Patent Application
20180292941
The present disclosure relates to techniques, for example, for a display device such as a liquid crystal display device (LCD), for a touch sensor (also called a touch panel [TP]), for a liquid crystal display device with a touch sensor (in other words, a liquid crystal touch panel module), and for an electronic apparatus. The present disclosure particularly relates to a technique for a liquid crystal display device with an in-cell capacitive touch sensor.
Examples of liquid crystal display devices with a touch sensor whose liquid crystal display function implements a touch sensor function, particularly for reducing thickness for example, include a liquid crystal display device with an in-cell touch sensor (called, for example, “in-cell touch LCD” or “in-cell liquid crystal touch panel”).
A liquid crystal display device with an in-cell capacitive touch sensor as a related example has an array substrate (also called a TFT substrate) and a color filter (CF) substrate that are elements constituting the liquid crystal display function, and a liquid crystal layer interposed between the array substrate and the CF substrate. The array substrate is provided with thin-film transistors (TFTs) including gate electrodes and source electrodes, pixel electrodes, retention capacitors, a common electrode, and the like. The CF substrate is provided with a color filter and the like. The liquid crystal display device with a touch sensor includes a touch drive electrode (transmitting electrode referenced as Tx) and a touch detection electrode (receiving electrode referenced as Rx) that are elements constituting the touch sensor function.
The above-described liquid crystal display device with a touch sensor particularly has a particular example configuration (called “combined use type”) in which an electrode unit and a wiring layer for the liquid crystal display function is partially used also as an electrode unit and a wiring layer for the touch sensor function. A configuration example is described, for example, in Japanese Patent Application Laid-open No. 2009-244958.
For example, in a configuration example (first related configuration example) of the combined use type liquid crystal display device with a touch sensor corresponding to a vertical electric field mode LCD, the array substrate includes a first electrode that is a first common electrode unit (referenced as COM1), and an electrode unit used as both a second common electrode unit (referenced as COM2) and the transmitting electrode Tx is configured as a second electrode on the inner side (on the side nearer to the liquid crystal layer) of the CF substrate, and the receiving electrode Rx is configured as a third electrode on the outer side (front surface) of the CF substrate.
In a configuration example (second related configuration example) of the combined use type liquid crystal display device with a touch sensor corresponding to a horizontal electric field mode LCD, an electrode unit used as both a common electrode (referenced as COM) and the transmitting electrode Tx is configured as a first electrode on the array substrate, and the receiving electrode Rx is configured as a second electrode on the CF substrate.
The horizontal electric field mode or the vertical electric field mode is applicable as a driving method for the above-mentioned liquid crystal layer. A fringe field switching (FFS) mode and an in-plane switching (IPS) mode are examples of the horizontal electric field mode. A twisted nematic (TN) mode, a vertical alignment (VA) mode, and an electrically controlled birefringence (ECB) mode are examples of the vertical electric field mode.
A general liquid crystal display device with a touch sensor includes a display area corresponding to a screen of a panel unit, and a frame portion disposed outside the display area. The display area is a region constituted by pixels and touch detection units. The frame portion is formed with, for example, a peripheral circuit. The peripheral circuit is formed by a process such as a chip-on-glass (COG) process or a low-temperature polycrystalline silicon (LTPS) process. The peripheral circuit is, for example, a driver that drives electrodes of the panel. Examples of the driver include, but are not limited to, a gate driver that drives gate electrodes and gate lines.
General issues and requirements in devices such as the above-described liquid crystal display device with a touch sensor includes, for example, thickness reduction, space saving, simplification in the production process and the number of parts, cost reduction by simplification, and improvement in quality of display and accuracy of touch detection. Regarding particularly the simplification, the number of layers is reduced to reduce cost by employing the combined use type in-cell configuration in which the electrodes and the wiring layers are used for both of the different functions as illustrated in the above-described configuration example. In addition, there are special requirements on space saving: the display area and a touch detection area corresponding to the display area are desirable to be as large as possible, and the frame portion and the like are desirable to be as small as possible, relative to the overall size of the device. Regarding the accuracy of touch detection, the screen serving as the touch detection area is desirable to have an appropriate and uniform degree of sensitivity of touch detection.
Related art examples regarding the above-described liquid crystal display device with a touch sensor includes Japanese Patent Application Laid-open No. 2012-73783. Japanese Patent Application Laid-open No. 2012-73783 describes how to obtain a display device with a touch detection function that is capable of enhancing uniformity in sensitivity of detection of touch. In particular, Japanese Patent Application Laid-open No. 2012-73783 describes that a plurality of drive electrodes extends to a first position or a second position located outside of the first position, the first position being away from the center of a touch detection electrode located outermost among a plurality of touch detection electrodes disposed in an effective display region S, by half the length of an arrangement pitch of the touch detection electrodes.
In the related in-cell capacitive liquid crystal touch panel, particularly in the combined use type configuration example (such as Japanese Patent Application Laid-open No. 2009-244958) in which the same electrode unit is used for both the liquid crystal display function and the touch sensor function, the touch detection area corresponding to the display area is desirable to have an appropriate and uniform degree of sensitivity of touch detection.
