Patent Application
20180107317
This application claims priority of Japanese Patent Application No. 2016-202870, filed on Oct. 14, 2016, the disclosure of which is incorporated herein by reference.
The disclosed technology relates to a display device adapted for touch sensing.
Recent display devices are often configured to detect an input object such as user fingers and styli on a display panel. A display device is, for example, used in a device configured to operate in response to user input such as a smart phone and a tablet.
One technique may utilize capacitive touch sensing to detect an input object based on capacitance of a sensor electrode which varies as the input object approaches the sensor electrode. The capacitive touch sensing may include self-capacitance touch sensing which detects changes in the capacitive coupling between sensor electrodes and an input object and mutual capacitance touch sensing which detects changes in capacitance between transmitter sensing electrodes and receiver sensing electrodes.
In one configuration of a display device, a touch panel comprises electrodes for capacitive touch sensing arranged on the display panel.
In another configuration of a display device, touch sensing electrodes are embedded in the display panel. In a liquid crystal display panel, for example, common electrodes (or counter electrodes) may be used as the touch sensing electrodes. This configuration often has connection terminals respectively connected to the touch sensing electrodes in the display panel.
The display driver may comprise a source driver circuitry for driving source lines of the display panel. The source driver circuitry may be integrated with a touch sensing controller configured for the capacitive touch sensing in one or more chips. The external connection terminals may be connected to output pads of the source driver circuitry and the touch sensing controller. An increase in the number of the external connection terminals in the display panel may cause an increase in the number of the output pads.
As an art which may be related to the present disclosure, Japanese Patent Application Publication No. 2015-225381 discloses a touch sense circuitry adapted to both of the self-capacitance touch sensing and the mutual capacitance touch sensing.
In one embodiment a display driver includes: a plurality of source output terminals configured to be connected to a plurality of source input terminals of a display panel; a source driver circuitry configured to generate source signals to the source input terminals; a plurality of interconnections connected to a capacitance detection circuitry for touch sensing in a sensing region of the display panel; and a selector. The selector is configured to selectively connect the source output terminals the source driver circuitry and the interconnections.
In another embodiment, a display device includes: a display panel including a plurality of source lines and a plurality of source input terminals; a source driver circuitry configured to supply to a plurality of source input terminals source signals to be supplied to the plurality of source lines; a capacitance detection circuitry for touch sensing in a sensing region of the display panel; and a selector. The selector is configured to selectively connect the source input terminals to the source driver circuitry and the capacitance detection circuitry.
In still another embodiment, a display panel includes: a plurality of source lines, a plurality of source input terminals configured to receive source signals to be supplied from a display driver to the plurality of source lines; a plurality of common electrodes; a first switch connected between each of the plurality of common electrodes and at least one associated source input terminal of a plurality of source input terminals, the associated source input terminal being associated with each of the plurality of common electrodes.
Various embodiments will be described below with reference to the attached drawings. In the following, same or similar components may be denoted by the same or corresponding reference numerals. It will be also appreciated that for simplicity and clarity of illustration, elements in the figures have not necessary drawn to scale. For example, the dimensions of some of the elements are exaggerated relative to other elements.
In the present embodiment, the display device 1 includes a display panel 2 and a display driver 3. Examples of the display panel 2 may include a liquid crystal display panel and an OLED (organic light emitting diode) display panel.
The display panel 2 comprises display circuitry 11 and gate driver circuitry 12. The display circuitry 11 includes a set of circuits used to display an image, for example, a plurality of source lines, a plurality of gate lines, a plurality of pixel circuits each disposed at an intersection of the corresponding source line and gate line. The pixel circuits may be variously configured. In a liquid crystal display panel, a pixel circuit includes, for example, a select transistor formed as a TFT (thin film transistor), a pixel electrode and a hold capacitor. In an OLED display panel, on the other hand, a pixel circuit includes, for example, a select transistor formed as a TFT (thin film transistor), a drive transistor, a hold capacitor and an organic light emitting diode element. The display panel 2 includes source input terminals 13. The source input terminals 13 are external input terminals used to receive source signals from the display driver 3. The source signals supplied to the source input terminals 13 are delivered to the respective pixel circuits via the source lines of the display circuitry 11 and an image is thereby displayed in the region in which the display circuitry 11 of the display panel 2 is formed.
