KR100349904B1 - A one body type liquid crystal display with input device - Google Patents

Abstract

PURPOSE: To provide an input device-integrated liquid crystal display device having a slim structure that does not separately attach an input panel such as a touch panel or a tablet to a display panel of a liquid crystal display device.

Composition: A liquid crystal display device having a structure in which transparent electrodes are patterned orthogonally in the x and y axis directions on opposite surfaces of upper and lower substrates arranged in parallel with a liquid crystal layer interposed therebetween, wherein the pattern of the x and y transparent electrodes Patterns of x and y input electrodes are formed on the blanks on the upper and lower substrates, respectively, so as to induce a change in capacitance due to a cell gap change between the x and y input electrodes during a touch operation pressed onto the upper substrate.

Effect: Since a user operation is input as a signal by using a cell gap change of an input electrode provided on opposite surfaces of the upper and lower substrates, it is necessary to attach a separate input panel for adding an input device on the display panel of the liquid crystal display element. none. Therefore, the display quality can be improved, the display panel thickness can be reduced, and the panel assembly process can be reduced, compared to the conventional liquid crystal display device combined with an input device, thereby improving productivity.

Description

Liquid crystal display device with integrated input device {A one body type liquid crystal display with input device}

The present invention relates to an input device-integrated liquid crystal display device, and more particularly, to an input device-integrated type that can implement a function of the input device while having a slim structure that does not separately attach an input panel such as a touch panel or a tablet to the display panel of the liquid crystal display device. It relates to a liquid crystal display device.

A touch panel as an input device is a device that inputs information by reading a user's input operation as a coordinate value, and is commonly used by laminating and bonding on a display panel such as a liquid crystal display (LCD).

Conventional input device-integrated liquid crystal display device, in which an input device such as a touch panel is integrated with an LCD, has a disadvantage in that image display floating due to parallax of light derived from the LCD is increased by stacking the touch panel on top of the LCD panel. have.

As a method for minimizing the problem of the display quality, a mixed panel structure using a plastic substrate serving as a touch panel and a glass substrate as a lower substrate is known as the upper substrate of the LCD. It is not solved enough to satisfy the parallax problem.

In addition, the above-described mixed panel structure has a problem in the manufacturing process that the panel bonding process is not easy due to the difference in thermal expansion coefficient between the upper plastic substrate and the lower glass substrate.

FIG. 5 is a side view illustrating a structure of a liquid crystal display device in which a conventionally known input device is integrated. The upper and lower substrates 2a of the light-transmitting agent in which transparent electrodes made of indium thin oxide (ITO) are patterned perpendicularly to each other vertically as an input device are shown in FIG. The touch panel 2 constituted by 2b) is laminated on the LCD panel 4 as a display element.

In the conventional input device-integrated liquid crystal display device configured as described above, the floating feeling of the display becomes severe due to the parallax of the light generated in the process where the display light of the image reproduced on the LCD panel 4 passes through the touch panel 2. As a result, an image of good contrast could not be provided.

In addition, the conventional input device-integrated liquid crystal display device requires a bonding process of the two panels 2 and 4, so that the number of processes is increased, which takes a lot of time to manufacture and increases the manufacturing cost.

Meanwhile, the conventional input device-integrated liquid crystal display device having the above-described structure has a total thickness of 1.5 mm and a total thickness of the LCD of about 2 mm even when the LCD is slim. In the case of reducing the thickness of the touch panel in order to reduce the problem of parallax, the electrode formed on the touch panel is easily broken when a touch input by a pen or the like is difficult to realize slimming.

The present invention devised to solve the above-mentioned problems of the prior art is a structure in which a touch panel and a liquid crystal display device which can be implemented without any additional process are integrated, and there is a concern about electrode breakage during touch input without increasing the overall panel thickness. It is an object of the present invention to provide a touch panel integrated liquid crystal display device capable of eliminating the problem and improving image quality reproduced.

