Patent Application
20190064966
Priority is claimed under 35 U.S.C. § 119 to Korean Patent Application No. 10-2017-0108391, filed Aug. 28, 2017, the disclosure of which is incorporated by reference in its entirety.
The present disclosure relates to a touch sensor panel and more particularly to a touch sensor panel which detects a touch occurring thereon and the position of the touch through a capacitance change.
Various kinds of input devices are being used to operate a computing system. For example, the input device includes a button, key, joystick and touch screen. Since the touch screen is easy and simple to operate, the touch screen is increasingly being used to operate the computing system.
The touch screen may constitute a touch surface of a touch input device including a touch sensor panel which may be a transparent panel including a touch-sensitive surface. The touch sensor panel is attached to the front side of a display screen, and then the touch-sensitive surface may cover the visible side of the display screen. The touch screen allows a user to operate the computing system by simply touching the touch screen by a finger, etc. Generally, the computing system recognizes the touch and a position of the touch on the touch screen and analyzes the touch, and thus, performs operations in accordance with the analysis.
Particularly, when the touch is input by using an object such as user's finger, a stylus pen with a small contact area, etc., there is a need to accurately detect the position of the touch on the touch screen without degrading the performance of a display module.
One embodiment is a touch sensor panel including: a plurality of drive electrodes formed in a first layer; and a plurality of receiving electrodes which are disposed to cross the plurality of drive electrodes and are formed in a second layer. The plurality of drive electrodes include a first electrode line and a first protrusion pattern, and the plurality of receiving electrodes include a second electrode line and a second protrusion pattern. The plurality of drive electrodes are arranged at a regular interval in a column direction, and the plurality of receiving electrodes are arranged at a regular interval in a row direction.
The first electrode line and the second electrode line may be formed to have the same width.
The first protrusion pattern may be formed to have the same width as that of the first electrode line, and the second protrusion pattern may be formed to have the same width as that of the second electrode line.
The first protrusion pattern may be formed to be orthogonal to the first electrode line, and the second protrusion pattern may be formed to be orthogonal to the second electrode line.
The first protrusion pattern may be formed as at least one of triangular, elliptical, semicircular structures, or a structure formed through a combination thereof, which protrude from the first electrode line in both directions, and the second protrusion pattern may be formed as at least one of triangular, elliptical, semicircular structures, or a structure formed through a combination thereof, which protrude from the second electrode line in both directions.
The first protrusion pattern and the second protrusion pattern may be formed at a center point between two adjacent crossing points of the first electrode line and the second electrode line.
The first protrusion patterns formed on the first electrode lines of adjacent columns may be spaced apart from each other, and the first protrusion pattern formed on the first electrode line and the second protrusion pattern formed on the second electrode line which crosses the first electrode line may be spaced apart from each other.
The first layer may be disposed on or under the second layer.
The touch sensor panel may further include an insulation layer between the first layer and the second layer.
Specific embodiments of the present invention will be described in detail with reference to the accompanying drawings. The specific embodiments shown in the accompanying drawings will be described in enough detail that those skilled in the art are able to embody the present invention. Other embodiments other than the specific embodiments are mutually different, but do not have to be mutually exclusive. Additionally, it should be understood that the following detailed description is not intended to be limited.
The detailed descriptions of the specific embodiments shown in the accompanying drawings are intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. Any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention.
Specifically, relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivative thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation.
Terms such as “attached,” “affixed,” “connected,” “coupled,” “interconnected,” and similar refer to a relationship wherein structures are attached, connected or fixed to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise.
The touch input device including the touch sensor panel according to the embodiment of the present invention can be used not only in a portable electronic product such as a smartphone, tablet PC, laptop computer, personal digital assistant (PDA), MP3 player, camera, camcorder, electronic dictionary, etc., but also in an electric home appliance such as a home PC, TV, DVD, refrigerator, air conditioner, microwave, etc. Also, the touch input device including the touch sensor panel according to the embodiment of the present invention can be used without limitation in all of the products requiring a device for display and input such as an industrial control device, a medical device, etc.
Hereinafter, a touch input device according to the embodiment of the present invention will be described with reference to the accompanying drawings. Hereinafter, while a capacitive touch sensor panel 100 is exemplified below, it is possible to apply the touch sensor panel 100 capable of detecting a touch position and/or a touch pressure in any manner.
