WO2021000292A1

WO2021000292A1 - Touch screen and control method for touch screen

Info

Publication number: WO2021000292A1
Application number: PCT/CN2019/094581
Authority: WO
Inventors: Noguchi Koji; Teranishi YASUYUKI; Kurasawa HAYATO; Ishizaki Koji
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2019-07-03
Filing date: 2019-07-03
Publication date: 2021-01-07
Also published as: CN114096941A; CN114096941B

Abstract

Provided is a touch screen capable of providing a small electronic device with a charging function while suppressing enlargement of the electronic device in size. The touch screen includes: a detection unit including a drive electrode Tx (2506) and a detection electrode Rx (2504) that detects a rechargeable detection target based on a change in capacitance by using a signal supplied from the drive electrode Tx (2506); and a charge coil disposed on a same layer where the detection unit is disposed. The charge coil is provided on a same plane where the detection electrode Rx (2504) is provided. A wiring of the detection electrode Rx (2504) operates as a charge coil at a time different from a time of detecting change in the capacitance.

Description

TOUCH SCREEN AND CONTROL METHOD FOR TOUCH SCREEN

Technical Field

The present invention relates to touch screen technology, and, more particularly, to a touch screen and a control method therefor.

Background Art

Accessory devices such as a wireless earphone, an active pen, a mouse, and a speaker system, which are used with electronic devices such as a mobile phone and a smartphone, are equipped with a battery to communicate wirelessly with electronic equipment, and are usable when this battery is charged.

In a case of charging any one of the above-mentioned accessory devices, a dedicated wireless charging system is used, and charging is usually performed by setting an accessory device fixed to the wireless charging system. During charging of the accessory device, therefore, the accessory device needs to remain stationary for a long time during which the accessory device cannot be used.

In addition, a technology has been proposed that provides an accessory device with a charging function instead of using such a separate charging system. According to this proposal, a charge coil is included inside a smartphone. Since the size of the conventional charge coil is large, however, inclusion of the coil in an accessory device enlarges the smartphone in size and increases manufacturing cost.

Furthermore, an accessory device having a charging function requires a battery, which also enlarges the accessory device in size.

Summary of Invention

It is an object of the present invention to provide a thin and cost-reduced module set including a touch screen and a coil.

Another object of the present invention is to provide a touch screen, which could be used for charging the accessory device, and the size of the accessory device could be reduced. Further, a charge system capable of charging an accessory device is also provided in the present invention.

According to a first aspect, there is provided a touch screen. And the touch screen includes a detection unit and a charge coil.

The detection unit is configured to detect existence of a rechargeable detection target based on a change in capacitance by using a signal supplied from a drive electrode. The detection unit includes the drive electrode and a detection electrode. The rechargeable detection target is corresponding to an accessory device.

The charge coil is for charging the detection target. Also, the charge coil is disposed on a same layer with the drive electrode or the detection electrode.

According to the first aspect, the charging coil and detection unit are provided on the same layer. It eliminates the need for a battery because an accessory device such as an active pen can be charged during its operation. Therefore, a small electronic device can be provided with a charging function while suppressing enlargement of the electronic device in size. Also, since the space for the charge coil is reduced, the cost for the touch screen can be reduced.

According to a possible implementation of the first aspect, the charge coil is provided on a same plane where the detection electrode is provided.

According to this implementation, both the charge coil and the detection electrode are provided on the same plane. This implementation can reduce a size of the touch screen by providing the charge coil on the same plane where the detection electrode is provided.

According to a possible implementation of the first aspect, a wiring of the detection electrode operates as a charge coil at a time different from a time of detecting change in the capacitance.

According to this implementation, it is possible to share the wiring of the detection electrode and coil. Therefore, additional wiring is not needed for a coil because wiring is comprised of only wiring of the detection electrode.

According to a possible implementation of the first aspect, the charge coil is provided on a same plane where the drive electrode is provided.

According to this implementation, both the charge coil and the drive electrode are provided on the same plane. This implementation can provide an electronic device with a charging function while suppressing enlargement of the electronic device in size as well as can reduce the cost for the touch screen.

According to a possible implementation of the first aspect, the charge coil includes an array of a plurality of coils.

According to this implementation, the array of the plurality of coils can be arranged from one end the other end of the touch screen. This implementation allows a charging operation to be performed on the entire touch surface of the touch screen.

According to a possible implementation of the first aspect, the plurality of coils are connected in series.

According to this implementation, the plurality of coils are connected in series. Such a configuration can drive multiple charge coils at a time.

According to a possible implementation of the first aspect, the plurality of coils are connected in parallel, and only those coils which correspond to coordinates of the accessory device to be charged comes close are driven.

According to this implementation, the plurality of coils are connected in parallel. The parallel connection can efficiently increase charging power in comparison to connection in series.

According to a possible implementation of the first aspect, the plurality of coils are connected in parallel, and are driven simultaneously.

According to this implementation, the plurality of coils connected in parallel are driven simultaneously. Therefore, charging operation can be realized even when a detection target is moving rapidly.

According to a possible implementation of the first aspect, the drive electrode or the detection electrode and the plurality of coils are alternately arranged.

According to this implementation, both the drive electrode or detection electrode and the plurality of coils are alternately arranged. Since they can be placed in front of the display, output from the display can be uniform. This implementation also allows charging to be carried out at any location on the surface of the touch screen.

According to a possible implementation of the first aspect, the drive electrode or the detection electrode is a metal formed in a mesh.

According to this implementation, the drive electrode or the detection electrode is a metal formed in a mesh. Therefore, approaching of a detection target can be detected over a wide range covered by the mesh, thus ensuring efficient touch detection.

According to a possible implementation of the first aspect, the drive electrode or the detection electrode formed in a mesh and a metal which is formed in a mesh and is not connected to a power supply are alternately arranged.

According to this implementation, the drive electrode or the detection electrode formed in a mesh and a mesh not connected to a power supply are alternately arranged. Since they can be placed in front of the display, it is possible to uniformly cover the surface of the display with the mesh.

