KR20130095451A - Touch screen device having antena formed on display panel or backlight unit - Google Patents

Abstract

The present invention includes a display unit in which a light transmission control element whose operation is controlled by an input image signal is arranged, and a backlight unit disposed at the rear of the display unit and emitting light forward through the display unit. A display panel; A first line selection circuit configured to select one of the plurality of first line antennas and the plurality of first line antennas and to set the first output in an insulated state from the loop structure; In this case, the present invention relates to a touch screen device having an antenna pattern integrated into a backlight unit including a tablet including a coordinate sensing circuit that determines a position of the electronic pen using the induced voltage appearing at the first output. In this case, the plurality of first line antennas are formed by printing a conductive material on one surface of the backlight unit, in particular, a reflective sheet.

Description

TOUCH SCREEN DEVICE HAVING ANTENA FORMED ON DISPLAY PANEL OR BACKLIGHT UNIT}

The present invention relates to a touch screen device, and more particularly, to a touch screen device that operates by forming an antenna pattern for sensing a user's manipulation on a part of a display panel or a part of a panel constituting a backlight unit.

The touch screen is disposed on a display panel, such as an LCD or LED panel, and a front surface (front facing surface on which an image is displayed) or a rear surface of the display panel, and a conductive antenna for sensing the approach or contact of an electronic pen manipulated by a user. And a position sensing circuit configured to sense a position of the electronic pen by sensing an electromagnetic change generated in the antenna pattern.

In a conventional touch screen, the antenna substrate has a structure in which antennas formed in a loop or mesh pattern are stacked in several layers through an insulating layer. Thus, since the antenna substrate overlapping the multilayer antenna pattern is inevitably thickened, it acts as a factor for thickening the overall thickness of the touch screen.

As an example of an antenna substrate in such a conventional touch screen, Korean Patent Laid-Open No. 2008-86829 (hereinafter referred to as reference) can be referred to. In the above reference, the structure of the loop coil for detecting the position of the electronic pen in any one axial direction is configured in such a manner that at least three loop coils are insulated from each other. Therefore, assuming that the coordinates in the X-axis and Y-axis directions are to be measured, and that the antenna pattern is configured by using a conductive material and an insulating sheet on one antenna substrate, at least 12 layers (= 6 layers × 2 axes) Since it has a laminated structure, the thickness of the substrate is inevitably thickened.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is intended not to significantly increase the overall thickness of the touch screen by improving an antenna structure for detecting a user's manipulation, particularly the position of the electronic pen.

In addition, to form an antenna to minimize the laminated structure to facilitate the manufacture.

The present invention for achieving the object as described above, the display unit is arranged in the light transmission control element is controlled by the input image signal, and disposed behind the display unit and forward through the display unit A display panel including a backlight unit emitting light; A plurality of first line antennas are formed by printing a conductive material on one surface of the backlight unit, wherein one side of the plurality of first line antennas is connected to each other to form parallel comb-shaped shapes and the other side of the backlight unit extends to an edge of one surface of the backlight unit. Wow; Is formed on a separate substrate from the display panel, the outermost line antennas of the plurality of first line antennas are connected to each other to form a loop structure and connected to ground, and any one of the plurality of first line antennas The first line selection circuit for selecting the other side and setting it as the first output in a state insulated from the loop structure, and the induction voltage appearing at the first output when the electronic pen for outputting the AC electromagnetic force is approached. The present invention provides a touch screen device having an antenna pattern integrated into a backlight unit including a tablet including a coordinate sensing circuit that determines a position of the electronic pen based on the selected first line antenna.

The plurality of first line antennas may be formed on the reflective sheet of the backlight unit, and the plurality of first line antenna patterns may be formed on the rear surface of the reflective surface of the reflective sheet.

The tablet may include a plurality of second line antennas having the same shape as the plurality of first line antennas and arranged in a direction crossing the first line antennas, and an outermost line of the plurality of second line antennas. A second line selection circuit connecting the antennas to each other to form a loop structure and connecting the antennas to ground, and selecting one of the plurality of second line antennas and setting the second output to be insulated from the loop structure The coordinate sensing circuit may further include determining the position of the electronic pen using the induced voltages appearing at the first output and the second output, and determining the plurality of first line antennas and the plurality of second lines. The antenna may include the reflective sheet, the plurality of first line antennas printed and formed on the reflective sheet, an insulating layer covering the plurality of first line antennas, and an image. And a laminated structure in the order of the plurality of second line antennas printed and formed on the insulating layer.

