KR20020092628A - An analogue touch panel - Google Patents

Abstract

PURPOSE: An analog touch panel is provided to intercept external noises by installing noise elimination wire along the edge of a base board and connecting the noise elimination wire to a ground so that it can prevent a wrong operation. CONSTITUTION: The device comprises Y1, Y2 electrodes(511, 512), power lines(513, 514), and a noise elimination line(700). The Y1, Y2 electrodes(511, 512) are vertically formed at the up and down ends of a lower board. The power lines(513, 514) are horizontally formed at the left and right ends of a lower board for supplying an electric power to X1, X2 electrodes of an upper board. The electrodes(511, 512) and the power lines(513, 514) are connected to contact terminals for easily being connected to a flexible printed cable. The noise elimination line(700), having a rectangular cross section and a preset width, is formed along the edge of the lower board and connected to a ground for intercepting external noises induced from external environment.

Description

Analog touch panel {An analogue touch panel}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch panel, and more particularly, to an analog touch panel with improved noise reduction performance.

In general, a touch screen is one of several ways in which a user communicates with an information communication device employing a variety of displays and the user's hand or pen without additional peripherals such as a keyboard or a mouse. It is an input device that can interface with the device by directly touching the screen with a pen). The touch screen is classified into a capacitive type, a resistive film type, an ultrasonic type, an electric field type, and an infrared type according to the touch panel configuring the touch screen. Among the resistive touch panels, there are four-electrode touch panels, five-electrode touch panels, six-electrode touch panels, and eight-electrode touch panels depending on the number of electrodes connected to the outside.

As shown in FIG. 1, a typical touch screen includes a touch panel 10 installed on a display screen to sense a touch, and a driving circuit 20 for driving the touch panel 10. The X, Y coordinate data detected in 20) is transferred to the application program through a software drive of an information communication device employing a touch screen and processed in various ways. At this time, the driving circuit varies according to the type of the touch panel. As shown in FIG. 1, the conventional driving circuit 20 of the resistive film type depends on the interrupt circuit 22 and the control signal for generating start and end signals. A switch 24 for applying a voltage to the electrode, an analog-to-digital conversion (ADC) circuit 26 for converting the sensed analog voltage to digital, and a switch 24, and reading coordinate values of the touch points It is composed of a control unit 28 for transmitting to.

As shown in FIG. 2, the structure of the conventional analog touch panel includes an upper plate 12 of a transparent conductive film in which electrodes 12a and 12b are installed at left and right ends thereof, and electrodes 14a and 14b at both upper and lower ends thereof. ) Is formed of a lower plate 14 of a conductive glass substrate. When the conductive film of the upper plate 12 comes into contact with the conductive glass substrate of the lower plate 14 by external pressure, the resistance values measured at the upper, lower, left, and right sides of the conductive film vary depending on the contact position thereof. If the contact point (contact point) is known. In addition, in order to analyze the resistance value depending on the contact position, after applying a constant voltage between each electrode of each of the upper plate 12 and the lower plate 14, and converts the voltage changed according to the resistance value (Analog Digital Conversion: It is necessary to detect the quantized value through the ADC) circuit.

Therefore, in order to read the X coordinate in the resistive touch panel as shown in FIG. 2, after applying a voltage between the electrodes 12a and 12b of the upper plate 12 for detecting the X coordinate, the Y coordinate is detected. The lower plate 14 for detecting the voltage of the touch point (TP), and in order to read the Y coordinate, a voltage is applied between both electrodes 14a and 14b of the lower plate 14 for detecting the Y coordinate. The upper plate 12 for detecting the coordinates senses the voltage at the contact point.

3 is a bottom wiring diagram of a conventional touch panel, and FIG. 4 is a diagram illustrating an example of a malfunction caused by noise in a conventional touch panel.

Referring to FIG. 3, in the lower plate 510, power wires formed at both ends in the horizontal direction for applying power to the Y1 and Y2 electrodes 511 and 512 formed at both ends of the substrate in the vertical direction and the X1 and X2 electrodes at the top plate are provided. 513 and 514, and the electrodes 511 and 512 and the power supply wirings 513 and 164 are connected to the contact terminals X1, X2, Y1 and Y2 so that they can be easily connected to the flexible printed cable FPC. In addition, the + 5V DC is connected to one electrode when the driving power source is connected to the other electrode.

However, such a conventional touch panel has a problem that an error is generated by inserting noise from the outside into each electrode as shown in FIG. 4. That is, in the conventional 4-wire analog touch panel, noise is introduced from LCDs and PCBs mounted at the bottom of the touch panel to generate an error, and about 90% or more of the noise is affected through the outer edge of the touch panel. To be analyzed.

Accordingly, the present invention has been made to solve the above problems, by blocking the noise (noise) flowing into the touch panel from the outside to prevent the malfunction of the set (SET), and also to enable stable driving analog touch panel The purpose is to provide.