According to an aspect, a display device with a touch sensor has a display function and a touch sensor function. The display device includes: a panel unit that comprises a first substrate, a second substrate, and a display function layer between the first substrate and the second substrate; a first electrode on the first substrate having a function as a first touch drive electrode that constitutes the touch sensor function; a second electrode on the second substrate having a function as a second touch drive electrode that constitutes the touch sensor function; a third electrode on the second substrate having a function as a touch detection electrode that constitutes the touch sensor function; and a capacitor for the touch sensor function. The capacitor is formed between either of the first electrode and the second electrode and the third electrode, or between both the first electrode and the second electrode and the third electrode. When the touch sensor function is used, a first signal is applied to the first electrode and the second electrode, and a second signal is detected from the third electrode through the capacitor. The first electrode of the first substrate is disposed in a display area of the panel unit, and the second electrode of the second substrate is disposed in a frame portion outside the display area, and the first electrode and the second electrode are connected to each other by an upper/lower conducting portion provided at the frame portion. The frame portion comprises, on the first substrate side thereof, a peripheral circuit, and the second electrode is provided in a position more distant upward from the peripheral circuit than the first electrode.
According to another aspect, an electronic apparatus includes the display device with a touch sensor.
Additional features and advantages are described herein, and will be apparent from the following Detailed Description and the figures.
Embodiments of the present disclosure will be described below in detail based on the accompanying drawings. In all of the drawings for explaining the embodiments, the same parts will be given the same reference numerals, and repetition of description thereof will be omitted. For convenience of explanation, various directions will be referred to as follows: directions of a panel display plane as the X- and Y-directions; the direction perpendicular thereto (sight-line direction) as the Z-direction; the direction of gate lines as the X-direction; and the direction of source lines as the Y-direction. In addition to reference numerals, abbreviated symbols such as G, S, Tx, and Rx will be used as appropriate. Cross-sectional views are illustrated with hatching lines partially omitted for ease of understanding.
Before describing the details of the embodiments of the present disclosure, description will be made below of techniques and the like of a liquid crystal display device with a touch sensor, for ease of understanding.
A touch panel T illustrated in
In the state in which the conductive body M is not close to the touch detection electrode E2 on the front surface side of the touch panel T, input of the signal s1 causes the capacitor C1 to charge and discharge, so that a current I1 corresponding to the capacitance value of the capacitor C1 flows therethrough. At this time, the potential waveform (waveform of the detected voltage Vdet) of the touch detection electrode E2 at the other end (point p) of the capacitor C1 is detected by the voltage detector DET, illustrated as the voltage V1 of the signal s2. The potential waveform has a substantially constant value of the voltage V1 while the conductive body M is not close to the touch detection electrode E2. The actual waveform of the voltage V1 has a form of decaying after steep rising, illustrated as a voltage V1a.
In the state in which the conductive body M is close to the touch detection electrode E2 on the front surface side of the touch panel T (in a touch-on state), the circuit takes a form in which a capacitor C2 formed by the conductive body M is additionally connected in series to the capacitor C1. In this state, the current I1 and a current I2 flow corresponding to the capacitance values of the capacitors C1 and C2, respectively, as the respective capacitors C1 and C2 are charged and discharged. At this time, the potential waveform (waveform of the detected voltage Vdet) of the touch detection electrode E2 at the other end (point p) of the capacitor C1 detected by the voltage detector DET changes to the voltage V2 of the signal s2 due to reduction of the electric field caused by the conductive body M. The above-described potential at the point p (touch detection electrode E2) results in a potential of a divided voltage determined by the values of the currents I1 and I2 flowing the capacitors C1 and C2. Consequently, when the conductive body M is close to the touch detection electrode E2, the voltage V2 of the signal s2 has a value lower than the voltage V1 obtained when the conductive body M is not close to the touch detection electrode E2. The voltage detector DET (or a touch detection circuit corresponding thereto) compares the detected voltage Vdet (voltage V1 or V2) of the signal s2 with a predetermined threshold voltage Vth, and detects the state as the state in which the conductive body M is close to the touch detection electrode E2 when the detected voltage Vdet is lower than the threshold voltage Vth, for example, as illustrated as the voltage V2 in
Not limited to the above-described configuration example, the touch drive electrode E1 (transmitting electrode Tx) may be formed as a solid layer on the surface of the first substrate, and the touch detection electrode E2 (receiving electrode Rx) may be formed in a matrix in units of regions divided in the X-direction and the Y-direction on the surface of the second substrate. The resolution of the touch detection is governed by the design of the above-described pattern. In the present specification, the “solid layer” refers to a layer that is not processed into a predetermined shape after deposition.
A structure (liquid crystal display device with an in-cell touch sensor [in-cell touch LCD]) can include the touch panel T built inside the liquid crystal display panel. As a driving method for an applied liquid crystal layer in a vertical electric field mode, an array substrate that is the first substrate includes a first common electrode unit (COM1), and a CF substrate that is the second substrate includes a second common electrode unit (COM2). In a horizontal electric field mode, the array substrate that is the first substrate includes a common electrode (COM).
A structure (combined use type in which the same electrode unit is used for both the liquid crystal display function and the touch sensor function) can include the above-described liquid crystal display device with an in-cell touch sensor that is simplified by including a common electrode unit originally provided in the liquid crystal display device also as one of the electrodes (touch drive electrode E1) constituting the touch sensor function (for example, in Japanese Patent Application Laid-open No. 2009-244958). A common drive signal (common voltage) to the common electrode for the liquid crystal display device is commonly used also as a signal for the touch sensor. As a driving method, signals for the respective functions are applied to the same electrode unit on a time-sharing basis (in
In the case of the combined use type in the vertical electric field mode (such as the TN, the VA, or the ECB mode), the structure is such that the first common electrode unit (COM1) on the array substrate is used commonly (for combined use) as the touch drive electrode (transmitting electrode Tx) for the touch sensor function, and the second common electrode unit (COM2) on the CF substrate is used commonly (for combined use) as the touch detection electrode (receiving electrode Rx). In the vertical electric field mode, the common drive signal (common voltage) to the upper and the lower common electrode units (the common electrode COM1 and the common electrode COM2) and a pixel signal of the pixel electrode generate an electric field VE in the vertical direction (Z-direction) with respect to the liquid crystal layer so as to control (modulate) the state of each pixel.
