1. Field of the Invention
The present invention relates to a dynamic control method for a touch panel, especially to a dynamic control method capable of adjusting the resolution, scan frequency, signal gain, or active condition of a touch panel.
2. Description of the Related Art
Ever since Apple's iPhone with a multi-touch function was delivered in 2007, touch screen products have taken the market by storm, and almost all mobile phones and tablet PCs have followed suit to provide a touch screen.
Please refer to
In processing the touch action, the prior art PCT panel 200 generally employs a fixed resolution, a fixed scan frequency, and a high signal gain. However, using a fixed resolution and a fixed scan frequency to detect the finger 300 posed at all the distances like D1, D2, D3 from the PCT panel 200, will cause the PCT panel 200 consuming power both in operation and in standby, and the setting of the threshold has to go through a time consuming process to overcome the dynamic interference coming from a LCD module or a circuit system.
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Besides, the prior art PCT panel has only a default signal gain and a fixed threshold. Please refer to
One objective of the present invention is to provide a dynamic control method for a touch panel, which can dynamically adjust the resolution of the touch panel.
Another objective of the present invention is to provide a dynamic control method for a touch panel, which can dynamically adjust the signal gain of the touch panel.
Another objective of the present invention is to provide a dynamic control method for a touch panel, which can dynamically adjust the scan frequency of the touch panel.
Another objective of the present invention is to provide a dynamic control method for a touch panel, which can dynamically adjust the active threshold of the touch panel.
Still another objective of the present invention is to provide a dynamic control method for a touch panel, of which a dynamic control mechanism with properly configured parameters not only can reduce the response time and power consumption of the touch panel, but also can provide a versatile GUI (Graphical User Interface) by detecting Z-axis approaching actions of an object.
To attain the foregoing objectives, the present invention proposes a dynamic control method for a touch panel, the method including the steps of: providing a dynamic resolution control circuit for configuring a touch panel to possess a first resolution and a second resolution; and providing an induced signal gain control circuit for configuring the touch panel to have a first gain corresponding to the first resolution, and a second gain corresponding to the second resolution, wherein, the resolution of the touch panel will change from the first resolution to the second resolution when an object is within a distance from the touch panel.
To attain the foregoing objectives, the present invention proposes another dynamic control method for a touch panel, the method including: providing a first stage, in which a touch panel operates with a first gain and a first scan frequency; and providing a second stage, in which the touch panel reduces the sensing area and operates with a second gain and a second scan frequency for locating an approached block, so as to facilitate a coordinate calculation of a touched point of the touch panel, wherein the touch panel will move from the first stage to the second stage when an object is within a distance from the touch panel.
To attain the foregoing objectives, the present invention proposes a touch panel system, including: a touch panel, having a glass, a sensor array and a display panel, wherein the sensor array is placed over one side of the glass for generating a sensing signal in response to an approaching movement of an object, and the glass is placed over the display panel; a dynamic resolution control circuit, coupled to the sensor array and used for configuring the touch panel to possess a first resolution and a second resolution, and thereby output an X-Y plane coordinate signal, wherein the resolution of the touch panel will change from the first resolution to the second resolution when the object is within a distance from the touch panel; an induced signal gain control circuit, coupled to the dynamic resolution control circuit and used for providing a first gain and a second gain corresponding to the first resolution and the second resolution respectively, so as to amplify the X-Y plane coordinate signal to generate an analog signal; an analog to digital conversion circuit, coupled to the induced signal gain control circuit and used for performing an analog to digital conversion on the analog signal to generate a digital signal; a digital signal processor, coupled to the analog to digital conversion circuit and used for processing the digital signal to generate a digital X-Y plane coordinate signal; and a controller, coupled to the digital signal processor and used for conveying the digital X-Y plane coordinate signal to a graphical user interface for executing a corresponding instruction.
