JP3225511B2 - Position detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a graphic or the like drawn by sequentially detecting the position of the stylus on a tablet when a graphic or the like is drawn on the tablet with a stylus. The present invention relates to a position detecting device suitable for being used as a part forming a portion including a tablet plate and a stylus in a graphic creation device or the like capable of obtaining data on

[Summary of the Invention] According to a first aspect of the present invention, there is provided a position indicating member capable of freely moving on a coordinate plate, data generating means for generating coordinate data of the position indicating member on the coordinate plate, and Data processing means for selecting valid and invalid coordinate data from the generated coordinate data and sending out the valid coordinate data, detecting the position of the position indicating member at predetermined time intervals, and In the position detecting device for obtaining the movement trajectory data of the pointing member, the data processing means may be configured to output || P _{n + 2} −P _n for coordinate data P _n , P _{n + 1} , and P _{n + 2} that are continuously input. ₊₁ | − | P _{n + 1} −P _n || = ΔD, and when ΔD as the calculation result is within the adjacent correlation distance value ΔL, the coordinate data P _n , P _{n + 1} , P and _{n + 2} at least one valid data, configuration child to determine as invalid data when it is not The one in which only can be eliminated independently of purely invalid data due to noise or the like in the moving speed of the position indicating member.

According to a second aspect of the present invention, there is provided a position indicating member which can freely move on a coordinate plate, data generating means for generating coordinate data of the position indicating member on the coordinate plate, and coordinate data generated by the data generating means. Data processing means for selecting valid ones and invalid ones and sending out valid coordinate data; detecting a position of the position indicating member at predetermined time intervals; In the position detecting device for obtaining data, the data processing means may be configured such that | P _{n + 2} −P _{n + 1} | = D ₁ for continuously input coordinate data P _n , P _{n + 1} , and P _{n + 2} , | P _{n + 1} −P _n | = D _{2 and} the equation || P _{n + 2} −P _{n + 1} | − | P _{n + 1} −P _n || = ΔD,
Both D ₁ and D ₂ which are the results of the previous calculation are within the correlation distance value L,
Further, when ΔD, which is the result of the subsequent calculation, is within the adjacent correlation distance value ΔL, at least one of the coordinate data P _n , P _{n + 1} , and P _{n + 2} is regarded as valid data. By configuring to discriminate as erroneous data, even if two erroneous data are consecutive, these can be eliminated and erroneous data purely due to noise or the like can be eliminated irrespective of the moving speed of the position indicating member. _{n + 2} −P
_{The result of n + 1} | = D ₁ , | P _{n + 1} −P _n | = D ₂ is affected by the moving speed of the position indicating member, so that even if the moving speed is high, all data is not invalid data. If the correlation distance value L is set to a large value, it is possible to eliminate a case where two erroneous data continue.

[Prior Art] When a graphic or the like is drawn on a tablet board with a stylus, data on the drawn graphic or the like is obtained, and the graphic or the like is displayed on a display device based on the data, or
In a graphic display device or a graphic creation device in which a display on a display device is changed, a portion including a tablet plate and a stylus constituting an input portion of a graphic or the like is sequentially detected by a position of a stylus moving on the tablet plate. To form a position detecting device.

Such a position detecting device includes a tablet plate serving as a coordinate plate, a stylus serving as a position indicating member capable of freely moving on the tablet plate, and data generating means for generating coordinate data of the stylus on the coordinate plate; The data generating means is provided with data processing means for discriminating the coordinate data generated and sending only valid data. One of the types is a type for detecting the position of the stylus by an electrostatic method. The applicant has proposed (Japanese Unexamined Patent Publication No.
201321 publication).