The display panel 2 comprises a touch sensing electrode group 14 and a switch circuitry 15, for sensing an input object. As described later in detail, the static capacitance of the respective touch sensing electrodes included in the touch sensing electrode group 14 is detected and the position of the input object is sensed on the basis of the capacitance of the touch sensing electrodes. The switch circuitry 15 is responsive to a control signal received from the display driver 3 for electrically connecting and disconnecting the source input terminals 13 and the touch sensing electrode group 14. In detail, the switch circuitry 15 electrically disconnects the touch sensing electrode group 14 from the source input terminals 13 in a display drive operation to drive the respective pixel circuits in the display circuitry 11 and electrically connects the touch sensing electrode group 14 to the source input terminals 13 in a touch sensing operation to sense an input object. As described later in detail, this configuration, which provides an access to the touch sensing electrode group 14 via the source input terminals 13, effectively reduces the number of external input terminals disposed on the display panel 2.
The display driver 3 drives the display panel 2 in response to externally-received image data and control data (from a host, for example). The display driver 3 includes source output terminals 31 connected to the source input terminals 13 of the display panel 2 and is configured to output source signals to be supplied to the source lines of the display circuitry 11 of the display panel 2 from the source output terminals 31. Additionally, the display driver 3 is configured to output gate control signals controlling the gate driver circuitry 12 and switch control signals controlling the switch circuitry 15.
Furthermore, the display driver 3 is configured to detect the capacitance of the respective touch sensing electrodes included in the touch sensing electrode group 14 and sense an input object on the basis of the detected capacitance. In other words, the display driver 3 also operates as a touch controller which senses an input object. This type of display driver is often referred to as touch-controller-embedded display driver.
In detail, the display driver 3 includes a panel interface circuitry 32, a source driver circuitry 33, a touch sense circuitry 34, a selector 35 and a controller 37.
The panel interface circuitry 32 generates the gate control signals to be supplied to the gate driver circuitry 12.
The source driver circuitry 33 provides the source signals to the respective source lines of the display circuitry 11 of the display panel 2. The outputs of the source driver circuitry 33 are connected to the selector 35 via interconnections 33a.
The touch sense circuitry 34 includes circuitry performing a touch sensing operation to sense an input object. The touch sense circuitry 34 includes capacitance detection circuitry configured to detect the capacitance of conductors connected to the inputs thereof and the inputs of the touch sense circuitry 34 (that is, the inputs of the capacitance detection circuitry) are connected to the selector 35 via interconnections 34a. When the touch sensing electrode group 14 is connected to the inputs of the touch sense circuitry 34 via the switch circuitry 15 and the selector 35, the touch sense circuitry 34 detects the capacitance of the respective touch sensing electrodes of the touch sensing electrode group 14 with the capacitance detection circuitry, and generates the capacitance data indicative of the detected capacitance. The touch sense circuitry 34 senses an input object on the basis of the capacitance data (that is, the capacitance detected by the capacitance detection circuitry). Additionally, the touch sense circuitry 34 generates control signals controlling the operation in the touch sensing and supplies the control signals to the switch circuitry 15 of the display panel 2 and the selector 35 of the display driver 3.
The selector 35 is configured to selectively connect the source output terminals 31 to the outputs of the source driver circuitry 33 or the inputs of the touch sense circuitry 34 (that is, selectively connect the source output terminals 31 to the interconnections 33a or 34a) in response to the control signals received from the touch sense circuitry 34.
The display device 1 illustrated in
When a touch sensing operation is performed, on the other hand, the switch circuitry 15 electrically connects the touch sensing electrode group 14 to the source input terminals 13 in the display panel 2 and the selector 35 electrically connects the source output terminals 31 to the inputs of the touch sense circuitry 34 in the display driver 3. This allows connecting the touch sensing electrode group 14 to the inputs of the touch sense circuitry 34 via the switch circuitry 15 and the selector 35. The touch sense circuitry 34 detects the capacitance of the respective touch sensing electrodes included in the touch sensing electrode group 14, and performs touch sensing, which may include, for example, sensing of the position where an input object such as human fingers and styli is placed into contact with the display panel 2, on the basis of the capacitance detected by the touch sense circuitry 34.
The display device 1 of the present embodiment, in which the touch sensing electrode group 14 included in the display panel 2 is connectable to any of the touch sense circuitry 34 via the switch circuitry 15, the source input terminals 13 and the selector 35, eliminates the need for providing external connection terminals dedicated to connect the touch sensing electrode group 14 to the touch sense circuitry 34. This allows reducing the number of external connection terminals disposed on the display panel 2.
