixed resistor R, and a _ground voltage V _GND is applied to an arbitrary second electrode 121. When the two electrodes 111 and 121 are in contact with each other, the output voltage Vout output from the node N between the fixed resistor R and the first electrode 111 is (Vcc-V _GND ) * (R1 + R2). ) / (R + R1 + R2). Here, R1 is a resistance between the end of the first electrode 111 and the contact point, and R2 is a resistance between the end of the second electrode 121 and the contact point. The resistance of the connecting wire or the contact resistance at the point of contact is very small compared to the other resistors and is ignored here.

In general, the surface resistance of ITO is 20 ohms / sq when the thickness is 500nm, 350 ~ 400 ohms / sq when the thickness is 30 ~ 35nm. Therefore, the maximum resistances R1 (max) and R2 (max) of R1 and R2 are as follows.

R1 (max) = 20 ohms / sq * 435 mm / 0.5mm = 17.4 kohms

R2 (max) = 20 ohms / sq * 275 mm / 0.5 mm = 11.0 kohms

Where R = 1Mohms, Vcc = 3.0V, V _GND = 0V, the maximum value of Vout, Vout (max) is 3.0 * 28.4 / 1028.4 = 0.083V.

In general, a digital logic circuit including a transistor recognizes, for example, 0.6 V or less as '0' (or low) and about 2 V or more as '1' (or high). Therefore, when the two electrodes 111 and 121 are in contact with each other when OV is input to the arbitrary second electrode 121, the output voltage of the arbitrary first electrode 111 is equal to or less than the first reference voltage (eg, 0.6 V), and If it is not in contact, the output voltage of the arbitrary first electrode 111 is designed to be equal to or greater than the second reference voltage (for example, 2V), so that only the output voltage of the first electrode 111 and the first electrode 111 and the second electrode ( 121) can be easily judged.

In the above example, Vout (max) is 0.083V when the two electrodes 111 and 112 are in contact with each other, and Vout = Vcc = 3.0V when the electrodes are not in contact with each other. However, since the numerical values of the first reference voltage (0.6V) and the second reference voltage (2V) described above are merely examples, it can be changed according to design needs. Vcc and V _GND can also be set differently than in the case described above.

In other respects, R1 + R2 must be 250kohms for Vout (max) to be 0.6V. That is, when the value of R1 + R2 is 250kohms or less, the output of the first electrodes 111 to 118 may be recognized as 0V in a normal digital logic circuit. This means that the normal operating range of R1 + R2 ranges from 28.4kohms to 250kohms, so that the contact between the first electrode 111 and the second electrode 121 may be affected even if the resistance of ITO is slightly changed by the influence of temperature or humidity. It means that you can judge accurately.

If the first and second electrodes 111 to 118 and 121 to 128 have a thickness of 30 nm, the values of R1 and R2 become very large. In this case, the fixed resistance R may be increased to about 10 Mohms.

Therefore, by appropriately selecting the resistance value of the fixed resistor R according to the type and thickness of the transparent conductive oxides used for the first and second electrodes 111 to 118 and 121 to 128, the switch type touch sensor is not affected by temperature or humidity. 100 can be manufactured. If the first and second electrodes 111 to 118 and 121 to 128 are made of metal, the values of R1 and R2 are fixed and their sizes are very small.

2, input device and coordinate data detection method using touch screen

Assuming that the touch sensor 100 according to the embodiment of the present invention includes eight first electrodes 111 to 118 and eight second electrodes 121 to 128 that cross each other, the touch sensor 100 is As illustrated in FIG. 9, 64 switches defined for each crossing area of the first and second electrodes may be represented by a circuit arranged in an 8 * 8 matrix.

For convenience of description, each column line c0 to c7 is a first electrode 111 to 118, and each row line r0 to r7 is a second electrode 121 to 118, respectively. 128). On the contrary, even if each column line is a second electrode and each row line is a first electrode, it is substantially the same circuit.

The common voltage Vcc is applied to each of the column lines c0 to c7 through the same fixed resistor R, and a predetermined scanning signal is input to each row line r0 to r7. The output voltage Vout is detected through a node between each column line c0 to c7 and each fixed resistor R.

10 is a block diagram showing the configuration of an input device using the touch sensor 100 of the present invention, the controller 210, the decoder 220, the analog mux 230, the latch unit 240, the buffer 250 and the like.