According to a second aspect, there is provided an electronic device. The electronic device includes a control circuit and a touch screen according to the first aspect or any one of the implementations of the first aspect. The control circuit is configured to control the touch screen to detect existence of a rechargeable detection target and charge the rechargeable detection target.

According to the second aspect, the control circuit is configured to control the touch screen to detect existence of a rechargeable detection target and charge the rechargeable detection target. The charging coil and detection unit of the touch screen are provided on the same layer. It eliminates the need for a battery because an accessory device such as an active pen can be charged during its operation. Therefore, a small electronic device can be provided with a charging function while suppressing enlargement of the electronic device in size. Also, since the space for the charge coil is reduced, the cost for the electronic device can be reduced.

According to a third aspect, there is provided a control method for a touch screen including a detection unit configured to detect existence of a rechargeable detection target based on a change in capacitance by using a signal supplied from a drive electrode, the detection unit including the drive electrode and a detection electrode, the rechargeable detection target corresponding to an accessory device, and a charge coil for charging the detection target, the charge coil being disposed on a same layer with the drive electrode or the detection electrode. The method includes:

causing the detection electrode to detect a change in capacitance; and

driving the charge coil.

According to the third aspect, the charging coil and detection unit are provided on the same layer. Therefore, a charging operation can be performed using a small electronic device. Also, since the space for the charge coil is reduced, the cost for the touch screen can be reduced.

According to a possible implementation of the third aspect, the charge coil is provided on a same plane where the detection electrode is provided.

According to this implementation, both the charge coil and the detection electrode are provided on the same plane. Therefore, a charging operation can be performed using an electronic device with a small size of the touch screen.

According to a possible implementation of the third aspect, the method further includes:

causing a wiring of the detection electrode to operate as a coil at a time different from a time of detecting change in the capacitance.

According to a possible implementation of the third aspect, the charge coil is provided on a same plane where the drive electrode is provided.

According to this implementation, both the charge coil and the drive electrode are provided on the same plane. This implementation can provide a charging function using a small sized electronic device in a small size as well as can reduce the cost for the touch screen.

According to a possible implementation of the third aspect, the charge coil includes an array of a plurality of coils.

According to this implementation, the array of the plurality of coils can be arranged from one end the other end of the touch screen. This implementation also allows a charging operation to be performed on the entire touch surface of the touch screen.

According to a possible implementation of the third aspect, the plurality of coils are connected in series.

According to a possible implementation of the third aspect, the plurality of coils are connected in parallel, and the driving the charge coil includes driving only those coils which correspond to a position to which a device to be charged comes close.

According to a possible implementation of the third aspect, the plurality of coils are connected in parallel, and the driving the charge coil includes driving the plurality of coils simultaneously.

According to a possible implementation of the third aspect, the drive electrode or the detection electrode and the plurality of coils are alternately arranged.

According to this implementation, both the drive electrode or detection electrode and the plurality of coils are alternately arranged. Since they can be placed in front of the display, output from the display can be uniform. This implementation allows charging to be carried out at any location on the surface of the touch screen.

According to a possible implementation of the third aspect, the drive electrode or the detection electrode is a metal formed in a mesh.

According to a possible implementation of the third aspect, the drive electrode or the detection electrode formed in a mesh and a metal which is formed in a mesh and is not connected to a power supply are alternately arranged.

According to this implementation, the drive electrode or the detection electrode formed in a mesh and a mesh not connected to a power supply are alternately arranged. Since they can be placed in front of the display, it is possible to realize a charging operation using an electronic device which uniformly cover the surface of the display with the mesh.

According to a fourth aspect, there is provided a method for an electronic device. The electronic device includes a control circuit and a touch screen according to the first aspect or any one of the implementations of the first aspect. The method includes:

controlling the touch screen to detect existence of a rechargeable detection target; and

charging the rechargeable detection target.

According to the fourth aspect, the control circuit is configured to control the touch screen to detect existence of a rechargeable detection target and charge the rechargeable detection target. The charging coil and detection unit of the touch screen are provided on the same layer. It eliminates the need for a battery because an accessory device such as an active pen can be charged during its operation. Therefore, a charging function is realized using a small electronic device can be provided with a charging function while suppressing enlargement of the electronic device in size. Also, since the space for the charge coil is reduced, the cost for the electronic device can be reduced.

Brief Description of Drawings

[Fig. 1] Fig. 1 is a diagram showing the configuration of a touch screen.

[Fig. 2] Fig. 2 is a perspective view of the configuration of the touch detection unit.

[Fig. 3] Fig. 3 is a diagram showing an equivalent circuit of a capacitive touch sensor.

[Fig. 4] Fig. 4 is a diagram showing an equivalent circuit of a capacitive touch sensor.

[Fig. 5] Fig. 5 is a diagram showing a change in voltage of the touch sensor when a finger approaches the touch sensor.

[Fig. 6] Fig. 6 is a diagram showing the configuration of a touch screen equipped with a charging function.

[Fig. 7] Fig. 7 is a diagram showing an example of a power transmitting coil unit.

[Fig. 8] Fig. 8 is a diagram showing a configuration example of a touch screen according to an embodiment.

[Fig. 9] Fig. 9 is a diagram showing an example of a pattern of an electrode in a touch detection unit.

[Fig. 10] Fig. 10 is a diagram showing an example of the touch detection unit.

[Fig. 11] Fig. 11 is an enlarged view of boundary portions in a combination of electrodes and dummy patterns.

[Fig. 12] Fig. 12 is a diagram showing another example of a combination of electrodes and dummy patterns.

[Fig. 13] Fig. 13A is a diagram showing a component of a touch detection unit according to an embodiment, Fig. 13B is a cross-sectional view of a part of the component, and Fig. 13C is a diagram showing a set of components.

[Fig. 14] Fig. 14A is a diagram showing a component of a touch detection unit according to an embodiment, and Fig. 14B is a diagram showing a set of components.

[Fig. 15] Fig. 15 is a timing chart related to an operation performed by the touch detection unit shown in Fig. 14.