In the case of the combined use type in the horizontal electric field mode (such as the FFS or the IPS mode), the structure is such that the first common electrode unit (COM) on the array substrate is used commonly (in other words, used for combined use) as the touch drive electrode (transmitting electrode Tx) for the touch sensor function, and the touch detection electrode (receiving electrode Rx) is provided on the CF substrate. In the horizontal electric field mode, the common drive signal (common voltage) to the common electrode COM and the pixel signal of the pixel electrode generate an electric field HE in the horizontal direction (X- or Y-direction) with respect to the liquid crystal layer so as to control (modulate) the state of each pixel.
However, the study by the inventor of the present disclosure has found that the display device with a touch sensor of related art has the following problems. Those problems will be described using
A first problem is that an end portion 73 (a region 901 adjacent to the frame portion 72) in the display area 71 tends to have a slightly lower degree of sensitivity of touch detection than that of a central portion (a region apart from the frame portion 72) in the display area 71. In other words, the touch detection area has room for improvement in the uniformity of the sensitivity of touch detection.
The lower sensitivity of touch detection described above is attributed to the fact that the structure of the electrode units and others configuring the pixels and the touch detection units in the display area 71, particularly in the end portion 73 differs from the structure in the frame portion 72 located outside the display area 71, particularly in a region 903 adjacent to the display area 71. For example, the frame portion 72 (region 903) is not formed with the touch drive electrode 1801 (transmitting electrode Tx) and the touch detection electrode 1802 (receiving electrode Rx) that are the electrode pair constituting the touch sensor function. Otherwise, even if the touch drive electrode 1801 and the touch detection electrode 1802 serving as the electrode pair are formed, the electrodes are ends of lines and have small electrode widths. For that reason, in the end portion 73 (region 901) of the display area 71, only a weak fringe electric field is generated between the touch drive electrode 1801 and the touch detection electrode 1802 serving as the electrode pair; in other words, the number of lines of electric force is smaller, and thus the sensitivity of touch detection is slightly lower.
Conventional configuration examples of Japanese Patent Application Laid-open No. 2012-73783, for example, describe configurations in which the touch drive electrode (common electrode) in the display area (effective display region) is extended into the frame portion as described above. Such a configuration reduces the amount of reduction of the fringe electric field in the end portion of the display area, so that the fringe electric field has the same intensity as that of the central portion of the display area, and thus enhances the uniformity of the touch detection sensitivity in the end portion of the display area. For example, FIG. 4 and Paragraph 0034 in Japanese Patent Application Laid-open No. 2012-73783 describe this. Enhancing the uniformity of the touch detection sensitivity can reduce, for example, the amount of correction calculation for touch detection signals, and can raise the accuracy of detection of a touch position.
However, as illustrated in
As described above, to prevent degradation in the sensitivity of touch detection in the end portion 73 of the display area 71, the liquid crystal display device with an in-cell capacitive touch sensor preferably has a configuration in which the electrodes constituting the touch sensor function are extended into the end portion 73 located outside the touch detection area corresponding to the display area. However, there is a concern of the adverse effects due to proximity to the peripheral circuit 80 caused by such a configuration. Therefore, it is needed to provide a configuration that can avoid the adverse effects due to proximity to the peripheral circuit 80 caused by extension of the electrode units, particularly the transmitting electrode Tx, etc., from the display area 71 into the frame portion 72, and that can improve or raise the touch detection sensitivity in the display area 71 including the end portion 73.
A second problem is that, as indicated by arrow 902 in
As illustrated in
Therefore, it is also needed to provide a configuration that can shield the noise from the peripheral circuit 80 toward the front surface while avoiding the mutual adverse effects between the electrode units and the peripheral circuit 80.
As described above, it is a main object of the present disclosure to provide a technique regarding an in-cell capacitive liquid crystal touch panel (particularly of a combined use type), the technique being capable of avoiding adverse effects due to proximity to a peripheral circuit caused by extension of electrode units from a display area into a frame portion, and capable of improving and/or raising the touch detection sensitivity of the touch detection area corresponding to the display area including an end portion thereof. Other problems and the like will be described in embodiments of the present disclosure.
Based on the description given above, an in-cell capacitive liquid crystal touch panel 1 of a first embodiment of the present disclosure will be described using
In the present configuration, the first electrode 51 (transmitting electrode Tx1) formed in the display area 71 on the inner side (on the side nearer to the liquid crystal layer 30) of the array substrate 10 is slightly extended into the frame portion 72, and to be connected from there, through the upper/lower conducting portion 61 in the frame portion 72, to the second electrode 52 (transmitting electrode Tx2) that is a wiring layer formed (extended) on the inner side (on the side nearer to the liquid crystal layer 30) of the CF substrate 20 in the frame portion 72. The first electrode 51 (transmitting electrode Tx1) and the second electrode 52 (transmitting electrode Tx2) have a function of the touch drive electrode (transmitting electrode Tx). The outer side (front surface) of the CF substrate 20 includes the touch detection electrode (receiving electrode Rx) as a third electrode 53 in a manner extending from the display area 71 into the frame portion 72. In the present configuration, the second electrode 52 (transmitting electrode Tx2) located on the upper side is extended more outward (in the X- or Y-direction) than the first electrode 51 (transmitting electrode Tx1) located on the lower side.