The controller 210 periodically applies a predetermined scanning signal to the touch sensor 100, and analyzes the output signal of the touch sensor 100 to determine the coordinate data of the contact point, the strength of the contact force, the movement direction of the contact position, and the movement. The distance, the moving speed, the acceleration or the moving angle is determined and then transmitted to the display panel controller 270. A detailed operation algorithm of the controller 210 will be described later with reference to FIG. 12.

The decoder 220 applies a predetermined row selection signal to the analog mux 230 using row data of a binary data string provided by the controller 210 and a decoding table provided by the decoder 210.

The analog mux 230 includes a plurality of switching circuits (not shown) operated by the low selection signal of the decoder 220, and among the row lines r0 to r7 of the touch sensor 100 of the decoder 220. The base voltage (eg, 0 V) is applied only to a row line corresponding to the row selection signal, and the remaining row lines serve to float.

The latch unit 240 converts the output voltage of each column line c0 to c7 of the touch sensor 100 into column data of a binary data string by using a plurality of latch circuits. FIG. 11 illustrates an embodiment of a latch circuit, which receives an output voltage Vout of eight column lines at the same time and outputs an 8-bit data string Q ₀ to Q ₇ , that is, a signal in a byte unit. Circuit.

If there are 256 column lines, 32 such latch circuits are provided. The byte signals output from each latch circuit are temporarily stored in the buffer 250 and then transmitted to the controller 210. In this case, the controller 210 must provide a predetermined column selection signal to control each latch circuit to sequentially output a byte signal.

The reason for using the latch circuit shown in FIG. 11 is to increase the contact detection speed when there are many column lines such as a touch screen. Therefore, the latch unit 240 may be configured in a different form depending on the size or design criteria of the touch sensor 100.

The buffer 250 temporarily stores column data generated by the latch unit 240, and the controller 210 reads column data stored in the buffer 250 and generates coordinate data of a contact point.

12 is a flowchart illustrating a process of generating coordinate data of a contact point in the controller 210.

If the touch of the user is not detected for the first time, the touch sensor 100 is switched to the standby mode. In the standby mode, for example, all of the switching circuits of the analog mux 230 are turned on to apply a ground voltage (eg, 0 V) to all row lines. The standby mode may be omitted and the operation mode described later may always be maintained.

When 0V is output from at least one column line in the standby mode, the controller 210 determines that there is a contact and immediately applies 0V to each row line while switching to the operation mode.

To this end, first, the column data stored in the buffer 250 is cleared, and the raw data and the low data count stored in the controller 210 are cleared.

Subsequently, the raw data count is incremented by 1 while transmitting raw data of the binary data string to the decoder 220. For example, if there are 256 row lines, 8-bit data strings ranging from 00000000 to 1111111 are sequentially transmitted to the decoder 220.

The decoder 220 selects and turns on only the switching circuit corresponding to the corresponding data string among the plurality of switching circuits of the analog mux 230 to apply 0V only to the corresponding low line.

The controller 210 clears the column line byte count (Col_Line_Byte_Cnt) while transmitting raw data to the decoder 220. The column line byte count (Col_Line_Byte_Cnt) is for sequentially selecting a plurality of latch circuits connected to every eight column lines as shown in FIG. 11, for example.

Accordingly, the controller 210 sequentially reads and stores the byte signals output from all the latch circuits from the buffer 250 while increasing the column line byte count (Col_Line_Byte_Cnt) by one.

After the above-described process for one row line, the same process is repeated for the remaining row lines until the low data count is equal to the actual number of row lines.

If the low data count exceeds the actual number of row lines, the coordinate detection process of one cycle is terminated, and the controller 210 detects the xy coordinate of the contact point by using the stored column data and the corresponding raw data, and further displaces the coordinates. Generate data such as (Δx, Δy), contact force, and the like.

The data generated by the controller 210 is transmitted to the display panel controller 270 through communication means (RS232, USB, I2C, etc.).

3. How to determine displacement (Δx, Δy) and contact force

Using the switch-type touch sensor 100 according to the present invention, it is possible to easily check the xy coordinate of the point pressed by the user, thereby determining the displacement (Δx, Δy) as well as the degree of contact force pressed by the user. .

