KR101602345B1 - Position Sensing Display - Google Patents

Abstract

The position sensing display integrates an active matrix LCD panel and a touch sensor. The x sensing electrodes and the y sensing electrodes in each layer on the front panel are capacitively coupled to the sensing circuits on the active back panel. The common electrode is driven, and the resultant signals of the x sense electrodes and the y sense electrodes are measured in each sense circuit. As the sensing object approaches, the resulting change in signal is measured to determine the position of the sensing object.

Display, position detection

Description

[0001] The present invention relates to a position sensing display,

The present invention relates to a position sensitive display and a method of operating such a display. This application claims priority to U.S. Patent Application No. 61 / 016,804, filed December 26, 2007, the entire contents of which are incorporated herein by reference. This application also claims priority from European Patent Application No. 08160966.1, filed on July 23, 2008, the entire contents of which are incorporated herein by reference.

A position sensor is combined with the display in the form of a transparent position sensitive overlay mounted on the display to record the touch or pen input. Such sensors may comprise an array of electrodes connected to a drive / sense circuit.

The sensors may be a capacitance sensor having a set of electrodes connected to a driving and / or sensing circuit. The position of an object, such as a stylus or a finger, is determined by measuring the change in capacitance capacitance associated with the electrodes that are affected by the object approaching.

The present invention relates to an active matrix display including a front panel and a rear panel, the front panel comprising: a transparent substrate; A common electrode for interlocking with the rear active substrate to drive the liquid crystal; A plurality of first sensing electrodes extending across the display, the back substrate comprising: a substrate; A display pixel array arranged in a row and a column; And a plurality of sensing circuits connected to each of the sensing electrodes, and coupling the sensing electrodes to capacitors of the sensing circuits to transfer sensing signals from the sensing electrodes to the sensing circuits, And further includes capacitors (Coupling Capacitors).

The present invention also provides a front transparent substrate of an active matrix liquid crystal display for interlocking with a rear active substrate having a sensing circuit, A common electrode; A plurality of first sensing electrodes extending in a first direction across the display; A plurality of second sensing electrodes extending in a second direction to intersect the first sensing electrodes across the display; And coupling electrodes connected to the first sensing electrodes and the second sensing electrodes, respectively, wherein the coupling electrodes are capacitively coupled to the coupling electrodes on the rear active substrate to generate a capacitance sensing signal And extends to the coupling region via the common electrode for transfer from the sensing electrodes to the sensing circuits on the backside active substrate.

According to another aspect of the present invention, there is provided a rear active substrate of an active matrix liquid crystal display for interfacing with a front transparent substrate having sensing electrodes, the active matrix substrate comprising: an active matrix pixel array; A plurality of first sensing circuits and a plurality of second sensing circuits; And capacitive coupling to coupling electrodes on the front transparent substrate to transmit a capacitive sensing signal from the sensing electrodes to the sensing circuits on the backside active substrate, And a plurality of coupling electrodes connected to the circuit.

The present invention also provides a liquid crystal display comprising a common electrode, a plurality of row sensing electrodes extending in a first x direction across the display, and a plurality of column sensing electrodes extending in a second y direction across the display The active matrix liquid crystal display includes an active matrix liquid crystal display including a transparent front substrate and an active rear substrate having a display pixel array, a plurality of row sensing circuits, and a column sensing circuit, The method comprising: driving the common electrode by a driving signal; Sensing the drive signal capacitively coupled in the x sense circuit and the y sense circuit by capacitively coupling the x sense electrode and the y sense electrode to the x sense circuit and the y sense circuit, respectively; And determining the position of the sensing object by detecting a change in the driving signal in a specific row sensing circuit and a thermal sensing circuit caused by the presence of the sensing object adjacent to each row sensing electrode and the thermal sensing electrode And a method of determining the position of a sensing object in an active matrix type liquid crystal display.

The following description is a best mode for carrying out the present invention. This description is intended to illustrate the general principles of the present invention and should not be construed in a limiting sense. The scope of the invention is best determined by reference to the claims.

By integrating the sense circuit with the display, the display is simplified compared to conventional display modules, potentially reducing production costs and increasing throughput. Furthermore, by not providing a separate touch panel, it is possible to prevent dust or small particles from being caught between the separated touch panel and the display.

Additionally, the discrete touch panel can affect the optical performance of the display by introducing additional surfaces that can cause reflection, which is reduced by incorporating a touch sensor.

The inventors have realized that by connecting the front panel and the rear panel, the sensing circuit can be mounted on the active back panel and connected to the electrodes on the front panel. By using a capacitor to connect the circuit to the electrodes, the manufacturing process difficulties due to ohmic contacts can be avoided.

1 to 4, an active matrix liquid crystal display includes a front panel 2, a back panel 4, and a liquid crystal 6 (see FIG. 1) between the front panel 2 and the back panel 4. [ ).