In the following, a description is given of further specific configuration examples of the display device 1. In the configuration examples described below, a liquid crystal display panel incorporating touch sensing electrodes is used as the display panel 2. A variety of configuration examples of the display device 1 will be described in the following.
Referring to
The TFT substrate 41 includes a glass substrate 44 and a semiconductor circuitry 45 integrated on the glass substrate 44. The semiconductor circuitry 45 incorporates the above-described display circuitry 11, gate driver circuitry 12 and switch circuitry 15 (not illustrated in
In the present embodiment, the counter substrate 42 includes a plurality of Y sensing electrodes 46. As illustrated in
The common electrodes 16 are used not only to drive the liquid crystal 43 by the respective pixel circuits, but also to sense the position of an input object. In other words, the common electrodes 16 are also used as the touch sensing electrodes of the touch sensing electrode group 14 in the configuration illustrated in
As described above, the display panel 2 incorporates the display circuitry 11, the gate driver circuitry 12 (not illustrated in
The display panel 2 further includes a switch circuitry 19, a VCOM input terminal (common voltage input terminal) 20, VCOM switch circuitry 21 and VCOM switch circuitry 22, a switch control terminal 23 and inverters 24 and 25.
The switch circuitry 19 has the function of electrically connecting each common electrode 16 to the source lines 17 associated therewith. The switch circuitry 19 is positioned away from the display driver 3 (at a position opposite to the display driver 3 across the common electrodes 16). As illustrated in
The VCOM input terminal 20 and the VCOM switch circuitry 21 and VCOM switch circuitry 22 have the function of supplying the common voltage VCOM received from the display driver 3 to the respective common electrodes 16. In detail, the VCOM input terminal 20 receives the common voltage VCOM from the display driver 3. The VCOM switch circuitry 21 and VCOM switch circuitry 22 electrically connect or disconnect the VCOM input terminal 20 to or from the respective common electrodes 16. The VCOM switch circuit 21 includes switches 27 connected between the VCOM input terminal 20 and the ends of the respective common electrodes 16 in the −Y direction and the VCOM switch circuit 22 includes switches 28 connected between the VCOM input terminal 20 and the ends of the respective common electrodes 16 in the +Y direction. The VCOM switch circuit 21 is positioned near the display driver 3 (between the display driver 3 and the common electrodes 16), while the VCOM switch circuit 22 is positioned away from the display driver 3 (at a position opposite to the display driver 3 across the common electrodes 16).
The switch control terminal 23 and the inverters 24 and 25 are used to control the switch circuitry 15 and the switch circuitry 19 and the VCOM switch circuitry 21 and VCOM switch circuitry 22. The switch control terminal 23 receives a switch control signal touch_sel from the display driver 3 and supplies the switch control signal touch_sel to the switch circuitry 15 and the switch circuitry 19. The inverters 24 and 25 generate inverted signals of the switch control signal touch_sel and supply the inverted signals to the switches 27 and 28 of the VCOM switch circuitry 21 and VCOM switch circuitry 22. The switches 18 and 26 of the switch circuitry 15 and the switch circuitry 19 and the switches 27 and 28 of the VCOM switch circuitry 21 and VCOM switch circuitry 22 are exclusively turned on in response to the switch control signal touch_sel. In detail, when the switch control signal touch_sel is asserted, the switches 18 and 26 of the switch circuits 15 and 19 are turned on and the switches 27 of the VCOM switch circuitry 21 and the switches 28 of the VCOM switch circuitry 22 are turned off. When the switch control signal touch_sel is negated, on the other hand, the switches 18 of the switch circuitry 15 and the switches 26 of the switch circuitry 19 are turned off and the switches of the VCOM switch circuitry 21 and the switches 28 of the VCOM switch circuitry 22 are turned on.