The displacements Δx and Δy may be calculated using coordinates obtained at the time t = t1 and coordinates obtained at the time t = t2. Through this, the user can express an image or text on the touch sensor 100 using a hand or a stylus pen. Furthermore, by using the displacement data, the moving distance, moving speed, moving direction, acceleration, moving angle, etc. of the touch point can be determined, and the information can be applied in various forms.

Hereinafter, a method of determining the strength of the contact force will be described.

First, the simplest method is to use the number of switches that are turned on among a plurality of switches defined for each region where the first electrodes 111 to 118 and the second electrodes 121 to 128 intersect. That is, as the user pushes harder, the contact points of the upper and lower electrodes increase, so that the strength of the contact force can be easily determined by using the number of ON switches.

Various applications are possible if the contact force can be determined. For example, if the number of ON switches exceeds the reference number, the shape, size, color, etc. of the object represented at the touch point on the touch screen may be modified to give a visual effect or generate a predetermined sound. It can also give an auditory effect. In addition, by using information on the displacement and the contact force together, the stronger the user presses when writing, the effect of the font becomes thicker.

In addition, the movement speed of the selected object may be controlled according to the change amount of the contact force. Information on the change amount of the contact force can be obtained through the difference in the number of the switch (ON) between any two time points.

The second method is to use the arrangement of the openings 132 of the spacer sheet 130 installed between the lower substrate 110 and the upper substrate 120.

That is, the opening 132 of the spacer sheet 130 is not formed in the same shape but is formed to have a predetermined pattern while changing the area of the opening 132 as shown in the plan view of FIG. 13. FIG. 13 illustrates a pattern in which the area of the opening 130 is regularly increased and decreased along the horizontal, vertical and diagonal directions. Alternatively, the opening area may be regularly increased or decreased along one or two directions. At this time, the area of the plurality of openings 132 is preferably increased or decreased in the form of a sine wave.

In order to regularly increase or decrease the area of the opening 132 of the spacer sheet 130, a plurality of openings 132 are set to a unit opening group (area A in FIG. 13), and a plurality of unit opening groups A are shown. It is preferable to repeat the arrangement in the horizontal and vertical direction. As described above, the plurality of openings 132 belonging to each of the opening groups A are arranged such that their area regularly increases and decreases along at least one of the horizontal, vertical, and diagonal directions.

The boundary line defining the unit opening group A may be set to pass through the middle of the two openings 132. In order to maintain the continuous increase / decrease pattern of the area of the opening 132, the opening 132 belonging to the outermost part of each unit opening group A is preferably set to belong to the adjacent unit opening group.

In FIG. 13, the contact force for turning on the g switch formed in the small opening 132 will be greater than the contact force for turning on the h switch formed in the large opening 132.

Accordingly, the weight of the contact force is increased by assigning different weights to all the switches defined in the touch sensor 100 based on the area of the opening 132 of the spacer sheet 130 and summing the weights of the ON switches. You can judge. Specifically, the smaller the area of the opening 132 is, the greater the weight is given.

The third method is to use the arrangement of the dot spacer 160 spaced apart from the lower substrate 110 and the upper substrate 120. That is, the dot spacer 160 is not formed in the same shape and spacing, but is formed to have a predetermined pattern while changing the height or diameter of the dot spacer 160 as shown in the plan view of FIG. 14 and the cross-sectional view of FIG. 15. That's how.

FIG. 14 illustrates a pattern in which the height or diameter of the dot spacer 160 is regularly increased or decreased along the horizontal, vertical and diagonal directions. Alternatively, the height or diameter of the dot spacer 160 may be regularly increased or decreased along one or two directions. At this time, the height or diameter of the plurality of dot spacers 160 is preferably increased or decreased in the form of a sine wave.

In addition, in order to regularly increase or decrease the height or diameter of the dot spacer 160, a plurality of dot spacers 160 are set as a unit dot spacer group (region B in FIG. 14), and a plurality of unit dot spacer groups B ) Is preferably arranged along the horizontal and vertical direction, the plurality of dot spacers 160 belonging to each unit dot spacer group (B) is formed along at least one of the horizontal, vertical and diagonal directions as described above. The height or diameter is arranged to increase and decrease regularly.

