JPS59121484A - Coordinate input device - Google Patents

Abstract

PURPOSE:To execute an input of a character pattern even in case of a small- sized electronic apparatus by constituting a titled device so that a human body contact coordinate position is detected from a capacity component of a touch electrode whose value of a contact capacity component is the maximum, and that of its adjacent touch electrode. CONSTITUTION:A data (a) outputted by a control part when a character recognizing processing is executed is impressed to a decoder 21. This data (a) is decoded by the decoder 21, converted to signals 1-16, and supplied to corresponding transmission gates G1-G16. Also, the input side of the gates G1-G16 are connected to output terminals of corresponding touch electrodes T1-TF, respectively. Also, a signal (f) synchronizing with a high frequency signal (d) outputted from a timing signal generating circuit 22 through an AND gate is impressed to a clock input terminal CK of a counter 25, and counted. As a result, a count value of the counter 25 becomes proportional to magnitude of a contact capacity component of the electrodes T1-TF, and its count value is sent out to an RAM and an arithmetic part.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a coordinate input device for inputting the coordinate position of a character/seven turns using a touch electrode.

[Prior art]

Conventionally, various input devices have been proposed for inputting and recognizing characters, figures, etc.

For example, the coordinate positions of characters and figures drawn on the tablet by a pen-shaped jig are detected by detection lines arranged in a matrix in the VcX-axis and Y-axis directions on the tablet, and the input is converted into n'i pulse signals. device, also C
There is a device that inputs information using a light ben on an RT display device, or a device that arranges pushbuttons in a matrix and turns on the necessary pushbuttons in line with characters and graphics.

[Problems with conventional technology]

When inputting characters and graphics by applying the principles of the above-described conventional input devices to a small electronic device such as a wristwatch, each of the conventional input devices has the following problems. In other words, input devices using tablets and pen-type jigs do not require special jigs, and since the devices are complex, they are small electronic devices and have a small surface area, so they are difficult to use, for example, on a wristwatch. In some cases, it is necessary to fully overlap the time display section and the input section for characters and figures, but for this purpose, the tablet must be transparent, but a transparent tablet is difficult to manufacture. . In addition, with input devices that use push buttons, the detection accuracy of coordinate positions is determined by the number of push buttons, so in order to achieve the same accuracy, the number must be completely increased, making it unsuitable for small electronic devices. Also, because it is a mechanical switch, it has poor durability and cannot be made transparent.

[Purpose of the invention]

A coordinate input device that uses touch electrodes to enable highly accurate input of the coordinate positions of character patterns such as characters and figures, even in small electronic devices. It is to provide.

[Key points of the invention]

A plurality of touch electrodes are arranged in a square shape on the XY coordinate system, and when a human body such as a finger comes into contact with the plurality of touch electrodes when inputting 4 turns of letters, the contact capacitance component of each touch electrode is The coordinate input device detects and stores the human body contact coordinate position from the capacitance component of the touch electrode with the maximum value of the detected contact capacitance component and the capacitance component of the adjacent touch electrode. .

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an electronic wristwatch having a function of displaying a preset message at an alarm time will be described below with reference to the drawings. FIG. 1 is an external view of the electronic wristwatch. A transparent surface glass 2 is fixed on the top surface of the watch case l, and on the top surface of the surface glass 2 there are also a total of 4 x 4 matrix shapes along the XY coordinate system, which will be described later. Sixteen transparent touch electrodes 3 are arranged at regular intervals, and the touch electrodes 3
A dot display section 4 made of a liquid crystal display device is also disposed above the dot display section 4. In addition, in addition to electronic circuit components such as a timekeeping circuit, a liquid crystal drive circuit, and a character/turn processing circuit, the watch case 1 includes batteries and the like. Numbers ZO to KF expressed in hexadecimal as shown in the figure are assigned to the touch electrodes.

2 and 3 are principle diagrams of the switching characteristics of the touch electrode 3. FIG. In FIG. 2, the watch case l is made of metal, and the back cover is also made of metal (as shown in the diagram).
It is attached to the arm via. And watch case IK: ij
, is connected to the high potential VDD (logical value "1#") side of the power supply voltage, and is also used as one touch electrode. For this reason, a watch? When the human body touches the touch electrode 3 while the touch electrode 3 is worn on the arm, the touch electrode 3 can be turned ON.

Further, the symbol Cx is a stray capacitance component, which is caused by the electrode wiring capacitance caused by the wiring of the touch electrode 3 and the gate capacitance caused by the high input impedance of the dirt of the 0MO8IC used in this example. . Further, the symbol Cy is a contact capacitance component of the human body that occurs between the watch case l and the touch electrode 3 when the touch electrode 3 is touched.

Therefore, although the stray capacitance component Cx always exists, the contact capacitance component Cy is artificially generated.