Referring back to
The capacitance detection circuitry 36 and the controller 37 are components corresponding to the touch sense circuitry 34 illustrated in
Additionally, the display driver 3 includes a transmitter driver 38 and a VCOM amplifier 39 in the configuration illustrated in
It should be noted that, in the configuration illustrated in
Next, a description is given of the operation of the display device 1 configured as illustrated in
When the drive operation is performed, the display driver 3 of the display device 1 operates as follows: The controller 37 of the display driver 3 negates the switch control signal touch_sel. In response to the negation of the switch control signal touch_sel, the switches 27 of the VCOM switch circuitry 21 and the switches 28 of the VCOM switch circuitry 22 are turned on and the switches 18 of the switch circuitry 15 and the switches 26 of the switch circuitry 19 are turned off. This allows connecting the respective common electrodes 16 to the VCOM amplifier 39. The VCOM amplifier 39 supplies the common voltage VCOM to the respective common electrodes 16. Meanwhile, the selector 35 connects the source output terminals 31 to the outputs of the source driver circuitry 33 under the control of the controller 37. This allows connecting the respective source lines 17 of the display panel 2 to the outputs of the source driver circuitry 33. The source driver circuitry 33 supplies the source signals to the respective source lines 17 of the display panel 2 from the source output terminals 31 via the selector 35. This operation allows driving the respective pixel circuits of the display circuitry 11.
When self-capacitance touch sensing is performed, the display driver 3 operates as follows: The controller 37 of the display driver 3 asserts the switch control signal touch_sel. In response to the assertion of the switch control signal touch_sel, the switches 18 of the switch circuitry 15 and the switches 26 of the switch circuitry 19 are turned on and the switches 27 of the VCOM switch circuitry 21 and the switches 28 of the VCOM switch circuitry 22 are turned off. This allows connecting the respective common electrodes 16 to the source input terminals 13 in the display panel 2. Meanwhile, the selector 35 connects the source output terminals 31 to the inputs of the capacitance detection circuitry 36 under the control of the controller 37. This allows connecting the respective common electrodes 16 of the display panel 2 to the inputs of the capacitance detection circuitry 36. The capacitance detection circuitry 36 detects the capacitance of the respective common electrodes 16 and the respective Y sensing electrodes 46 and generates capacitance data indicative of the detected capacitance. The controller 37 senses an input object on the basis of the capacitance data received from the capacitance detection circuitry 36. More specifically, the controller 37 calculates the position at which an object is placed into contact with the display panel 2 in the X axis direction, on the basis of the capacitance of the respective common electrodes 16 and calculates the position at which the object is placed into contact with the display panel in the Y axis direction, on the basis of the capacitance of the respective Y sensing electrodes 46.
When mutual capacitance touch sensing is performed, the display driver 3 operates as follows: The controller 37 of the display driver 3 asserts the switch control signal touch_sel. In response to the assertion of the switch control signal touch_sel, the switches 18 of the switch circuitry 15 and the switches 26 of the switch circuitry 19 are turned on and the switches 27 of the VCOM switch circuitry 21 and the switches 28 of the VCOM switch circuitry 22 are turned off. This allows connecting the respective common electrodes 16 to the source input terminals 13 in the display panel 2. Meanwhile, the selector 35 connects the source output terminals 31 to the outputs of the transmitter driver 38 under the control of the controller 37. The transmitter driver 38 supplies drive voltages to the respective common electrodes 16 from the source output terminals 31 via the selector 35, to thereby drive the common electrodes 16. The capacitance detection circuitry 36 detects the capacitance between the respective common electrodes 16 and the respective Y sensing electrode 46 to generate the capacitance data. The controller 37 calculates the position at which an object is placed into contact with the display panel 2, on the basis of the capacitance between the respective common electrodes 16 and the respective Y sensing electrode 46 indicated in the capacitance data received from the capacitance detection circuitry 36.
The configuration of the display device 1 illustrated in
It should be noted that the display device 1 illustrated in
Although
Illustrated in
The capacitance detection circuitry 62 is configured to detect the capacitance of conductors connected to the inputs thereof and generate capacitance data indicative of the detected capacitance. The capacitance detection circuitry 62 is used to detect the capacitance of the respective common electrodes 16, the capacitance of the respective Y sensing electrodes 46 and the capacitance between the respective common electrodes 16 and the respective Y sensing electrodes 46.
The transmitter driver 63 drives the common electrodes 16, which are used as transmitter electrodes when mutual capacitance touch sensing is performed.