[Fig. 16] Fig. 16A is a diagram showing a component of a touch detection unit according to an embodiment, and Fig. 16B is a diagram showing a set of components.

[Fig. 17] Fig. 17 is a diagram showing an example of a charge coil to be implemented in the touch detection unit.

[Fig. 18] Fig. 18 is a diagram showing an example of a charge coil to be implemented in the touch detection unit.

[Fig. 19] Fig. 19 is a diagram showing an example of a combination of a charge coil shown in Fig. 18 and a Tx line.

[Fig. 20] Fig. 20 is a diagram showing an example of the touch detection unit.

[Fig. 21] Fig. 21 is a diagram for describing an operation of detecting an active pen by a charging system.

[Fig. 22] Fig. 22 is a diagram showing a functional configuration of the active pen.

[Fig. 23] Fig. 23 is a diagram showing a configuration example of an active pen and a touch panel.

[Fig. 24] Fig. 24 is a flowchart illustrating procedures of a method performed in the touch panel.

[Fig. 25] Figs. 25A to 25C are diagrams showing examples of the arrangement of drive electrodes Tx and touch detection electrodes Rx.

[Fig. 26] Fig. 26 is a diagram showing a combination of a touch detection unit and a charge coil.

[Fig. 27] Fig. 27 is a diagram for describing an operation of charging an active pen.

[Fig. 28] Fig. 28 is a diagram for describing an operation of charging an active pen.

[Fig. 29] Fig. 29 is a diagram for describing an operation of detecting an active pen.

[Fig. 30] Fig. 30 is a diagram for describing an operation of detecting an active pen.

Description of Embodiments

(First Embodiment)

The following will describe the configuration of a touch screen according to an embodiment of the present disclosure is implemented, with reference to Fig. 1. This touch screen may be implemented in an electronic device such as a mobile phone and a smartphone. The electronic device includes the touch screen and a control circuit. The control circuit is configured to control the touch screen to detect existence of a rechargeable detection target. The rechargeable detection target corresponds to an accessory device. The control circuit may be configured by a processor which may include, but not limited to, a central processing unit (CPU) and a graphics processing unit (GPU) . The accessory device may include, but not limited to, a wireless earphone, an active pen, a mouse, and a speaker system.

A touch screen 200 includes a gate driver 202, a source driver 210, a drive processor 226, a drive electrode driver 214, a touch-detection function equipped display unit 204, and a touch IC 216. The gate driver 202, the source driver 210, the drive electrode driver 214, the touch-detection function equipped display unit 204, and the touch IC 216 are configured to operate in synchronization with one another in response to an external timing control signal.

The touch-detection function equipped display unit 204 is a touch screen incorporating a touch detection function, and includes a display part 206 constituted by liquid crystal or the like, and a touch detection unit 212. The display part 206 is configured to sequentially scan and display horizontal lines in accordance with scan signals supplied from the gate driver 202, as will be described later. The touch detection unit 212 is configured to detect approaching of a detection target based on a drive signal V _drv from the drive electrode driver 214 and output a touch detection signal V _det.

The gate driver 202 is configured to apply scan signals to gates of thin film transistors (TFTs) each constituting a pixel to sequentially select a horizontal line of pixels from among pixels arrayed in a matrix form on the display part 206 of the touch-detection function equipped display unit 204. The source driver 210 is configured to supply pixel signals to the individual pixels included in the horizontal line selected by the gate driver 202 to display the horizontal line.

The drive electrode driver 214 is configured to supply drive signals V _drv to the touch detection unit 212 based on a control signal supplied from the drive processor 226. The touch detection unit 212 outputs touch detection signals V _det and supplies the touch detection signals V _det to the touch IC 216.

The touch IC 216 includes an analog low pass filter (LPF) 218, an A/D converter 220, a signal processor 222, and a coordination extractor 224. The analog LPF 218 is an analog filter that removes high frequency noise components from the touch detection signal V _det supplied from the touch detection unit 212. The A/D converter 220 is configured to sample each analog signal output from the analog LPF 218 and convert the analog signal into a digital signal, in synchronization with the touch detection drive signal. The signal processor 222 is configured to detect approaching of a detection target to the touch detection unit 212 based on the output from the A/D converter 220. The coordination extractor 224 is configured to acquire coordinates of a detection position on the touch panel when the signal processor 222 detects approaching of the detection target. A detection timing is controlled in such a way that these circuits operate in synchronization with one another.

The touch screen 200 may be implemented on various electronic devices equipped with a touch panel, such as a mobile phone, a smart phone, and a personal digital assistant (PDA) .

Fig. 2 is a perspective view of the configuration of the touch detection unit 212. The touch detection unit 212 includes drive electrodes (hereinafter, it may be referred to as Tx) 240 provided on a substrate 236 and touch detection electrodes (hereinafter, it may be referred to as Rx) 234 provided on a substrate 230 facing the substrate 236 at a distance. The drive electrodes (Tx) 240 constitute an electrode pattern 238 extending in the horizontal direction of the figure. At the time of performing a touch detection operation, the touch detection drive signals V _drt are sequentially supplied to the individual electrode patterns by the drive electrode driver 214, so that scan driving is sequentially performed on the time-sequential basis. The touch detection electrodes (Rx) 234 constitute an electrode pattern 235 extending in a direction crossing the extending direction of the electrode pattern of the drive electrodes (Tx) 240. The individual touch detection electrodes (Rx) 234 are connected to the analog LPF 218 of the touch IC 216.

In the touch detection operation, as the drive electrode driver 214 drives the drive electrodes (Tx) 240 so as to sequentially scan the drive electrodes (Tx) 240 in a time-divisional manner, the touch detection unit 212 sequentially select horizontal lines. Also in the touch detection operation, the touch detection signals V _det is output from the touch detection electrodes (Rx) 234. As shown in Fig. 2, the electrode patterns intersecting with each other constitute a capacitive touch sensor on a matrix. Therefore, scanning the entire electrode patterns 238 on the substrate 236 ensures detection of the position where an active pen 232 to be detected is in contact with or comes close to the touch detection unit 212.