The code A is a rectangular wave signal with a predetermined period (for example, 64H2). It has been entered. The source side of the transistor 6 is supplied with a low potential yss (logical value ``0'') of the power supply voltage, and the source side of the transistor 7 is supplied with a high potential VDD via the watch case 1. There is. And C.M.O.
The output signal of the S inverter 8 is input to the touch electrode 3 and is also output as a signal B via the CMOS inverter 9. That is, the signal B is a signal to be determined that is used to determine whether or not a human body is in contact with the touch terminal &3, and whether or not there is a pinch touch.

When the rectangular wave signal A reaches a high potential level and is input to the CMOS inverter 8 as shown in FIG. 3(1) in a state where the human body is not touching the touch electrode 3,
The output signal of CMOS inverter 8 is at a low potential level, and therefore the output signal of inverter 9 is at a high potential level. At this time, since the output signal of the CMOS inverter 8 is affected by the stray capacitance component Cx, the output signal of the inverter 9 has a rising edge with respect to the rectangular wave signal A, as shown in FIG. 3(2). You will be delayed by the time TO.

Next, when a human body touches the touch electrode 3, a contact capacitance component Cy is formed between the touch electrode 3 and the watch case 1, and this contact capacitance component Cy is a stray capacitance component Cx.
, the output signal B of the inverter 9 is output with a delay corresponding to the combined capacitance of the stray capacitance component Cx and the contact capacitance component Cy with respect to the rectangular wave signal A. .

Incidentally, the magnitude of the contact capacitance component cy varies depending on the contact area between the human body and the touch electrode 3 or the contact state such as the pressing force, but is approximately proportional to the contact area. Then,
The output signal B of the inverter 9 when the contact capacitance component Cy is small is as shown in FIG. 3
), the upper limit is further delayed by a time T1 and output. Further, when the contact capacitance component Cy is large, the output signal B of the inverter 9 is outputted with its rise delayed by the time T1+T2, as shown in the third LN(4). In this way, the output signal B of the CMOS inverter 9
The magnitude of the contact capacitance component Cy, which is output as a value approximately proportional to the contact area, can be determined according to the output state of the contact area.

FIG. 4 illustrates the XY coordinate system set for the touch electrodes 3 arranged in a 4×4 matrix. Therefore, as shown in the figure, the XY coordinate system of 12 touch electrodes 3 (Fl,
gO,, g'x, g'2, Z3, 16X16=2
Coordinate positions of 56 points are set. The XY coordinate position & is expressed by points (0,0) to (15,15).

Next, with reference to FIG. 5 and FIG. That is, in the case of the present invention, as described above, the delay in the rise of the signal B is caused by the contact capacitance component C.
Since it is proportional to y, that is, proportional to the contact area, the entire delay amount of the signal B is detected by a counter, which will be described later, and by processing the detection i, it is possible to determine the center of the area where the human body is currently in contact. This is to find the coordinate position. Therefore, in Fig. 5 (a), the human fingers are now marked with symbols A, B,
It shows a state in which a plurality of touch electrodes 3, indicated by C, D%E, etc., are in contact at the same time. At this time, the counter executes a counting operation for each touch electrode 3, and as a result, a count value proportional to the contact area of each touch electrode 3 is detected. Then, the control unit, which will be described later, first calculates the touch with the maximum value from among these count values -@4L32 (touch electrode 3 indicated by symbol B in the illustrated example), and then calculates the touch with the maximum count value ' fIL
Each of the touch electrodes 3 above, below, right, and left of the pole 3 (as shown in FIG. 5(b), symbols E, A
%C and 3) 1, and using their respective count values, the center coordinate position of the current contact area indicated by diagonal lines is the touch it pole 3 (touch electrode indicated by symbol B) with the maximum count value. 3) Calculate how far and in which direction the contact area is deviated from the center coordinate position, and determine the coordinates of the center position of the current contact area. In this case, 1) The touch with the maximum count value is assigned the number t- of pole 3.
Km.

ti) Km count value? B, III) All 1 count value of 30 touch electrodes above Km +V) E 30 count values of touch electrodes below K7n.

V) The left touch electrode 30 count value of Km is A.

Vi) If the count value of touch t63 on the right side of Km is 1, then the coordinates of the center position can be found from the five count values 11) to Vi) by calculations performed on the X axis and Y@. That is, FIG. 6 shows the calculation algorithm, and the horizontal axis is the center position of the touch electrode 3 (i.e., points a, b, and c, respectively, and each touch electrode [i3] indicated by symbols A, B, and C). (indicating the center position), and the vertical axis indicates the count value. Further, in the figure, a point S indicates the entire center position of the current contact area, its count value is S, and the coordinate position of the point S is determined by congruence of isosceles triangles.