In addition, the electronic pen includes a resonant circuit having a predetermined resonant frequency, and the tablet is formed to surround the plurality of first line antennas in an insulated state and by printing a conductive material on one surface of the backlight unit. And a power supply driver configured to apply AC power having a waveform corresponding to the resonance frequency of the electronic pen to the formed power coil and the power coil.

In another embodiment of the present invention for achieving the above object, a plurality of light emitting elements whose operation is controlled by an input image signal is arranged on the front surface to display an image forward; And a plurality of first line antennas formed by printing a conductive material on the rear surface of the display panel and having one side connected to each other to form parallel comb-shaped shapes and the other side separated from each other and extending to the rear edge of the display panel; It is formed on a substrate separate from the display panel, and the outermost line antennas of the plurality of first line antennas are connected to each other to form a loop structure and connected to ground, and the other side of any one of the plurality of first line antennas. Selects and sets the first line selection circuit to be set as the first output in an insulated state from the loop structure, and when the electronic pen for outputting the AC electromagnetic force approaches, the induced voltage that appears at the first output, Coordinate sensing for determining the position of the electronic pen based on the selected first line antenna It provides a touch screen device having the antenna pattern is integrated in the display panel consisting of a tablet containing a.

The touch screen according to the present invention having the above-described configuration increases the thickness of the panel for implementing the touch screen by efficiently adding an additional substrate to the structure of the general display panel and efficiently using the internal space of the display panel. Do not increase.

In addition, since the antenna pattern can be implemented by a simple process and by a minimal stacked structure, the manufacturing is simple and the cost is reduced.

1 is a view for explaining the basic principle of detecting the position of the electronic pen using a loop antenna and a line antenna.
FIG. 2 is a diagram for explaining waveforms of voltages appearing in various parts of a tablet in a structure using a line antenna and a loop antenna as shown in FIG. 1.
3 is a view for explaining the structure and operation that can more accurately detect the position of the electronic pen using a loop antenna and a plurality of line antennas.
4 is a view for explaining the schematic structure of the tablet for detecting the structure of the electronic pen and the position of the electronic pen.
5 is a view schematically showing the configuration of a tablet according to the present invention.
6 is an enlarged view for explaining a method of configuring a circuit pattern in the tablet according to the present invention.
7 is a view briefly illustrating a structure of a backlight unit for a general LCD display panel.
8 is a view for explaining various methods of forming an antenna pattern on a base substrate in the tablet according to the present invention.
9 is a view for explaining a method of forming an antenna pattern by a screen printing method.
10 is a diagram illustrating a backlight unit configured using a reflector plate having an antenna pattern in the tablet according to the present invention.
11 is a view showing a form in which the antenna pattern according to the present invention is applied to the surface of the OLED display panel.

First, the structure and operation of an electronic pen sensing principle in a tablet used in the present invention and a tablet having a flexible and transparent sensing area according to the present invention using the principle will be described.

1 is a view for explaining the basic principle of detecting the position of the electronic pen having a resonant circuit using a loop antenna and a line antenna. First, a structure of antennas for detecting the electronic pen P in a tablet will be described with reference to FIG. 1A. In the figure, the line antenna 20 is arranged in a direction crossing the loop shape of the loop antenna 10 in a state where one end of the loop antenna 10 having a closed loop shape is connected to one side of the loop antenna 10. It is. The other end of the line antenna 20 is connected to the input of the amplifier 17. The other input of the amplifier 17 is connected to the loop antenna 10. The amplifier 17 is, for example, a differential amplifier and outputs a potential difference Vout obtained by subtracting the potential of the loop antenna 10 from the potential of the line antenna 20. In such an antenna configuration, there is a point where the pattern of the line antenna 20 crosses the pattern of the loop antenna 10, at which point the line antenna 20 and the loop antenna 10 must be insulated from each other.

Meanwhile, FIG. 1A illustrates a state where the electronic pen P including the inductor and the AC power source is located at the point ①. In the electronic pen P, an electromagnetic force is generated from the inductor L as the AC power source pulsates. The line antenna 20 and the loop antenna 10 generate induced current by the electromagnetic force from the electronic pen P.

FIG. 1 (b) shows the potential difference Vout output from the amplifier 17 when the electronic pen P is located at the ①, ②, and ③ points on the antenna structure as shown in FIG. First, if the electronic pen is located at the point ① within the loop shape of the loop antenna 10 as shown in FIG. 1 (a), the induced current flowing in the line arrow direction occurs in the line antenna 20. On the other hand, the generated induction current causes not only the flow of the current like a solid line but also the flow of the induced current in the form of a dotted line. When such an induced current is generated, the amplifier 17 outputs, for example, a potential difference in the negative direction (indicated by a down arrow in the figure).