As shown in FIG. 7, the data processing means D of the position detecting device includes a microprocessor 30 and first memories 31x, 31.
y and second memories 32x and 32y. The microprocessor 30 transfers the data of the first memory 31x, 31y to the second memory 32x, 32y each time the X data and the Y data are output from the data generating means, and transfers the data of the second memory 32x, 32y. Is controlled to take in new data into the first memories 31x and 31y. Therefore, _assuming that arbitrary coordinate data continuously inputted are P _n and P _{n + 1} , P _n is stored in the first memories 31x and 31y.
_{n + 1} and _Pn are stored in the second memories 32x and 32y. Also, the microprocessor 30 sets | P _{n + 1} −P _n | every time data is updated.
Is calculated, and when the value of | P _{n + 1} −P _n | is smaller than the correlation distance value L, the data of P _n is regarded as valid data and | P _{n + 1} −P _n |
Is larger than L, the _Pn data is determined to be invalid data, and only valid data is output to a data memory (not shown).

Thus, the stylus is moved on the tablet board with the movement trajectory shown in FIG. Then, the X data and the Y data of each point at predetermined time intervals are input from the data generating means to the data processing means D due to the influence of noise or the like. The data processing means D executes the operation of | P _{n + 1} −P _n | every time new data is input, and obtains the following result. | P ₂ −P ₁ | ≦ L, | P ₃ −P
₂ | ≦ L, | P ₄ −P ₃ |> L, | P ₅ −P ₄ |> L, | P ₆ −P ₅ | ≦ L, | P ₇ −P ₆ |
.Ltoreq.L,..., And the data circled in FIG. 8A is determined as valid data. And due to the influence of noise etc.
Erroneous data P ₄ is excluded is determined as invalid data.

[Problems to be Solved by the Invention] However, as shown in FIG. 8 (b), when two erroneous data P ₄ and P ₅ due to the influence of noise or the like are continuous, the calculation result is | P ₂ − P ₁ | ≦ L, | P ₃ −P ₂ | ≦ L, | P ₄ −P ₃ |> L, | P ₅
−P ₄ | ≦ L, | P ₆ −P ₅ |> L, | P ₇ −P ₆ | ≦ L,..., And the data circled in FIG. 8B is determined to be valid data. You. Therefore, there is a disadvantage that P ₄ is erroneous data is not excluded.

Further, as shown in FIG. 8 (c), when the moving speed of the stylus is high, the interval between the input points is widened, so that there is a disadvantage that all data is determined to be invalid data.

Further, in order to prevent this drawback, it is conceivable to set the correlation distance value L so that the data does not become invalid data even if the stylus moves at a high speed. There is a disadvantage that erroneous data due to the influence of the above cannot be effectively eliminated.

Therefore, an object of the present invention is to provide a position detecting device capable of solving the various disadvantages described above.

[Means for Solving the Problems] To achieve the above object, a position detecting device according to a first aspect of the present invention includes a position indicating member which can be freely moved on a coordinate plate, and a position indicating member for the position indicating member on the coordinate plate. Data generating means for generating coordinate data, and data processing means for selecting valid and invalid data from the coordinate data generated by the data generating means and transmitting coordinate data that has been made valid,
In a position detecting device for detecting the position of the position indicating member at predetermined time intervals and obtaining movement trajectory data of the position indicating member, the data processing means may be configured to continuously input coordinate data P _n , P _{n + 1} , P _{n + 2} , an equation of || P _{n + 2} −P _{n + 1} | − | P _{n + 1} −P _n || = ΔD is calculated, and ΔD which is a result of the calculation is an adjacent correlation distance value ΔL. At least one of the coordinate data P _n , P _{n + 1} , P _{n + 2} as valid data when it is within, and discriminate as invalid data when it is not. It was done.

According to a second aspect of the present invention, there is provided a position detecting device comprising: a position indicating member which can freely move on a coordinate plate; and a data generating unit which generates coordinate data of the position indicating member on the coordinate plate. Means, and data processing means for selecting valid data and invalid data from the coordinate data generated by the data generating means and sending out the valid coordinate data. In a position detecting device that obtains the movement trajectory data of the position indicating member by detecting every time, the data processing unit may be configured to perform the following processing on the coordinate data P _n , P _{n + 1} , and P _{n + 2} input continuously. P _{n + 2} −P _{n + 1} | = D ₁ , | P _{n + 1} −P _n | = D ₂ and || P _{n + 2} −P _{n + 1} | − | P _{n + 1} −P _n || = Δ
The formula of D is calculated, and when both D ₁ and D ₂ which are the previous calculation results are within the correlation distance value L and ΔD which is the later calculation result is within the adjacent correlation distance value ΔL, the coordinate data P is calculated. _n , P _{n + 1} , P
_At least one of _{n + 2} is regarded as valid data, and otherwise, it is determined as invalid data.