In Fig. 6, the intersection 't of the straight line mbc and the straight line b'c'
``Pl, and to the left of point a on the direct Mab,
Take point P2 where 1c=La'P2a. Furthermore, the straight line P
2 Let the intersection of a' and the straight line b'c' be the point g, and let the intersection with the perpendicular line descended from the point of the chisel to the straight line ab be the point S. Then, the following equation (1) is obtained from the relationship ΔSs'Pl3''S S'P 2 , and as a result, the equation (2
) is obtained. Note that the pinch of the touch electrode 3 (that is, the distance between the point a and the point, for example) is defined as f L x, and the distance between the point S and the point is k d x.

Ax Lx+bx Ax -dx
The same holds true for the B-C y-axis direction, and formula (3) is obtained. That is, when equations (2) and (3) are applied to the XY coordinates of FIG. 4, the following equation is obtained. In other words, this XY coordinate is the point (
0,0) to (15,15), Lx=Ly=5 (4).

In addition, the numbers of the 16 touch electrodes 3 are respectively (5x s
5 y ), the value of X%y is 0
．． It is either 1, 2, or 3. Now Km = (5xm,
5ym), its coordinate position (X.

Y) is becomes.

However, Km is the end electrode and there is no adjacent touch electrode 3, that is, x m = 0, x m = 3, ym
=0. When ym=3, the count values C,
A, E, and D' are each set to "0".

As described above, in the XY coordinate system of FIG. 4, the center coordinate position of the current contact area can be found by calculating equation (5).

Next, the circuit configuration of the VC will be explained with reference to FIGS. 7 and 8. The control unit 11 stores a microprogram that controls all operations of this electronic wristwatch, and executes microinstructions AD.
, DA, OP, and NA are output in parallel. The microinstruction ADfl is then applied to a ROM (read only memory) 12 and a RAM (random access memory) 13 as address data, respectively. Further, the microinstruction DA is applied to the RAM 13 or the arithmetic unit 14 as data. Further, the micro order name OP is applied to the operation decoder 15, and as a result, the operation decoder 15 outputs various control signals C8I, GS2, R/W,
Outputs X, Y, Z'. Also, the microinstruction NAi'
t is applied to the address section 16, and the address section 56 receives microinstruction NA and signals d and c%16■2, which will be described later.
microinstructions AD, DA, O that execute the next process from
Address data for reading P and NA is output and applied to the control section 11.

The ROM 12 stores standard vector sequences (described later) for each character pattern of numbers and alphabets as data, and when the control signal C31O is applied, the data is successively outputted and given to the arithmetic unit 14.

The RAM 13 has various types of registers as shown in FIG. 9, and is used for various processes performed by the arithmetic unit 14, such as timekeeping processing, time processing, character recognition processing, and the like. The T register is used to store the current time, the A register is used to store the alarm time, and the TM register is used to store the timer time.Other registers will be described later. Furthermore, RAM1
In the other area 3, there is an area Ml for storing data of the coordinate position (X, Y) calculated by the calculation of the above formula (5).
-M4 is provided as shown in Fig. 1θ. That is,
Area MI M2, M3, M4, respectively, 1st stroke, 2nd stroke of character pattern data input from touch electrode 3
A maximum of 20 pieces of coordinate position data (X%Y) can be written for each stroke, third stroke, and fourth stroke. During the character recognition processing in the calculation unit 14, RAMI 4 (D each area M1 to M4VC, CO(
2) First, the total length of each stroke (stroke length) is calculated from the data written in this way, and then each stroke length is divided into six equal parts, and the vectors of each part are determined to obtain a vector sequence. , further store this vector string in the ROM1
A process is performed in which the standard vector string for each character R turn in Z is compared, and the most similar character/4' turn of the standard vector string is set as the input character or turn data. Note that the RAM 13 receives control signals C82, R/
Data is read and written by the WIC.

Next, we will explain the strokes and vectors. 1st
Figure 8 shows a state in which the number "2" with a stroke number of 1 is input from the touch electrode 3. As shown in Figure 18 (A), when the character pattern data "2" is fully input, its coordinate position data As described above, since this position in RAMI 3 is the first stroke, area MIK is written.

Then, as shown in FIG. 18(B), after calculating the stroke length of the first stroke, the stroke is divided into six equal parts. Then, as shown in Figure 18 (C), each equally divided point is approximated by a straight line from the starting point side to the ending point side, W;
The vectors of each part are determined according to the type (type), and a vector sequence is calculated.

FIGS. 20, 21, 22, and 23 show standard vector sequences for each character/f turn with stroke numbers l2.3 and 4, respectively, which are stored in the ROM 121c.