On the other hand, if the electronic pen P is located at the point ③, the induced current in the opposite direction will occur in the line antenna 20, the amplifier 17 will output a positive potential difference.

And, if the electronic pen P is located at the point ②, that is, directly above the line antenna 20, the induced currents do not cancel each other in the line antenna 20, and the potential difference does not appear in the amplifier 17. .

According to such an antenna structure, it is possible to detect whether the electronic pen P is located on the right side or the left side of the line antenna or on the line antenna in the loop form of the loop antenna 10.

In addition, the distance between the electronic pen and the line antenna may be determined by using the magnitude of the output potential difference Vout.

On the other hand, the above description, it is assumed that the direction of the electromagnetic force output from the electronic pen (P) is constant. However, the direction of the electromagnetic force generated in the electronic pen is actually switched according to the pulsation of the AC power source. Therefore, the potential difference output from the amplifier 17 will also oscillate in accordance with the pulsation frequency of the AC power supply. This will be described later with reference to FIG.

FIG. 2 is a diagram illustrating a structure in which a line antenna and a loop antenna as shown in FIG. 1 are used, and may be operated by wirelessly supplying energy from an external source without using a consumable power source such as a battery to drive a resonance circuit. A diagram for explaining the waveform of the voltage appearing in each part during operation of the pen and the electronic pen and the tablet.

Referring to FIG. 2 (a), the power coil 30 is disposed in a form surrounding the outside of the loop antenna 10, and the power coil 30 is connected to the electronic pen from the power supply driver (PWD) 32. The oscillating AC power is supplied at the resonance frequency f0 of the resonance circuit built in P).

At this time, the power coil 30 outputs an electromagnetic force by vibrating electric power supplied from the power supply driver 32, and an induced current is generated in the resonance circuit of the electronic pen P by this electromagnetic force. The induced current in the electronic pen P charges energy by the capacity of the built-in resonant circuit (including at least the inductor and capacitor). Thereafter, even when the power supply from the power supply driver 32 to the power coil 30 is stopped, the electronic pen P may continue resonance for a predetermined time by energy charged in the resonance circuit.

On the other hand, if the resonant circuit of the electronic pen P resonates while the power supply to the power coil 30 is stopped, the induced current as described in FIG. 1 is generated in the line antenna 20 on the tablet side, and the amplifier At 17, the potential difference Vout between the line antenna and the loop antenna is output.

In this manner, the power coil driving by the power supply driver 32 is controlled and the potential difference output from the amplifier 17 is used in a section in which power is not supplied to the power coil 30 through the power supply driver 32. Thus, the position of the electronic pen P can be detected.

FIG. 2 (b) is a voltage waveform measured at a point 1, which is a control signal (power oscillating at the resonant frequency f0 in the power coil 30) for driving the power supply driver 32. At this time, by setting a section for supplying the power of the resonant frequency and a section for not supplying power, it is possible to configure a section for supplying energy to the electronic pen and a section for detecting the position of the electronic pen by allowing the electronic pen to resonate itself. . The several rising pulses shown in the figures are exemplary and may, in practical implementations, consist of frequencies from several Hz to several MHz or more.

FIG. 2 (c) is a voltage waveform appearing in the power coil 30. Even when the power supply driver 32 supplies square wave power having a resonance frequency, the power coil 30 slowly rises due to the counter electromotive force. It can be seen that. At this time, the electromagnetic force will be output from the power coil 30 in a direction perpendicular to the ground. On the other hand, since the power coil 30 has no charge storage element (for example, capacitance) coupled to the power coil to form a resonant circuit, when the power supply is stopped in the power supply driver 32, the voltage waveform is abruptly stopped. do.

FIG. 2 (d) is a voltage waveform measured at point 3, which is a waveform of a voltage caused by an induced current induced in the resonant circuit of the electronic pen P by the electromagnetic force output from the power coil 30. In the resonant circuit of the electronic pen P, energy is charged by its capacity, and even if the output of the electromagnetic force is stopped in the power coil 30, the resonance is continued for a predetermined time by the energy charged in the resonant circuit.