As described above, the extended portion from the first electrode 51 (transmitting electrode Tx1) in the display area 71 of the array substrate 10 is provided as the second electrode 52 (transmitting electrode Tx2) in the frame portion 72 of the CF substrate 20. Therefore, as indicated by the dotted line A2, a larger distance d2 (d2>d1) is obtained above (in the Z-direction of) the peripheral circuit 80 to the electrode unit (particularly, to the second electrode 52 [transmitting electrode Tx2]) extended in the frame portion 72. This can reduce the capacitive load caused by coupling of the second electrode 52 with the peripheral circuit 80. Consequently, for example, the above-described adverse effects on operations of the peripheral circuit 80 can be avoided. The touch detection sensitivity can be improved by the structure that includes, near the end portion 73 of the display area 71, the transmitting electrode Tx2 and the receiving electrode Rx that are the electrodes extended in the frame portion 72, as indicated by the dotted line A1. Although the present configuration (
In the present configuration, the transmitting electrode Tx2 that is the electrode unit extended at the distance d2 above (in the Z-direction of) the peripheral circuit 80 in the frame portion 72 of the array substrate 10 is arranged so as to overlap the receiving electrode Rx. This configuration with the electrode units (particularly, with the transmitting electrode Tx2) provides the effect of being capable of shielding the noise from the peripheral circuit 80 toward the front surface.
A description will be made using
The first electrode 51 (transmitting electrode Tx1) is formed of ITO or the like on the inner side (on the side nearer to the liquid crystal layer 30) of the array substrate 10 mainly in the display area 71. The second electrode 52 (transmitting electrode Tx2) is formed of ITO or the like on the inner side (on the side nearer to the liquid crystal layer 30) of the CF substrate 20 in the frame portion 72, and the third electrode 53 (receiving electrode Rx) is formed of ITO or the like on the outer side (front surface) over the display area 71 and the frame portion 72. The first electrode 51 (transmitting electrode Tx1) has a function of a first touch drive electrode (transmitting electrode Tx1) for the touch sensor function. The second electrode 52 (transmitting electrode Tx2) has a function of a second touch drive electrode (transmitting electrode Tx2) for the touch sensor function. The third electrode 53 (Rx) has a function of the touch detection electrode (receiving electrode Rx) for the touch sensor function. The transmitting electrodes Tx (transmitting electrodes Tx1 and Tx2) and the receiving electrode Rx form a pair to constitute the capacitance C for touch detection.
In
One end of the first electrode 51 (transmitting electrode Tx1) of the array substrate 10 and one end of the second electrode 52 (transmitting electrode Tx2) of the CF substrate 20 are electrically connected by the upper/lower conducting portion 61 of the frame portion 72. The upper/lower conducting portion 61 may be formed as a part of the sealing portion 60, or may be formed independently. Supplying a common voltage Vcom gives the transmitting electrodes Tx1 and Tx2, which are electrically connected, a common potential. For example, the sealing portion 60 having the sealing function is used also as the upper/lower conducting portion 61 having the electrical connection function.
The peripheral circuit 80, etc. such as a driver connected to the gate lines G are implemented on the side of the array substrate 10 of the frame portion 72. While, here, the peripheral circuit 80 is illustrated inside the array substrate 10, circuit elements are formed on the substrate according to implementation details as described above. The driver, etc. connected to the transmitting electrode Tx2 or the receiving electrode Rx, which is the electrode on the side of the CF substrate 20, may be implemented in the frame portion 72 on the side of the CF substrate 20, or may be implemented in the frame portion 72 on the side of the array substrate 10 so as to be connected via wiring, the upper/lower conducting portion, or the like. In particular, the driver, etc. are preferably collectively implemented as the peripheral circuit 80 on the side of the array substrate 10.
The transmitting electrode Tx2 and the receiving electrode Rx, which are the electrode units extended in the frame portion 72 on the side of the CF substrate 20, have also the function of shielding the noise from the peripheral circuit 80, etc. located therebelow toward the front surface, depending on the wiring patterns of the electrodes Tx2 and Rx. For example, the noise shielding effect is obtained when the transmitting electrode Tx2 has a shape of stripes in a first direction and the receiving electrode Rx has a shape of stripes in a second direction.
In the present configuration of the panel unit 1 of the liquid crystal display device with a touch sensor illustrated in
A description will next be made using
A description will next be made using
The first electrode 51 serving as the transmitting electrode Tx1 and as the first common electrode unit COM1 is formed on the surface on the inner side of the array substrate 10 mainly in the display area 71, and the pixel electrode 43 is formed above the first electrode 51 with an insulation layer interposed therebetween. The pixel electrode 43 is an electrode for generating the vertical electric field VE. The second electrode 52 serving as the transmitting electrode Tx2 and as the second common electrode unit COM2 is formed on the surface on the inner side of the CF substrate 20 over the display area 71 and the frame portion 72. The third electrode 53 (receiving electrode Rx) is correspondingly formed on the surface on the outer side of the CF substrate 20 over the display area 71 and the frame portion 72. The pixel electrode 43 is included in a position (layer) between the transmitting electrodes Tx1 and Tx2. The transmitting electrode Tx1 forms the above-described terminals of the retention capacitor 45 for each pixel. The transmitting electrode Tx1 includes, for example, the retention capacitor line 46 to which the terminal is connected.