Next, the basic principle of touch detection in the touch detection unit 212 will be described with reference to Figs. 2 to 5. In the present embodiment, the touch detection unit 212 is implemented as a capacitive touch sensor. In Fig. 2, the drive electrode (Tx) 240 and the touch detection electrode (Rx) 234 facing each other constitute a capacitor. This structure is represented as an equivalent circuit shown in Fig. 3. In Fig. 3, a capacitor C1 has one end connected to an AC drive signal source via the drive electrode (Tx) 240, and an other end connected to the touch IC 216 via the touch detection electrode (Rx) 234. When an AC signal having a predetermined frequency is applied to the drive electrode (Tx) 240 from the AC signal source, an electric force line Ef shown by a broken line in Fig. 3 appears.

For example, when the detection target such as a finger is not in contact with, or does not come close to, the touch detection unit 212 as shown in Fig. 3, a current according to the capacitance of the capacitor C1 flows as the capacitor C1 is charged or discharged. The waveform of the potential of the touch detection electrodes (Rx) 234 stored in the capacitor C1 at this time becomes, for example, a waveform V0 in Fig. 5.

When a finger is in contact with, or comes close to, the touch detection unit 212, as shown in Fig. 4, a capacitor C2 formed by the finger is added in series to the capacitor C1. In this state, different voltages are applied to the capacitors C1 and C2 according to the charging or discharging of the capacitors C1 and C2, respectively. At this time, the electric force line Ef changes as shown by a broken line in Fig. 4, so that the waveform of the potential of the touch detection electrode (Rx) 234 becomes a waveform V1 in Fig. 5. At this time, the potential of the touch detection electrode (Rx) 234 is a divided potential which is determined by the currents flowing through the capacitors C1 and C2. Therefore, the value of the waveform V1 becomes smaller than the value of the waveform V0 in the non-contact state. The signal processor 222 compares the detected voltage with a predetermined threshold voltage V _th, and determines that it is a non-contact state when the detected voltage is higher than this threshold voltage. Thus, touch detection can be performed by detecting a change in capacitance in this manner.

Fig. 6 shows a configuration example of a touch screen equipped with a function of charging an approaching accessory device. In the case of Fig. 6 (a) , a touch screen 600 includes a layered structure including a touch panel 602, a display 604, and a charge coil 606 from the top to the bottom of the figure. The touch panel 602 and the display 604 respectively correspond to the touch detection unit 212 and the display part 206 in Fig. 1. In addition, the charge coil 606 is disposed on the top side or the bottom side of the display 604 which is opposite to that side of the display 604 on which the touch panel 602 is disposed. Such a configuration allows the charge coil 606 to be used to charge a rechargeable accessory device such as a wireless earphone, an active pen, a mouse, or a speaker system.

The order of elements in the touch screen is not limited to the above example. As shown in Fig. 6 (b) , the touch screen 600 may include the touch panel 602, the charge coil 606 and the display 604 from the top to the bottom of the figure.

Fig. 7 shows an example of a coil unit for charging applied to the charge coil 606. A coil unit 700 includes three coils, and has a thickness exceeding about 4 mm. Therefore, implementing the coil unit on the touch screen of Fig. 6 significantly influences the size of the device. In addition, many components such as a TFT array, a color filter (CF) array, a polarizer, and a backlight lie under the display 604, which makes implementation of the coil unit difficult.

In the present embodiment, enlargement of the touch screen in size is suppressed by providing the charge coil for charging an approaching accessory device in the same layer as the touch detection unit.

Fig. 8 shows a configuration example of a touch screen on which the touch screen according to the present embodiment is implemented. In the case of a touch screen 800 in Fig. 8 (a) , the touch screen 800 may include a combination of the touch panel and charge coil 802, and the display 804 from the top to the bottom of the figure, a combination 802 of a touch panel and a charge coil is provided in a layer overlying a display 804. The touch panel and charge coil combination 802 corresponds to the touch panel 602 and the charge coil 606 in Fig. 7.

The order of elements in the touch screen is not limited to the above example. As shown in Fig. 8 (b) , the touch screen 800 may include the display 804, and a combination of the touch panel and charge coil 802 from the top to the bottom of the figure.

Fig. 9 shows an example of the drive electrodes or touch detection electrodes used for a touch detection unit 900, and a pattern of charge coils. For the wiring electrodes provided on the display, a transparent electrode of indium tin oxide (ITO) is usually used. However, the resistance value of ITO is about 50 Ω/sq. This value is high compared to those of metals, causing a relatively small current to flow, so that ITO is not suitable for wireless charging. In this respect, a metal such as Ag, Ag nanowire, Cu, or Al is used for the electrodes provided on the display. The resistance values of those metals are on the order of 0.01 Ω/sq, which can definitely reduce the power consumption of the coil. Since these metals are not transparent, the electrode pattern used for the touch detection unit is formed in a mesh as shown in Fig. 9. The mesh structure has diamond-shaped openings so that an image output from the display part can be viewed through the openings.

Fig. 10 shows an example of the touch detection unit according to the present embodiment. In the touch detection unit 900, touch detection electrodes (Rx) 902 and dummy patterns 904, both of which are formed in a mesh, are alternately arranged in the horizontal direction x in the figure. A plurality of touch detection electrodes (Rx) 902 are connected to the touch IC, and are spaced apart so that horizontal coordinates can be specified when a detection target approaches. Since the touch detection electrodes (Rx) 902 are placed in front of the display, a user will view an image on the display via the touch detection electrodes (Rx) 902. Since the touch detection electrodes (Rx) 902 are formed by a metal having a low resistance value in the form of an opaque mesh, however, the touch detection electrodes (Rx) 902 affect an image to be viewed even if the wiring is thin. Therefore, an image at a portion where the touch detection electrode (Rx) 902 is present is observed differently from an image of a portion where the touch detection electrode (Rx) 902 is not present. Therefore, the touch detection unit is des igned such that dummy patterns 904 not connected to the power supply or the touch IC are disposed at intervals between the touch detection electrodes (Rx) 902. Therefore, the entire image is displayed through regular meshes.