According to an aspect of the present invention, there is provided a liquid crystal display device having a structure in which transparent electrodes are orthogonally patterned in the x and y axis directions on opposing surfaces of an upper substrate and a lower substrate disposed in parallel with a liquid crystal layer interposed therebetween. Patterns of the x and y input electrodes are formed on the blanks on the upper and lower substrates without the pattern of the x and y transparent electrodes, respectively, so that the capacitance change due to the change of the cell gap between the x and y input electrodes is applied during the touch operation pressed onto the upper substrate. There is provided an input device-integrated liquid crystal display device which is configured to induce.

The x, y input electrode may be formed of a conductive film of black color, so as to replace the role of the black matrix normally interposed between the color filters. The x, y input electrode may be formed of the same material as the x, y transparent electrode.

The transparent electrode and the input electrode further extend the pattern length by a predetermined length in a direction opposite to each other on the same substrate, so that respective pads for connecting the upper and lower transparent electrodes with the row and column drivers are provided on the upper and lower substrates. It is disposed on the outer side of the, and also characterized in that each pad for connecting the x, y input electrode with the coordinate scan unit can be disposed on the outer side of the upper and lower substrates.

1 is an exploded perspective view showing the schematic structure of an input device-integrated liquid crystal display device according to the present invention in an open front;

2 is a side cross-sectional view showing a layer structure of an input device-integrated liquid crystal display device according to the present invention;

3 is a plan view of an input device-integrated liquid crystal display device according to the present invention.

4 is a configuration diagram showing a circuit connection of an input device-integrated liquid crystal display device according to the present invention.

5 is a perspective view showing the structure of a conventional liquid crystal display device integrated with an input device;

Explanation of symbols on the main parts of the drawings

2-touch panel 2a, 2b-upper and lower substrates of touch panel

4-LCD Panel 14a, 14b-Upper, Lower Board

16a, 16b-polarizer 18-liquid crystal layer

142a, 142b-transparent electrode 144a, 144b-input electrode

152-Controller 154-Row Drive

156-Column Drive Unit 158-Coordinate Scan Unit

Pd1-Pd4- Pad

According to the features of the present invention described above, unlike the prior art that separately manufactured by bonding the LCD panel and the touch panel, it is implemented together in the LCD panel without making a separate touch panel.

The features of the present invention will be described in detail with reference to the embodiments based on the drawings.

In the exemplary embodiment of the present invention, as shown in FIGS. 1 and 2, indium thin oxide (ITO) is formed in the x and y-axis directions on opposite surfaces of the upper substrate 14a and the lower substrate 14b facing each other. When the transparent electrodes 142a and 142b are patterned, respectively, and the upper substrate 14a and the lower substrate 14b overlap with the liquid crystal layer 18 interposed therebetween, the upper and lower substrates 14a and 14b are viewed from the top. In the LCD structure, the transparent electrodes 142a and 142b form a lattice arrangement, in addition to the x and y axes of a blank on the upper and lower substrates 14a and 14b without the pattern of the transparent electrodes 142a and 142b. The input electrodes 144a and 144b in the directions are patterned.

The structure of this embodiment is based on the capacitance caused by the change of the upper and lower cell gaps of the x and y coordinate points of the input electrodes 144a and 144b located at the bottom of the touch point during the touch operation in which the pressing force is applied to the upper substrate 14a. The change can be detected. That is, the x input electrode 144a of the upper substrate 14a and the y input electrode 144b of the lower substrate 14b include a liquid crystal layer 18 interposed therebetween as a dielectric to eventually form a capacitor. Will be done.

The x and y input electrodes 144a and 144b are formed of a black conductive film to serve as a black matrix. To this end, the input electrodes 144a and 144b should be aligned precisely in correspondence with a color filter, which is not shown. Since the color filters and the transparent electrodes 142a and 142b are normally aligned, they are naturally followed. This is realized. The x, y input electrodes 144a and 144b may be formed of an ITO film made of the same material as the x and y transparent electrodes 142a and 142b.

In addition, polarizing plates 16a and 16b are attached to the upper and lower substrates 14a and 14b, respectively. In the case of a reflective LCD, a reflecting plate is attached to the lower substrate 14b instead of the polarizing plate 16b.