As a driving method corresponding to the third embodiment, waveforms for the respective functions are applied on a time-sharing basis. Specifically, during a pixel writing period in one horizontal period, the common voltage Vcom for the common electrodes COM (first common electrode unit COM1 and second common electrode unit COM2) is supplied to the first electrode 51 and the second electrode 52, whereas during a touch sensing period, the signal s1 serving as the touch drive signal for the transmitting electrodes Tx (transmitting electrodes Tx1 and Tx2) is applied and the signal s2 serving as the touch detection signal is correspondingly output (detected) from the third electrode 53 (receiving electrode Rx).
The third embodiment also provides the same effect as that of the first and the second embodiments.
A description will next be made using
As a driving method corresponding to the fourth embodiment, waveforms for the respective functions are applied on a time-sharing basis. Specifically, during the pixel writing period, the common voltage Vcom for the first common electrode COM1 is supplied to the first electrode 51, whereas during the touch sensing period, the signal s1 serving as the touch drive signal for the transmitting electrodes Tx (transmitting electrodes Tx1 and Tx2) is applied and the signal s2 serving as the touch detection signal is correspondingly output (detected) from the third electrode 53 (receiving electrode Rx).
In the case of the horizontal electric field mode, the configuration of
The fourth embodiment also provides the same effect as that of the first embodiment.
A description will next be made using
The CF substrate 20 includes, on a glass substrate 21 (on the side of the liquid crystal layer 30), a color filter 22, an overcoat 23, a light-shielding film 24, the second electrode 52, etc., and includes the third electrode 53 on the outer side (front surface) of the glass substrate 21. The light-shielding film 24 is also called a black matrix (BM). The color filter 22 is, for example, a pattern of a periodic array of colors of red (R), green (G), and blue (B). Each color corresponds to one pixel (subpixel). The overcoat 23 covers the color filter 22. The light-shielding film 24 is formed at the frame portion 72.
The first electrode 51 serving as the transmitting electrode Tx1 and as the common electrode COM1, the second electrode 52 serving as the transmitting electrode Tx2 and as the common electrode COM2, and the third electrode 53 serving as the receiving electrode Rx are configured to form a pattern of transparent electrodes made of ITO or the like. For example, the transmitting electrodes Tx (transmitting electrodes Tx1 and Tx2) are formed into stripes in the X-direction, and the receiving electrode Rx is formed into stripes in the Y-direction.
In a region indicated by arrow A51 in the frame portion 72, the second electrode 52 serving as the transmitting electrode Tx2 and as the common electrode COM2 is extended more widely outward (in the X- or Y-direction) than the first electrode 51 serving as the transmitting electrode Tx1 and as the common electrode COM1, and has a part overlapping the peripheral circuit 80. Consequently, the second electrode 52 has the effect of shielding the noise of the peripheral circuit 80 as described above. In a region indicated by arrow A52, the second electrode 52 serving as the transmitting electrode Tx2 and as the common electrode COM2 is extended more widely outward (in the X- or Y-direction) than the third electrode 53 serving as the receiving electrode Rx and the upper/lower conducting portion 61.
As viewed on the X-Y plane on the side of the array substrate 10 illustrated in
A description will next be made using
In the related configuration of the vertical electric field mode, the touch drive electrode provided on the CF substrate is a solid layer of ITO, and an opposed ITO layer that is a touch drive electrode resides in a position overlapping a gate electrode on the array substrate. Consequently, a capacitive load increases between the gate electrode on the array substrate and the opposed ITO layer serving as a touch drive electrode on the CF substrate. In other words, the capacitive load between the gate electrode on the array substrate and the opposed ITO layer serving as a touch drive electrode on the CF substrate is large. Therefore, the configuration of the sixth embodiment is a configuration in which the shape of the transmitting electrode Tx pattern is contrived so as to avoid the increase in the capacitive load, and is a configuration in which this pattern shape prevents a disorder in the liquid crystal orientation from appearing on the display.
In the sixth embodiment, the pattern of the second electrode 52 (transmitting electrode Tx2) as illustrated in
Corresponding to the configuration in which the transmitting electrode Tx2 is extended from the display area 71 into the frame portion 72 as described above, the transmitting electrode Tx2 blocks have a shape that continues into the frame portion 72. The configuration of the transmitting electrode Tx2 blocks described above reduces the capacitance between the gate lines G and the transmitting electrode Tx2 in the display area 71, and extends the transmitting electrode Tx2 blocks so as to make them overlap the peripheral circuit 80 in the frame portion 72.
A slit SLB is provided in each of the transmitting electrode Tx2 blocks as illustrated in
The slit SLB is not limited to have the above-described shape, but may be, for example, an open portion in positions where the gate line G overlaps the source lines S and a non-open portion in other positions on the gate line G. In one block of the second electrode 52 (transmitting electrode Tx2), the pixel lines arranged in the Y-direction are separated by the slit SLB, but are connected at the non-open portions to have an electrically common potential. A non-open portion serving as a place to provide a connection in the Y-direction only needs to be present at some place. As another configuration example, the transmitting electrode Tx2 block may have a structure in which the pixel lines are not connected (because of an open portion) in the display area 71 but connected in the frame portion 72. Alternatively, in the case of placing the blocks separated by the above-described slits at a common potential, the blocks only need to be configured such that the same signal (voltage) is applied to the blocks.
Therefore, as illustrated in
In a driving method corresponding to the panel unit 1 of the liquid crystal display device with a touch sensor of the sixth embodiment, the signal s1 serving as the touch drive signal is applied to the transmitting electrode Tx1 (retention capacitor lines 46) on the side of the array substrate 10 and to the pattern (blocks) of the transmitting electrode Tx2 on the side of the CF substrate 20 connected to the transmitting electrode Tx1, during the touch sensing period. For example, the signal s1 is sequentially applied to the blocks. In response to this, the signal s2 serving as the touch detection signal is detected from the receiving electrode Rx pattern. The receiving electrode Rx pattern is, for example, of blocks extending in parallel in the Y-direction that correspond to the transmitting electrode Tx pattern in the X-direction.