FIG. 2 (e) shows that current is induced to the line antenna 20 and the loop antenna 10 by the resonant circuit of the electronic pen that continues to resonate even after the power supply driver 32 stops supplying power. As a waveform of the potential difference generated between the line antenna 20 and the loop antenna 10, the waveform of the voltage output from the amplifier 17 at the point ④ is shown. In this way, the voltage is sampled (H) at any time point T of the waveform of the potential difference output from the amplifier 17 (a voltage as shown in FIG. The position of the electronic pen P with respect to 20 is determined.

3 is a view for explaining the structure and operation of the position of the electronic pen P more accurately by using the loop antenna 10 and the plurality of line antennas 20. Here, each of the plurality of line antennas 20, the one end is traversed in a loop form parallel to each other in the state that is electrically connected to the loop antenna 10, the other ends are comb teeth connected to the input of the multiplexer 15. The structure of the shape. The line antennas 20 should not be connected to the loop antenna 10 except that one end is connected to the loop antenna 10. That is, the other ends of the loop antennas 20 are insulated from the loop antenna 10.

On the other hand, the multiplexer 15 is connected to the input of the amplifier 17, the output, it is possible to select the other end of any one line antenna according to the selection signal input from the external (for example, MCU). (The power coil and the power supply driver are not shown in FIG. 3, so refer to FIG. 4)

In such an antenna structure, for example, in the state where the electronic pen P is located at a position as shown in FIG. 3 (a), the multiplexer 15 is controlled to move the plurality of line antennas 20 from ① to ⑤. When sequentially selected in the direction, the potential difference Vout in the form as shown in FIG. 3 (b) can be obtained.

That is, if the line antenna 1 is selected, since the electronic pen P is located near the right side of the line antenna 1, a positive potential difference can be output from the amplifier 17, for example.

Subsequently, if the line antenna 2 is selected, since the electronic pen P is positioned on the line antenna 2, the potential difference is not output from the amplifier 17.

Next, when the line antenna ③ is selected, the electronic pen P is positioned to the left of the selected line antenna ③, so that the negative potential difference Vout may be output from the amplifier 17.

After that, when the line antenna ④ or ⑤ is selected, a negative potential difference is output since the electronic pen P is also present on the left side of the line antenna, and the line antenna ④ or ⑤ has a relatively long distance from the electronic pen. Since it is far, the potential difference smaller than the potential difference output when the line antenna (3) is selected is output.

In this way, if the potential difference is obtained from all the line antennas, a drawing as shown in FIG. can do. On the other hand, even if the electronic pen P is not located on the line antenna but is present between the line antennas, since the potential difference will appear in the form of inversion in both line antennas adjacent to the electronic pen P, the position of the electronic pen There is no problem in determining.

The operation of detecting the potential difference by selecting the line antennas 20 one by one is expressed as 'scan'. On the other hand, the scanning method may be sequentially performed from the line antenna at one end to the line antenna at the other end as described above, and the position of the electronic pen can be more quickly determined by selecting the line antenna disposed at an arbitrary position in various ways. It may be implemented to detect. In addition, if the position of the electronic pen is identified while scanning some line antennas without scanning all the line antennas, the scan of the remaining line antennas may be terminated.

Next, referring to FIG. 4, the schematic structure of the tablet for detecting the structure of the electronic pen and the position of the electronic pen will be described. First, referring to FIG. 4 (a), a plurality of X-axis line antennas 20X arranged in a longitudinal direction (Y-axis direction) and arranged in parallel in the vertical direction (X-axis direction) and in the X-axis direction The structure of the Y-axis line antennas 20Y, which are arranged long and arranged in parallel in the Y-axis direction, can be seen (in this case, the X-axis line antennas and the Y-axis line antennas are insulated from each other). In this way, the X-axis position and the Y-axis position of the electronic pen can be detected by the X-axis line antennas 20X and Y-axis line antennas 20Y, respectively. As a result, two-dimensional coordinates of the electronic pen can be calculated. It becomes possible.

At this time, the area (the area indicated by the dotted line) where the X-axis line antennas 20X and the Y-axis line antennas 20Y are formed becomes an electronic pen detection area A in which the position of the electronic pen P can be detected. .

On the outer side of the electronic pen detecting region A (outer side of the electronic pen detecting region), the power coil 30 is disposed to surround the X axis line antennas 20X and the Y axis line antennas 20Y. Thus, it is possible to supply energy to the electronic pen by electromagnetic force.

One ends of the X-axis line antennas 20Y are connected to the loop antenna 10 and the other ends are connected as inputs to the multiplexer 15. The output of the multiplexer 15 is connected to one input of the amplifier 17.