Returning to FIG. 7, the calculation unit 14Vi executes the various calculations described above under the control of the control signal X, and the resulting data ((R
It is applied to the AM 13, the dot display section 4, and the input section 17. Further, when all the calculations have been executed, a signal d indicating the existence of the operation result data and a signal cf indicating the generation of the carrier IJ- are outputted and supplied to the address section 16, which causes the next address to be output.

Under the control of the control signal Y, the dot display section 4 displays a message stored in advance for a certain period of time at the alarm time. Further, the input section 17Fi outputs the count value as input data from the touch electrode 3 and the like under the control of the control signal 20, and outputs the count value as input data to the RAM 13 and the calculation section 1.
4 for processing.

The oscillation circuit 18Vi constantly oscillates a reference frequency signal of, for example, 32.768 KHz and supplies it to the frequency dividing circuit 19.

Then, the frequency dividing circuit 19 outputs a signal 16Hy whose frequency has been divided to 16 Hz, and the signal 16Hy is outputted to the address section 6. In response to this, the timing processing flow is executed once every 1/16 seconds.

Next, the configuration of the input section 17 will be specifically explained with reference to FIG. In the decoder 21, when executing character recognition processing,
4-bit data a output from the control section 11 is applied. This data a is numbered IO to JrF' in FIG.
This is for sequentially specifying the 16 touch electrodes TI to TF attached to each other in a time-sharing manner, and sequentially outputting a corresponding signal B (see FIG. 3) from each touch electrode. That is,
The data a is decoded by the decoder 21 and sequentially outputted as a signal at the high potential VDD level as a signal u1.
# to "16" and supplied to the corresponding transmission darts Gl to G16, respectively. Also,
The input sides of the transmission gates G1 to G160 are connected to the output terminals of the corresponding touch terminals QTI to TF, respectively,
Furthermore, the output sides of the transmission Gl-G16 are both connected to the CMOS inverters 8 and 9 described in FIG. 2, respectively. And tying signal generation circuit 2
2 outputs a rectangular wave signal C (this rectangular wave signal C has the same purpose as the rectangular wave signal A explained in FIG. 2) is sent to the CMOS inverter 8 and the AND gate 23 as a dart control signal. is being applied. Further, the tying signal generation circuit 22 outputs a high frequency signal d' for causing the counter 25Vc to perform an actual counting operation, and applies it to the AND gate 231C. Further, the output signal of the inverter 9 (the signal B) is inverted by the inverter 24 and supplied to the AND gate 23 as a signal e. As a result, the AND gate 23 outputs a signal f synchronized with the signal d, which is applied to the clock input terminal CKIC of the counter 25 and counted. Then, the count value X is sent to the RAM 13 and the calculation section 14. As mentioned above, this count value X is
It is proportional to the magnitude of the contact capacitance component Cy of the touch electrodes TI-TF. Note that the clear input terminal CLKF! of the counter 25 is connected to the clear input terminal CLKF! , when each touch electrode TI-TF is time-divisionally designated by VCI@next, it is cleared by the signal S output by the timing signal generation circuit 22, and is prepared for the next touch electrode counting operation. Further, the output of the AC switch, which has one end connected to the high potential MDI) level and the other end connected to the low potential VS8 level via the resistor 26, is sent to the control unit 11 as an AC signal via the tri-state buffer 27. has been done. This is because the stray capacitance component Cx of the touch electrodes T1 to TF changes greatly depending on the environmental conditions. It is provided to output data a and scan the touch electrodes T1 to TF at least once to obtain count values for each stray capacitance component Cx, and to store them in the RAM 13.

Next, the operation will be specifically explained with reference to the flowcharts shown in FIGS. 12 to 17. First, a general outline of the overall operation will be explained with reference to general 70- in FIG. This general 70- receives the signal 1 from the frequency divider circuit 19 in FIG.
Execution is started every time 6Hz is output, that is, every 1/16 second. First, the time measurement process of step Sl is executed, and the calculation section 14 performs a predetermined calculation on the previous data in the T register of the RAM 13 to calculate current time data. And this current time data is
It is sent to the dot display section 4 and displayed.

Next, timer processing in step S2 is executed.

This timer processing is performed for a certain period of time in the flow described later.
If it is necessary to perform some processing and a certain time period is preset in the TM resoster, the predetermined time period is subtracted each time this processing is executed.

Next, a process for determining whether or not the message setting mode is set is executed in step S3. In this judgment process, it is determined whether the message setting mode r has been set depending on whether the mode switch for message setting (as shown) is turned on or not, and if rYESJ, the process proceeds to step S8. If the answer is "NO", the process proceeds to the determination process of step S4. In this judgment process, it is judged whether or not the alarm time preset in the AL recorder has been reached, and rYES is selected.
If it is J, the process proceeds to step S5, where the message data is read out from the RAM and displayed, and when it is displayed for a certain period of time, this is determined by the step fs6,
In step S7, the entire display of the display is erased. On the other hand, when the determination in both steps S4 and S6 is "NO", the VC ends this general flow process and starts other processes (as shown).