[Operation] According to the first invention, the absolute value of the difference between each pair of adjacent coordinate data P _n , P _{n + 1} , and P _{n + 2} is obtained (| P _{n +2} −P _{n + 1} | = D ₁ , | P _{n + 1} −P _n | = D ₂ ),
Since it is determined that the data is valid data only when both of the calculation results are within the relative distance value L, if two erroneous data are consecutive, for example, the absolute value of the difference between the erroneous data is determined by the relative distance value L.
Even within the range, the absolute value of the difference between the correct data and the erroneous data is equal to or greater than the correlation distance value L, so that the case where two erroneous data continue is also excluded.

According to the second invention, for three coordinate data P _n , P _{n + 1} , and P _{n + 2} that are successively input, the absolute value of the difference between each pair of adjacent data is obtained. Find the absolute value (||
P _{n + 2} −P _{n + 1} | − | P _{n + 1} −P _n || = ΔD) Since the calculation result is determined to be valid data only when it is within the adjacent relative distance value ΔL, the position indicating member The absolute value of the difference between adjacent data (| P _{n + 2} −P _{n + 1} |, | P
_{n + 1−} P _n |) have substantially the same value, and when there is a difference (ΔD) between the two difference data, the difference data is purely affected by noise or the like regardless of the moving speed of the position indicating member. Therefore, only erroneous data due to the influence of noise or the like is excluded.

According to the third aspect, as described in the first aspect and the second aspect, it is possible to eliminate the case where two erroneous data are consecutive and to obtain pure noise or the like irrespective of the moving speed of the position indicating member. Error data is eliminated. Also,
If the correlation distance L is set so that all data is not invalid data even if the moving speed is high, all data will not be erroneously determined as invalid data even if the moving speed is high, and || P _{n + 2} −P _{n + 1} | − | P _{n + 1} −P _n || = ΔD can eliminate erroneous data due to noise or the like purely and | P
_{When the} correlation distance value L is exceeded by the calculation of _{n + 2−} P _{n + 1} | = D ₁ , | P _{n + 1} −P _n | = D ₂ , it is possible to eliminate the case where two erroneous data are consecutive.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

1 to 6B show an embodiment of the present invention.

FIG. 4 is a sectional view of the tablet plate A.
In FIG. 4, a stylus B serving as a position indicating member has a substantially pen shape, and a creator of a figure or the like can freely move on the tablet plate A. The tablet plate A, which is a coordinate plate, has three insulating layers 1a, 1b, 1c, and a plurality of strip conductors X ₁ to X which form a part of the data generating means C between the insulating layers 1a, 1b, 1c. X _n , Y _{1 to} Y
_m is located. That is, the upper insulating layer 1a, a plurality of strip-conductor X ₁ to X _n are arranged parallel to at regular intervals between 1b, also,
Lower insulating layer 1b, the inter-1c a plurality of strip-conductor Y ₁ to Y _m perpendicular to the plurality of strip-conductor X ₁ to X _n are the same center as the center distance of the strip conductor X ₁ to X _n They are arranged in parallel with an interval.

FIG. 1 shows a circuit configuration diagram of the data generating means C. In Figure 1, strip conductors X _1, X _2, ... X _n and strips conductors Y _1, Y _2, ... at one end of each of Y _m, the switch circuit 3 to form a driver circuit portion together with the shift register 2 Switch
3 _1, 3 _2, ... 3 _m and the switch circuit switches 5 _1, 5 ₂ 5 forming the driver circuit portion together with the shift register 4, ... which is 5 _n provided, each of these switch circuits 3 and 5 switch The terminal A is grounded, and the terminal B is connected to a common voltage supply terminal 6.