The boundary line of the unit dot spacer group B is preferably set to include a switch defined between the dot spacers 160. In order to maintain the continuous increase / decrease pattern of the dot spacer 160, the dot spacer 160 belonging to the outermost portion of each unit dot spacer group B may be set to belong to the adjacent unit dot spacer group.

In FIG. 14, a contact force for turning on a, b, c or d switches formed around the dot spacer 160 having a large height or diameter is formed around the dot spacer 160 having a relatively small height or diameter. It will be greater than the contact force with the e or f switch on.

Accordingly, the weight of the contact force is increased by assigning differentiated weights to all the switches defined in the touch sensor 100 based on the height or diameter of the dot spacer 160 formed at the periphery and summing the weights of the ON switches. You can judge. Specifically, the larger the height or diameter of the dot spacer 160, the greater the weight.

Meanwhile, the strength of the contact force may be determined by forming all the dot spacers 160 in the same shape but only changing the intervals in a predetermined pattern. In general, the contact force of turning on the switch defined in the narrowly spaced dot spacer 160 will be greater than the contact force of turning on the switch defined in the widely spaced dot spacer 160.

Accordingly, the strength of the contact force may be determined by weighting all the switches defined in the touch sensor 100 based on the interval of the dot spacers 160 and summing the weights of the ON switches. In addition, at least one of the height, diameter, and interval of the dot spacer 160 may be regularly increased or decreased along at least one direction.

Meanwhile, in FIGS. 13 to 15, the shapes and patterns of the openings 132 and the dot spacer 160 are exaggerated for clarity.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment and may be modified or modified in various forms. And if the modified or modified embodiment as described also includes the technical spirit of the present invention disclosed in the claims to be described later of course belongs to the scope of the present invention.

1 is an exploded perspective view of a 4-wire resistive touch screen

2 is a cross-sectional view of a four-wire resistive touch screen

3 is an exploded perspective view of a touch sensor according to an embodiment of the present invention;

4 is a cross-sectional view of a touch sensor according to an embodiment of the present invention.

5 is a view showing a user pressed state

6 is an exploded perspective view showing a state in which a dot spacer is formed on a first substrate;

7 is a cross-sectional view when the dot spacer is formed

8 is a diagram illustrating a state in which an output voltage is detected by a touch sensor according to an exemplary embodiment of the present invention.

9 is a circuit diagram of a touch sensor according to an embodiment of the present invention.

10 is a block diagram of an input device using a touch sensor according to an embodiment of the present invention

11 is a circuit diagram showing an example of a latch circuit;

12 is a flowchart illustrating a process of determining coordinates and displacements using the touch sensor of the present invention.

FIG. 13 is a plan view showing a state in which the area of the opening of the spacer sheet is increased or decreased in a predetermined pattern; FIG.

14 and 15 are a plan view and a cross-sectional view showing a state in which the diameter or height of the dot spacer is increased or decreased in a constant pattern;

* Description of the symbols for the main parts of the drawings *

100: touch screen 110: first substrate

111,112,113,114,115,116,117,118: first electrode

121,122,123,124,125,126,127,128: second electrode

120: second substrate 130: spacer sheet

132: opening 140: adhesive sheet

150: terminal 160: dot spacer

210: controller 220: decoder

230: analog mux 240: latch unit

250: buffer

Claims (16)