To make it easier for our examiner to understand the objective of the invention, its structure, innovative features, and performance, we use preferred embodiments together with the accompanying drawings for the detailed description of the invention.
a) illustrates the operation of a prior art PCT (Projected Capacitive Touch) panel by a finger at distances D1.
b) illustrates the operation of a prior art PCT (Projected Capacitive Touch) panel by a finger at distances D2.
c) illustrates the operation of a prior art PCT (Projected Capacitive Touch) panel by a finger at distances D3.
a) illustrates the operation of a prior art PCT panel using self-capacitors for Z-axis sensing.
b) illustrates the operation of a prior art PCT panel using mutual-capacitors for Z-axis sensing.
a) illustrates a first preferred embodiment of the present invention's dynamic control method operating in a first stage having a resolution of 2×3.
b) illustrates the first preferred embodiment of the present invention's dynamic control method operating in a second stage having 6×3 blocks with each block capable of being divided into 10×5 sensing elements.
a) illustrates a second preferred embodiment of the present invention's dynamic control method operating in a first stage having a resolution of 1×1.
b) illustrates the second preferred embodiment of the present invention's dynamic control method operating in a second stage having 6×3 blocks with each block capable of being divided into 10×5 sensing elements.
a) illustrates a preferred embodiment of the present invention's dynamic control method for a touch panel operating in a first stage having a first threshold.
b) illustrates the preferred embodiment of the present invention's dynamic control method for the touch panel operating in a second stage having a second threshold.
a) illustrates a preferred embodiment of the present invention's dynamic control method providing a high sensitivity for a touch panel in a first stage.
b) illustrates the preferred embodiment of the present invention's dynamic control method providing a high sensitivity for the touch panel in a second stage.
c) illustrates the preferred embodiment of the present invention's dynamic control method providing a normal sensitivity for the touch panel in a third stage.
The present invention will be described in more detail hereinafter with reference to the accompanying drawings that show the preferred embodiments of the invention.
Please refer to
In step a, the dynamic resolution control circuit will cause the touch panel to change the resolution from a first resolution to a second resolution when an object is within a first distance from the touch panel; wherein, the object can be for example but not limited to a finger or a touch stylus having a conductive tip; the touch panel can be for example but not limited to a capacitive touch panel, which can be a self-capacitor type touch panel or a mutual-capacitor type touch panel, and capable of multi-touch sensing. The first distance is for example but not limited to 2 cm; the first resolution is for example but not limited to 1×1 or 2×3; the second resolution is for example but not limited to have 6×3 blocks, with each block capable of being further divided into 10×5 sensing elements. When configured to have the first resolution, the touch panel will have a high sensitivity and a low scan frequency (for example but not limited to a LCD frame rate—once per 1/60 sec); and when configured to have the second resolution, the touch panel will have a low sensitivity and a high scan frequency (for example but not limited to 100 times per 1/60 sec).
In step b, the gain control circuit configures the touch panel to have a first gain corresponding to the first resolution and a second gain corresponding to the second resolution, wherein the resolution of the touch panel will change from the first resolution to the second resolution when an object is within a distance from the touch panel. The gain control circuit is an analog signal gain control circuit, and the first gain is larger than the second gain. Besides, when the touch panel is in the second resolution, the dynamic resolution control circuit will further configure the touch panel to form a maximum resolution and use basic sensing elements to finally detect the coordinates of the touch locations after the object is in contact with the touch panel. In addition, by such multi stages arrangement including resolution control, signal gain control, and scan frequency control, the touch system can also shun the interfering noise of the touch panel to provide a high signal to noise ratio (SNR).
The operation principle of the present invention's dynamic control method will be further elaborated as follows. Please refer to
a) and
In the first preferred embodiment, when the distance between an object and a touch panel is larger than a predetermined distance, for example but not limited to 2 cm, a dynamic resolution control circuit will maintain the resolution of the touch panel at 2×3 as illustrated in
In the second preferred embodiment, when the distance between an object and a touch panel is larger than a predetermined distance, for example but not limited to 2 cm, a dynamic resolution control circuit will maintain the resolution of the touch panel at 1×1 as illustrated in
To further demonstrate how the dynamic control method of the present invention can make a touch panel possess a dynamic control function, the present invention proposes
The dynamic control method for a touch panel in
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As illustrated in
To further demonstrate the high sensitivity of the present invention in detecting an object approaching a touch panel in the vertical direction (Z-axis), the present invention proposes
As illustrated in the figures, the preferred embodiment of the present invention's dynamic control method having three stages for adjusting the sensitivity of the touch panel 30 includes the steps of: configuring the touch panel 30 to have a first gain and a first scan frequency in a first stage, and entering a second stage when an object 20 is within a distance from the touch panel 30 (step a); and configuring the touch panel 30 to have smaller sensing areas, a second gain, and a second scan frequency in the second stage for locating approached sensing areas, and entering a third stage when an object 20 is in contact with the touch panel 30 to calculate the coordinates of the touch locations (step b).