Then, in a predetermined unit detection period, the output terminal N ₁ of the shift register 2, N _2, ... switch 3 _1, 3 ₂ of the switching circuit 3 from N _n, the pulse signal having a constant width ... 3 _n is given sequentially The switches 3 ₁ , 3 ₂ ,..., 3 _n are sequentially switched from the terminal A to the terminal B for a short period Ts, for example. This allows
Strip conductors X _1, X _2, ... to each of X _n, the voltage Vcc of the voltage supply terminal 6 are sequentially supplied one by a short period of time Ts. Further, in a separate unit detection period to this, similarly, the output terminal M ₁ of the shift register 4, M _2, from ... M _m of the switching circuit 5 switches
5 _1, 5 _2, ... 5 pulse signal having a constant width are sequentially applied to the _m, the switch 5 _1, 5 _2, is ... 5 _m, for example, sequentially terminal A by a short period of time Ts
Side is switched to the terminal B side. Thus, strip conductors X _1, X _2, ... as in the case of X _n, strip conductors _{Y 1, Y 2, ... Y} m
, The voltage Vcc from the voltage supply terminal 6 is sequentially supplied for each short period Ts. That is, strip conductors _{X 1, X 2, ... X} n and strips conductors Y _1, Y _2, ... when the center distance of the respective Y _m and Lp, substantially, the position detection plate 10, strip conductors _{X 1, X 2, ... X} n X direction or the strip conductor which is the arrangement direction of the _{Y 1, Y 2, ... Y} m in the Y direction which is the arrangement direction to be scanned with a scanning speed Ss = Lp / Ts of Become.

The strip conductors _{X 1, X 2, ... X} n and Y _1, Y _2, ... for driving the shift register 2 and 4 to perform the voltage supply to Y _m, the clock pulse generating circuit 7, frequency divider 8 And a signal generation circuit 9.

For example, a basic clock pulse Cc of 2400 KHz is obtained from the clock pulse generation circuit 7, and this clock pulse
Co is supplied to the frequency dividing circuit 8 and frequency-divided.
The clock pulse Cs as shown in FIG. 3 is obtained. This clock pulse Cs is supplied to the signal generation circuit 9 and, as shown in FIG. 3, a unit detection period in which the position detection in the X direction, which alternately arrives, is performed.
Tx and a detection start signal Sp having a cycle corresponding to each of the unit detection periods Ty in which the position detection in the Y direction is performed, and having a pulse width of one cycle of the clock pulse Cs, The drive start signal St delayed by one cycle of the clock pulse Cs, the detection period identification signal Sxy whose level is inverted every one cycle of the detection start signal Sp, and the detection period identification signal of the drive start signal St A signal Stx composed of a pulse in a period Tx in which Sxy is at a high level and a signal Sty composed of a pulse in a period Ty in which the detection period identification signal Sxy of the drive start signal St is in a low level are obtained.

Then, the clock pulse Cs is supplied to the shift register 2 as a shift pulse, and the signal Stx is supplied to the shift register 2 as a start pulse. From the time of the leading edge of the signal Stx in each period Tx, n cycles of the clock pulse Cs are supplied. in the drive period until the time when the time elapses, the output terminal n ₁ of the shift register 2, n _2, ... to n _n, in as shown in FIG. 3, the one period of the pulse width of the respective clock pulses Cs The pulse signals P _x1 , P _x2 ,... P _xn have clock pulses Cs
This pulse signal is sequentially obtained for each short period Ts for one cycle.
P _x1 , P _x2 ,... P _xn are switches 3 ₁ , 3 _{2 ,.}
Is supplied to the switches _{3 1, 3 2, ... 3} n are sequentially switched by a short period of time Ts in the terminal B from the terminal A side, thereby strip conductors X _1, X _2, the voltage supply terminal to ... X _n The voltage Vcc from 6 is sequentially supplied for each short period Ts.