Referring to Figs. 1 and 2, Fig. 2 is a front view of the front panel 2. Fig. The front panel 2 has a transparent substrate 10 facing forward in the finished device (not shown in Fig. 2 for clarity). An x-sense electrode layer 12 composed of a plurality of x-sense electrodes 14 extending parallel to each other in the column direction is formed on the transparent substrate 10 have.

An insulating layer (16) covers the x-sensing electrode layer (12). A y-sense electrode layer 18 is mounted on the insulating layer 16, and the y-sense electrodes 20 extend in a row direction in parallel with each other.

Although only three x- and y-sense electrodes are shown in Fig. 2 for clarity, they may actually be much larger. For example, tens to hundreds of electrodes may be used depending on the required resolution.

A filter layer 21 is provided on the y-sensing electrode layer, which includes red, green and blue filters to provide a color display.

A common electrode 22 is mounted across the front panel 2 on the filter layer 21.

Each of the x-sense electrodes 14 includes a coupling region 24, which will be described below. The y-sense electrodes 20 include a coupling region 28. A contact area 26 is also provided for direct contact with the common electrode 22. [

The electrodes 14,20, 22 are suitably transparent and can be made of a transparent conductor such as ITO (Indium Tin Oxide). Similarly, the substrate 10 is also transparent and can be made of, for example, glass or plastic.

1 and 3, the back panel 4 includes an active circuit layer 32 on the backside substrate 30 and the backside substrate 30 do. The active circuit layer 32 includes an active matrix pixel array 34 composed of a plurality of pixels 36 arranged in rows and columns. This can be any type of active matrix array well known in the art and thus will not be described in further detail herein.

A row drive circuit 38 is installed along one edge of the pixel array 34 to drive a row of pixels and a column drive circuit 40 drives a row of pixels For example, along the adjacent edges of the pixel array 34. Any suitable drive circuit may be used.

The x-sense circuits 42 are arranged along the opposite edge of the column drive circuit 40 in the pixel array 34 and are arranged in rows. Each x-sense circuit 42 is coupled to a respective coupling electrode 46, each coupling electrode 46 of which corresponds to the corresponding x-sense electrode 14 on the passive substrate To the coupling region 24, which is shown in Fig.

Similarly, the y-sense circuits 44 are installed along the opposite edge of the row drive circuit 38 in the pixel array 34. Each y-sense circuit 44 is coupled to a respective coupling electrode 48 which is coupled to a corresponding coupling region 28 of each y- .

The common electrode driving circuit 50 is arranged to directly contact (in ohmic contact) with the contact region 26 to drive the common electrode 22. [

Unlike the connection between the common electrode drive circuit 50 and the contact region 26, the coupling regions 24 and 28 of the sensing electrodes are not directly connected to the corresponding coupling electrodes 46 and 48, Capacitive Coupling. In this embodiment, since the coupling region and the coupling electrode are arranged outside the pixel array, the liquid crystal functions as a dielectric, but in another embodiment, the solid dielectric supporting structure or the spacer acts as a dielectric It is possible.

This structure provides a circuit as shown in Fig. 4, in which the common electrode drive circuit 50 is connected to the sense electrodes 14,20 by a sense-common coupling capacitance 52, (Not shown). The capacitance between the coupling regions 24 and 28 and the coupling electrodes 46 and 48 is graphically represented as the coupling capacitor 54 between the sensing electrodes 14 and 20 and the sensing circuits 42 and 44.

In operation, the common electrode drive circuit 50 drives the common electrode 22, which is connected to the sensing electrodes 14, 20 by sensing-common coupling capacitance 52. Signals on the sensing electrodes 14 and 20 are transferred to the sensing circuits 42 and 44 via coupling capacitors 54. [

When a stylus or finger 60 as a sensed object is placed close to the screen it is detected that it is a valid sensor connected to the sensing circuits 42 and 44 through a capacitor 56 affecting the sensed signals in the sensing circuits 42 and 44 And acts as a grounded capacitor. Thereby allowing the position of the stylus or finger 60 to be determined by confirming whether a change in the sense signal of either the x-sense circuitry 42 or the y-sense circuitry 44 occurs.

The common electrode 22 and the pixel array 34 may be simultaneously driven by the drive circuits 38, 40, 50 to display a sequence of images or images on the display.

The ease of manufacture of the touch sensitive display can be improved by integrating the sensing and active matrix liquid crystal display. Furthermore, this embodiment avoids significant unreliability by not using Ohmic Contact.

By connecting the sense electrodes 14 and 20 to the sense circuits 42 and 44 by the capacitances formed between the active and passive substrates, the sense circuits 42 and 44 can be connected to the electrodes 14, 20). Thus, in this way, all the active circuits can be installed on the active back panel 4, and the front panel 2 can be kept in the passive state. In this embodiment, only the driving circuit 50 and the contact area 26 are brought into direct and only direct contact.