The controller 64 supplies timing control signals controlling the operation timing in the touch sensing to the capacitance detection circuitry 62, the transmitter driver 63 and the controller 37 of the display driver 3. Additionally, the controller 64 calculates the position at which an object is placed into contact with the display panel 2, on the basis of the capacitance detected by the capacitance detection circuitry 62 (including the capacitance of the respective common electrodes 16, the capacitance of the respective Y sensing electrodes 46 and the capacitance between the respective common electrodes 16 and the respective Y sensing electrodes 46). Provided in the display driver 3 are interconnections 62a which connect the capacitance detection circuitry 62 to the selector 35 and interconnections 63a which connect the transmitter driver 63 to the selector 35. The selector 35 is responsive to a control signal received from the controller 37 for connecting the source output terminals 31 to any of the interconnections 62a connected to the capacitance detection circuitry 62, the interconnections 63a connected to the transmitter driver 63 and the interconnections 33a connected to the source driver circuitry 33.
The operation of the display device 1 illustrated in
The operation of the display device 1 illustrated in
In the display device 1 illustrated in
The controller 37 of the display driver 3 negates the switch control signal touch_sel. In response to the negation of the switch control signal touch_sel, the switches 27 of the VCOM switch circuitry 21 are turned on to thereby connect the respective common electrodes 16 to the VCOM amplifier 39. The VCOM amplifier 39 supplies the common voltage VCOM to the respective common electrodes 16. Meanwhile, the selector 35 connects the source output terminals 31 to the outputs of the source driver circuitry 33 under the control of the controller 37. This allows the respective source lines 17 of the display panel 2 to the outputs of the source driver circuitry 33. The source driver circuitry 33 supplies source signals to the respective source lines 17 from the source output terminals 31 via the selector 35. This allows driving the respective pixel circuits of the display circuitry 11.
When self-capacitance touch sensing is performed, the display driver 3 operates as follows: The controller 37 of the display driver 3 asserts the switch control signal touch_sel. In response to the assertion of the switch control signal touch_sel, the respective switches 27 of the VCOM switch circuitry 21 are turned off. Meanwhile, the selector 35 connects the source output terminals 31 to the inputs of the capacitance detection circuitry 36 under the control of the controller 37. This allows connecting the respective source lines 17 of the display panel 2 to the inputs of the capacitance detection circuitry 36. The capacitance detection circuitry 36 detects the capacitance of the respective source lines 17 and the respective Y sensing electrodes 46 and generates capacitance data indicative of the detected capacitance. The controller 37 senses an input object on the basis of the capacitance data received from the capacitance detection circuitry 36 (that is, on the basis of the capacitance of the respective source lines 17 and the respective Y sensing electrodes 46). More specifically, the controller 37 calculates the position at which an object is placed into contact with the display panel 2 in the X axis direction, on the basis of the capacitance of the respective source lines 17 and calculates the position at which the object is placed into contact with the display panel 2 in the Y axis direction, on the basis of the capacitance of the respective X sensing electrodes 46.
When mutual capacitance touch sensing is performed, the display driver 3 operates as follows: The controller 37 of the display driver 3 asserts the switch control signal touch_sel. In response to the assertion of the switch control signal touch_sel, the switches 27 of the VCOM switch circuitry 21 are turned off. Meanwhile, the selector 35 connects the source output terminals 31 to the outputs of the transmitter driver 38 under the control of the controller 37. The transmitter driver 38 supplies drive voltages to the source lines 17 of the display panel 2 from the source output terminals 31 via the selector 35. The capacitance detection circuitry 36 detects the capacitance between the respective common electrodes 16 and the respective Y sensing electrodes 46 and generates capacitance data indicative of the detected capacitance.
The controller 37 calculates the position at which an object is placed into contact with the display panel 2 on the basis of the capacitance data received from the capacitance detection circuitry 36 (that is, the capacitance between the respective source lines 17 and the respective Y sensing electrodes 46).
The configuration illustrated in
As illustrated in
In the configuration illustrated in
Next, a description is given of the operation of the display device 1 illustrated in
When the drive operation is performed, the display driver 3 operates as follows. The controller 37 of the display driver 3 negates the switch control signal touch_sel. In response to the negation of the switch control signal touch_sel, the switches 27 of the VCOM switch circuitry 21 are turned on and the switches 18 of the switch circuitry 15 are turned off. This allows connecting the respective common electrodes 16 to the VCOM amplifier 39. The VCOM amplifier 39 supplies the common voltage VCOM to the respective common electrodes 16. Meanwhile, the selector 35 connects the source output terminals 31 to the outputs of the source driver circuitry 33 under the control of the controller 37.