As shown in
The plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be arranged to cross each other. The drive electrode TX may include the plurality of drive electrodes TX1 to TXn extending in a first axial direction. The receiving electrode RX may include the plurality of receiving electrodes RX1 to RXm extending in a second axial direction crossing the first axial direction. Here, when the drive electrode TX is formed in a row direction, the receiving electrode RX is formed in a column direction in such a way as to cross the drive electrode TX. Also, when the drive electrode TX is formed in the column direction, the receiving electrode RX is formed in the row direction in such a way as to cross the drive electrode TX.
The plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be formed in different layers. For example, the plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be formed on both sides of one insulating layer (not shown) respectively. Alternatively, the plurality of drive electrodes TX1 to TXn may be formed on one side of a first insulating layer (not shown) and the plurality of receiving electrodes RX1 to RXm may be formed one side of a second insulating layer (not shown) different from the first insulating layer.
The plurality of drive electrodes TX1 to TXn and the plurality of receiving electrodes RX1 to RXm may be made of a transparent conductive material (for example, indium tin oxide (ITO) or antimony tin oxide (ATO) which is made of tin oxide (SnO2), and indium oxide (In2O3), etc.), or the like. However, this is only an example. The drive electrode TX and the receiving electrode RX may be also made of another transparent conductive material or an opaque conductive material. For instance, the drive electrode TX and the receiving electrode RX may be formed to include at least any one of silver ink, copper, or carbon nanotube (CNT). Also, the drive electrode TX and the receiving electrode RX may be made of a metal mesh or nano silver material.
The drive unit 20 according to the embodiment of the present invention may apply the drive signal to the drive electrodes TX1 to TXn. In the embodiment, the drive signal may be sequentially applied to one electrode at a time from the first drive electrode TX1 to the n-th drive electrode TXn. The drive signal may be applied again repeatedly. This is only an example. The drive signal may be applied to the plurality of drive electrodes TX1 to TXn at the same time in accordance with the embodiment.
Through the receiving electrodes RX1 to RXm, the sensing unit 10 receives the sensing signal including information on a capacitance (Cnm) 101 generated between the receiving electrodes RX1 to RXm and the drive electrodes TX1 to TXn to which the drive signal has been applied. For example, the sensing signal may be a signal coupled by the capacitance (Cnm) 101 generated between the receiving electrode RX and the drive electrode TX to which the drive signal has been applied. As such, the process of sensing the drive signal applied from the first drive electrode TX1 to the n-th drive electrode TXn through the receiving electrodes RX1 to RXm can be referred to as a process of scanning the touch sensor panel 10.
For example, the sensing unit 10 may include a receiver (not shown) which is connected to each of the receiving electrodes RX1 to RXm through a switch. The switch becomes the on-state in a time interval during which the signal of the corresponding receiving electrode RX is sensed, thereby allowing the receiver to sense the sensing signal from the receiving electrode RX. The receiver may include an amplifier (not shown) and a feedback capacitor coupled between the negative (−) input terminal of the amplifier and the output terminal of the amplifier, i.e., coupled to a feedback path. Here, the positive (+) input terminal of the amplifier may be connected to the ground. Also, the receiver may further include a reset switch which is connected in parallel with the feedback capacitor. The reset switch may reset the conversion from current to voltage that is performed by the receiver. The negative input terminal of the amplifier is connected to the corresponding receiving electrode RX and receives and integrates a current signal including information on the capacitance (Cnm) 101, and then converts the integrated current signal into voltage. The sensing unit 10 may further include an analog to digital converter (ADC) (not shown) which converts the integrated data by the receiver into digital data. Later, the digital data may be input to the controller 30 and processed to obtain information on the touch on the touch sensor panel 100. The sensing unit 10 may be integrally formed with the ADC and controller 30 as well as the receiver.
The controller 30 may perform a function of controlling the operations of the drive unit 20 and the sensing unit 10. For example, the controller 30 generates and transmits a drive control signal to the drive unit 20, so that the drive signal can be applied to a predetermined drive electrode TX1 at a predetermined time. Also, the controller 30 generates and transmits the drive control signal to the sensing unit 10, so that the sensing unit 10 may receive the sensing signal from the predetermined receiving electrode RX at a predetermined time and perform a predetermined function.
In
As described above, a capacitance (Cnm) with a predetermined value is generated at each crossing point of the drive electrode TX and the receiving electrode RX. When an object like fingers, palms or stylus, etc., approaches close to the touch sensor panel 100, the value of the capacitance may be changed. In
More specifically, when the touch occurs on the touch sensor panel 100, the drive electrode TX to which the drive signal has been applied is detected, so that the position of the second axial direction of the touch can be detected. Likewise, when the touch occurs on the touch sensor panel 100, a capacitance change is detected from the reception signal received through the receiving electrode RX, so that the position of the first axial direction of the touch can be detected.
