Touch system

Abstract

A touch system includes a touch panel including a plurality of emission lines and a plurality of reception lines; the transmitter is used for transmitting at least one transmitting signal to the corresponding transmitting line; the receiver receives at least one receiving signal from the corresponding receiving line; and a non-tapered continuous wave generator which generates a non-tapered continuous wave signal as a transmission signal of the transmitter.

Description

Technical Field

[0001] The present invention relates to a touch system, and more particularly to a touch system using a non-tapering continuous wave signal as a transmitted signal. Background Art

[0002] A touch panel is a sensing device for detecting touch inputs on a display screen. Touch panels are widely used in smart phones, tablet computers, laptop computers, and other electronic devices.

[0003] There are various types of touch panels, including resistive touch panels, capacitive touch panels, and infrared touch panels. A resistive touch panel operates by detecting pressure on the screen. A resistive touch panel includes two layers of conductive material with a small gap therebetween. When pressure is applied to the screen, the two layers come into contact with each other, thereby detecting the touch position.

[0004] A capacitive touch panel operates by detecting changes in capacitance values. A capacitive touch panel includes a layer of glass or plastic coated with a transparent conductor (such as indium tin oxide (ITO)). When a finger touches the screen, the electric field on the screen surface changes, and this change is detected by sensors located at the corners of the screen.

[0005] An infrared touch panel operates by detecting interruptions in an infrared grating. An infrared touch panel includes an infrared light emitting diode (LED) grid and sensors located at the edges of the screen. When a finger touches the screen, the infrared grating is interrupted, and this interruption is detected by the sensors.

[0006] Electromagnetic interference (EMI) can have a negative impact on the performance of a touch panel. Electromagnetic interference can be caused by various sources, such as radio frequency (RF) signals, power lines, and other electronic devices.

[0007] Smart phones and other portable devices typically use capacitive touch panels, which are particularly vulnerable to electromagnetic interference. Therefore, there is an urgent need to propose a novel mechanism to reduce the impact of electromagnetic interference on touch panels. Summary of the Invention

[0008] In view of the above, one of the objectives of the embodiments of the present invention is to provide a touch system that uses a non-tapering continuous wave signal as a transmitted signal to effectively reduce the impact of interference on the touch system.

[0009] According to an embodiment of the present invention, a touch system includes a touch panel, a transmitter, a receiver, and a non-tapering continuous wave generator. The touch panel includes a plurality of transmitting lines and a plurality of receiving lines. The transmitter transmits at least one transmitted signal to a corresponding transmitting line, and the receiver receives at least one received signal from the corresponding receiving line. The non-tapering continuous wave generator generates a non-tapering continuous wave signal as the transmitted signal of the transmitter.

[0010] According to an embodiment of the present invention, the plurality of transmitting lines are disposed on the first layer and the plurality of receiving lines are disposed on the second layer.

[0011] According to an embodiment of the present invention, the touch panel includes a capacitive touch panel.

[0012] According to an embodiment of the present invention, the touch panel includes a plurality of capacitors respectively disposed at intersections of the plurality of transmitting lines and the plurality of receiving lines.

[0013] According to an embodiment of the present invention, it further includes:

[0014] An analog-to-digital converter that converts an analog received signal into a digital signal.

[0015] According to an embodiment of the present invention, it further includes:

[0016] A digital signal processor for processing the digital signal from the analog-to-digital converter.

[0017] According to an embodiment of the present invention, the non-tapering continuous wave signal includes a sine wave signal, a square wave signal, or a triangular wave signal.

[0018] According to an embodiment of the present invention, the bandwidth of the non-tapering continuous sine wave signal is less than the bandwidth of the tapering wave signal, and the tapering wave signal is generated by using a window function to process a wave signal so that both ends gradually taper to zero.

[0019] According to an embodiment of the present invention, the transmitter simultaneously transmits a plurality of encoded non-tapering continuous wave signals through the plurality of transmitting lines.

[0020] According to an embodiment of the present invention, the plurality of encoded non-tapering continuous wave signals are combined to form a non-tapering continuous wave sum signal.

[0021] According to an embodiment of the present invention, the plurality of encoded non-tapering continuous wave signals include at least two sets of encoded non-tapering continuous wave signals with different frequencies.

[0022] According to an embodiment of the present invention, the transmitter transmits a sequence of non-tapering continuous wave signals, wherein the beginning of the first non-tapering continuous wave signal and the end of the last non-tapering continuous wave signal are tapered. When starting to transmit the signal, the first non-tapering continuous wave signal with a tapered beginning is used, and when ending the transmission of the signal, the last non-tapering continuous wave signal with a tapered end is used.