In one embodiment, a combination of mesh electrodes and dummy patterns may be configured on the Tx side.

Further, in implementation, as shown by broken lines in Fig. 10, a plurality of rectangular dummy patterns 904 may be prepared and arranged in accordance with the length of the touch detection electrodes (Rx) 902.

Fig. 11 is an enlarged view of boundary portions in the combination of the mesh electrodes and the dummy patterns. Gaps are formed in the wirings as shown by broken lines in the figure in such a way that the dummy pattern shown in the upper part of the figure is not connected to lines on the Rx side (hereinafter referred to as Rx lines) or lines on the Tx side (hereinafter referred to as Tx lines) , which constitute the touch detection unit.

Fig. 12 shows another example of the combination of mesh electrodes and dummy patterns. For a pattern A used for the drive electrodes Tx or the touch detection electrodes Rx, the entire wirings are connected. On the other hand, a pattern B has zigzag lines combined to form a pseudo mesh wiring structure comprised of a set of rhombuses. In both of the patterns A and B, a thickness L1 of the wirings in use can be 2 to 5 μm. In the patterns A and B, a distance L3 between the centers of the rhombuses is 200 to 50 μm.

As described above, according to the present embodiment, the touch screen includes a detection unit including a drive electrodes and detection electrodes that detect a chargeable detection target based on a change in capacitance by using a signal supplied from the drive electrodes, and further has a charge coil for charging the detection target provided in the same layer as the detection unit. This configuration makes it possible to provide an electronic device with a charging function while suppressing an increase in size.

Moreover, the use of mesh electrodes can reduce the cost.

(Second Embodiment)

Fig. 13 shows an example of a combination of a touch detection unit and a charge coil according to another embodiment of the present disclosure. As shown in Fig. 13A, one component 1300 of the touch detection unit has a touch detection electrode (Rx) 1304, connected to the touch IC, provided on the same side where a charge coil 1302 for wireless charging connected to an AC power supply S is formed. Fig. 13B is a cross-sectional view of a region including an insulator 1306 disposed at the intersection of the charge coil 1302 for wireless charging and the touch detection electrode (Rx) 1304. Fig. 13C shows a set of the components shown in Fig. 13A.

The touch detection electrode (Rx) 1304 is formed as an elongated coil, and is disposed so that the lengthwise direction thereof is in parallel to the lengthwise direction of the charge coil 1302 for wireless charging. Forming the touch detection electrode (Rx) 1304 as a coil in this manner allows the touch detection electrode (Rx) 1304 to be operated as a charge coil at a time the touch detection electrode (Rx) 1304 is not used for a touch detection operation. In this case, the touch detection electrode (Rx) 1304 may have a switch so that the touch detection electrode (Rx) 1304 is connected to the touch IC when used for a touch detection operation, and is connected to the AC power supply S when used for charging, and this switch may be controlled from an external control unit.

According to the present embodiment, the sensitivity of touch detection can be efficiently enhanced by operating the wiring of the touch detection electrode as a coil at a time different from the time of detection of a change in capacitance.

(Third Embodiment)

Fig. 14 shows an example of a combination of a touch detection unit on the touch detection electrode (Rx) side and a charge coil according to a different embodiment of the present disclosure. One component 1400 of the touch detection unit shown in Fig. 14A has a touch detection electrode (Rx) 1402 on the left side in the figure, and a charge coil 1404, connected to the AC power supply S, on the right side in the figure.

Fig. 14B shows an example in which the combinations each shown in Fig. 14A is arranged in a horizontal direction. As shown in the figure, the component 1400 includes a surface on which the touch detection electrodes (Rx) 1402 connected to the touch IC and the charge coils 1404 are alternately arranged in the horizontal direction. The Rx lines and coil wires are identical in shape and size. The touch detection electrodes (Rx) 1402 are connected to switches 1406 so that opening/closing of each touch detection electrode (Rx) 1402 can be controlled by the corresponding switch 1406.

Fig. 15 shows a timing diagram related to an operation performed by the touch detection unit shown in Fig. 14. The touch detection unit turns on the switches 1406 of the Rx lines in the first half of one frame, and performs a touch detection operation upon reception of an AC signal from the AC power supply. In Fig 15, a drive signal from a drive electrode driver is received by the component 1400. A coil can be driven by sequential scan by applying one or more pulses to the touch detection electrodes (Tx) . Also, it can be driven by completely dividing capacitive touch detection and driving the coil as shown in Fig. 15. Further, driving of the coil can be inserted in the middle of scanning the entire surface of the touch panel. On the other hand, in the second half of one frame in Fig. 15, the switches 1406 are turned off, causing an AC signal from the AC power supply to be supplied to the charge coils 1404, so that a charging operation for an approaching accessory device is performed.

In the present embodiment, additional wiring is not needed for a coil because wiring is comprised of only Rx lines. Also, the sensitivity of a capacitive touch panel is extremely high, and it is possible to share the Rx wiring and coil.

The wiring configuration shown in Fig. 14 may also be applied to both the Rx and Tx lines.

(Fourth Embodiment)

Fig. 16 shows an example of a combination of a Tx line in a touch drive electrode (Tx) and a charge coil according to a further embodiment of the present disclosure. In one component shown in Fig. 16A, a touch drive electrode (Tx) 1602 of the touch detection unit is formed in a mesh. Further, this mesh surface is formed on the same plane as is formed by a charge coil 1604 connected to the AC power supply S. In implementation, a width L4 of the mesh rectangle of the Tx line is approximately 3 to 7 mm.

Fig. 16B shows a configuration in which a plurality of components each shown in Fig. 16A are arranged. According to the present embodiment, it is possible to add a charge coil around the line of the touch detection unit.

