KR20030094842A - Structure for getting signal in touch panel - Google Patents

Abstract

PURPOSE: A structure for a signal application part of a touch panel is provided to reduce an error among a pen contact point, and the first and the second substrate contact points on an edge of an active region in the touch panel. CONSTITUTION: The second substrate(140) is a lower electrode having a projection part(140a). The first substrate(130) is an upper substrate having the projection part(130a) matched with the projection part of the second substrate, and is adhered to the second substrate. X-axis potential compensation electrodes(170a,170b) are symmetrically installed on the second substrate. Y-axis potential compensation electrodes(180a,180b) are symmetrically installed under the first substrate and are perpendicular to a direction of the X-axis potential compensation electrodes. The signal application parts(182,183) comprise lead electrodes(182a,182b,183a,183b) contacting with an FPC(Flexible Printed Circuit)(180) by extended from the X and the Y-axis potential compensation electrode in a length matched with the projection part of both substrates. The FPC contacts with the signal application part in order to apply the signal to the touch panel from the outside.

Description

Structure of signal applying unit of touch panel {STRUCTURE FOR GETTING SIGNAL IN TOUCH PANEL}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch panel, and in particular, a structure of a signal applying unit of a touch panel for maintaining an even cell gap in an active area of a touch panel to prevent an error in an operation position coordinate when the touch panel is operated. It is about.

In general, a personal computer, a portable transmission device, and other personal information processing devices perform text and graphic processing using various input devices such as a keyboard, a mouse, and a digitizer.

In particular, the digitizer is a device that detects the position of a finger or pen analogously on a specially manufactured flat plate, digitally XY coordinates, outputs it, and transmits it to a personal computer as compared to a mouse, keyboard, and scanner. I have the advantage of entering pictures more easily and precisely.

One of the above-described digitizers, a touch panel has been commonly used in electronic organizers, personal digital assistants (PDAs), and the like.

As shown in FIG. 1, the digitizer device (Apparatus of Digitizer) which attaches the touch panel 20 to the front of the display 10 to perform various screen operations functions on the display 10 enables a graphical user interface (GUI.Graphic User Interface). It can be seen as a representative type.

The touch panel 20 usually consists of a sheet of two resistive components which are separated by a spacer and arranged to be in contact with each other by pressing.

Known types of touch panels can be classified into resistive, capacitive, ultrasonic, optical (infrared) sensor, and electromagnetic induction. Problems such as signal amplification, resolution difference, and difficulty of design and processing technology appear differently, and the method is selected by dividing them to take advantage of the advantages. The selection criteria selects a touch panel method in consideration of optical characteristics, electrical characteristics, mechanical characteristics, environmental characteristics, input characteristics, and the like, as well as durability and economy.

Among the touch panel methods, resistive is widely used as input devices such as electronic organizers, PDAs, and portable PCs in combination with LCDs, and has a merit that is thinner, smaller, lighter, and lower power consumption than other methods. That's the way.

The resistive film detection methods are matrix type and analog type, and as transparent electrode materials, there are 0.1 mm to 0.2 mm thick film substrates, 0.2 mm to 2 mm thick glass substrates, and 1 mm to 2 mm thick plastic substrates. And a lower electrode.

FIG. 2 schematically shows a resistive touch panel, in which a structure is coated with a transparent conductive film 50 on a first substrate 30 serving as an upper electrode and a second substrate 40 serving as a lower electrode. A dot spacer 65 for electrical insulation between the first and second substrates 30 and 40 is formed, and the signal distribution on the X and Y coordinates is distributed through a contactor using the first and second substrates 30 and 40. It is calculated and sent to external driver software.

According to the number of bus lines that recognize signals on the X and Y coordinates of the first and second substrates 30 and 40, the signal is divided into four, five, and eight lines again and distributed to the X and Y coordinates. The characteristics of the signal processing method are different depending on the number of bus lines.