Further, if the setting of the message setting mode is determined in step S3 and the process proceeds to step S8, in this step S8, U, the 7-lag FA;p(rOJ
It is determined whether or not. Therefore, normally it is set to "0" when character recognition processing is not being executed.
Next, the process advances to step 89, and data "l" is set in the flag FA.
is set, and it is stored that character recognition processing is being executed.

Then, in accordance with the flow described later, recognition processing of the letter + turn whose coordinates are input from the pinch switches T1 to TF of the input section 4 is executed (step 310), and the input message data is stored in the RAM 13 (step S11). ), and is further confirmed to be displayed on the dot display section 4 (
After step 512), the flag FA is cleared and the character recognition processing execution state is released. Note that in step S8, if the flag FA is not "0", the process returns to the process that was being executed previously.

FIG. 13 is a flowchart showing the specific contents of the character recognition process in step S0.

That is, when entering the character recognition processing step, first, the initialization processing of step SA is executed.

The specific contents of this initialization process are shown in FIG. First, in step SA+, the RAM
The data "work" is set in both the flags Fl and F2 in the RAM 13, and the stroke number counter 2 and the counter n in the RAM 13 are both cleared. Next, step SA
The process proceeds to step 2, where it is determined whether the AC switch has been turned on or not. If it has not been turned on, the process proceeds to another processing routine, and if it has been turned on, the process enters the data input process of step SE. The content of this data input process consists of a two-step process shown in the flowchart of FIG.
Data n1, ie, the data a' for specifying touch electrodes TI-TFk sequentially and time-divisionally, is output to the decoder 211C in FIG. In this case, data a (data n) is incremented by 1, so
The numbers change to correspond to the data numbers KO to KF, respectively. First, after reaching the touch electrode Tl and turning on the AC switch, the stray capacitance component Cx when the human body does not touch the touch electrode T1 is determined as the quant value X of the counter 25. That is, the high potential VDD from the decoder 21
When the level signal @l# is output and applied to the transduction Gl, it is opened. For this reason, the touch electrode T
The output of I is input to AND gate 23GC. As a result, as shown in FIG.
3 is opened, a signal f synchronized with the signal d is output, and the clock input terminal CKVc of the counter 25 is applied and counted, and the count value is set to X (step SE2). Next, proceeding to step 5A3Vc, a constant value ξ is added to the count value Xi of the touch electrode Tl (here, data n is "l", so it is written as XI), and the resultant data is stored in the RAM 13.
Yn register (register shown in Figure 9 for n=fii)
written to. This process takes into account the fluctuation of the stray capacitance component Cx, the counting error of the counter 35, etc., and sets it to ξ-2 to 3, and then selects the stray capacitance component Cx. Executed to keep the value slightly larger.

Next, it is determined whether the data n is KF at the step fsA4Vc, that is, whether each stray capacitance component Cxf has been detected from the touch electrodes T1 to TF. + is added and becomes "2",
Detection of the stray capacitance component Cx of the touch electrode T2 is started.

The subsequent processing is exactly the same as that for the touch electrode Tl, and steps SE and SA3 to SA5 are repeated 15 more times. As a result, each of the XZ1 to XIF renostars vc/ll in the RAM 13 is , each stray capacitance component Cx when the human body has not yet touched the touch terminals MTI to TFIC is stored, and the corresponding YKl to Y, g'F registers contain a correction value of the stray capacitance component Cx obtained by adding a constant value ξ. is memorized.

When the initialization process SA is completed, the process proceeds to a touch process in step SH. The details of this touch processing are shown in the flowchart of FIG. First, in step SBI, the M register in RAMI 3 is cleared and the counter n is reset. Next, the data input process of step 7'SE is executed in the same way, but in this case, the
When touching the Y coordinate with a human body such as a finger and inputting the character pattern of the number "2" as shown in FIG. 18, the stray capacitance component Cx and contact capacitance component Cy of each touch electrode T1 to TF A count value X based on the composite capacitance is detected. The operation shown in FIG. 8 at this time is the same as described above, so a complete explanation will be omitted. First, when the count value Xx (when n=x) of the touch electrode TI is detected, the stellar fsB2 Then, the calculation of XI-Yl is executed. That is, the stray capacitance component Cx is calculated from the count value XI based on the combined capacitance of the stray capacitance component Cx and the contact capacitance component Cy.
Count value Yl based on VC (now, add 1 to the correction value and Y
In other words, the force 9 nt value based only on the contact capacitance component cy is calculated, and the data is subtracted from the Tl register (TK1 to TfiF in FIG. 9). shown) [written.