Although specific embodiments have been disclosed, it will be appreciated that this is merely an example, and those skilled in the art will recognize that modifications may be made to the embodiments.

In particular, the present invention may be used in an active matrix organic light emitting diode (AMOLED) device.

Although the present invention has been described by way of example and as a preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements which will become apparent to those skilled in the art. Accordingly, the scope of the claims should be interpreted very broadly to include all such arrangements and variations.

1 is a side view of an active matrix LCD according to an embodiment of the present invention,

2 is a view showing a transparent front substrate in the configuration of FIG. 1,

3 is a view showing an active rear substrate in the configuration of FIG. 1,

Figure 4 is a circuit diagram illustrating capacitive coupling between the various components of Figure 1;

Description of the Related Art

2: Front panel 4: Rear panel

6: Display 10: Transparent substrate

12: x-sensing electrode layer 14: x-sensing electrode

16: insulating layer 18: y-sensing electrode layer

20: y-sensing electrode 21: filter layer

22: common electrode 24: coupling region

26: contact area 28: coupling area

30: Rear substrate 32: Active circuit layer

34: active matrix type pixel array

38: row drive circuit 40: thermal drive circuit

42: x-sense circuit 44: y-sense circuit

46, 48: coupling electrode 50: common electrode driving circuit

Claims (11)

In an active matrix display including a front panel and a rear panel, Wherein the front panel comprises: A transparent substrate; A liquid crystal layer disposed between the electrode and the back panel; A plurality of sensing electrodes extending across the display, Wherein the back panel comprises: Board; A display pixel array arranged in a row and a column; A plurality of sensing circuits connected to each of the sensing electrodes, wherein each of the sensing electrodes includes a coupling region, each of the sensing circuits being coupled to a respective coupling electrode; And And coupling capacitors coupling the sensing electrodes to respective sensing circuits to transmit a sensing signal from the sensing electrode to the sensing circuit, Wherein each of said coupling electrodes and said coupling region is arranged outside said display pixel array. delete The method according to claim 1, Wherein the sensing electrode includes first sensing electrodes and second sensing electrodes extending to intersect the first sensing electrodes, The transparent substrate on the front surface is a transparent substrate, A first sensing electrode layer on the transparent substrate on the front surface having one of the first sensing electrode and the second sensing electrode and a corresponding coupling electrode; An insulating layer on the first sensing electrode layer; A second sensing electrode layer on the insulating layer having the other one of the first sensing electrode and the second sensing electrode and the corresponding coupling electrode; A filter layer on the second sensing electrode layer including color filters; And And an electrode layer on the filter layer including the electrode facing the liquid crystal layer. The method of claim 3, Wherein the first sensing electrode is an x sensing electrode extending across the display in a column direction and the second sensing electrode is a y sensing electrode extending across the display in a row direction. Matrix type display. 5. The method of claim 4, Wherein the sensing circuit includes a first sensing circuit and a second sensing circuit, wherein the first sensing circuit is disposed along one edge of the display pixel array and the second sensing circuit is disposed along a vertical edge of the display pixel array Wherein the active matrix type display is arranged in a matrix. 6. The method of claim 5, Wherein the back panel comprises: A row drive circuit disposed in an opposite corner of the second sensing circuit in the display pixel array and a column drive circuit disposed in an opposite corner of the first sensing circuit in the display pixel array. Matrix type display. The method according to claim 1, Wherein the front panel for interlocking with the back panel having the sensing circuit comprises: The liquid crystal layer disposed between the electrode and the back panel; A plurality of first sensing electrodes extending in a first direction across the display; A plurality of second sensing electrodes extending in a second direction to intersect the first sensing electrodes across the display; And coupling electrodes connected to the plurality of first sensing electrodes and the plurality of second sensing electrodes, respectively, The coupling electrode is capacitively coupled to the coupling electrode on the rear panel to pass a capacitance sensing signal from the sensing electrodes to the sensing circuits on the rear panel, Of the active matrix type display. 8. The method of claim 7, Wherein the front panel comprises: A first sensing electrode layer on the front panel having coupling electrodes corresponding to any one of the first sensing electrode and the second sensing electrode; An insulating layer on the first sensing electrode layer; A second sensing electrode layer on the insulating layer having the other one of the first sensing electrode and the second sensing electrode and the corresponding coupling electrode; A filter layer on the second sensing electrode layer including color filters; And An electrode layer including the electrode facing the liquid crystal layer; And an active matrix type display. The method according to claim 1, A back panel for interlocking with the front panel having the plurality of sensing electrodes, An active matrix type pixel array; A plurality of first sensing circuits and a plurality of second sensing circuits; And And capacitive coupling to coupling electrodes on the front panel to transmit a capacitance sensing signal from the sensing electrodes to the sensing circuits on the back panel, wherein each of the first sensing circuit and the second sensing circuit A plurality of coupling electrodes connected to the coupling electrodes; And an active matrix type display. delete delete

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