3 is an exploded perspective view of a 4-wire (8-wire) resistive touch panel according to the prior art. As shown in FIG. 3, the 4-wire (8-line) resistive film structure has a transparent electrode coated on the second substrate 40 of the transparent substrate, which is a lower electrode. On the second electrode 40, the lower electrode coated with the transparent electrode, X-axis potential compensation electrodes 70a and 70b are formed symmetrically to form an equipotential perpendicular to the signal application direction. The adhesion part 100 is positioned on the X-axis potential compensation electrodes 70a and 70b, and the Y-axis potential compensation electrodes 60a and 60b are symmetrical to form an equipotential perpendicular to the directions of the X-axis potential compensation electrodes 70a and 70b. It is installed. The first substrate 30, which is an upper electrode coated with a transparent electrode, is formed on the Y-axis potential compensation electrodes 60a and 60b.

Further, the signal applying units 82 and 83 made up of the lead electrodes 82a and 82b extending from the Y-axis potential compensation electrodes 60a and 60b and the lead electrodes 83a and 83b extending from the X-axis potential compensation electrodes 70a and 70b. A signal is applied to the potential compensation electrodes 60a, 60b, 70a, and 70b by connecting to an FPC (Flexible Printed Circuit) that applies a signal from the outside.

The adhesive part 100 is to fix the first and second substrates 30 and 40 when the first and second substrates 30 and 40 are bonded to each other. The flexible printed circuit (FPC) 80 and the signal applying parts 82 and 83 may come into contact with each other. When the flexible printed circuit (FPC) 80 and the signal applying parts 82 and 83 are in contact with each other, the adhesive part 100 is also reduced.

In the case of the 5-wire (or 7-wire) resistive film type other than the 4-wire (or 8-wire) resistive film type, a transparent electrode is generally coated on the first substrate, which is a lower electrode, and the transparent electrode is coated. On the top, a potential compensation electrode is provided for forming an equipotential perpendicular to the X, Y bidirectional signal application direction. An adhesion part is disposed on the potential compensation electrode, and a potential sensing electrode for sensing the potential distribution is located on the adhesion part. The potential sensing electrode includes a first substrate as an upper substrate. Similarly to the case of the 4-wire (or 8-wire) resistive film, the adhesive portion has a structure in which the flexible printed circuit (FPC) and the signal applying portion are reduced by the area contacted with each other.

The touch panel 20 having the structure as shown in FIG. 3 generates a structural difference in which the operating point and the position of the cursor do not coincide at a portion where the flexible printed circuit (FPC) 80 and the signal applying units 82 and 83 are in contact with each other.

4A is a cross-sectional view taken along line AA ′ of FIG. 3, and FIG. 4B is a cross-sectional view taken along line BB ′ of FIG. 3.

As shown in FIG. 4A, the flexible printed circuit (FPC) 80 having a constant thickness T is inserted into the first and second substrates 30 and 40 and contacts the signal applying units 82 and 83 formed of lead electrodes to contact the potential compensation electrodes. Apply a signal from the outside.

When the flexible printed circuit (FPC) 80 having a constant thickness T is contacted between the first and second substrates 30 and 40, which are upper and lower electrodes, to contact the signal applying units 82 and 83, the flexible printed circuit The cell gap between the first and second substrates 30 and 40 in contact with the circuit 80 is increased, and the portion where the flexible printed circuit (FPC) 80 and the signal applying units 82 and 83 are in contact with each other is in the active region. Since the distance difference between phosphorus a1 becomes small, the distance difference D between the contact portion of the operation pen PEN and the first and second substrates 30 and 40, which are the upper and lower substrates, is amplified. Therefore, while the distortion of the potential distribution as shown in FIG. 5 occurs, the position of the actual operating point occurs differently, which causes a problem that the operating point and the cursor on the screen do not coincide.

In FIG. 4B, since the flexible printed circuit (FPC) 80 is not inserted between the upper and lower electrodes of the first and second substrates 30 and 40, the cell gap is not large and the operating point of the operating pen PEN and the first and second electrodes are not large. The points where the second substrates 30 and 40 are in contact are almost coincident with each other.