1 is a block diagram showing the overall configuration of a general touch screen;

2 is a schematic view of a general resistive touch panel;

3 is a lower wiring diagram of a conventional touch panel;

4 is an example of a screen malfunctioning due to noise in a conventional touch panel;

5 is a cross-sectional structural view of a general touch panel to which the present invention is applied;

6 is a manufacturing process diagram of a touch panel to which the present invention is applied;

7 is a lower wiring diagram of a touch panel according to the present invention;

8 is an example of a screen in which the touch panel according to the present invention operates normally by blocking noise.

* Explanation of symbols for main parts of the drawings

10: touch panel 12: top plate

14: lower plate 12a, 12b, 14a, 14b: electrode

511,512: Y electrode 513,514: X electrode power supply wiring

700: noise isolation wiring

In order to achieve the above object, the present invention is a touch panel formed by combining an upper plate having a transparent electrode and a lower plate having a transparent electrode and a dot spacer,

A noise blocking conductive line having a predetermined width is formed along an edge portion of the upper plate or the lower plate, and the noise blocking conductive line is connected to ground to block noise.

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

5 is a cross-sectional structural view of a general touch panel to which the present invention is applied, and the touch panel is largely composed of a combination of the upper plate 120 and the lower plate 140.

Referring to FIG. 5, the lower plate 140 includes a transparent conductive film 102 coated on the glass substrate 101, electrodes 103 and dot spacers 108 formed at both ends, and an upper plate 120. It consists of a transparent conductive film 106 coated on the silver film 107 and the electrode 105 formed on both ends, the upper plate 120 and the lower plate 140 is bonded by a double-sided tape (104).

FIG. 6 is a manufacturing process diagram of a touch panel to which the present invention is applied, FIG. 7 is a bottom wiring diagram of the touch panel according to the present invention, and FIG. 8 is a screen example in which the touch panel according to the present invention operates normally by noise blocking.

Referring to FIG. 6, the entire manufacturing process includes a lower plate process for forming a conductive film and an electrode on a glass substrate, an upper plate process for forming a conductive film and an electrode on a film, and a double-sided tape process for adhering the upper plate and a lower plate. After the assembly is completed, the assembly is shipped through a property test, a protective film, and a packaging.

The lower plate process includes forming a transparent conductive film 102 on the glass substrate 101, etching a pattern to form an electrode 402, forming an electrode 403, and forming a dot spacer. Forming step 404, scribing step 405, flexible printed cable (FPC) bonding step 406, cleaning step 407, and the like.

The upper plate process includes a step 408 of cutting a film, a step 409 of forming a transparent conductive film (ITO), and a step 410 of forming an electrode, and the double-sided tape process cuts a double-sided tape. Step 411 and half cutting step 412, attaching (laminating) the double-sided tape on the top plate (413), full cutting step 414, the top plate 120 and It is composed of an assembly step (415) for attaching the lower plate (140).

After the assembly is completed as described above, the product is shipped as a finished product through a characteristic and appearance inspection step 416, a protective film attaching step 417, a packaging step 418, and the like.

7 is a lower wiring diagram of the touch panel according to the present invention, and FIG. 8 is a screen example in which the touch panel according to the present invention operates normally due to noise blocking.

Referring to FIG. 7, the lower plate 510 has power lines formed at both ends in the horizontal direction to apply power to the Y1 and Y2 electrodes 511 and 512 formed at both ends of the glass substrate in the vertical direction and the X1 and X2 electrodes of the upper plate. 513 and 514, and the electrodes 511 and 512 and the power supply wirings 513 and 514 are connected to the contact terminals X1, X2, Y1 and Y2 so that they can be easily connected to the flexible printed cable FPC. As a driving power source, when + 5V DC is normally connected to one electrode, the ground is connected to the other electrode.

In particular, in the touch panel according to the present invention, a noise blocking wire 700 having a square shape having a predetermined width (for example, 0.5 mm to 5 mm) is installed along the edge of the lower plate and is connected to ground, thereby introducing noise into the touch panel. It is designed to be removed. That is, as shown in FIG. 7, noise introduced from the outside may be cut off in the noise blocking line 700, and noise may not enter the electrode. The noise blocking wire 700 is not necessarily a rectangular shape, but it is preferable to be installed at the outermost side along the edge of the substrate. In the embodiment of the present invention, an example is provided on the lower plate, but may be installed on the upper plate. have.

As described above, the touch panel of the present invention can prevent the malfunction of the SET by blocking noise introduced from the outside by installing a noise blocking wire along the edge of the substrate and connecting the ground. There is an advantage.

Claims (3)

In the touch panel formed by combining the upper plate formed with a transparent electrode, the lower plate formed with a transparent electrode and dot spacer, A conductive wire for noise blocking of a predetermined width is formed along an edge portion of the upper plate or the lower plate, and the noise blocking conductive wire is connected to ground to block the noise flowing from the outside. Touch panel. The analog touch panel of claim 1, wherein the noise blocking wire is a rectangular wire. The analog touch panel of claim 1, wherein the predetermined width is about 0.5 mm to 5 mm.