(Fifth Embodiment)

Fig. 17 shows an example of a combination of a touch detection unit and a charge coil according to still another embodiment of the present disclosure. Two

charge coils

1702 and 1704 are connected in series to the AC power supply S, and one line constitutes one circuit so that those charge coils are driven simultaneously. A third charge coil 1706 in which the current flows in the opposite direction to the current flowing direction of the charge coils 1702 and 1704 is formed between the charge coils 1702 and 1704. The charge coils 1702 and 1704 are spaced apart like the widths of those charge coils, so that the three

charge coils

1702, 1704 and 1706 are formed in the same size. Such a configuration can drive multiple charge coils at a time.

In addition, although the charge coil shown in Fig. 17 is an example in which three charge coils are formed, four or more charge coils may be formed.

The wiring configuration shown in Fig. 17 may also be applied to both the Rx and Tx lines.

(Sixth Embodiment)

The wiring configuration of the series connection shown in Fig. 17 has long wiring length suited for charging an accessory device whose power consumption is small. Next, still another embodiment of the present disclosure, which is effective when more charging power is required, will be described referring to Fig. 18.

Fig. 18 shows an example of a combination of a touch detection unit and a charge coil according to a further embodiment of the present disclosure. Two

charge coils

1802 and 1804 are connected in parallel to the AC power supply S, and one line constitutes one circuit. The charge coils 1802 and 1804 are spaced apart like the widths of these coils. This configuration allows the Tx lines to be disposed at equal intervals when the Tx lines are disposed at the centers of the coils as shown in Fig. 13, for example. In addition, it is possible to form the mesh Tx line on the same plane as is formed by the charge coil.

According to this embodiment, a plurality of coils are connected in parallel so that each coil can be selectively driven. Therefore, only a coil which corresponds to coordinates of the accessory device to be charged comes close can be driven.

Further, a larger current may be made to flow by simultaneously driving a plurality of coils. Therefore, power can be increased as compared with the case where the coils are connected in series.

In addition, although two charge coils are formed in the example shown in Fig. 18, three or more charge coils may be formed.

The wiring configuration shown in Fig. 18 can also be applied to the Rx line.

Fig. 19 shows an example of the combination of the charge coil and the Tx line shown in Fig. 18. In a touch detection unit 900, the charge coil includes a circuit 1902 which is driven by the AC power supply S and a circuit 1904 which is also driven by the AC power supply S. Tx lines 1 to 7 are formed in a mesh, and are formed on the same plane as is formed by the charge coil. The Tx lines 1, 3, 5 and 7 are formed inside the charge coil, while the Tx lines 2, 4 and 6 are formed outside the charge coil.

The arrangement of the Tx lines in this manner makes it possible to uniformly arrange the Tx lines formed in a mesh.

(Seventh Embodiment)

Next, an example of a combination of a touch detection unit and a charge coil according to yet another embodiment of the present disclosure will be described with reference to Fig. 20. In a touch detection unit 2000, coil lines 2004 are connected to a line 2006 connected to one electrode of the AC power supply S via switches SW1 to SW16. A line 2008 connected to the other electrode of the AC power supply S is connected to the coil lines 2004 via switches SW17 to SW32. The plurality of vertically extending coil lines 2004 are all connected to a horizontal line 2003 shown at the top in the figure. The plurality of coil lines 2004 are equally spaced apart from one another, with an Rx line 2002 extending in parallel with the coil lines 2004 provided between two coil lines. The Rx lines are connected to the touch IC in the lower part of the figure.

The opening/closing of the switches SW1 to SW32 is controlled by a control unit (not shown) . Thus, a desired number of coil lines 2004 and at desired locations can be opened or closed to form a charge coil. In the example shown in Fig. 20, among the switches connected to the line 2006, the switches SW1, SW2, SW9 and SW10 are turned on. Further, among the switches connected to the line 2008, the switches SW23, SW24, SW31 and SW32 are turned on.

According to such a configuration, the resistance value can be reduced to allow a larger current to flow by turning on more switches and increasing the number of coil lines connecting the line 2008 and the line 2006. Therefore, the power for charging can be increased.

Also, controlling the locations of the switches to be turned on makes it possible to enlarge or reduce the cross-sectional area of a coil to be formed.

Fig. 21 is a diagram for describing an operation of detecting an active pen by the touch detection unit according to the present embodiment. In the figure, the switches SW3 to SW6 and the switches SW25 to SW28 are turned on. Therefore, a 4-turn charge coil including the lines from the switches SW6 to SW25, the lines from the switches SW5 to SW26, the lines from the switches SW4 to SW27, and the lines from the switches SW3 to SW28 is formed. Approaching of an active pen 2102 is detected by the Rx line 2002 located between the switches SW7 and SW8. The active pen 2102 can be charged based on a magnetic field from the charge coil.

The charge coil according to this embodiment may be provided on the Tx side instead of the Rx side.

Fig. 22 is a diagram showing a functional configuration of the active pen 2102. The active pen 2102 includes a battery 2204, a super capacitor 2206, a coil 2208, a micro processor unit (MCU) 2210, a 15-V Tx circuit 2212, and a pressure sensor 2214. The pressure sensor 2214 senses the energy to the touch panel at a pointed end 2216 at the bottom in the figure, and is constituted by a strain gauge type sensor, a piezo sensor or the like. The Tx circuit 2212 is a circuit for outputting a sine wave from the pointed end 2216. The MCU 2210 is an arithmetic processor that acquires pressure information from the pressure sensor 2214, transmits and receives data to and from the touch panel via the pointed end 2216, or the like. The coil 2208 receives power from the touch detection unit. The super capacitor 2206 and the battery 2204 accumulate the power received from the touch detection unit.

With such a configuration, the active pen 2102 detects the pressure of the pointed end 2216 by the pressure sensor 2214. In addition, the coil 2208 generates an AC signal according to the power from the touch detection unit, and stores the AC signal in the super capacitor 2206 or the battery 2204. The MCU operates based on the stored power and performs an operation such as transmission of a control signal to the touch detection unit.

Here, the super capacitor 2206 and the battery 2204 have similar functions, so that implementation of only the super capacitor 2206 can reduce the size of the active pen 2102. However, since the super capacitor 2206 has a short storage time, charging needs to be performed quickly. As described below, in the present embodiment, charging is performed while the active pen 2012 is in operation.