Although not shown in the drawings, the upper surface of the upper substrate 14a may include a compensation plate having uniaxial or biaxial refractive index anisotropy.

Meanwhile, the patterns of the input electrodes 144a and 144b are printed on the mask used in the photo process together with the patterns of the transparent electrodes 142a and 142b to form the transparent electrodes 142a and 142b during exposure. The patterns of 144a and 144b can also be simultaneously transferred onto the substrates 14a and 14b.

In designing a mask pattern for forming the input electrodes 144a and 144b as described above, since the line widths of the transparent electrodes 142a and 142b become smaller toward the high resolution screen, the pattern of the miniaturized transparent electrodes 142a and 142b is reduced. If all of the blanks form a pattern of the input electrodes 144a and 144b, the number of matrices for scanning the touch-manipulated input coordinates increases, so that the input interface board (in case of parallel transmission of input data) or process board Since a large number of data bits should be allocated and configured, the present invention can adopt the following two methods to solve this problem.

One is that it is not necessary to form the patterns of the input electrodes 144a and 144b for each blank between the transparent electrodes 142a and 142b, and to form the bits at appropriate intervals for determining the touch input operation to reduce the number of bits. The other is to connect the input electrodes 144a and 144b in a predetermined region in a state where all the patterns of the input electrodes 144a and 144b are formed on the blanks between all the transparent electrodes 142a and 142b. This is to reduce the number of bits.

In addition, in forming the patterns of the transparent electrodes 142a and 142b and the input electrodes 144a and 144b, the patterns of the transparent electrodes 142a and 142b and the input electrodes 144a and 144b are illustrated in FIG. 1. When the length of the pattern is formed to further extend in a direction opposite to each other on the same substrate, as shown in FIG. 3, when the upper substrate 14a and the lower substrate 14b overlap, the nodes of the transparent electrodes 142a and 142b To one side of the upper and lower substrates 14a and 14b, a node of the input electrodes 144a and 144b is exposed to the other side of the upper and lower substrates 14a and 14b.

As shown in FIG. 4, the exposed patterns of the transparent electrodes 142a and 142b and the input electrodes 144a and 144b are row and column drivers for generating driving signals required for driving the LCD under the control of the controller 152. 154 and 156, and the input electrodes 144a and 144b are scanned to form an arrangement structure for connecting to the coordinate scan unit 158 which detects x, y coordinate points of the touch input.

That is, the nodes of the transparent electrodes 142a and 142b are connected to the row and column driving units 154 and 156 through the pads Pd1 and Pd2, and the nodes of the input electrodes 144a and 144b connect the pads Pd3 and Pd4. The pads Pd1 and Pd2 attached to the nodes of the transparent electrodes 142a and 142b and the pads Pd3 attached to the nodes of the input electrodes 144a and 144b. And Pd4 are disposed at positions opposite to each other on the substrates 14a and 14b, respectively.

Meanwhile, the coordinate scan unit 158 applies a predetermined AC signal to the input electrodes 144a and 144b arranged in the x and y directions to read the change in capacitance. At this time, the voltage of the AC signal applied from the coordinate scan unit 158 to the x, y input electrodes 144a and 144b should be set to be less than the threshold voltage at which the liquid crystal molecules of the liquid crystal layer 18 are transferred. Will not interfere with.

In the embodiment of the present invention, more preferably, the driving voltage applied from the row and column drivers 154 and 156 to the transparent electrodes 142a and 142b of the upper and lower substrates 14a and 14b is also required to transfer liquid crystal molecules. Compensation, such as setting the bias voltage higher than before, should be taken.

As described above, the part related to the display quality of the LCD may be obtained by theoretical calculation, but it is preferable to obtain it through a plurality of experiments based on the calculated value.

According to the present invention configured as described above, the input electrodes 144a and 144b are formed on the blanks between the transparent electrodes 142a and 142b formed on the upper and lower substrates 14a and 14b to have the following effects.