In step a, the touch panel 30 is configured to have the first gain and the first scan frequency in the first stage (as illustrated in
In step b, the touch panel 30 will eventually switch to have minimum sensing areas (i.e., the basic sensing elements), a low gain, and a high scan frequency (as illustrated in
Please refer to
In the system, the touch panel 30 has a glass 31, a sensor array 32, and a display panel 33, wherein the sensor array 32 is placed over one side of the glass 31, for example, above or below the glass 31, to generate an induced signal in response to the approaching of the object 20, wherein the induced signal can be a voltage, a current, or a count of pulses. The sensor array 32 can be for example but not limited to of mutual-capacitor type or self-capacitor type, and the number of sensing elements is determined by the resolution. For example, when the touch panel 30 has 6×3 blocks and each block has a resolution of 10×5, then the number of the sensing elements in the sensor array 32 will be 6×3×10×5. The glass 31 is placed over the display panel 33, and the display panel 33 is for example but not limited to a TFT display panel.
The dynamic resolution control circuit 10 is coupled to the sensor array 32 and capable of making the touch panel 30 possess a first resolution and a second resolution, and output an X-Y plane coordinates signal. When the object 20 is within a distance, for example 2 cm, from the touch panel 30, the resolution of the touch panel 30 will change from the first resolution to the second resolution, wherein the first resolution is for example 1×1 or 2×3, and the second resolution includes for example 6×3 blocks with each block capable of being further divided into 10×5 sensing elements. As the principle of the resolutions switching has been elaborated above, it will not be readdressed here.
The induced signal gain control circuit 40 is coupled to the dynamic resolution control circuit 10 for providing a first gain corresponding to the first resolution and a second gain corresponding to the second resolution, so as to amplify the X-Y plane coordinate signal to generate an analog signal, wherein the first gain is larger than the second gain. As the principle of the gain control has been elaborated above, it will not be readdressed here.
The analog to digital conversion circuit 50 is coupled to the induced signal gain control circuit 40 for performing an analog to digital conversion on the analog signal to generate a digital signal.
The digital signal processor 60 is coupled to the analog to digital conversion circuit 50 for processing the digital signal to generate a digital X-Y plane coordinate signal, wherein, the digital signal processor 60 further includes a digital signal mask unit 61 for providing a one dimension convolution mask function for the touch panel 30 in the first resolution, and a two dimension convolution mask function for the touch panel 30 in the second resolution. The digital signal processor 60 can be for example but not limited to a micro controller, a DSP chip, or an SOC chip.
The formula for the one dimension convolution mask is:
y[n]=Σx[k]·h[n−k], wherein y[n] represents the convolution output, Σx[k] represents the output of the induced signal gain control circuit 40, and h[n−k] stands for the kernel of the one dimension mask.
The formula for the one dimension convolution mask is:
y(m,n)=ΣΣx(m+i,n+j)h(i,j), wherein y[m,n] represents the convolution output, ΣΣx(m+l,n+j) represents the output of the induced signal gain control circuit 40, and h(I,j) stands for the kernel of the two dimension mask.
The controller 70 is coupled to the digital signal processor 60 for conveying the digital X-Y plane coordinate signal to a graphical user interface (GUI) for executing a corresponding instruction, wherein the controller 70 is for example but not limited to a SOC chip.
Preferably, the touch panel system further includes a dynamic analog noise filtering unit 80, coupled between the induced signal gain control circuit 40 and the analog to digital conversion circuit 50, so as to provide a first order low-pass filtering function for the touch panel 30 in the first resolution, and a second order band-pass filtering function for the touch panel 30 in the second resolution.
In virtue of the novel design specified above, the present invention's dynamic control method for a touch panel possesses the following advantages: 1. it is capable of adaptively adjusting the touch panel's resolution; 2. it is capable of adjusting the touch panel's signal gain adaptively, 3. it is capable of adjusting the touch panel's scan frequency adaptively, and 4. it is capable of adjusting the touch panel's active threshold adaptively. The dynamic control method for a touch panel of the present invention therefore greatly improves the prior art PCT panel.
While the invention has been described by way of example and in terms of preferred embodiments, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.
In summation of the above description, the present invention herein enhances the performance than the conventional structure and further complies with the patent application requirements and is submitted to the Patent and Trademark Office for review and granting of the commensurate patent rights.
Number | Date | Country | Kind |
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100130445 | Aug 2011 | TW | national |