When the pixel circuits of the red-colored subpixels are driven, the controller 37 asserts the red select signal R_sel and negates the green select signal G_sel and the blue select signal B_sel. This results in that the switches 30r are turned on and the source lines 17r associated with the red-colored subpixels are connected to the source input terminals 13. The source driver circuitry 33 supplies source signals to the source input terminals 13 of the display panel 2 via the selector 35. As a result of this operation, the source signals are supplied to the pixel circuits connected to the source lines 17r (that is, the pixel circuits of the red-colored subpixels).
Similarly, when the pixel circuits of the green-colored subpixels are driven, the controller 37 asserts the green select signal G_sel and negates the blue select signal B_sel and the red select signal R_sel. This results in that the switches 30g are turned on and the source lines 17g associated with the red-colored subpixels are connected to the source input terminals 13. The source driver circuitry 33 supplies source signals to the source input terminals 13 of the display panel 2 via the selector 35. As a result of this operation, the source signals are supplied to the pixel circuits connected to the source lines 17g (that is, the pixel circuits of the green-colored subpixels).
Furthermore, when the pixel circuits of the blue-colored subpixels are driven, the controller 37 asserts the green select signal B_sel and negates the red select signal R_sel and the green select signal G_sel. This results in that the switches 30b are turned on and the source lines 17b associated with the red-colored subpixels are connected to the source input terminals 13. The source driver circuitry 33 supplies source signals to the source input terminals 13 of the display panel 2 via the selector 35. As a result of this operation, the source signals are supplied to the pixel circuits connected to the source lines 17b (that is, the pixel circuits of the blue-colored subpixels). The respective pixel circuits of the display circuitry 11 are driven through the above-described operation.
When self-capacitance touch sensing is, the display driver 3 operates as follows: The controller 37 of the display driver 3 asserts the switch control signal touch_sel. In response to the assertion of the switch control signal touch_sel, the switches 18 of the switch circuitry 15 are turned on and the switches 27 of the VCOM switch circuitry 21 are turned off. This allows connecting the respective common electrodes 16 to the source input terminals 13 in the display panel 2. Meanwhile, the selector 35 connects the source output terminals 31 to the inputs of the capacitance detection circuitry 36 under the control of the controller 37. This allows connecting the respective common electrodes 16 of the display panel 2 to the inputs of the capacitance detection circuitry 36. The capacitance detection circuitry 36 detects the capacitance of the respective common electrodes 16 and the respective Y sensing electrodes 46 and generates capacitance data indicative of the detected capacitance. The controller 37 senses an input object on the basis of the capacitance data received from the capacitance detection circuitry 36. More specifically, the controller 37 calculates the position at which an object is placed into contact with the display panel 2 in the X axis direction, on the basis of the capacitance of the respective common electrodes 16 and calculates the position at which the object is placed into contact with the display panel in the Y axis direction, on the basis of the capacitance of the respective Y sensing electrodes 46.
When mutual capacitance touch sensing is performed, the display driver 3 operates as follows: The controller 37 of the display driver 3 asserts the switch control signal touch_sel. In response to the assertion of the switch control signal touch_sel, the switches 18 of the switch circuitry 15 are turned on and the switches 27 of the VCOM switch circuitry 21 are turned off. This allows connecting the respective common electrodes 16 to the source input terminals 13 in the display panel 2. Meanwhile, the selector 35 connects the source output terminals 31 to the outputs of the transmitter driver 38 under the control of the controller 37. The transmitter driver 38 supplies drive voltages to the respective common electrodes 16 from the source output terminals 31 via the selector 35, to thereby drive the common electrodes 16. The capacitance detection circuitry 36 detects the capacitance between the respective common electrodes 16 and the respective Y sensing electrode 46 to generate the capacitance data. The controller 37 calculates the position at which an object is placed into contact with the display panel 2, on the basis of the capacitance data received from the capacitance detection circuitry 36 (that is, on the basis of the capacitance between the respective common electrodes 16 and the respective Y sensing electrode 46).
In the present embodiment, the common electrodes 51 arrayed in rows and columns are used as touch sensing electrodes. It should be noted that the configuration illustrated in
Accordingly, mutual capacitance touch sensing is not performed in the display device 1 illustrated in
Each switch 53 is connected between the associated contact 52 and one of the source lines 17 associated with each common electrode 51 (the source lines 17 intersecting with each common electrode 51). The switch 53 connected to each common electrode 51 has the function of electrically connecting each common electrode 51 to the associated source input terminal 13 (via the associated source line 17). The switches 53 are operated in response to the switch control signal touch_sel.
