1. Field of the Invention
The present invention relates to a signal sampling method and a sensing system, and particularly relates to a signal sampling method and a sensing system which apply different single period sampling numbers to different sensing regions.
2. Description of the Prior Art
A conventional capacitive sensing apparatus always comprises a capacitive sensing matrix. Each capacitive sensing matrix comprises a plurality of sensing regions, for example, cells. Traditionally, detecting signals generated by the sensing regions are sampled by the same single period sampling number. The term single period sampling number means a sampling number for a fixed time period, for example, 100 times per second. However, different sensing regions may have different states. Accordingly, it is improper to apply the same single period sampling number for different sensing regions. Also, such method may limit the selection of the single period sampling number.
For example, if the capacitive sensing apparatus is applied to a touch control screen, the single period sampling number is limited by a frame rate. A controller in the capacitive sensing apparatus, for example, a DSP (digital signal processing circuit), does not process data until complete data of a frame is received while receiving data from an analog to digital converter. Also, the number for the frames that the controller processes per second must meet a requirement for a minimum number. Accordingly, the selection of the single period sampling number is limited by such minimum number. Furthermore, some single period sampling numbers are not suitable for some sensing regions, thus the selection of the single period sampling number is further limited.
Therefore, one objective of the present application is to provide a signal sampling method which can apply different single period sampling numbers to sample sensing values for different sensing regions.
Another objective of the present application is to provide a signal sampling system which can apply different single period sampling numbers to sample sensing values for different sensing regions.
On embodiment of the present application provides a signal sampling method applied to a sensing system comprising a sensing matrix comprising a first sensing region and a second sensing region. The signal sampling method comprises: (a) applying a first single period sampling number to sample sensing values of the first sensing region to generate a first sensing signal; (b) applying a second single period sampling number to sample sensing values of the second sensing region to generate a second sensing signal. The first single period sampling number and the second single period sampling number have different values.
Another embodiment of the present application provides a sensing system comprising a sensing matrix comprising a first sensing region and a second sensing region; a sampling apparatus; and a controller. The controller is configured to perform following steps: (a) controlling the sampling apparatus to apply a first single period sampling number to sample sensing values of the first sensing region to generate a first sensing signal; (b) controlling the sampling apparatus to apply a second single period sampling number to sample sensing values of the second sensing region to generate a second sensing signal. The first single period sampling number and the second single period sampling number have different values.
In view of above-mentioned embodiments, the present invention can apply different single period sampling numbers to sample different sensing regions. According, the conventional issue that the selection for the single period sampling number is limited can be solved.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
For the convenience for explaining, different single period sampling numbers are respectively applied to different capacitive sensing units in above-mentioned embodiments. However, in another embodiment, a plurality of capacitive sensing units are combined to a single sensing region which applies the same single period sampling number. Therefore, in such embodiment, different single period sampling numbers are respectively applied to different sensing regions.
Many methods can be applied to decide values for a first single period sampling number and a second single period sampling number. In one embodiment, the device characteristics (ex. durability or sensitivity for voltage variation) of the first capacitive sensing unit SR_1 and second capacitive sensing unit SR_2 are detected. After that, the first single period sampling number and the second single period sampling number are set according to the device characteristics of the first capacitive sensing unit SR_1 and second capacitive sensing unit SR_2.
The capacitive sensing units of the capacitive sensing matrix CM may have different noise disturbance levels or different anti-noise levels due to the process issue, the hardware defect or other factors. Therefore, the “over-sampling” number can be raised if the capacitive sensing units have a high noise disturbance levels or a low anti-noise level, thereby the qualities for sampled sensing values can be increased. That is, the single period sampling numbers for these capacitive sensing units or corresponding sensing regions can be increased to improve the qualities for sampled sensing values.
Please note, the embodiment illustrated in
For more detail, in the embodiment of
The above-mentioned capacitive sensing unit can comprise various structures.
It should be noted that, the method for controlling the single period sampling numbers to capacitive sensing units is not limited to above-mentioned method, which means controlling the single period sampling number for a corresponding capacitive sensing unit via the first sampling apparatus SA_1. In one embodiment, the driving part (not illustrated) of the capacitance sensing matrix CM is applied to control single period sampling numbers for capacitive sensing units. For example, adjust a frequency of a driving signal to change the single period sampling number. It will be appreciated that other methods for controlling at least one single period sampling number for at least one capacitive sensing units can be applied to the present application as well.
The above-mentioned embodiments change the single period sampling number before the analog to digital converter processes the sensing signal. However, the sampling number for the analog to digital converter itself can also be changed to reach the same effect.
In one embodiment, the capacitive sensing system 400 further comprises a digital filter DF. Such digital filter DF filters the digital sensing signal output from the analog to digital converter AD, and then the remained sensing data is stored to the storage SU (ex. a buffer). After that, the controller CU computes the sensing data stored in the storage SU.
Please note the above-mentioned embodiments can be combined. For example, the embodiment in
Furthermore, the above-mentioned embodiments can be applied to other kinds of sensing systems rather than limited a capacitive sensing matrix. That is, the sampling apparatus can sample a sensing signal which is generated from a sensing matrix other than a capacitive sensing matrix. Accordingly, the sensing system provided by the present application can be summarized as follows: A sensing system, comprising: a sensing matrix, comprising a first sensing region and a second sensing region; a sampling apparatus; and a controller. The sensing matrix can be the above-mentioned capacitive sensing matrix, or other kind of sensing matrix, for example, an optical sensing matrix. The controller is configured to perform following steps: (a) controlling the sampling apparatus to apply a first single period sampling number to sample sensing values of the first sensing region to generate a first sensing signal; (b) controlling the sampling apparatus to apply a second single period sampling number to sample sensing values of the second sensing region to generate a second sensing signal. The first single period sampling number and the second single period sampling number have different values. Please note the sensing matrix means a sensing device or a sensing apparatus comprising a plurality of sensing regions, thus are is not limited to have a structure of “matrix”.
In view of above-mentioned embodiments, a signal sampling method applied to a sensing system comprising a sensing matrix comprising a first sensing region and a second sensing region can be acquired. The signal sampling method comprises: (a) applying a first single period sampling number to sample sensing values of the first sensing region to generate a first sensing signal; (b) applying a second single period sampling number to sample sensing values of the second sensing region to generate a second sensing signal. The first single period sampling number and the second single period sampling number have different values.
In view of above-mentioned embodiments, the present invention can apply different single period sampling numbers to sample different sensing regions. According, the conventional issue that the selection for the single period sampling number is limited can be solved.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
Number | Date | Country | Kind |
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104138844 | Nov 2015 | TW | national |