In the touch input device according to the embodiment of the present invention, the touch sensor panel 100 for detecting where the touch has occurred may be positioned outside or inside a display module.
The display module of the touch input device on which the touch sensor panel 100 according to the embodiment of the present invention is mounted may be a display panel included in a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting diode (OLED), etc. Accordingly, a user may perform the input operation by touching the touch surface while visually identifying an image displayed on the display panel. Here, the display module may include a control circuit which receives an input from an application processor (AP) or a central processing unit (CPU) on a main board for the operation of the touch input device and displays the contents that the user wants on the display panel. The control circuit may be mounted on a second printed circuit board (hereafter, referred to as a second PCB). Here, the control circuit for the operation of the display module may include a display panel control IC, a graphic controller IC, and a circuit required to operate other display panels.
Referring to
The first insulating sheet 110 and the second insulating sheet 130 may be an insulation material layer such as Polyethylene terephthalate (PET), glass, or the like. The patterns of the drive electrode and the receiving electrode may be formed respectively such that the drive electrode is included on the same plane (a first layer) of the first insulating sheet 110 and the receiving electrode is included on the same plane (a second layer) of the second insulating sheet 130.
The first adhesive layer 120, the second adhesive layer 140, and the third adhesive layer 160 may be made of an optical clear adhesive (OCA) or resin. The first adhesive layer 120 can cause the first insulating sheet 110 and the second insulating sheet 130 to adhere to each other. The second adhesive layer 140 can cause the first insulating sheet 110 and display module to adhere to each other. The third adhesive layer 160 can cause the second insulating sheet 130 and the cover glass 150 to adhere to each other.
Here, the drive electrode and the receiving electrode may be an Indium Tin Oxide (ITO) electrode respectively or may be composed of tin oxide (SnO2), indium oxide (In2O3), silver ink, copper, or carbon nanotube (CNT), etc. The drive electrode and the receiving electrode are formed in different layers (the first layer and the second layer). When a part of the user's body or a stylus pen approaches, the mutual capacitance may be changed. As such, by detecting the change of the mutual capacitance, it is possible to detect whether or not the touch has occurred on the touch sensor panel and/or the touch position. The cover glass 150 made of glass may be further formed at the uppermost portions of the drive electrode and the receiving electrode in order to protect the electrode.
It is shown that the touch sensor panel 100 according to the embodiment of the present invention is laminated on and attached to the display module by means of an adhesive. However, according to the embodiment of the present invention, the touch sensor panel 100 may be disposed within the display module, or may be fixed only at the edge of the display module by means of an adhesive and may include an air gap.
Referring to
Referring to
Specifically, the touch position of a part of the user's body or the stylus pen 3 is the crossing point of the drive electrode and the receiving electrode, that is to say, is just above the touch nodes (TP2 and TP5), the accuracy of touch position detection is increased. However, when the touch position gets further from the touch nodes (TP1 and TP4), the accuracy of the touch position detection may be reduced. This accuracy is somewhat affected by the touch areas TP3 and TP6 of the object touching the touch sensor panel 1. However, the accuracy may be greatly changed according to the width of the drive electrode constituting the touch sensor panel 1. The capacitance change amount according to the width or pattern shape of the drive electrode will be described in detail with reference to
Referring to
Referring to
Referring to
The center point of the touch node [RX3, TX5] are represented by an index [0], and the center points of the touch nodes [RX3, TX4] and [RX3, TX6] adjacent to the right or left of the touch node [RX3, TX5] are respectively represented by an index [−1] and an index [1]. The indices [−1] to [1] are obtained by distinguishing from the center point of the touch node [RX3, TX4] to the center point of the touch node [RX3, TX6] at the same interval.
Specifically, when the touch is input to the center point of the touch node [RX3, TX5], that is, to the index [0] point, the electric field on the touch node [RX3, TX5] is shielded most, so that the value of y becomes maximum. On the other hand, when the touch is input to the center point of the touch node [RX3, TX4], that is, to the index [−1] point or when the touch is input to the center point of the touch node [RX3, TX6], that is, to the index [1] point, the electric field on the touch node [RX3, TX5] is not shielded, so that the value of y becomes minimum (ideally ‘0’). As such, the capacitance change amount ΔCm at the index point obtained by distinguishing respective touch nodes at the same interval is actually measured as a curve L-R.
