Abstract:
A touch device includes a plurality of row electrodes, a plurality of column electrodes and a plurality of sensing units. The sensing units are used for detecting touched positions according to potentials of the row electrodes and column electrodes. The sensing units include at least a first sensing unit and a second sensing unit. The first sensing unit is coupled to a first portion of the row electrodes and a first portion of the column electrodes. The second sensing unit is coupled to a second portion of the row electrodes that is different from the first portion of the row electrodes, and a second portion of the column electrodes that is different from the first portion of the column electrodes.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a touch device, and more particularly, to a touch device capable of shortening scanning time. 
         [0003]    2. Description of the Prior Art 
         [0004]    Buttons, keyboards or mice are generally utilized to input data into computer products. With the touch panels entrance to the market, however, users can input data in a more convenient fashion. Touch panels and related control devices are very common in modern portable products. Touch devices include projected capacitive touch devices and passive matrix resistive touch devices, wherein the projective capacitive touch devices are widely exploited in portable devices, e.g., cell phones and navigators for mobile vehicles due to features such as supporting multi-touch functionality, higher light transmittance, lower power consumption, etc. As the need for touch control on notebook computers increases, projected capacitive touch devices are also gradually being utilized in display panels with larger sizes. As the size of the display panel grows, the number of sensing electrodes is also increased for implementing the projected capacitive touch devices, and therefore more sensing chips are required to achieve accurate touch control functionality. The greater then number of sensing electrodes, however, the longer the time required to sense touch events. As a result, the speed of the touch device responding to a host (e.g., a cell phone or a computer) will decrease. 
         [0005]    Please refer to  FIG. 1 .  FIG. 1  is a diagram of a conventional projected capacitive touch device  100 . The projected capacitive touch device  100  includes a plurality of row electrodes R 1 ˜R n , a plurality of column electrodes C 1 ˜C m  which are perpendicular to the row electrodes R 1 ˜R n , a first sensing unit  110  and a second sensing unit  120 . The first sensing unit  110  includes a multiplexer  112  and an analog-to-digital converter (ADC)  114 . The second sensing unit  120  also includes a multiplexer  122  and an ADC  124 . The row electrodes R 1 ˜R n  and the column electrodes C 1 ˜C m  are utilized to sense potentials of capacitances, and the sensed potentials are processed by the ADCs  114  and  124  to thereby generate digital output voltages acting as output signals of the projected capacitive touch device  100 . Furthermore, any one of the electrodes corresponds to an environment capacitance parameter according to its physical characteristic; therefore, when the projected capacitive touch device  100  is being touched, some variations will occur to analog output voltages of certain specific electrodes correspondingly. The first sensing unit  110  is coupled to the row electrodes R 1 ˜R n  for generating digital output voltages according to potential variations of the row electrodes R 1 ˜R n  to determine a location of the touch event; in addition, the second sensing unit  120  is coupled to the column electrodes C 1 ˜C m  for generating digital output voltages according to potential variations of the column electrodes C 1 ˜C m  to determine a location of the touch event 
         [0006]    The projected capacitive touch device  100  determines a location of the touch event via a scanning process. During scanning, the row electrodes R 1 ˜R n  are responsible for providing potentials and the column electrodes C 1 ˜C m  are responsible for performing the sensing scanning, or the column electrodes C 1 ˜C m  are responsible for providing potentials and the row electrodes R 1 ˜R n  are responsible for performing the sensing scanning. That is, when the row electrodes R 1 ˜R n  are providing potentials, only the multiplexer  122  in the second sensing unit  120  will transmit voltage signals on the column electrodes C 1 ˜C m  to the following ADC  124  for sensing scanning, and when the column electrodes C 1 ˜C m  are providing potentials, only the multiplexer  112  in the first sensing unit  110  will transmit voltage signals on the row electrodes R 1 ˜R n  to the following ADC  114  for sensing scanning. In the conventional component arrangement, only one of the ADCs  114  and  124  is actually performing the sensing scanning action, such that the overall sensing scanning time cannot be optimized. Therefore, how to lower the scanning time of touch devices without increasing fabricating cost thereof is still a problem to be solved in this field. 
       SUMMARY OF THE INVENTION 
       [0007]    Therefore, one of the objectives of the present invention is to provide a touch panel capable of shortening the scanning time to solve the aforementioned problems. 