The coordinate scan unit 158 connected to the upper and lower substrates 14a and 14b through the pads Pd3 and Pd4 and the x and y input electrodes 144a and 144b arranged in a row is predetermined as the input electrodes 144a and 144b. AC signal voltage is applied. When an AC voltage is applied to the input electrodes 144a and 144b as described above, a predetermined gap between the input electrodes 144a and 144b disposed up and down with the liquid crystal layer 18 therebetween at each point of the matrix where the input electrodes 144a and 144b overlap. Capacitance is generated.

At this time, if a pressing force is applied to an arbitrary position of the upper substrate 14a according to a user's touch operation, the distance between the upper and lower x, y input electrodes 144a and 144b of the corresponding coordinate point to which the pressing force is applied, that is, the cell gap is As a result, the capacitance accumulated between the upper and lower x, y input electrodes 144a and 144b of the coordinate point is changed. The change in capacitance is detected by the coordinate scan unit 158 which scans the x and y coordinates of the input electrodes 144a and 144b.

The detected coordinate input value of the touch input is converted into input data corresponding to the coordinate value through an input interface circuit (not shown), so that a user can input a large amount of information through the liquid crystal display device integrated with the input device of the present invention. Will be.

As such, since the present invention forms the input electrodes 144a and 144b constituting the input device on the same layer as the transparent electrodes 142a and 142b, a separate touch panel is formed and attached to the upper portion of the LCD panel. It can be excluded that the thickness of the panel is increased.

In addition, as described above, the input electrodes 144a and 144b provided by the present invention may be masked together with the patterns of the input electrodes 144a and 144b at the time of designing the mask. There is no process.

Therefore, the LCD may be configured to include an input device integrally without increasing the manufacturing process and manufacturing cost.

As described above, the present invention provides an input device-integrated liquid crystal display device in which an input electrode is formed on a blank between transparent electrodes of upper and lower substrates, thereby obtaining the following effects.

Compared to the conventional input device integrated liquid crystal display device, the overall panel thickness is reduced.

The problem of electrode breakdown due to touch pressure, which is commonly seen in a conventionally manufactured thin touch panel, can be eliminated, thereby increasing the life of the product.

The floating feeling of the display image due to the touch panel laminated on the upper part of the conventional liquid crystal display device can be eliminated, thereby improving the image quality.

Since the input electrode embodying the present invention is formed on the same layer together with the transparent electrode in the same process and can be formed without an additional process, the number of processes is reduced compared to the conventional manufacturing and attaching the touch panel and LCD separately. Can improve the production cost and reduce the production cost.

Claims (4)

An upper substrate and a lower substrate arranged in parallel with the liquid crystal layer interposed therebetween, a plurality of x transparent electrodes patterned in the x-axis direction on a surface opposite to the lower substrate of the upper substrate, and opposed to the upper substrate of the lower substrate; A liquid crystal display device having a plurality of y transparent electrodes patterned in a y-axis direction so as to be orthogonal to the x transparent electrodes on one surface. A plurality of x input electrodes patterned in the x-axis direction on a blank between the x transparent electrodes; A plurality of y input electrodes patterned in the y-axis direction on a blank between the y transparent electrodes; The x and y input electrodes inducing a change in capacitance due to a cell gap change between the x and y input electrodes during a touch operation pressed onto the upper substrate; An input device integrated liquid crystal display device. The liquid crystal display device of claim 1, wherein the x and y input electrodes are formed of a black conductive film so as to substitute for a black matrix interposed between the color filters. The liquid crystal display of claim 1, wherein the x, y input electrode is formed of the same material as the x, y transparent electrode. The pattern length of the transparent electrode and the input electrode further extends in directions opposite to each other on the same substrate; Pattern length portions of the more extended transparent electrodes on the upper and lower substrates are attached to pads disposed at each outer side of the upper and lower substrates so that the extended length portions are connected to the row and column drivers; The pattern length portions of the more extended input electrodes on the upper and lower substrates are attached to different pads arranged on the outer side of each side of the upper and lower substrates so that the extended length portions are connected to the coordinate scan unit. ; An input device integrated liquid crystal display device.