When the touch is input to the index point obtained by distinguishing the touch nodes at the same interval, the closer the capacitance change amount ΔCm according to the position of the touch input is to a straight line L-I, the position calculation of the touch input in a touch input position detection processor can be simpler and more accurate. When the capacitance change amount ΔCm at the index points [−1] to [−0.5] and the index points [0.5] to [1] is increased and when the capacitance change amount ΔCm at the index points [−0.5] to [0] and the index points [0] to [0.5] is reduced, the capacitance change amount ΔCm according to the position of the touch input is linearly changed, so that the touch input position detection can be easily performed when the touch input point is moved.
Interpolability which represents the appropriate degree of interpolation can be obtained by measuring the magnitude of capacitance change ΔCm between two adjacent cells (touch nodes) in accordance with the distance. The following equation 1 represents a quantified difference between an ideal interpolation response profile L-I (IRP: Interpolation Response Profile) and an actual interpolation response profile L-R. The equation 1 shows that the larger the Interpolability value is, the closer the actual value is to an ideal value.
According to the embodiment of the present invention, the patterns of the drive electrode and the receiving electrode can be designed such that the actual interpolation response profile get close to the ideal interpolation response profile. Since the interpolation response profile has a symmetrical shape, this profile needs to be designed such that each touch node of the touch sensor panel has a pattern which is right-and-left and/or up-and-down symmetrical with respect to the node center point. Particularly, the shape of the electrode pattern needs to be designed such that the capacitance change amount ΔCm in the range of the index [0.2] to [0.3] and index [−0.2] to [−0.3] is less than that of a general electrode pattern (a pattern in which a quadrangular drive electrode and a quadrangular receiving electrode are orthogonal to each other to have a certain width) and the capacitance change amount ΔCm in the range of the index [0.6] to [0.7] and index [−0.6] to [−0.7] is greater than that of the general electrode pattern.
The touch sensor panel according to the embodiment of the present invention may include the plurality of drive electrodes TX1 to TX4 formed in the first layer and include the plurality of receiving electrodes RX1 to RX4 which are disposed to cross the plurality of drive electrodes TX1 to TX4 and are formed in the second layer. Here, the plurality of drive electrodes TX1 to TX4 include a first electrode line and a first protrusion pattern P1 formed on the first electrode line. The plurality of receiving electrodes RX1 to RX4 include a second electrode line and a second protrusion pattern P2 formed on the second electrode line. Here, the plurality of drive electrodes TX1 to TX4 may be arranged at a regular interval in the column direction, and the plurality of receiving electrodes RX1 to RX4 may be arranged at a regular interval in the row direction.
Referring to
The first electrode line and the second electrode line may have the same width or different widths. The first quadrangular protrusion pattern P1 and the second quadrangular protrusion pattern P2 may be formed to have the same width or different widths. The widths of the first electrode line, the second electrode line, the first protrusion pattern P1, and the second protrusion pattern P2 can be properly controlled according to the thickness and material of the used electrode, the thickness and material of an insulation layer, the interval between the electrode lines, etc.
The first quadrangular protrusion pattern P1 and the second quadrangular protrusion pattern P2 may be formed to be right-and-left or up-and-down symmetrical with respect to the center lines of the first electrode line and the second electrode line, respectively. The first quadrangular protrusion pattern P1 and the second quadrangular protrusion pattern P2 may be formed at the center point between adjacent crossing points of the first electrode line and the second electrode line. Also, the first quadrangular protrusion patterns P1 formed on the first electrode lines of the adjacent columns may be spaced apart from each other, and the first quadrangular protrusion pattern P1 formed on the first electrode line and the second quadrangular protrusion pattern P2 formed on the second electrode line which crosses the first electrode line may be spaced apart from each other.
The first quadrangular protrusion pattern P1 and the second quadrangular protrusion pattern P2 may be formed to protrude from the first electrode and the second electrode line respectively in both directions. For example, the first quadrangular protrusion pattern P1 may be formed to protrude in both directions in such a manner as to be orthogonal to the first electrode line, and the second quadrangular protrusion pattern P2 may be formed to protrude in both directions in such a manner as to be orthogonal to the second electrode line.
According to the embodiment of the present invention, the widths of the first electrode line and the second electrode line, the sizes of the first quadrangular protrusion pattern and the second quadrangular protrusion pattern, the interval between the drive electrodes of each column, the interval between the receiving electrodes of each row, etc., may be determined such that the mutual capacitance between the plurality of drive electrodes TX1 to TX4 and the plurality of receiving electrodes RX1 to RX4 is approximately linearly changed. Particularly, when the widths of the first and second electrode lines are fixed, the sizes of the first and second quadrangular protrusion patterns can be formed such that the mutual capacitance is approximately linearly changed.