In addition, one ends of the Y-axis line antennas 20Y are also connected to the loop antenna 10, the other ends are connected to the input of the multiplexer 25, and the output of the multiplexer 25 is an input of the amplifier 17. .

Here, the loop antenna to which the X-axis line antennas are connected and the loop antenna to which the Y-axis line antennas are connected may share a single loop antenna as shown in FIG. 4, but may be independently configured.

The amplifier 17 inputs the potential of either the outputs of the multiplexers 15 and 25 and the loop antennas (the loop antennas remain at the same potential), and outputs the potential difference between them. The output potential difference is input to the MCU 18.

The MCU 18 sends a selection signal to the multiplexers 15 and 25 to select the other end of either line antenna (one of the X-axis line antennas and the Y-axis line antennas), thereby providing a voltage from the selected other end. This is input to the amplifier 17. Then, the control unit scans the other line antennas by changing the selection signal and continuously outputs the input signal. The potential difference output from the amplifier 17 is input whenever one line antenna is selected, and the electronic pen P for the selected line antenna is input. Detect the positional relationship. When all or part of the line antennas are scanned, the coordinates of the electronic pen P are calculated using the detected positional relationships.

In addition, the MCU 18 may generate a control signal according to the resonance frequency of the electronic pen to control the operation of the power supply driver 32.

Here, the electronic pen detecting region A in which the antenna patterns for detecting the position of the electronic pen and the power coil are formed may include a driving circuit region including the multiplexers 15 and 25, the amplifier 17, and the MCU 18. It can be separated from, and formed on a separate substrate.

Next, Figure 4 (b) shows a schematic configuration of the electronic pen. The electronic pen P has a resonant circuit including at least an inductor L and a capacitor C, and is caused by an induced current generated in the inductor L when the resonant circuit is located in an electromagnetic field in which electromagnetic force is applied. The capacitor C causes resonance while charging and discharging. This resonance phenomenon persists for a predetermined time according to the time constant of the resonance circuit even after the electromagnetic force is removed.

In addition, the electronic pen may be provided with circuit elements that operate using the generated induced current. These circuit elements allow digital communication between the electronic pen and the MCU 18 of the tablet by generating on / off of the electromagnetic force emitted from the electronic pen or variation of the resonant frequency.

Hereinafter, a method of inexpensively implementing a circuit pattern for configuring an electronic pen sensing region in a simpler manufacturing process in using the tablet having the structure described above will be described.

5 is a view schematically showing the configuration of a tablet according to the present invention, which implements an electronic pen sensing region with an improved structure.

Referring to FIG. 5, the electronic pen sensing region A is configured using three circuit patterns. That is, the first circuit pattern 111 having the pattern of the X-axis line antenna 20X and the pattern of the X-axis loop antenna 10A, the pattern of the Y-axis line antenna 20Y, and the Y-axis loop antenna 10B. The second circuit pattern 112 having a pattern of and the third circuit pattern 113 of the power coil 30 are the same.

Meanwhile, each circuit pattern may be formed on a predetermined base substrate by a simple printing process such as pattern printing or nano-imprinting technique or gravure offset technique.

Each of the circuit patterns 111, 112, and 113 is formed by forming a first circuit pattern 111 on one base substrate, applying an insulating material thereon, and forming a second circuit pattern 112 again thereon. It may be formed (see Fig. 8 (a)). Alternatively, each circuit pattern may be independently formed on a separate substrate, and the electronic pen sensing region may be configured by overlapping each substrate on which the circuit pattern is formed (not shown).

First, the structure of the first circuit pattern 111 including the X-axis line antenna and the X-axis loop antenna will be described. The X-axis loop antenna 10A formed in this circuit pattern 111 does not form a complete loop and is open to the outside at the end of the first circuit pattern 111. Further, although each line antenna 20X is also connected to the X-axis loop antenna 10A at one end, the other side of the line antennas 20X is parallel to the pattern of the loop antenna 10A without intersecting with the loop antenna 10A. The circuit pattern 111 flows outward from the end (that is, the corner portion of the base substrate).

In this configuration, the pattern of the loop antenna and the pattern of the plurality of line antennas may be formed so as not to cross each other in the first circuit pattern 111. Thus, at least the antenna pattern of the first circuit pattern 111 can be manufactured in a simple manner by printing a conductive material in one layer.

On the other hand, the loop shape of the X-axis loop antenna 10A is completed in combination with the driving substrate 120 on which the driving circuit is mounted. That is, the conductive substrate 10E is formed on the driving substrate 120, which is the remaining portion of the pattern for closing the open portion of the X-axis loop antenna 10A to form a complete loop (see FIG. 6).