'rKVc In step SB3, a judgment process is executed to determine whether the data in the TI register is greater than the data in the M register (itrOJ), and since it is greater, the process proceeds to step 5B4IC, and the data in the TI register is transferred to the M register. The data of counter n (currently n=1) is transferred to and held in the m register.

Therefore, each process of steps SB3 and KB4 is a process of finding the maximum value among the count values based only on the contact capacitance component cy of the touch electrode TI-TF that is sequentially detected. This is for detecting the touch electrode with the maximum Cy.

Next, in step SB5, it is determined whether or not the touch electrodes Tl to TF have been detected all at once, and the counter ntrt
+1 and detection of the touch electrode T2 is started. Thereafter, steps SE and SB2 to SB6 are repeated VCl five more times, and the - different touch processes for the touch electrodes TI-TF are completed. During this time, step SB3.
By executing SB4, the number of the touch electrode with the largest contact capacitance component Cy detected as a result of the current touch processing is stored in the m register, and the count value for the largest contact capacitance component CyVC is stored in the M register. It will be remembered.

When the touch processing is completed, the process proceeds to step SCI, where it is determined whether the data in the M register is greater than "o". That is, when the human body touches 'IfL pole Tl-TF
This is a judgment process to determine whether or not the person has already touched the character pattern, and if the character pattern has been input and the human body has touched it, as already mentioned, the data in the M register will be rO,,L; , Stellag 5c2VC progresses. and step S
At C2, it is determined whether the 7-lag Fl is "1" or not, and since it is "1", the process proceeds to step fsc3, the TMm register constant time is reset, and a timer is started. This is a process for making a character pattern input within a certain period of time set in the TMm register into one character. Next, proceed to step sc4, and 7 lag Fl
is cleared. Then, the program proceeds to stayfsc5, and it is determined whether or not the flag /'F27)(rlJ is negative, and since it is currently "l", the program proceeds to step SC6, where the stroke number counter 2 is incremented by 1 and becomes "1". The content shows the first stroke.Next, from step 5C71C, 7 lag F
2 is cleared, and then the key-in process of step SD is entered. Therefore, this key-in process 11-1.7 in Figure 817
0 - Show the details on the chart.

In this key-in process, first, by the process of step SDI, the number <go ~ jrp>i of the touch electrode with the largest contact capacitance component Cy stored in the m register is determined.
It is converted into a t coordinate (x m N y m). Therefore, this coordinate is xm=0.1 in the XY coordinate system of FIG.
, 2.3, and Vm=0.1, 2.3. For example, the coordinates of 50 touch electrodes Tl are (3, 3).

Note that this coordinate (xm, ym) is xm in RAM1a.
The data are stored in the register and the y11n register, respectively.

Next, the process proceeds to step SD2, and it is determined whether xm is "0" or not, that is, in FIG. 4, the rightmost number is 3, x7, KB,
KF (D tap N pole T3, Tl, TB.

It is determined whether the TF is TF or not, and if so, the correction process when calculating the coordinates based on the equation (5) is performed in step SD3.
It will be held in That is, the C register in the RAM 3 is cleared (that is, the contact capacitance component of the right touch electrode is "0"), and the fCA registers each have a number Z.
2, H6, KA.

Each data in the Tfl-TJlrFL/register required for the touch electrodes T2, Tc, TA, and TEK of BE is transferred.

On the other hand, if the data of Xm is not "0" in step SD2, the process proceeds to step fsD4, and it is further determined whether or not Xm is "3", that is, the number K at the left end in FIG.
O, H4, E'8, IC touch electrode TO1T4, T8
, Tc is determined. If so, the A register is cleared for the correction of equation (5) (i.e., the contact capacitance component of the left touch electrode is "0"), Also, in the C register, the numbers are J'l, 75, H9, KDo yf.
The data in the Tfil-T, gF registers required for the poles Tl, T5, TD, TD are transferred.

Furthermore, when the data of
, TD, and TA. Therefore, in that case, the number g'4. is stored in the A register by the process of step SD6. , gs,18, touch electrode T4 of H9,
Tz1~TfF required for T5, T8, TD
The data in the register is transferred, and the C register [is the number 6. ”E'7, fA, XB touch electrode T
6. 'r, gt required for T7, TA%TB
~Data in the TXF register is transferred.

The above is the process of correcting the X-axis direction when determining the center coordinates of the current contact area using the formula (5) Vc, but the process Fi of each step of the next steps SD7 to 5D11 corrects the Y-axis direction. It is processing. And STETSU fsD7, SD8, SD9.5DIO5SDI 1
are respectively the steps SD2, SD3. ,,SD4,S
They correspond to D5 and SD6, respectively, and are self-evident, so detailed explanation thereof will be omitted.