The capacitance change amount is related to the width of the drive electrode and the shape of the protrusion pattern. In the embodiment, the best linearity can be realized when the widths of the first and second electrode lines are 0.4 millimeters, the interval between the drive electrodes of each column and the interval between the receiving electrodes of each row are 2.5643 millimeters, a pitch of the drive electrode is 2.9643 millimeters, and the sizes of the first and second protrusion patterns are 0.4 millimeters. However, this may be changed according to the material and/or thickness of the used electrode, the material and/or thickness of the insulator, the voltage magnitude of the drive signal, pulse width, etc.
Referring to
In this case, only the shapes of the first and second protrusion patterns are different from each other. The shapes and arrangement methods of the first and second electrode lines can be the same.
According to another embodiment of the present invention, the widths of the first electrode line and the second electrode line, the sizes of the first triangular or circular protrusion pattern and the second triangular or circular protrusion pattern, the interval between the drive electrodes of each column, the interval between the receiving electrodes of each row, etc., may be determined such that the mutual capacitance between the plurality of drive electrodes TX1 to TX4 and the plurality of receiving electrodes RX1 to RX4 is approximately linearly changed. Particularly, when the widths of the first and second electrode lines are fixed, the sizes (widths and heights) of the first and second triangular or circular protrusion patterns can be formed such that the mutual capacitance is approximately linearly changed.
Further, as described above, an insulation layer (e.g., an adhesive layer) may be further included between the first layer in which the drive electrode is formed and the second layer in which the receiving electrode is formed. The first layer may be disposed on or under the second layer.
Referring to (a) of
In order to improve the linearity, it is shown in (b) of
Specifically, with respect to the touch sensor panel (2.9 mm-TX Width w/o Bump) including the drive electrode which has the conventional rectangular drive electrode pattern having a width of 2.9 millimeters and has no protrusion pattern, the touch sensor panel (0.4 mm-TX Width w/o Bump) including the drive electrode which has the conventional rectangular drive electrode pattern having a width of 0.4 millimeters and has no protrusion pattern, and the touch sensor panel (0.4 mm-TX Width w/0.4 mm Bump) including the drive electrode which includes the protrusion pattern according to the embodiment of the present invention and has a 0.4 millimeter wide electrode line shape, and the receiving electrode,
Comparing the graphs from the index [−1] point to the index [1] point, it can be seen that the touch sensor panel including the drive electrode of 0.4 mm-TX Width w/0.4 mm Bum has a relatively better linearity than the touch sensor panel including the drive electrode of Tx width 2.9 mm-TX Width w/o Bump or 0.4 mm-TX Width w/o Bump. This will be described in more detail with reference to
Referring to
However, the above result is obtained by measuring the capacitance change at one reference touch node TX (N)-RX (N). When the capacitance change is measured at adjacent touch nodes TX (N−1)-RX (N) and TX (N+1)-RX (N)) as the reference touch node, the same waveform is repeated and an area affected by both touch nodes occurs in a certain interval. In particular, the points of the indices [−0.5] and [+0.5] are affected the same by two adjacent touch nodes (e.g., TX (N)-RX (N) and TX (N−1)-RX (N), or TX (N)-RX (N) and TX (N+1)-RX (N)). Therefore, this needs to be reflected in the linearity calculation. That is, it can be seen that the capacitance change by the touch node TX (N−1)-RX (N) is dominant in the interval [−1, −0.5], the capacitance change by the touch node TX (N)-RX (N) is dominant in the interval [−0.5, +0.5], and the capacitance change by the touch node TX (N+1)-RX (N) is dominant in the interval [+0.5, +1]. Specifically, in the case where W1 is 2.55 mm and W2 is 2.95 mm, when the effect of the capacitance change of the superior touch node is set as a weight ‘1’, the effect of the capacitance change of the adjacent touch node may be set as a weight ‘0.7’.
Specifically, referring to
Referring to
Referring to
The comparative relationship shown in
Referring to
Referring to
The features, structures and effects and the like described in the embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Furthermore, the features, structures, effects and the like provided in each embodiment can be combined or modified in other embodiments by those skilled in the art to which the embodiments belong. Therefore, contents related to the combination and modification should be construed to be included in the scope of the present invention.
Although embodiments of the present invention were described above, these are just examples and do not limit the present invention. Further, the present invention may be changed and modified in various ways, without departing from the essential features of the present invention, by those skilled in the art. For example, the components described in detail in the embodiments of the present invention may be modified. Further, differences due to the modification and application should be construed as being included in the scope and spirit of the present invention, which is described in the accompanying claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1020170108391 | Aug 2017 | KR | national |