Further, the intersection and insulation of the X-axis loop antenna 10A and the X-axis line antenna 20X is also made at the conductive pattern portion of the drive substrate 120. That is, the other ends of the X-axis line antennas 20X extend to the first extension patterns 20XE of the driving substrate, and the extension patterns are disposed to cross the conductive patterns 10E in an insulated state. The first extension patterns 20XE of the X-axis line antennas crossing the conductive pattern 10E are connected to an input of a multiplexer mounted on the driving substrate 120. In FIG. 6, the red solid line is a conductive pattern 10E that is a part of the loop antenna pattern and is insulated from the first extension patterns 20XE that are part of the black solid line antenna pattern.

The substrate on which the first circuit pattern 111 constituting the electronic pen sensing region A is printed, and the driving substrate 120 on which the multiplexers 15 and 25, the amplifier 17, the MCU 18, and the like are mounted are mutually different. It is preferred to consist of separate substrates.

As described above, the antenna structure according to the exemplary embodiment of the present invention is completed when the first circuit pattern 111 and the driving substrate 120 are coupled to each other.

The conductive pattern 10E of the X-axis loop antenna 10A is connected to a circuit pattern (red pattern) having a common potential on the driving substrate 120 to become a common potential (or ground).

The second circuit pattern 112 on which the Y-axis line antenna 20Y and the Y-axis loop antenna 10B are formed is also configured similarly to the first circuit pattern 111. That is, the Y-axis loop antenna 10B is open to the outside of the substrate through one side of the second circuit pattern 112, and the other ends of the Y-axis line antenna 20Y are also connected to the Y-axis loop antenna 10B. It shows the form flowing outward side by side with the pattern.

When the second circuit pattern 112 is coupled to the driving substrate 120, an open portion of the Y-axis loop antenna 10B of the second circuit pattern 112 is formed on the driving substrate 120 (the X-axis loop). Integrated with a conductive pattern connected to the antenna, which can be configured to the same potential) to form a loop antenna with a fully closed loop shape. In addition, in the driving substrate 120, the plurality of Y-axis line antennas 20Y cross each other in an insulated state with the conductive pattern 10E forming the remaining portion of the Y-axis loop antenna 10B in the insulating portion S and multiplexer. Connected to the input of (25).

Meanwhile, the power coil 30 may be formed to surround the periphery of the electronic pen sensing region A, and may be formed on a substrate on which each loop antenna or line antenna is formed by printing or the like (for example, FIG. 8). (b)). However, in order to output more energy to the electronic pen, the number of windings and the thickness of the conductive wire must be controlled, so that the pattern of the power coil 30 is formed on a separate coil substrate (not shown) by printing or the like. In the inner part of the loop form of the coil 30, that is, the structure which penetrated the board | substrate of the part corresponding to the electronic pen detection area | region A (in the part which the circuit patterns 111 and 112 which comprise the electronic pen detection area | region were drilled). To be arranged). Alternatively, a configuration in which coils are formed by winding conducting wires and arranged separately without forming a power coil on a predetermined substrate may be used.

Both ends of the power coil 30 are connected to a power supply driver 32 that may be provided on the driving substrate 120.

In the driving substrate 120, as shown, the remaining portions of the line antenna and the loop antenna (ie, the conductive pattern and the first and second extension patterns) are disposed, and they are insulated from each other to form the insulation region S. Achieve. In addition, the amplifier 17 receives the multiplexers 15 and 25 for selecting any one of the other ends of the plurality of line antennas, and the output of the multiplexers and the potential of the loop antenna (ie, the common potential). And the MCU 18 which calculates the coordinates of the electronic pen P by the output of the amplifier. In addition, the power supply driver 32 for driving the power coil 30 by receiving power from the outside may be arranged. The power supply driver 32 may provide a common potential for each loop antenna.

The type of components mounted on the driving substrate 120 and their arrangement may be variously set.

According to the tablet having the antenna pattern structure having the above-described configuration, when manufacturing the substrate on which the electronic pen sensing region is formed, the antenna pattern can be formed by printing a single layer on the surface of the insulating material, so that the process is performed. It is simple and can reduce manufacturing cost.

In addition, since the thickness of the substrate constituting the electronic pen sensing region may be thin, it is possible to minimize the thickness of the product when implementing the tablet.