When each of the above processes is completed, the formula (5
) is executed, and the center coordinates of the current contact area (
Ks%xB) is determined and temporarily stored in the x8 register and ys register in the RAM 13, respectively. In this case, since the data for the maximum contact capacity acid is currently stored in the M register, data M is written in place of data B in step 5DI2. Also, the data S is θ~
It takes a value of 19 (see RAM 13 in FIG. 10).

Once the center coordinates (xs%yg) are obtained in this way, the process proceeds to step 5D13, where the current coordinates (
It is determined whether the coordinates (xs, ys) match the previous coordinates (xs-1, ys-1), that is, whether the finger has stopped at one place and the center coordinates have not changed. If so, the process advances to step fSD14, and the dust * (x
s.

ys) is stored. Then, the S register in the RAM 13 is incremented by 1 and becomes "1". On the other hand, when it is determined in step fSD13 that the center coordinates have not changed, the process immediately returns to the touch processing in step SB.

With the above steps, the center coordinates of the first address of the first stroke of the input character pattern data have been found.
The processing of B%5CI-8C7 and SD is repeated, during which the data S changes by 1 from 2 to 19, with a maximum of 19.
The center coordinates (X8%ys) of the area M1 are 1 to 1
Written to address 9. Also, 2-stroke characters (e.g. "4"), 3-stroke characters (e.g. "F"), 4
Regarding the 2nd stroke, 3rd stroke, and 4th stroke of a stroke character (for example, rEJ), if each character is input within the timer time set in the TM shi・zosume, the RAM 13 is stored in the same way. inside +7), Xsu7M
2, H3, M4117) A maximum of 20 center coordinates (it, ys) are written in addresses 0 to 20, respectively.

On the other hand, after executing the initialization process in step SA,
The touch processing in step SB has been executed, but in the next step SCI, if it is determined that M>0 is not present because the human body has not touched the touch electrodes T1 to TF yet, the process proceeds to step SC8 and a flag is It is determined whether F1 is "1" or not. Since it has already been set to "1" in the initialization process, the process returns to the touch process in step SB. Then, step SB until the human body touches.

SC1, SC8, SB, . . . are repeated.

In addition, if the 7-lag F1 is not "1J" in step S08, the process proceeds to step SC9, and the 7-lag F2 is "1J".
0" is determined. If it is not ``0'', the process goes to step 5CII, and if it is ``0'', the υ flag F2 is set to ``】'' by the stellar fsc10, and then the process goes to step 5CII. In Stella 7'5C11, it is determined whether or not the timer time has elapsed, and if it has not elapsed, the process proceeds to step 5C12.

After characters and seven turns are input within the timer time,
If proceeding to step 5C12, this step SCI
2, the flag F1 is set to "1".

Then, proceed to step 5C13, but for example, now,
As shown in FIG. 18, the entire data has already been stored in area M1 of one stroke M13. For this reason, Stella 7'5
In C13, each center coordinate (xs.

As shown in 8E9(B), the image is divided into six equal parts and the coordinates of the dividing points are determined. Next, in step 5C15, FIG.
As shown in Figure 18 (C), the starting point and dividing point are separated.
) The vector sequence obtained in the example is “l 75570J.

Next, in step SCI 6, the vector sequence is stored in the ROM.
Compare with standard vector sequence in IZ. In this case, since the character is a one-stroke character, the direction difference of each component is determined with respect to the standard vector of each character shown in FIG. 20, and then the sum of the direction differences is determined. That is, the components of the standard vector sequence are
la2a3a4a5a6'', and the components of the detected vector sequence are rblb2b3b4b5b6J. First, the difference between each component (al-bl), I C2-b2 ) ・-(
Find a 6-b6). As a result, values from -7 to +7 are obtained. In the case of -4 to +4, the absolute value is taken as the direction difference, and in the case of -7 to -5, the value converted to 1 to 3 is calculated as +5 to +7. In the case of , the value converted from 3 to l is used as the direction difference, and the sum of these six direction differences is calculated.

If it's evening 1, it's the 20th day! Among the standard vectors, the character ``
Taking the standard vector sequence r467012J of “0” as an example,
4. between the vector sequence r175570J; −]=
3.6-7=÷1.7-5=2.0-5=-5,1-7
After each calculation of =-6, 2-02, direction difference 3.1.2.3
．． 2.2 is obtained, and the sum of the direction differences of 3+1+2+3+2+2=13 is obtained. Then other characters "0", "1",
The same applies to "2", . . . . In Stella 7'5C17, the one with the smallest value is extracted from the sum of the direction differences obtained as described above.
The character is determined as the input character. Next, in step 5C18, it is determined whether or not multiple characters have been output as similar characters in step fSC17, and if multiple characters have been output, further step 7'5C1
9, detailed characteristics of each input character are confirmed and determined. In this case, the input characters are determined to be similar characters.
For example, as shown in Figure 24, the characters rPJ and rD
J, "ENG" and rFJ, for example, r
In the case of PJ and "D", the determination is made by comparing the magnitude of the distance between the end points of the first stroke and the second stroke. As a result, one character is extracted from the plurality of similar characters (step 5C20), and that character is displayed on the dot display section 4 as the input character/main character, and is also stored in the RAM 13 as message data. Ru.