The switches 54 are connected between the VCOM line 55 and the contacts 52. In the configuration illustrated in
Although
Next, a description is given of the operation of the display device 1 configured as illustrated in
When the drive operation is performed, the display driver 3 of the display device 1 operates as follows: The controller 37 of the display driver 3 negates the switch control signal touch_sel. In response to the negation of the switch control signal touch_sel, the switches 54 associated with the respective common electrodes 51 are turned on and the switches 53 associated with the respective common electrodes 51 are turned off. This allows connecting the respective common electrodes 51 to the VCOM amplifier 39. The VCOM amplifier 39 supplies the common voltage VCOM to the respective common electrodes 51. Furthermore, the selector 35 connects the source output terminals 31 to the outputs of the source driver circuitry 33 under the control of the controller 37. The source driver circuitry 33 supplies the source signals to the respective source lines 17 of the display panel 2 from the source output terminals 31 via the selector 35. This operation allows driving the respective pixel circuits of the display circuitry 11.
When self-capacitance touch sensing is performed, the display driver 3 operates as follows: The controller 37 of the display driver 3 asserts the switch control signal touch_sel. In response to the assertion of the switch control signal touch_sel, the switches 53 associated with the respective common electrodes 51 are turned on and the switches 54 associated with the respective common electrodes 51 are turned off. This allows connecting the respective common electrodes 51 to the associated source input terminals 13 via the associated source lines 17 in the display panel 2. Meanwhile, the selector 35 connects the source output terminals 31 to the inputs of the capacitance detection circuitry 36 under the control of the controller 37. This allows connecting the respective common electrodes 51 of the display panel 2 to the inputs of the capacitance detection circuitry 36. The capacitance detection circuitry 36 detects the capacitance of the respective common electrodes 51 and generates capacitance data indicative of the detected capacitance. The controller 37 senses an input object on the basis of the capacitance data received from the capacitance detection circuitry 36 (that is, on the basis of the capacitance of the respective common electrodes 51). More specifically, the controller 37 calculates the position at which an object is placed into contact with the display panel 2, on the basis of the capacitance of the respective common electrodes 51.
As described above, the display device 1 may be configured to be adapted to mutual capacitance touch sensing, also in the configuration in which the common electrodes 51 are arrayed in rows and columns.
When mutual capacitance touch sensing is performed, the display driver 3 operates as follows: The controller 37 of the display driver 3 asserts the switch control signal touch_sel. In response to the assertion of the switch control signal touch_sel, the switches 53 associated with the respective common electrodes 51 are turned on and the switches 54 associated with the respective common electrodes 51 are turned off. This allows connecting the respective common electrodes 51 to the source input terminals 13 in the display panel 2. Meanwhile, the selector 35 connects the source output terminals 31 to the outputs of the transmitter driver 38 under the control of the controller 37. The transmitter driver 38 supplies drive voltages to the respective common electrodes 51 from the source output terminals 31 via the selector 35. The capacitance detection circuitry 36 detects the capacitance between the respective common electrodes 51 and the respective Y sensing electrode 46 to generate the capacitance data. The controller 37 calculates the position at which an object is placed into contact with the display panel 2, on the basis of the capacitance data received from the capacitance detection circuitry 36 (that is, on the basis of the capacitance between the respective common electrodes 51 and the respective Y sensing electrode 46).
Although all the common electrodes 51 are connected to the VCOM line 55 via the switches 54 in the configurations illustrated in
As illustrated in
A source line select circuitry 29 is provided in the display panel 2 to achieve time-divisional driving. The source line select circuitry 29 includes switches 30r connected between the source input terminals 13 and the source lines 17r associated with the red-colored subpixels, switches 30g connected between the source input terminals 13 and the source lines 17g associated with the green-colored subpixels, and switches 30b connected between the source input terminals 13 and the source lines 17b associated with the blue-colored subpixels. The switches 30r, 30g and 30b respectively receive a red select signal R_sel, a green select signal G_sel and a blue select signal B_sel, which are generated by the controller 37 of the display driver 3. The switches 30r are responsive to the red select signal R_sel, the switches 30g are responsive to the green select signal G_sel, and the switches 30b are responsive to the blue select signal B_sel.