In general, since the contact point of the pen PEN and the contact point of the first and second substrates coincide in the center portion of the active area, the operating point of the pen PEN coincides with the cursor on the screen. However, since the distance difference D between the pen PEN contact point and the first and second substrate contact points increases toward the edge of the active area of the touch panel, the cursor and the operating point do not coincide. The difference D between the contact point of the pen PEN and the contact point of the first and second substrates increases as the potential is closer to the potential compensation electrode.

Accordingly, an object of the present invention is to provide a structure of a signal applying unit of a touch panel for reducing an error between a PEN contact point and first and second substrate contact points, which are upper and lower electrodes, at an edge of an active region of a touch panel.

In the resistive touch panel for achieving the above object, a second substrate which is a lower electrode having a protrusion and a protrusion corresponding to the protrusion of the second substrate is formed and is an upper electrode which is bonded to the second substrate. An X-axis potential compensation electrode symmetrically installed on the second substrate, consisting of one substrate and a low resistance metal, and a symmetrical perpendicular to the direction of the X-axis potential compensation electrode below the first substrate, consisting of a low resistance metal. Y-axis potential compensation electrode is installed in the bonding portion, the bonding portion for fixing the first and second substrates while surrounding the outer portion that is in contact with each other when the first and second substrates are bonded to each other, the first and second Dot spacers formed between the two substrates for electrical insulation made by the second substrate, and extended from the X-axis potential compensation electrode and the Y-axis potential compensation electrode to correspond to the protrusions of the first and second substrates. And a signal applying unit made of a lead electrode contacting an FPC (Flexible Printed Circuit) in length, and an FPC (Flexible Printed Circuit) contacting the signal applying unit to apply a signal to the touch panel from the outside. It is done.

1 is an explanatory diagram of a related driving circuit of a touch panel;

2 is a schematic view of a touch panel.

3 is an exploded perspective view of a touch panel according to the prior art;

4A is a cross-sectional view along the line AA ′ of FIG. 3;

4B is a cross-sectional view taken along line B-B 'in FIG.

5 is a view showing a potential distribution characteristic on a touch panel according to the related art.

6 is an exploded perspective view of the touch panel according to the present invention;

7A is a cross-sectional view taken along line C-C 'in FIG.

FIG. 7B is a sectional view taken along the line D-D 'in FIG. 6; FIG.

8 is a diagram illustrating potential distribution characteristics on a touch panel according to the present invention;

DETAILED DESCRIPTION Hereinafter, detailed descriptions of preferred embodiments of the present invention will be described with reference to the accompanying drawings.

6 is an exploded perspective view of a touch panel according to the present invention. As shown in FIG. 6, in the 4-wire (8-wire) resistive touch panel according to the present invention, the second substrate 140, which is a lower electrode, forms a protrusion 140a and is coated with a transparent electrode. On the second substrate 140 coated with the transparent electrode, X-axis potential compensation electrodes 170a and 170b for forming an equipotential perpendicular to the signal application direction are installed symmetrically. The adhesion part 200 is positioned on the X-axis potential compensation electrodes 170a and 170b, and the Y-axis potential compensation electrodes 160a and 160b are formed on the adhesion part 200 to form an equipotential perpendicular to the directions of the X-axis potential compensation electrodes 170a and 170b. It is installed symmetrically under the first substrate 130 which is an electrode. The Y-axis potential compensation electrodes 160a and 160b are disposed below the first substrate 130, which is an upper electrode coated with a transparent electrode, and a protrusion 130a corresponding to the protrusion 140a of the second substrate is formed.

In addition, the signal applying units 182 and 183 contacting the FPC 180 for applying a signal from the outside to apply a signal to the touch panel 120 are gathered in the center direction at the ends of the X-axis potential compensation electrodes 170a and 170b. The lead electrodes 183a and 180b and the lead electrodes 182a and 182b extending from the Y-axis potential compensation electrodes 160a and 160b. The signal applying units 182 and 183 contact the FPC 180 within the protrusions 130a and 140a of the first and second substrates 130 and 140, which are the upper and lower electrodes, to contact the potential compensation electrodes 160a, 160b, 170a and 170b of the touch panel. Apply.

In addition, when the first and second substrates 130 and 140 are bonded to each other, the adhesive part 200 surrounds the outer portion of the portion where the first and second substrates 130 and 140 abut with a predetermined width and maintains a cell gap between the upper and lower plates. While fixing the first and second substrates 130,140.