The third electrode 53 (receiving electrode Rx) of the CF substrate 20 is preferably configured to have a shape corresponding to the pattern of the second electrode 52 (transmitting electrode Tx2). In other words, the receiving electrode Rx pattern is shaped as blocks extending in parallel in the Y-direction so as to intersect (particularly at a right angle) the transmitting electrode Tx pattern (blocks) formed in parallel in the X-direction. The blocks of the receiving electrode Rx can be formed so that one block includes a plurality of pixel lines in the same manner as the blocks of the transmitting electrode Tx2.
In the sixth embodiment, corresponding to the above-described pattern configuration of the transmitting electrode Tx2, in other words, the configuration in which the slit SLA or the slit SLB exists at each pixel line, it is preferable to apply column inversion driving or frame inversion driving as a driving method, that is, as a pixel writing method for the liquid crystal display device. In other words, these driving methods can reduce or prevent the disorder in the liquid crystal orientation at the slit positions, and thus can improve the quality of display.
Next, using
The liquid crystal touch panel module 100 includes the panel unit 1 of the liquid crystal display device with a touch sensor, and a touch sensor driver 101 and a liquid crystal display driver 102 that are connected to the panel unit 1. The touch sensor driver 101 and the liquid crystal display driver 102 can be called as a first controller and a second controller, respectively. The liquid crystal touch panel module 100 and the control unit 501 are connected to each other via an interface 502 (also called I/F) of the touch sensor driver 101. The interface 502 includes an interface of a power supply and an interface of the touch sensor. The touch sensor driver 101 and the liquid crystal display driver 102 are configured to synchronize with each other. The present configuration example uses the touch sensor driver 101, which is the first controller, as a main controller of the liquid crystal touch panel module 100 (the panel unit 1 of the liquid crystal display device with a touch sensor), thereby, in other words, places the touch sensor driver 101 at a level higher than the liquid crystal display driver 102. However, the levels may be inverted or may be integrated into one. Each driver, that is, each of the touch sensor driver 101 and the liquid crystal display driver 102 is implemented, for example, as IC on an FPC board connected to the panel unit 1. These drivers only need to be implemented, for example, by any method such as a chip on film (COF) method.
The panel unit 1 of the liquid crystal display device with a touch sensor is configured, for example, as described in
The drives may be separated from each other or integrated with each other, as appropriate. For example, the gate driver 301 and the Tx driver 201 may be integrated into one, and the source driver 302 and the Rx driver 202 may be integrated into one. Alternatively, the Tx driver 201 and/or the Rx driver 202 may be integrated with the touch sensor driver 101, and the gate driver 301 and/or the source driver 302 may be integrated with the LCD driver 102.
The touch sensor driver 101 receives a video signal, etc., from the control unit 501 of the electronic apparatus 500, and performs, for example, timing control for the liquid crystal display driver 102 and touch detection control for the panel unit 1 of the liquid crystal display device with a touch sensor. The touch sensor driver 101, for example, gives the liquid crystal display driver 102 a video signal (image information) and a control signal such as a timing signal. The touch sensor driver 101, for example, also gives the Tx driver 201 and the Rx driver 202 a control signal for the touch detection control. The touch sensor driver 10 gives, as a response, the electronic apparatus 500 information on results of control of several functions (such as information on whether touching is made and/or the touch position).
Based on the control signal from the touch sensor driver 101, the liquid crystal display driver 102 gives the gate driver 301 and the source driver 302 a signal for display control in the display area 71 of the panel unit 1 of the liquid crystal display device with a touch sensor. The signal may be given in the form of connecting the control unit 501 to the liquid crystal display driver 102 to give the video signal, etc. from the control unit 501 to the liquid crystal display driver 102. The gate driver 301 sequentially applies gate signals (scan pulses) to the group of the gate lines 41 (gate lines G). In synchronization therewith, the source driver 302 applies source signals (image signals) to the group of the source lines 42 (source lines S). As a result, the image signals are applied to the pixel electrodes 43 via the TFTs 44. The retention capacitors 45 are charged as soon as the image signals are applied to the pixel electrodes 43. Thus, the state of each pixel of the liquid crystal layer 30 is controlled (modulated).
In accordance with the control signal from the touch sensor driver 101, the Tx driver 201 serving as a touch drive driver supplies the common voltage Vcom for the common electrodes COM and sequentially applies the signal s1 serving as the touch drive signal for the transmitting electrodes Tx to the first electrode 51 and the second electrode 52. It should be noted that the first electrode 51 serves as the transmitting electrode Tx1 and as the common electrode COM1, and that the second electrode 52 serves as the transmitting electrode Tx2 and as the common electrode COM2.