A plurality of first electrodes formed parallel to each other along a first direction, a plurality of second electrodes formed parallel to each other along a second direction crossing the first direction, the plurality of first electrodes and the plurality of first electrodes In the touch sensor comprising a spacing means for separating the two electrodes, When the maximum resistance of the selected first electrode among the plurality of first electrodes and the maximum resistance of the selected second electrode among the plurality of second electrodes are R1max and R2max, respectively, the fixed resistance R is defined in the first electrode. In the case of applying the first voltage (V1) and the second voltage (V2) to the second electrode, When the first electrode and the second electrode are in contact with each other, the maximum output voltage [[Vout (max) = (V1-V2) * (R1max +) output from the node between the fixed resistor R and the first electrode. R2max) / (R + R1max + R2max)] is equal to or less than the first reference voltage, If the first electrode and the second electrode is not in contact with the touch sensor, characterized in that the maximum output voltage is greater than the second reference voltage greater than the first reference voltage. The method of claim 1 Wherein the first reference voltage is a reference voltage recognized as low in the digital logic circuit, and the second reference voltage is a reference voltage recognized as high in the digital logic circuit. The method of claim 1 The plurality of first electrodes and the plurality of second electrodes are made of a material including a transparent conductive oxide (TCO). The method of claim 1 The space maintaining means is a touch sensor, characterized in that the spacer sheet (spacer sheet) formed with a plurality of openings The method of claim 4 The plurality of openings are touch sensors, characterized in that formed in a pattern that regularly increases and decreases the area along at least one direction. The method of claim 1 The gap maintaining means is a touch sensor, characterized in that the porous polymer having a plurality of openings The method of claim 1, The gap maintaining means may be a plurality of dot spacers formed on a surface of a first substrate having a plurality of first electrodes or a second substrate having a plurality of second electrodes. The method of claim 7, wherein The plurality of dot spacers are formed in a pattern in which at least one of the height, diameter, and interval regularly increases and decreases along at least one direction. A plurality of first electrodes formed parallel to each other along a first direction, a plurality of second electrodes formed parallel to each other along a second direction crossing the first direction, the plurality of first electrodes and the plurality of first electrodes A touch sensor comprising a space keeping means disposed between the plurality of first electrodes and the plurality of second electrodes to space the two electrodes; An analog mux sequentially inputting electrical signals for scanning to the plurality of first electrodes and having a plurality of switching circuits; A decoder for selecting a switching circuit to input the electrical signal among the plurality of switching circuits of the analog mux; A latch unit including a latch circuit for converting signals output from the plurality of second electrodes into binary data signals; A controller for transmitting a selection signal for selecting the switching circuit of the analog mux to the decoder and determining coordinates of the touched point by using the output signal of the latch unit; Input device of an electronic device including a A plurality of first electrodes parallel to each other along a first direction and a plurality of second electrodes parallel to each other along a second direction crossing the first direction cross each other while being spaced apart from each other, and the plurality of first electrodes In the method for detecting a user's input using a touch sensor that is defined for each switch crossing the intersection of the plurality of second electrodes, (a) applying a first voltage to each end of each of the plurality of first electrodes through a fixed resistor R, and applying a second voltage to only one second electrode selected from the plurality of second electrodes; ; (b) detecting an output voltage Vout at a node between the one end of the plurality of first electrodes and the fixed resistor R, and for each intersection region of the selected second electrode and the plurality of first electrodes; Determining whether the plurality of switches that are defined are on or off; (c) selecting second electrodes other than the selected second electrode one by one to apply the second voltage and repeating the step (b); (d) checking coordinates of switches in an ON state among the switches; Input detection method of the touch sensor comprising a The method of claim 10, In the step (b), if the output voltage Vout is less than or equal to the first reference voltage, it is determined to be in a switched-on state. Input sensing method of the touch sensor, characterized in that The method of claim 11, The first reference voltage is a reference voltage recognized as low in the digital logic circuit, and the second reference voltage is a reference voltage recognized as high in the digital logic circuit. Way The method of claim 10, The step (d) further comprises the step of determining the degree of contact force according to the number of switches in the ON state input sensing method of the touch sensor, characterized in that The method of claim 13, A plurality of dot spacers are formed on the first substrate on which the plurality of first electrodes are formed or on the second substrate on which the plurality of second electrodes are formed to separate the first substrate from the second substrate. The plurality of dot spacers are formed in a pattern in which at least one of the height, diameter, and interval is regularly increased and decreased along at least one direction. The plurality of switches are given different weights based on at least one of height, diameter, and spacing of the dot spacer, In the step (d), the input sensing method of the touch sensor, characterized in that to determine the degree of contact force by summing the weight of the switch in the ON (ON) state The method of claim 13, Spacer sheets having a plurality of openings are provided on the first substrate on which the plurality of first electrodes are formed or the second substrate on which the plurality of second electrodes are formed to separate the first substrate from the second substrate. The plurality of openings of the spacer sheet is formed in a pattern in which the area regularly increases and decreases along at least one direction. The plurality of switches are weighted differently according to the area of the corresponding opening, In the step (d), the input detection method of the touch sensor, characterized in that by determining the degree of the contact force by summing the weight of the switch in the ON state. The method of claim 10, After the step (d) further comprises the step of confirming the coordinate displacement by using the first coordinate confirmed at time t1 and the second coordinate confirmed at time t2.

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