Next, a structure of a backlight unit used in a general display panel, particularly an LCD display panel, will be described with reference to FIG. 7. Referring to the drawings, the backlight unit 50 is an edge light type and includes a lamp 51, a lamp cover 52, a light guide plate 53, a diffusion sheet 58, and a prism sheet 55, 56. And a protective sheet 58.

The lamp 51 is formed in the shape of an elongated rod along the side of the light guide plate 53, and is formed of a cold cathode fluorescent lamp (CCFL) or an LED.

The lamp cover 52 is for reflecting light emitted from the lamp 51 in all directions toward the light guide plate 53 to face in one direction.

The light guide plate 53 evenly distributes and radiates light rays incident from one side of the light guide plate 53 to the entire surface of the light guide plate 53 so that the entire light guide plate acts as a surface light source. To this end, the light guide plate 53 may be made of various materials capable of uniformly scattering light rays passing through the inside in various directions, and a plurality of refractive means (for example, micro lenses, etc.) may be mixed.

The diffusion sheet 58 makes the light emitted evenly scattered in the light guide plate 53 more uniform.

The prism sheet 58 is provided with a plurality of vertical and horizontal flat prisms, respectively, and allows the light incident from the light guide plate 53 to have a constant direction toward the front.

The protective sheet 58 prevents damage to the backlight unit surface when the backlight unit 50 contacts another substrate such as an LCD panel.

On the other hand, the reflective sheet 58 is disposed on the rear surface of the light guide plate 53, which reflects the light beam toward the rear surface of the light guide plate 53 forward to prevent the loss of light and to maintain the brightness toward the front side. It is to improve. The reflective sheet 58 is mainly a white opaque polyester film or a coating of an organic or inorganic material on such a film.

Next, with reference to FIG. 8, the method of forming an antenna pattern in a base substrate (antenna substrate) in the tablet which concerns on this invention is demonstrated. Here, the base substrate may be any one of the substrates constituting the backlight unit of the LCD panel, or an LED-formed substrate of a self-luminous display panel such as an OLED panel.

By using the above-described antenna pattern according to the present invention, each of the circuit patterns 111 and 112 can be formed by a simple printing method on the same plane of a predetermined substrate. The X-axis antenna pattern 111 is formed by screen printing or the like, the formed X-axis antenna pattern 111 is covered with an insulating material (S1), and the Y-axis antenna pattern 112 is formed thereon by screen printing or the like, The formed pattern is again coated with an insulating material (S2) to show a structure in which the electronic pen sensing region is formed.

On the other hand, Figure 8 (b), to configure the electronic pen detection area in the structure as shown in Figure 8 (a), and to surround the line antenna and the loop antenna in the circumferential portion of the base substrate also by the method of screen printing, etc. Show the formed form. In this case, the power coil 30 may be formed by forming one layer of the power coil pattern and then covering the insulating material S3 and forming another layer of the power coil pattern.

FIG. 9 is a view illustrating a method of forming an antenna pattern on one side of a reflecting plate of a backlight unit serving as a base substrate by screen printing, and showing a state of printing a conductive material on the substrate by using a screen printing roller. . As described above, in the present invention, the antenna pattern for realizing the function of the touch screen can be simply completed by simply printing the conductive material using the screen.

As described above, the touch screen device having the antenna pattern integrated in the backlight unit 50 according to the present invention forms an antenna pattern for sensing the position of the electronic pen P on the surface of the reflective sheet 58. The internal space and structure of the display panel can be efficiently used without affecting the display operation.

That is, when the antenna pattern as described above of the present invention is used, the antenna pattern in the uniaxial direction can be configured by printing one layer using the reflective sheet 58 as the base substrate 110. Here, as shown in FIG. 8, if the insulating layer is stacked and another antenna pattern in the axial direction is formed again, an antenna pattern capable of measuring two-dimensional coordinates of the electronic pen P may be easily implemented. .

At this time, the antenna pattern is preferably formed on the rear surface (downward in the drawing) of the reflective sheet 58, so that the antenna pattern does not affect the reflection of light. In addition, if the antenna pattern is formed on the back side of the reflective sheet 58, the transparency according to the thickness of the antenna pattern does not affect the display operation at all.

Referring to FIG. 8A, the base substrate 110 becomes the reflective sheet 58, and the lower portion of the figure corresponds to the front surface from which light is emitted, and the upper portion of the figure corresponds to the rear surface of the reflective sheet 58. . Therefore, a reflective material for reflecting light incident from the bottom may be applied to the outside of the bottom surface or the inside of the top surface of the base substrate 110.