[0023] According to an embodiment of the present invention, the beginning of the first non-tapering continuous wave signal and the end of the last non-tapering continuous wave signal are tapered using a window function, and the window function only tapers one end of the signal. Description of the Drawings

[0024] Figure 1 Show the block diagram of the touch control system according to an embodiment of the present invention.

[0025] Figure 2A Illustrate the timing diagram of a non-tapering continuous sine wave signal according to an embodiment of the present invention.

[0026] Figure 2B Show the timing diagram of a tapering wave signal that is conventionally used as a transmission signal.

[0027] Figure 2C Show the Figure 2A of the non-tapering continuous sine wave signal and the Figure 2B of the tapering wave signal. Figure 3A Show the simplified block diagram of the multi-touch detection method according to an embodiment of the present invention, which uses a multi-tone non-tapering continuous wave signal.

[0028] Figure 3B Illustrate Figure 3A of the multi-tone non-tapering continuous wave signal.

[0029] Figure 4 Illustrate the timing diagram of a sequence of non-tapering continuous (sine) wave signals according to an embodiment of the present invention.

[0030] Reference numerals:

[0031] 11: Touch panel

[0032] 12: Transmitter

[0033] 13: Receiver

[0034] 14: Analog-to-digital converter

[0035] 15: Digital signal processor

[0036] 16: Non-tapering continuous wave generator

[0037] 21: Non-tapering continuous sine wave signal

[0038] 22: Tapering wave signal

[0039] 41: First non-tapering continuous wave signal

[0040] 42: Last non-tapering continuous wave signal

[0041] TX1~TXm: Transmission lines

[0042] RX1~RXn: Reception lines

[0043] TXsum: Non-tapering continuous wave sum signal Detailed description

[0044] Figure 1 The block diagram of the touch system according to an embodiment of the present invention is shown. In this embodiment, the touch system may include a touch panel 11, which includes a plurality of transmit lines TX1 to TXm disposed on the first layer, and a plurality of receive lines RX1 to RXn disposed on the second layer. Capacitors are respectively provided at the intersections of the transmit lines TX1 to TXm and the receive lines RX1 to RXn for detecting a touch position (i.e., single touch) or a plurality of touch positions (i.e., multi-touch). In this embodiment, the touch panel 11 may be a capacitive touch panel, and the touch position is determined by detecting the change in the capacitance value of the capacitor. Although a capacitive touch panel is taken as an example, this embodiment can also be applied to other types of touch panels.

[0045] The touch system may include a transmitter 12 that transmits at least one transmit signal to the corresponding transmit lines TX1 to TXm each time. The touch system may include a receiver 13 that receives at least one receive signal from the corresponding receive lines RX1 to RXn each time.

[0046] The touch system of this embodiment may include an analog-to-digital converter (ADC) 14 that converts the analog receive signal (from the receiver 13) into a digital signal, which can be processed by a digital signal processor 15.

[0047] According to one of the features of this embodiment, the touch system may include a non-tapered continuous wave generator 16 for generating a non-tapered continuous (basic) wave signal as the transmit signal of the transmitter 12. Although a sine wave signal is taken as an example in the following embodiments, other basic wave signals such as a square wave signal or a triangular wave signal can also be used.

[0048] Figure 2A The timing diagram of the non-tapered continuous sine wave signal 21 according to an embodiment of the present invention is illustrated. Figure 2B The timing diagram of the tapered wave signal 22 that is conventionally used as a transmit signal is shown. The tapered wave signal 22 can be obtained by processing (or multiplying) a sine wave signal with a window function to gradually reduce both ends to zero. Figure 2C Showing ( Figure 2A of) the non-tapered continuous sine wave signal 21 and ( Figure 2B of) the tapered wave signal 22. Since the bandwidth of the non-tapered continuous sine wave signal 21 is much smaller than the bandwidth of the tapered wave signal 22, the non-tapered continuous sine wave signal 21 used in this embodiment can effectively reduce the electromagnetic interference (EMI) of the touch system.