Fig. 23 is a diagram showing a configuration example of the active pen and the touch detection unit. A touch detection unit 2310 is configured to detect the position of contact of the active pen 2102. The touch detection unit 2310 has a power supply 2309 which converts a DC signal from a 3-V battery to generate an AC signal of about 5 to 10 V. The touch detection unit 2310 includes a resonance circuit 2308 including a plurality of charge coils 2312 and a capacitor C3. The individual charge coils generate magnetic fields indicated by the upward arrows and the downward arrows.

The active pen 2102 includes the coil 2208 and a capacitor C4, which constitute a resonance circuit. The capacitor C4 is connected to a rectifier circuit constituted by

diodes

2302, 2303, 2304 and 2306. A capacitor C5 connected to the rectifier circuit performs a smoothing process. The capacitor C3 is connected to a combination circuit 2307 of a DC-DC conversion unit and a low dropout type linear regulator (LDO) . The combinational circuit 2307 controls the voltage value of the smoothed signal, and the DC-DC conversion unit or the LDO is selected according to the magnitude of the voltage value. When charges from the coil are small, for example, the voltage is increased in the DC-DC converter, whereas when the charges from the coil are large, the voltage is reduced by the LDO. The combination circuit 2307 is connected to a configurable level shifter 2311.

Next, an interactive operation of the active pen 2102 and the touch detection unit 2310, which are configured as described above, will be described. The active pen 2102 generates an AC signal in accordance with the magnetic field generated by the charge coil 2312 of the touch detection unit 2310, and supplies a signal of a specific frequency to the rectifier circuit via the capacitor C4. The rectifier circuit converts the input AC signal into a DC (pulsating current) signal. The capacitor C5 smoothes the DC (pulsating current) signal from the rectifier circuit. The combination circuit 2307 controls the voltage value of the smoothed input signal and inputs the voltage-controlled signal to the configurable level shifter 2311. The configurable level shifter 2311 is driven based on the signal from the combination circuit 2307. The configurable level shifter 2311 controls the voltage level of the signal supplied to the MCU 2210 or the signal supplied to the touch detection unit 2310 to convert the signal to a about 5 to 60 V in voltage, and transmit the signal from the active pen side to the touch panel side. The signal is used for detecting a coordinate of a location of the touch pen. As the converted signal is supplied to the corresponding Rx line of the touch detection unit 2310, the touch detection unit 2310 can detect the coordinates of the contact position.

Next, with reference to Fig. 24, the procedures of the method executed in the touch detection unit according to the present embodiment will be described.

In step S2402 of the method, the touch detection unit performs scanning to perform capacitive touch detection. Next, in step S2404, when the touch detection unit detects a contact of the active pen, the coordinates of the active pen are calculated. Then, in step S2406, the charge coil corresponding to the calculated coordinates is powered on.

In this way, the touch detection operation of the active pen and the charging operation of the active pen can be performed at different times.

(Eighth Embodiment)

Fig. 25 shows examples of the arrangement of the drive electrodes Tx and the touch detection electrodes Rx. In the embodiment described above, as shown in Fig. 25A, the lamination may be formed by adhering and stacking drive electrodes (Tx) 2506, a film 2502 made of an optically clear adhesive (OCA) or the like, and touch detection electrodes (Rx) 2504 in the named order from the bottom. In this case, the touch detection electrodes (Rx) 2504 are located on the side of the contact surface. For example, the structure shown in Fig. 10 may be formed for either the touch detection electrodes (Rx) 2504 or the drive electrodes (Tx) 2506 or both.

The arrangement of the drive electrodes (Tx) and the touch detection electrodes (Rx) is not limited to the illustrated arrangement, and the touch detection electrodes (Rx) 2504, the film 2502, and the drive electrodes (Tx) 2506 may be adhered together into a lamination in the named order from the bottom as shown in Fig 25B, for example. Furthermore, as shown in Fig. 25C, the lamination may be formed by adhering the drive electrodes (Tx) 2506 and the touch detection electrodes (Rx) 2504 alternately on the film 2502 in the horizontal direction.

(Ninth Embodiment)

Fig. 26 is a diagram showing a combination of capacitive touch detection Tx lines 2701, a capacitive touch detection Rx lines 2706, Tx lines 2705 for charging an active pen, and Rx lines 2703 for detecting a pen output in which these four types of sensors exist independently. The capacitive touch detection unit is configured to include a plurality of Tx lines 2701 outlined and extending in the horizontal direction, and a plurality of Rx lines 2706 outlined and positioned on the deeper side in the figure than the Tx lines 2701 and extending in the vertical direction, the Tx lines 2701 crossing the Rx lines 2706. Rx lines 2706 are connected to a touch IC for touch detection.

Tx lines 2705 for charging are depicted in thin black lines. The charging side can the same operation as that shown in Fig. 21. The Tx lines 2705 are connected to the AC power supply S via a switch on the left side in the figure, so that AC signals sequentially supplied from the AC power supply S to the individual Tx lines 2705 for charging is generated to charge a coil of an active pen by a current. The Rx lines 2703 for detecting pen output are each connected to the pen output detection IC.

The charge coil, which serves to charge the active pen, includes a line 2704 extending vertically and a plurality of lines 2705 connected to the line 2704 and extending horizontally. The lines 2705 are located on the nearer side in the figure than the Tx lines. The number of Tx lines 2705 to be selected and the cross-sectional area of the charge coil to be formed are controlled by selecting the switches from an external control unit.

The discharge detection coil, which serves to detect discharging from the active pen, includes a line 2702 extending horizontally and a plurality of Rx lines 2703 connected to the line 2702 and extending vertically. The lines 2702 and Rx lines 2703 are located on the deeper side in the figure than the Rx lines 2706. The line 2702 is connected via the lines 2703 to the AC power supply S at the bottom in the figure. The lines 2703 are each connected via a switch to the AC power supply S at the bottom in the figure. The number of Rx lines 2703 to be selected and the cross-sectional area of the charge coil to be formed are controlled by selecting the switches from an external control unit.