It is a figure explaining the form which comprises a backlight unit using the reflecting plate as a base substrate in the tablet which concerns on this invention.

First, in the reflective sheet 58 in which the antenna pattern is formed, the antenna patterns can be protected by a shield. The shield may use the insulation layer described with reference to FIG. 8 as it is, or may be formed by attaching or applying a separate film.

Meanwhile, in the figure, a connector for connecting the antenna pattern with an external driving circuit is further shown.

The light guide plate and the display panel are coupled to the reflective surface side of the reflective sheet 58 configured as described above, thereby completing a touch screen.

Next, a touch screen device having an antenna pattern integrated into the display panel according to the present invention, which is applied to another type of display panel, in particular, an apparatus which emits light by itself and performs a display operation, with reference to FIG. 10. Explain.

In FIG. 11, the display panel 60 is schematically illustrated in a single layer. Here, the upper part of the drawing corresponds to the front side where the image is displayed. On the back of the display panel 60, which is the lower part of the figure, the antenna pattern for sensing the electronic pen P is formed in multiple ways by printing or the like. According to this configuration, a touch screen integrated with a tablet capable of detecting the electronic pen P can be manufactured without adding a separate substrate for the antenna pattern.

Claims (6)

A display panel including a display unit in which an optical transmission control element whose operation is controlled by an input image signal is arranged, and a backlight unit disposed at the rear of the display unit and emitting light forward through the display unit;
A plurality of first line antennas are formed by printing a conductive material on one surface of the backlight unit, wherein one side of the plurality of first line antennas is connected to each other to form parallel comb-shaped shapes, and the other side of the backlight unit extends to an edge of one surface of the backlight unit. Wow;
Is formed on a separate substrate from the display panel, the outermost line antennas of the plurality of first line antennas are connected to each other to form a loop structure and connected to ground, and any one of the plurality of first line antennas A first line selection circuit which selects the other side and sets it as a first output in an insulated state from the loop structure; and
When the electronic pen for outputting the AC electromagnetic force is approached, the tablet comprising a coordinate sensing circuit for determining the position of the electronic pen with respect to the selected first line antenna using the induced voltage appearing in the first output Touch screen device having an antenna pattern integrated into the backlight unit. The method of claim 1,
And the plurality of first line antennas are formed on a reflective sheet of the backlight unit. The method of claim 2,
And the plurality of first line antenna patterns are formed on a rear surface of a reflective surface of the reflective sheet. The method according to claim 2 or 3,
The tablet,
A plurality of second line antennas which have the same shape as the plurality of first line antennas and are arranged in a direction crossing the first line antennas, and
The outermost line antennas of the plurality of second line antennas are connected to each other to form a loop structure and connected to ground, and the other side of the plurality of second line antennas is selected to be insulated from the loop structure. A second line selection circuit for setting to a second output,
The coordinate sensing circuit is configured to determine the position of the electronic pen using the induced voltage appearing at the first output and the second output,
The plurality of first line antennas and the plurality of second line antennas may include the reflective sheet, the plurality of first line antennas formed by being printed on the reflective sheet, an insulating layer covering the plurality of first line antennas, and the A touch screen device having an antenna pattern integrated in a backlight unit, characterized in that it is formed as a stacked structure of the plurality of second line antennas printed and formed on an insulating layer. The method of claim 1,
The electronic pen includes a resonant circuit having a predetermined resonant frequency,
The tablet may include a power coil formed to surround the plurality of first line antennas in an insulated state and formed by printing a conductive material on one surface of the backlight unit, and corresponding to a resonance frequency of the electronic pen on the power coil. The touch screen device having an antenna pattern integrated into the backlight unit, further comprising a power supply driver for applying an AC power having a waveform. A display panel in which a plurality of light emitting elements whose operation is controlled by an input image signal is arranged on a front surface to display an image forward;
It is formed by printing a conductive material on the back of the display panel, a plurality of first line antenna is connected to each other to form a comb-like parallel to each other and the other side is separated from each other extending to the rear edge of the display panel;
Is formed on a separate substrate from the display panel, the outermost line antennas of the plurality of first line antennas are connected to each other to form a loop structure and connected to ground, and any one of the plurality of first line antennas A first line selection circuit which selects the other side and sets it as a first output in an insulated state from the loop structure; and
When the electronic pen for outputting the AC electromagnetic force is approached, the tablet comprising a coordinate sensing circuit for determining the position of the electronic pen with respect to the selected first line antenna using the induced voltage appearing in the first output Touch screen device having an antenna pattern integrated into the display panel.

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