[0049] Figure 3A A simplified block diagram showing the multi-touch detection method according to an embodiment of the present invention, which uses a multi-tone non-tapered continuous wave signal. Figure 3B Illustrate Figure 3A A timing diagram of the multi-tone non-tapered continuous wave signal. In this embodiment, the transmitter 12 simultaneously transmits encoded non-tapered continuous (e.g., sinusoidal) wave signals through the transmission lines TX1 to TX4. For example, the transmission line TX1 sequentially transmits the encoded non-tapered continuous wave signal [-1 +1 +1 +1], the transmission line TX2 sequentially transmits the encoded non-tapered continuous wave signal [+1 -1 +1 +1], the transmission line TX3 sequentially transmits the encoded non-tapered continuous wave signal [+1 +1 -1 +1], and the transmission line TX4 sequentially transmits the encoded non-tapered continuous wave signal [+1 +1 +1 -1]. Among them, the encoded non-tapered continuous wave signal "+1" is opposite (or 180 degrees out of phase) to the encoded non-tapered continuous wave signal "-1". All the encoded non-tapered continuous wave signals (through the transmission lines TX1 to TX4) are combined to form a non-tapered continuous wave sum signal TXsum, whose bandwidth is similar to Figure 2C The narrow bandwidth of the non-tapered continuous sine wave signal 21 shown, so electromagnetic interference can be effectively reduced.

[0050] In an alternative embodiment, the multi-touch detection method uses a multi-tone and multi-frequency non-tapered continuous wave signal (such as Figure 3A / Figure 3B ). For example, a first set of encoded non-tapered continuous wave signals with a first frequency is transmitted through the transmission lines TX1 to TX4, and a second set of encoded non-tapered continuous wave signals with a second frequency is transmitted through the transmission lines TX5 to TX8 (not shown).

[0051] Figure 4 A timing diagram illustrating a sequence of non-tapered continuous (sinusoidal) wave signals according to an embodiment of the present invention. In this embodiment, the start of the first non-tapered continuous wave signal 41 of this sequence and the end of the last non-tapered continuous wave signal 42 of this sequence can be reduced using a window function, which only reduces one end of the signal. When starting to transmit the signal, the first non-tapered continuous wave signal 41 with a reduced start is used; when ending the transmission of the signal, the last non-tapered continuous wave signal 42 with a reduced end is used.

[0052] The above are only the preferred embodiments of the present invention and are not intended to limit the scope of the patent application of the present invention; any equivalent changes or modifications made without departing from the spirit disclosed by the invention shall be included in the following scope of patent application.

Claims

1. A touch control system, characterized in that: Include: A touch panel including a plurality of transmitting lines and a plurality of receiving lines; A transmitter, transmitting at least one transmission signal to a corresponding transmission line; A receiver receives at least one receiving signal from a corresponding receiving line; and The non-tapered continuous wave generator generates a non-tapered continuous wave signal as a transmission signal of the transmitter.

2. The touch control system according to claim 1, wherein: The plurality of transmitting lines are arranged on the first layer and the plurality of receiving lines are arranged on the second layer.

3. The touch control system according to claim 1, wherein: The touch panel includes a capacitive touch panel.

4. The touch control system according to claim 3, wherein: The touch panel includes a plurality of capacitors which are respectively arranged at the intersections of the plurality of transmitting lines and the plurality of receiving lines.

5. The touch control system according to claim 1, wherein: Also includes: Analog to digital converter, converts the analog received signal into a digital signal.

6. The touch control system according to claim 5, wherein: Also includes: A digital signal processor is used to process the digital signal from the analog-to-digital converter.

7. The touch control system according to claim 1, wherein: The non-tapered continuous wave signal includes a sine wave signal, a square wave signal or a triangle wave signal.

8. The touch control system according to claim 1, wherein: The bandwidth of the non-tapered continuous sine wave signal is smaller than the bandwidth of the tapered wave signal. The tapered wave signal is generated by processing a wave signal using a window function so that both ends are gradually reduced to zero.

9. The touch control system according to claim 1, wherein: The transmitter simultaneously transmits a plurality of coded non-tapered continuous wave signals through the plurality of transmission lines.

10. The touch control system according to claim 9, wherein: The plurality of encoded non-tapered CW signals are combined to form a non-tapered CW sum signal.

11. The touch control system according to claim 9, wherein: The plurality of coded non-tapered CW signals include at least two groups of coded non-tapered CW signals with different frequencies.

12. The touch control system according to claim 1, wherein: The transmitter transmits a sequence of non-tapered continuous wave signals, wherein the beginning of a first non-tapered continuous wave signal and the end of a last non-tapered continuous wave signal are shortened. When the transmission signal starts, the first non-tapered continuous wave signal with the shortened beginning is used, and when the transmission signal ends, the last non-tapered continuous wave signal with the shortened end is used.

13. The touch control system according to claim 12, wherein: The beginning of the first non-tapered CW signal and the end of the last non-tapered CW signal are truncated using a window function that truncates only one end of the signal.

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