         [0008]    According to an embodiment of the present invention, a touch device is provided. The touch device comprises a plurality of row electrodes, a plurality of column electrodes and a plurality of sensing units. The sensing units are used for detecting touched positions according to potentials of the row electrodes and column electrodes. The sensing units include at least a first sensing unit and a second sensing unit. The first sensing unit is coupled to a first portion of the row electrodes and a first portion of the column electrodes. The second sensing unit is coupled to a second portion of the row electrodes that is different from the first portion of the row electrodes, and coupled to a second portion of the column electrodes that is different from the first portion of the column electrodes. 
         [0009]    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. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a diagram of a conventional projected capacitive touch device. 
           [0011]      FIG. 2  is a diagram of a touch device according to an embodiment of the present invention. 
           [0012]      FIG. 3  is a diagram of a touch device according to another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Certain terms are used throughout the following description and claims to refer to particular system components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ” The terms “couple” and “couples” are intended to mean either an indirect or a direct electrical connection. Thus, if a first device couples to a second device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections. 
         [0014]    Please refer to  FIG. 2 .  FIG. 2  is a diagram of a touch device according to an embodiment of the present invention. The touch device  200  includes (but is not limited to) a plurality of row electrodes Ro 1 ˜Ro n , a plurality of column electrodes Co 1 ˜Co m  perpendicular to the row electrodes Ro 1 ˜Ro n , a first sensing unit  210  and a second sensing unit  220 , wherein the row electrodes Ro 1 ˜Ro n  and the column electrodes Co 1 ˜Co m  are all driving/sensing electrodes. The first sensing unit  210  includes a multiplexer  212  and a digital-to-analog converter (ADC)  214 ; likewise, the second sensing unit  220  includes a multiplexer  222  and an ADC  224 . The row electrodes Ro 1 ˜Ro n  and the column electrodes Co 1 ˜Co m  are utilized to sense potentials of capacitances and then digital output voltages acting as output signals of the touch device  200  are generated via ADCs  214  and  224 . The first sensing unit  210  is coupled to a first portion Ro 1 ˜Ro n/2  of the row electrodes Ro 1 ˜Ro n  and a first portion Co 1 ˜Co m/2  of the column electrodes Co 1 ˜Co m , and is utilized to generate digital output voltages according to potential variations of the row electrodes Ro 1 ˜Ro n/2  and column electrodes Co 1 ˜Co m/2 , wherein the generated digital output voltages are used to determine the position of the touch event. The second sensing unit  220  is coupled to a second portion Ro n/2+1 ˜Ro n  of the row electrodes Ro 1 ˜Ro n  and a second portion Co m/2+1 ˜Co m  of the column electrodes Co 1 ˜Co m , and is utilized to generate digital output voltages according to potential variations of the row electrodes Ro n/2+1 ˜Ro n  and column electrodes Co m/2+1 ˜Co m , wherein the generated digital output voltages are used to determine the position of the touch event. 
         [0015]    During sensing scanning, if the row electrodes Ro 1 ˜Ro n  are utilized to provide potentials, the multiplexer  212  of the first sensing unit  210  and the multiplexer  222  of the second sensing unit  220  transmit voltage signals on the column electrodes Co 1 ˜Co m/2+1 , Co m/2+1 ˜Co m  to following ADCs  214  and  224 , respectively; if the row electrodes Co 1 ˜Co m  are utilized to provide potentials, the multiplexer  212  of the first sensing unit  210  and the multiplexer  222  of the second sensing unit  220  transmit voltage signals on the row electrodes Ro 1 ˜Ro n/2 , Ro n/2+1 ˜Ro n  to following ADCs  214  and  224 , respectively. 
         [0016]    Therefore, during the sensing scanning procedure, no matter whether the row electrodes Ro 1 ˜Ro n  or the column electrodes Co 1 ˜Co m  are used to provide potentials, the ADCs  214  and  224  can simultaneously perform sensing scanning, which efficiently reduces the overall time required for sensing scanning. 