Based on the control signal from the touch sensor driver 101, the Rx driver 202 serving as a touch detection driver detects the signal s2 serving as the touch detection signal from the third electrode 53 (receiving electrode Rx) of the panel unit 1 of the liquid crystal display device with a touch sensor. A signal of a detection result based on the signal s2 serving as the touch detection signal detected by the Rx driver 202 is output to the touch sensor driver 101. The Rx driver 202 receives the signal s2 serving as the touch detection signal from the receiving electrode Rx (third electrode 53), integrates the signal s2, and converts the integrated signal into a digital signal. Based on the digital signal, the Rx driver 202 performs operations such as determination of whether touching is made in the touch detection area corresponding to the display area 71 and calculation of touch position coordinates, and outputs signals indicating the results of the operations. The touch detection circuit provided in the Rx driver 202 is constituted by, for example, an amplifier, a filter, an AD converter, a rectifying and smoothing circuit, and a comparator. An input level signal based on the signal s2 from the receiving electrode Rx is compared with the threshold voltage Vth by the comparator as described above (
The drive frequency in each period, that is, in each of the pixel writing period PW and the touch sensing period TS can be designed as appropriate. For example, the drive frequency is set to 60 Hz in the pixel writing period PW, and to a double frequency of 120 Hz in the touch sensing period TS. In other words, in this case, the touch detection is performed at a rate of twice each time an image (pixel) is displayed. The order of the pixel writing period PW and the touch sensing period TS in 1 H may be reversed.
The HSYNC signal of
During the pixel writing period PW, the Tx driver 201 supplies the common voltage Vcom (common drive signal) to the first electrode 51 serving as the transmitting electrode Tx1 and as the common electrode COM1 and to the second electrode 52 serving as the transmitting electrode Tx2 and as the common electrode COM2, and Rx driver 202 supplies the common voltage Vcom (common drive signal) to the third electrode 53 serving as the receiving electrode Rx. As a result, all of the first electrode 51 serving as the transmitting electrode Tx1 and as the common electrode COM1, the second electrode 52 serving as the transmitting electrode Tx2 and as the common electrode COM2, and the receiving electrode Rx are controlled so as to have the common voltage Vcom.
During the touch sensing period TS, the Tx driver 201 sequentially applies the signal s1 serving as the touch drive signal to the transmitting electrodes Tx (transmitting electrodes Tx1 and Tx2), so that the first electrode 51 and the second electrode 52 function as the touch drive electrode (transmitting electrode Tx) and the third electrode 53 functions as the touch detection electrode (receiving electrode Rx). The Rx driver 202 detects the signal s2 serving as the touch detection signal from the third electrode 53 serving as the receiving electrode Rx.
The common drive signal (common voltage Vcom) defines a pixel voltage applied to the pixel electrode 43 and a display voltage of each pixel for the liquid crystal display function, and defines the signal s1 serving as the touch drive signal to the transmitting electrodes Tx for the touch sensor function. Although
In particular, the gate lines G and the source lines S are arranged in the display area 71. The transmitting electrodes Tx and the receiving electrode Rx are extended from the display area 71 into the frame portion 72. From the Tx driver 201 to the transmitting electrodes Tx (transmitting electrodes Tx1 and Tx2), the common voltage Vcom is supplied during the period PW, and the signal s1 serving as the touch drive signal, which is a Tx signal, is applied during the touch sensing period TS. The Rx driver 202 supplies the common voltage Vcom to the receiving electrode Rx during the pixel writing period PW, and detects the signal s2 serving as the touch detection signal, which is an Rx signal, from the receiving electrode Rx during the touch sensing period TS.
In addition to placing the lines of the transmitting electrode Tx and the receiving electrode Rx in extending directions thereof, the present configuration example arranges the lines repeatedly in directions perpendicular to the extending directions so that the lines overlap the frame portion 72 (area 1301). For example, lines 1302 of the transmitting electrode Tx2 are repeatedly arranged not only in the place where pixels are formed in the display area 71, but also in the frame portion 72 in the Y-direction so as to overlap the area 1301. The same applies to lines 1303 of the receiving electrode Rx. The lines 1302 and 1303 are not limited to be arranged independently (floating), but may be arranged continuously over the end portion 73 of the display area 71 and the frame portion 72 when the width of one line (block) is large. The present configuration example enhances the sensitivity and uniformity of touch detection of the end portion 73 of the display area 71, and shields the peripheral circuit 80 provided in the frame portion 72.
As has been described above, regarding the panel unit 1 of the liquid crystal display device with an in-cell capacitive touch sensor (particularly of the combined use type), the embodiments can avoid the adverse effects due to proximity to the peripheral circuit 80 caused by extension of the transmitting electrodes Tx and the receiving electrode Rx, which are electrodes, from the display area 71 to the frame portion 72, and can improve and/or raise the touch detection sensitivity in the touch detection area corresponding to the display area 71 including the end portion 73.
While the invention made by the inventor of the present disclosure has been specifically described above based on the embodiments, it is obvious that the present disclosure is not limited to the above-described embodiments, but can be variously modified within the scope not departing from the gist of the present disclosure.
For example, the panel unit 1 of the liquid crystal display device with a touch sensor of the present disclosure is applicable not only to the liquid crystal display device but also generally to other display devices. The panel unit 1 of the present disclosure is also applicable to other systems such as an electrophoretic display (EPD) system. For example, in the case of applying the liquid crystal display device with a touch sensor of the present disclosure to the EPD, it is only necessary to use a display function layer such as a microcapsule layer instead of the liquid crystal layer 30 illustrated in
Next, with reference to
The electronic apparatus illustrated in
The electronic apparatus illustrated in
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The electronic apparatus illustrated in
Regarding an in-cell capacitive liquid crystal touch panel (particularly of a combined use type), aspects of the present disclosure can avoid adverse effects due to proximity to a peripheral circuit caused by extension of electrode units from a display area into a frame portion, and can improve and/or raise touch detection sensitivity of a touch detection area corresponding to the display area including an end portion thereof.