In the case of the 5-wire (or 7-wire) resistive film, which is a resistive film type other than the 4-wire (or 8-wire) resistive film type, a transparent electrode is generally coated on the first substrate, which is a lower electrode, and the first electrode is coated. On the substrate, a potential compensation electrode for forming an equipotential perpendicular to the X, Y bidirectional signal application direction is provided. An adhesion part is positioned on the potential compensation electrode, and a potential sensing electrode for sensing the potential distribution is installed on the first substrate as the upper electrode. The first substrate is coated with a transparent electrode.

In particular, even in the 5-wire (7-wire) resistive film method, the area where the signal applying portion composed of the flexible printed circuit (FPC) and the lead electrode contacts to apply a signal from the outside to the potential compensation electrode of the touch panel is as shown in FIG. 7A. Projections corresponding to each other are formed on the first and second substrates, which are upper and lower electrodes, and the flexible printed circuit (FPC) and the signal applying unit are in contact with each other in the protrusions of the first and second substrates. Therefore, the adhesive part maintains a constant width and surrounds the outside of the touch panel to maintain a cell gap between the upper and lower plates.

FIG. 7A is a cross-sectional view taken along line C-C 'of FIG. 6, and FIG. 7B is a cross-sectional view taken along line D-D' of FIG.

In the touch panel according to the present invention, as shown in FIG. 7A, the flexible printed circuit (FPC) 180 and the signal applying units 182 and 183 come into contact with each other in the protrusions 130a and 140a of the first and second substrates, which are upper and lower electrodes. The portion where the circuit 180 contacts the signal applying units 182 and 183 is far from the boundary of the active area a1. Therefore, the distance between the first and second substrates 130 and 140, which are the vertical electrodes, tends to decrease toward the boundary line of the active region a1 at the contact portion between the flexible printed circuit (FPC) 180 and the signal applying unit 182,183.

As a result, almost the same cell gap is maintained as shown in FIG. 7B in which the flexible printed circuit (FPC) 180 is not inserted between the first and second substrates 130 and 140, which are upper and lower electrodes, at the active region interface. Indicates a distribution.

As described above, the present invention maintains the same cell gap between the first and second substrates 130 and 140, which are the upper and lower electrodes, and applies a signal to the boundary line of a1, the active region of the touch panel, and the FPC 180. By increasing the distance difference between the contact portions of the parts 182 and 183, the operating point of the pen PEN at the edge portion of the touch panel and the contact points of the first and second substrates, which are upper and lower electrodes, are substantially coincident with each other.

That is, as described above, according to the present invention, the FPC (flexible printed circuit) and the signal applying unit come into contact with the protrusions formed on the upper and lower substrates, thereby improving the distortion of the potential distribution occurring at the edge of the active region of the touch panel, thereby expressing the operation position coordinates. There is an effect that can improve the precision of.

Claims (2)

In the resistive touch panel, A second substrate which is a lower electrode on which a protrusion is formed; A first substrate formed as a protrusion corresponding to the protrusion of the second substrate and bonded to the second substrate; X-axis potential compensation electrode made of a low resistance metal and symmetrically installed on the second substrate, A Y-axis potential compensation electrode made of a low resistance metal and symmetrically disposed below the first substrate in a symmetrical direction to the direction of the X-axis potential compensation electrode; An adhesive part for fixing the first and second substrates while surrounding the outer portions contacting each other with a predetermined width when the first and second substrates are bonded to each other; A dot spacer formed between the two substrates for electrical insulation made by the first and second substrates; A signal applying unit comprising a lead electrode extending from the X-axis potential compensation electrode and a Y-axis potential compensation electrode and contacting a flexible printed circuit (FPC) at a length corresponding to the protrusions of the first and second substrates; And a flexible printed circuit (FPC) in contact with the signal applying unit to apply a signal to the touch panel from the outside. The method of claim 1, The flexible printed circuit (FPC) and the signal applying unit are in contact with each other at the protrusions formed on the first and second substrates.