Additionally, a connection line 58 associated with each source input terminal 13 is provided. The connection line 58 is provided along three source lines 17r, 17g and 17b associated with each source input terminal 13. A plurality of connection lines 58 are disposed for each column of the common electrodes 51 and the common electrodes 51 are connected to different connection lines 58. It should be noted that, although each common electrode 51 may be connected to a plurality of connection lines 58, the number of the common electrode 51 connected to each connection line 58 is one. Each connection line 58 is connected to the associated source input terminal 13 via the associated switch 18 of the switch circuitry 15.
Next, a description is given of the operation of the display device 1 configured as illustrated in
When the pixel circuits of the red-colored subpixels are driven, the controller 37 asserts the red select signal R_sel and negates the green select signal G_sel and the blue select signal B_sel. This results in that the source lines 17r associated with the red-colored subpixels are connected to the source input terminals 13. The source driver circuitry 33 supplies source signals to the source input terminals 13 of the display panel 2 via the selector 35. As a result of this operation, the source signals are supplied to the pixel circuits connected to the source lines 17r (that is, the pixel circuits of the red-colored subpixels).
Similarly, when the pixel circuits of the green-colored subpixels are driven, the controller 37 asserts the green select signal G_sel and negates the blue select signal B_sel and the red select signal R_sel. This results in that the source lines 17g associated with the red-colored subpixels are connected to the source input terminals 13. The source driver circuitry 33 supplies source signals to the source input terminals 13 of the display panel 2 via the selector 35. As a result of this operation, the source signals are supplied to the pixel circuits connected to the source lines 17g (that is, the pixel circuits of the green-colored subpixels).
Furthermore, when the pixel circuits of the blue-colored subpixels are driven, the controller 37 asserts the green select signal B_sel and negates the red select signal R_sel and the green select signal G_sel. This results in that the source lines 17b associated with the red-colored subpixels are connected to the source input terminals 13. The source driver circuitry 33 supplies source signals to the source input terminals 13 of the display panel 2 via the selector 35. As a result of this operation, the source signals are supplied to the pixel circuits connected to the source lines 17b (that is, the pixel circuits of the blue-colored subpixels). The respective pixel circuits of the display circuitry 11 are driven through the above-described operation.
When self-capacitance touch sensing is performed, the display driver 3 operates as follows: The controller 37 of the display driver 3 asserts the switch control signal touch_sel. In response to the assertion of the switch control signal touch_sel, the switches 18 of the switch circuitry 15 are turned on and the switches 27 of the VCOM switch circuitry 21 are turned off. This allows connecting the respective common electrodes 51 to the source input terminals 13 in the display panel 2. Meanwhile, the selector 35 connects the source output terminals 31 to the inputs of the capacitance detection circuitry 36 under the control of the controller 37. This allows connecting the respective common electrodes 51 of the display panel 2 to the inputs of the capacitance detection circuitry 36. The capacitance detection circuitry 36 detects the capacitance of the respective common electrodes 51 and generates capacitance data indicative of the detected capacitance. The controller 37 senses an input object on the basis of the capacitance data received from the capacitance detection circuitry 36. More specifically, the controller 37 calculates the position at which an object is placed into contact with the display panel 2, on the basis of the capacitance of the respective common electrodes 51.
When mutual capacitance touch sensing is performed, the display driver 3 operates as follows: The controller 37 of the display driver 3 asserts the switch control signal touch_sel. In response to the assertion of the switch control signal touch_sel, the switches 18 of the switch circuitry 15 are turned on and the switches 27 of the VCOM switch circuitry 21 are turned off. This allows connecting the respective common electrodes 51 to the source input terminals 13 in the display panel 2. Meanwhile, the selector 35 connects the source output terminals 31 to the outputs of the transmitter driver 38 under the control of the controller 37. The transmitter driver 38 supplies drive voltages to the respective common electrodes 16 from the source output terminals 31 via the selector 35, to thereby drive the common electrodes 51. The capacitance detection circuitry 36 detects the capacitance between the respective common electrodes 51 and the respective Y sensing electrode 46 to generate the capacitance data. The controller 37 calculates the position at which an object is placed into contact with the display panel 2, on the basis of the capacitance data received from the capacitance detection circuitry 36 (that is, on the basis of the capacitance between the respective common electrodes 51 and the respective Y sensing electrode 46).
The configuration illustrated in
Although various embodiments of the present disclosure have been specifically described, the present invention must not be construed as being limited to the above-described embodiments. It would be understood by persons skilled in the art that the present invention may be implemented with various modifications.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2016-202870 | Oct 2016 | JP | national |