The present disclosure includes aspects as follows:
a panel unit that comprises a first substrate, a second substrate, and a display function layer between the first substrate and the second substrate;
a first electrode on the first substrate having a function as a first touch drive electrode that constitutes the touch sensor function;
a second electrode on the second substrate having a function as a second touch drive electrode that constitutes the touch sensor function;
a third electrode on the second substrate having a function as a touch detection electrode that constitutes the touch sensor function; and
a capacitor for the touch sensor function, the capacitor being formed between either of the first electrode and the second electrode and the third electrode, or between both the first electrode and the second electrode and the third electrode; wherein
when the touch sensor function is used, a first signal is applied to the first electrode and the second electrode, and a second signal is detected from the third electrode through the capacitor;
the first electrode of the first substrate is disposed in a display area of the panel unit, and the second electrode of the second substrate is disposed in a frame portion outside the display area, and the first electrode and the second electrode are connected to each other by an upper/lower conducting portion provided at the frame portion; and
the frame portion comprises, on the first substrate thereof, a peripheral circuit, and the second electrode is provided in a position more distant upward from the peripheral circuit than the first electrode.
the frame portion includes an extended portion of the first electrode provided on the first substrate and includes the second electrode provided on the second substrate; and
the second electrode is extended wider outward than the extended portion of the first electrode in plan view.
the display function layer is a layer in which display is performed by application of a voltage between the first substrate and the second substrate;
the first substrate comprises a pixel electrode in a position between the first substrate and the second substrate for each pixel;
the first electrode is configured to form a retention capacitor for each of the pixels;
the second electrode is disposed over the display area on the second substrate;
the first electrode has both a function as a first common electrode unit that constitutes the display function and the function as the first touch drive electrode that constitutes the touch sensor function;
the second electrode has both a function as a second common electrode unit that constitutes the display function and the function as the second touch drive electrode that constitutes the touch sensor function; and
during a touch sensing period when the touch sensor function is used, the first signal is applied to the first electrode and the second electrode, and the second signal is detected from the third electrode through the capacitor.
the display function layer is a layer in which display is performed by application of a voltage in a direction substantially parallel to an in-plane direction of the first substrate or the second substrate;
the first substrate comprises a pixel electrode for each pixel;
the first electrode has both a function as a first common electrode unit that constitutes the display function and the function as the first touch drive electrode that is constitutes the touch sensor function;
the second electrode has the function as the second touch drive electrode that constitutes the touch sensor function; and
during a touch sensing period when the touch sensor function is used, the first signal is applied to the first electrode and the second electrode, and the second signal is detected from the third electrode through the capacitor.
the second substrate has a first surface and a second surface, wherein the first surface is closer to the display function layer than the second surface,
the second electrode is formed on the first surface of the second substrate; and
the third electrode is formed on the second surface of the second substrate.
the upper/lower conducting portion includes conductive particles dispersed in sealing material; and
the second electrode comprises, in the frame portion, a portion overlapping the area of the peripheral circuit, the second electrode, and the upper/lower conducting portion in plan view.
each of the first electrode and the second electrode is formed in a pattern of transparent electrodes extending in parallel in a first direction;
the third electrode is formed in a pattern of transparent electrodes in parallel in a second direction;
touch detection units are formed in intersection regions of the patterns of the second electrode and the third electrode; and
the first signal is sequentially applied to each of a plurality of lines of the patterns of the first electrode and the second electrode, so that the second signal is detected from each of a plurality of lines of the pattern of the third electrode through the capacitor corresponding to the touch detection units.
the first substrate comprises gate lines in parallel in a first direction that are elements constituting pixels;
the second electrode is disposed over the display area;
the second electrode is formed in a pattern of transparent electrodes in parallel in the first direction;
the third electrode is formed in a pattern of transparent electrodes in parallel in a second direction; and
the pattern of the second electrode comprises first slits in parallel in the first direction in positions overlapping, in plan view, the gate lines for a plurality of pixel lines so as to be divided into a plurality of blocks.
the first substrate comprises:
the driver comprises:
the touch drive driver is configured to apply, to the first electrode and the second electrode, a signal for pixel writing during a pixel writing period of one horizontal period, and the first signal during a touch sensing period of one horizontal period; and
the touch detection driver is configured to apply, to the third electrode, the signal for pixel writing during the pixel writing period of one horizontal period, and to detect, from the third electrode, the second signal during the touch sensing period of one horizontal period.
a first controller that is connected to the touch drive driver and the touch detection driver and performs drive control of the touch sensor function; and
a second controller that is connected to the gate driver and the source driver and performs drive control of the display function.
the display device with a touch sensor according to (1).
It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012175215 | Aug 2012 | JP | national |
| 2013155265 | Jul 2013 | JP | national |
The present application is a continuation of U.S. patent application Ser. No. 15/131,227, filed Apr. 18, 2016, which is a continuation of U.S. patent application Ser. No. 14/703,462, filed May 4, 2015, issued as U.S. Pat. No. 9,335,882 on May 10, 2016, which application is a continuation of U.S. patent application Ser. No. 13/955,079, filed Jul. 31, 2013, issued as U.S. Pat. No. 9,052,768 on Jun. 9, 2015, which application claims priority to Japanese Priority Patent Application JP 2012-175215 filed in the Japan Patent Office on Aug. 7, 2012, and JP 2013-155265 filed in the Japan Patent Office on Jul. 26, 2013, the entire content of which is hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15131227 | Apr 2016 | US |
| Child | 16005033 | US | |
| Parent | 14703462 | May 2015 | US |
| Child | 15131227 | US | |
| Parent | 13955079 | Jul 2013 | US |
| Child | 14703462 | US |