In Fig. 26, the Tx lines 2701 and Rx lines 2706 are driven as described with respect to Fig. 2. Next, the charging operation of the active pen which is performed in the Tx lines 2705 and Rx line 2703 shown in Fig. 26 will be described with reference to Figs. 27 and 28.

As shown in Fig. 27, adjacent horizontal Tx lines 2705 are selected from the upper side in the figure to form a charging circuit 2804, and an AC signal is supplied to the charging circuit 2804 from the AC power supply S. Thereafter, the charging circuit 2804 is sequentially formed in the vertical direction indicated by an arrow 2802, and an AC current is caused to flow therethrough for scanning.

Fig. 28 shows a state in which charging is in progress at the position where the active pen 2102 is in contact. The active pen 2102 has a circuit composed of a coil 2208 and a capacitor C4, and this circuit generates an AC signal for charging the active pen 2102 based on the signal from the charging circuit 2804.

When charging is completed, the active pen 2102 discharges. The active pen 2102 can be detected by detecting this discharge. Next, with reference to Figs. 29 and 30, the operation of detecting the active pen 2102 will be described.

As shown in Fig. 29, adjacent vertical Rx lines 2703 are selected from the left side in the figure to form a discharge detection circuit 3010. The discharge detection circuit 3010 is connected to a capacitor C6, and forms a resonance circuit with the lines 2702 and Rx lines 2703. The discharge detection circuit 3010 is further connected to a power supply V via a rectifier circuit composed of

diodes

3002, 3004, 3006 and 3008. The pen output detection IC monitors a change in voltage in the power supply V, and detects discharging from the active pen 2102. The discharge detection circuit 3010 shown in Fig. 29 is sequentially formed in the horizontal direction indicated by an arrow 2902 to carry out scanning for detecting discharging.

As shown in Fig. 30, when the discharge detection circuit 3010 is formed at the position where the active pen 2102 is in contact, a voltage +V corresponding to the voltage generated by the coil 2208 is generated in the power supply V. A coordinate of the active pen 2102 is detected base on the change of the voltage using the pen output detection IC. Through the operation described above, the movement of the position of the charge coil that generates power can follow the moving active pen, thus detecting the coordinate of the active pen using charge/discharge of the coil.

The foregoing descriptions are merely specific implementation manners of the present invention, but are not intended to limit the protection scope of the present invention. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed shall fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

A touch screen comprising:

a detection unit configured to detect existence of a rechargeable detection target based on a change in capacitance by using a signal supplied from a drive electrode, the detection unit including the drive electrode and a detection electrode, the rechargeable detection target corresponding to an accessory device; and

a charge coil for charging the detection target, the charge coil being disposed on a same layer with the drive electrode or the detection electrode.
The touch screen according to claim 1, wherein the charge coil is provided on a same plane where the detection electrode is provided.
The touch screen according to claim 2, wherein a wiring of the detection electrode operates as a charge coil at a time different from a time of detecting change in the capacitance.
The touch screen according to claim 1, wherein the charge coil is provided on a same plane where the drive electrode is provided.
The touch screen according to any one of claims 1 to 4, wherein the charge coil includes an array of a plurality of coils.
The touch screen according to claim 5, wherein the plurality of coils are connected in series.
The touch screen according to claim 5, wherein the plurality of coils are connected in parallel, and only those coils which correspond to coordinates of the acces sory device to be charged comes close are driven.
The touch screen according to claim 5, wherein the plurality of coils are connected in parallel, and are driven simultaneously.
The touch screen according to claim 5, wherein the drive electrode or the detection electrode and the plurality of coils are alternately arranged.
The touch screen according to any one of claims 1 to 9, wherein the drive electrode or the detection electrode is a metal formed in a mesh.
The touch screen according to claim 10, wherein the drive electrode or the detection electrode formed in a mesh and a metal which is formed in a mesh and is not connected to a power supply are alternately arranged.
An electronic device comprising a control circuit and a touch s creen according to any one of claims 1 to 11, the control circuit is configured to control the touch screen to detect existence of a rechargeable detection target and charge the rechargeable detection target.
A control method for a touch screen comprising a detection unit configured to detect existence of a rechargeable detection target based on a change in capacitance by using a signal supplied from a drive electrode, the detection unit including the drive electrode and a detection electrode, the rechargeable detection target corresponding to an accessory device, and a charge coil for charging the detection target, the charge coil being disposed on a same layer with the drive electrode or the detection electrode, the method comprising:

causing the detection electrode to detect a change in capacitance; and

driving the charge coil.
The method according to claim 13, wherein the charge coil is provided on a same plane where the detection electrode is provided.
The method according to claim 14, further comprising:

causing a wiring of the detection electrode to operate as a charge coil at a time different from a time of detecting change in the capacitance.
The method according to claim 13, wherein the charge coil is provided on a same plane where the drive electrode is provided.
The method according to any one of claims 13 to 16, wherein the charge coil includes an array of a plurality of coils.
The method according to claim 17, wherein the plurality of coils are connected in series.
The method according to claim 17, wherein

the plurality of coils are connected in parallel, and

the driving the charge coil includes driving only those coils which correspond to coordinates of the accessory device to be charged comes close.
The method according to claim 17, wherein

the plurality of coils are connected in parallel, and

the driving the charge coil includes driving the plurality of coils simultaneously.
The method according to claim 17, wherein the drive electrode or the detection electrode and the plurality of coils are alternately arranged.
The method according to any one of claims 13 to 21, wherein the drive electrode or the detection electrode is a metal formed in a mesh.
The method according to claim 22, wherein the drive electrode or the detection electrode formed in a mesh and a metal which is formed in a mesh and is not connected to a power supply are alternately arranged.
A method for an electronic device comprising a control circuit and a touch screen according to any one of claims 1 to 11, comprising:

controlling the touch screen to detect existence of a rechargeable detection target; and

charging the rechargeable detection target.