Similarly, the clock pulse Cs is supplied to the shift register 4 as a shift pulse, the signal Sty is supplied to the shift register 4 as a start pulse, and m periods of the clock pulse Cs from the leading edge of the signal Sty in each period Ty in the drive period until the time when the minute time passes, the output terminal M ₁ of the shift register 4, M _2, ... to M _m, as shown in FIG. 3, the one period of the pulse width of the respective clock pulses Cs .. _Pym are sequentially obtained for each short period Ts for one cycle of the clock pulse Cs, and the pulse signals P _y1 , P _{y2 ,.
y1,} P _y2, ... P _ym switch 5 ₁ of the switch circuit 5, 5 _2, is supplied to ... 5 _m, the switch 5 _1, 5 _2, ... 5 _m the terminal B from the terminal A side
Side are sequentially switched by a short period of time Ts in, thereby strip conductors _{Y 1, Y 2, ... Y} m voltage Vcc of the voltage supply terminal 6 are sequentially supplied one by each short period Ts.

Further, the stylus B is provided with a voltage detecting means 10,
This voltage detecting means 10 is provided with a detecting electrode 11, and the detecting electrode 11 has a shield case whose head is grounded.
The shield case 12 faces the outside of the stylus B, and is grounded via a capacitor 13 having a capacitance Cf inside the shield case 12. Further, the detection electrode 11 is connected to the gate of the field effect transistor 14 inside the shield case 12, and a bias resistor 15 is connected between the gate of the field effect transistor 14 and the ground potential point. Then, in each period Tx, electrostatic formed between the strip conductors X _1, X _2, ... strips conductor and the detection electrode 11 to which a voltage Vcc is supplied from the voltage supply terminal 6 of the X _n capacity, as the sequentially changed by a short period of time Ts, the level of the voltage Vo is a detection output obtained in the detection electrode 11 also changes, strips conductors X _1, X _2, ... detection electrode of the X _n It becomes maximum when the voltage Vcc from the voltage supply terminal 6 is supplied to the strip conductor closest to the position 11. Similarly, in each period Ty, electrostatic formed between the strip conductors Y _1, Y _2, ... Y strips conductor and the detection electrode 11 to which a voltage Vcc is supplied from the voltage supply terminal 6 of the _m with the the capacitance is sequentially changed by a short period of time Ts, the level of the voltage Vo is a detection output obtained in the detection electrode 11 also changes, strips conductors Y _1, Y _2, ... detection electrode of the Y _m It becomes maximum when the voltage Vcc from the voltage supply terminal 6 is supplied to the strip conductor closest to the position 11.

The voltage Vo, which is a detection output obtained at the detection electrode 11, is
A signal of a predetermined frequency having a large peak level portion is supplied to the tuning amplifier circuit 16 through the field effect transistor 14 and has two large peak levels at two points in time, as shown in FIG. However, in each period Tx, Sbx
And Sby in each period Ty.

The signals Sbx and Sby obtained in this manner are supplied to a Schmitt trigger circuit 17, and as shown in FIG. 3, the signals Sbx and Sby change the predetermined positive level Vs to this level.
A signal Sz that falls from a high level to a low level when crossing to become greater than Vs, and then rises from a low level to a high level when the signals Sbx and Sby cross the ground potential in a positive to negative direction is obtained. .

Then, the drive start signal St obtained from the signal generation circuit 9
Is supplied to the set terminal S of the RS flip-flop circuit 18, and the signal Sz obtained from the Schmitt trigger circuit 17 is RS
The signal is supplied to the reset terminal R of the flip-flop circuit 18 and is supplied from the RS flip-flop circuit 18 for the period Tx or
The beginning of the drive period in Ty, voltage strip conductors X ₁ or Y ₁
Rises at time t ₁ in which Vcc is supplied, then the time when the signal Sbx or Sby from tuning amplifier circuit 16 first crosses the ground potential after exceeding the level Vs from positive to negative direction, i.e., then the Schmitt trigger signal Sz of the circuit 17 falls signal Gc at time t ₂ initially rises is obtained.

Time Then, the signal Gc obtained from a clock pulse Co and RS flip-flop circuit 18 obtained from the clock pulse generator 7 is supplied to the AND gate circuit 19, the high level period of the signal Gc, that is, from the time t ₁ Period Td up to t ₂
, The clock pulse Co is extracted.