         [0017]    Please note that, in the aforementioned embodiments, the electrode number of the first portion Co 1 ˜Co m/2  of the column electrodes is equal to the electrode number of the second portion Co m/2+1 ˜Co m  of the column electrodes, the electrode number of the first portion Ro 1 ˜Ro n/2  of the row electrodes is equal to the electrode number of the second portion Ro n/2+1 ˜Ro n  of the row electrodes, the first portion Ro 1 ˜Ro n/2  and the second portion Ro n/2+1 ˜Ro n  of the row electrodes have a plurality of sequential row electrodes, respectively, and the first portion Co 1 ˜Co m/2  and the second portion Co m/2+1 ˜Co m  of the column electrodes have a plurality of sequential column electrodes, respectively; however, the aforementioned arrangement of the row electrodes Ro 1 ˜Ro n  and the column electrodes Co 1 ˜Co m  is for illustrative purposes only, i.e., evenly distributing the row electrodes Ro 1 ˜Ro n  and the column electrodes Co 1 ˜Co m  to a plurality of sensing units is only a preferred embodiment of the present invention. Without departing from the spirit of the present invention (i.e., a single sensing unit coupled to different kinds of electrodes instead of coupled to one single kind of electrode), other arrangements of the row electrodes Ro 1 ˜Ro n  and the column electrodes Co 1 ˜Co m  are feasible and still fall within the scope of the present invention. For example, as long as the electrode number of the first portion of the row electrodes is equal to the electrode number of the second portion of the row electrodes, the electrode number of the first portion of the column electrodes is equal to the electrode number of the second portion of the column electrodes, the first portion of the row electrodes has a plurality of sequential row electrodes, the second portion of the row electrodes has a plurality of sequential row electrodes, the first portion of the column electrodes has a plurality of sequential column electrodes, or the second portion of the column electrodes has a plurality of sequential column electrodes, it should be categorized within the scope of the present. 
         [0018]    Please refer to  FIG. 3 .  FIG. 3  is a diagram of a touch device according to another embodiment of the present invention. The touch device  300  includes (but is not limited to) a plurality of row electrodes Re 1 ˜Re n , a plurality of column electrodes Ce 1 ˜Ce m  perpendicular to the electrodes Re 1 ˜Re n , a first sensing unit  310  and a second sensing unit  320 , wherein the row electrodes Re 1 ˜Re n  and the column electrodes Ce 1 ˜Ce m  are all driving/sensing electrodes. The first sensing unit  310  includes a multiplexer  312  and an ADC  314 ; likewise, the second sensing unit  320  includes a multiplexer  322  and an ADC  324 . The row electrodes Re 1 ˜Re n  and the column electrodes Ce 1 ˜Ce m  are utilized to sense potentials of capacitances, and then digital output voltages acting as output signals of the touch device  300  are generated via the ADCs  314  and  324 . The first sensing unit  312  is coupled to a first portion Re 1 ˜Re n/2  of the row electrodes Re 1 ˜Re n  and a first portion Ce 1 ˜Ce m/2  of the column electrodes Co 1 ˜Co m , and is utilized to generate digital output voltages according to potential variations of the row electrodes Re 1 ˜Re n/2  and column electrodes Ce 1 ˜Ce m/2 , wherein the generated digital output voltages are used to determine the position of the touch event. The second sensing unit  320  is coupled to a second portion Re n/2 ˜Re n  of the row electrodes Re 1 ˜Re n  and a second portion Ce m/2 ˜Ce m  of the column electrodes Ce 1 ˜Ce m , and is utilized to generate digital output voltages according to potential variations of the row electrodes Re n/2 ˜Re n  and column electrodes Ce m/2 ˜Ce m , wherein the generated digital output voltages are used to determine the position of the touch event. The difference between the touch device  300  in  FIG. 3  and the touch device  200   FIG. 2  is that the first sensing unit  310  and the second sensing unit  320  are coupled to the row electrode Re n/2  and the column electrode Ce m/2  simultaneously. In this way, the touch device  300  can perform sensing scanning to determine the position of the touch event more accurately. 
         [0019]    The aforementioned embodiments are only for describing the technical characteristics of the present invention, and are not meant to be taken as limitations to the scope of the present invention. To summarize, the present invention provides a touch device capable of shortening sensing scanning time by assigning row electrodes and column electrodes to a plurality of sensing units properly. During the sensing scanning procedure, no matter whether row electrodes or column electrodes are utilized for providing potentials, the ADCs in the sensing units can perform sensing scanning simultaneously, thereby effectively reducing the overall time required for completing the sensing scanning. 
         [0020]    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.