On the other hand, if the minimum sum of differences is one character in step 5C18, that character is immediately taken as the input character.

Furthermore, in cases where the total number of strokes is 2.3.4, each process of steps 5C13 to 5C17 is performed in the same manner as the process for the first stroke for the second stroke, third stroke, and fourth stroke. Of course, other processing is executed.

In the above embodiment, 16 touch electrodes arranged in a 4×4 matrix along the XY coordinate system were used; however, 1. The number of touch electrodes is not limited to 16, but is arbitrary. Further, although the XY coordinate system is composed of 256 points arranged in a 16×16 matrix, the scale of the XY coordinate system is not limited to the above embodiment. Furthermore, in the above embodiment, the number of strokes of characters to be inputted was up to 4 numbers and alphabets, but the number of strokes can be arbitrary, and the types of characters can also be katakana, hiragana, kanji, symbols, and even arbitrary figures. It may be. Also, increase the stroke length to 6
Although it is divided into equal parts, the number of divisions is not limited to six but can be arbitrary. Furthermore, the present invention is applicable not only to electronic wristwatches but also to other electronic devices.

〔Effect of the invention〕

As described above, this invention arranges a plurality of touch electrodes in a matrix on an XY coordinate system, and when a human body such as a finger comes into contact with the plurality of touch electrodes when inputting a character pattern, each The contact capacitance component of the touch electrode is detected, and the human body contact coordinate position is calculated and stored from the contact capacitance component of the touch electrode with the maximum value of the detected contact capacitance component and the contact capacitance component of the adjacent touch electrode. Since we have provided a coordinate input device that allows for easy input of character pattern coordinates of characters, figures, etc. even in small electronic devices such as electronic wristwatches, it is possible to easily and accurately input character pattern coordinates, and various applications can be performed. It has the advantage of being easy to use.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is an external view of the electronic wristwatch on the same side, FIG. 2 is a configuration diagram showing the basic principle of the invention, and FIG. 3 is a diagram showing a time chart thereof. Fig. 4 is a configuration diagram of the XY coordinate system, and Fig. 5 is an example of the contact state of the human body to the touch electrode 3 and the maximum contact capacitance component of the touch electrode 3.
6 is a diagram illustrating the calculation algorithm for determining the center coordinates of the human body contact area, FIG. 7 is an overall circuit configuration diagram, and FIG. 8 is an input diagram. The specific circuit diagram of section 17, FIG. 9, and FIG.
FIG. 11 is a diagram conceptually showing the configuration of the AM 13, and FIG. 11 is a diagram showing a time chart explaining the operation of the input section 17.
Figures 2 to 17 are flowcharts explaining the operation, Figure 18 is a diagram explaining the operation of enshrining the vector string in the case of the number "2", Figure 19 is an explanatory diagram of vectors, and Figure 20. 1. Figures 21, 22, and 23 are diagrams showing standard vector strings of character patterns with stroke numbers of 1, 2, 3, and 40, respectively, and Figure 24 is an example of similar characters/4' main. FIG. 1... Watch case, 2... Surface glass, 3 (T1 to ffF)... Touch electrode, 4...
...Dot display, Cx... Stray capacitance component, Cy... Contact capacitance component, 8.9...
CMOS inverter, 11... Control 1 part, 12
...ROM, 13...RAM, 14.
·····Calculation! , 15...O<ration decoder, 16...Address section, 17...
...Input section, Engineering 8... Oscillation circuit, 19...
...Frequency divider circuit, 21...Decoder, 22...
. . . Timing signal generation circuit, 23 . . . AND gate, 24 . . . CMOS inverter, 25
・・・・・・Counter, Gl~G16・・・・Tonsumitsunyoguto, AC・・・・AC switch. Figure 1 Figure 2 Figure 3 Figure 4 Fig. 20 Fig. 21 Fig. 22 E Fig. 23

Claims (1)

[Claims] A plurality of touch electrodes arranged in a matrix, a first detection means for respectively detecting a contact capacitance component when a human body contacts the plurality of touch electrodes, and each touch detected by the first detection means. The touch electrode with the largest value among the contact capacitance components of the electrodes is determined, and the predetermined value of the touch electrode with the largest contact capacitance component is determined from the contact capacitance component of this touch electrode and the contact capacitance component of the adjacent touch electrode. a second detection means for detecting which of a plurality of coordinate positions the user has touched, and a storage means for storing the coordinate position detected by the second detection means.
-Featured coordinate input device.