On the other hand, the detection start signal Sp obtained from the signal generation circuit 9 is supplied to the clear terminal CLR of the counter 20, and the counter 20 is cleared at the beginning of the period Tx or Ty, and the period after the counter 20 is cleared Signal in Tx or Ty
During the high level period of Gc, the clock pulse obtained from the AND gate circuit 19 is applied to the clock terminal CK of the counter 20.
And is counted. Counter Thus, time from time t ₁ to time t _2, therefore, to address this time
20 output data are strip conductors in X direction or Y direction
X ₁ , X ₂ ,..., X _n or Y ₁ , Y ₂ ,..., Y _m , the distance from the reference one (first strip conductor X ₁ to Y ₁ ), that is, the X direction on tablet board A Alternatively, the counter 20 corresponds to the position in the Y direction.
From the RS point t ₂ is a fall time of the signal Gc obtained from the flip-flop circuit 18, then the signal generating circuit 9
In the period up to the leading edge of the obtained detection start signal Sp, the output data (X data) indicating the position of the detection electrode 11 in the X direction on the tablet plate A at that time is held. from the time t ₂ is a fall time of the signal Gc obtained from the middle of the RS flip-flop circuit 18, in a period from the leading edge of the detection start signal Sp obtained from the subsequent signal generation circuit 9, the detection electrodes at that time The output data (Y data) having the contents indicating the position of the eleventh tablet board A in the Y direction is held. Then, the X data and the Y data from the counter 20 are supplied to the data processing means D.

The signal Sz from the Schmitt trigger circuit 17 is supplied to the set terminal S of the RS flip-flop circuit 21, and the detection start signal Sp obtained from the signal generation circuit 9 is supplied to the reset terminal R of the RS flip-flop circuit 21. Therefore, the output level of the counter 20 from the RS flip-flop circuit 21 becomes high during a period in which the content indicates the time of the period Td. A signal Sa as shown in FIG. 3 is obtained. The signal Sa, the output data of the counter 20, and the detection period identification signal Sxy obtained from the signal generation circuit 9 are supplied to the data processing means D.

As described above, the position of the detection electrode 11 moving on the tablet plate A, that is, the position of the stylus B in the X direction and the Y direction on the tablet plate A is determined by the unit detection period Tx and the unit detection period, respectively. In the Ty, the X data from the counter 20 indicating the position in the X direction and the detected X data in the Y direction are sequentially detected alternately with the detection periods Tpx and Tpy corresponding to the sum of the period Tx and the period Ty, respectively. The Y data from the counter 20 indicating the position are obtained alternately with the detection periods Tpx and Tpy, respectively.

FIG. 2 shows a circuit block diagram of the data processing means D. In FIG. 2, X data and Y data from a counter 20 are input to a changeover switch 21, which is controlled by a changeover control signal of a CPU 22.
The changeover switch 21 has an a terminal and a b terminal in addition to the neutral terminal. The a terminal is connected to the buffer Ax (23x), and the b terminal is connected to the buffer Ay (23y). Buffer Ax (2
3x) on the output side are two buffers Bx (24x) and buffer C
x (25x) are connected in series, and two buffers By (24y) and a buffer Cy (25y) are provided on the output side of the buffer Ay (23y).
Are connected in series. Each of these six buffers is configured so that its output can be input to the CPU 22 and is controlled by a read / write control signal of the CPU 22. The CPU 22 outputs the control signal so as to execute the flowchart shown in FIG. That is, the signal Sa is sent to the CPU 22.
The detection period identification signal Sxy is input, and the counter 2 is set based on the detection period identification signal Sxy during a period when the signal Sa takes a high level.
A switching control signal for outputting X data from 0 to the buffer Ax (23x) and outputting Y data to the buffer Ay (23y) is output. Before the X data or Y data is input from the counter 20 to the buffer Ax (23x) or the buffer Ay (23y), the X data of the buffer Ax (23x) is transferred to the buffer Bx (24x).
x) into buffer Cx (25x)
x) and to discharge the data in buffer Cx (25x), and to transfer the data in buffer Ay (23y) to buffer B
Data of buffer By (24y) is buffered to y (24y).
(25y) and outputs a read / write control signal to discharge the data in the buffer Cy (25y).
That is, the X data or Y data input from the counter 20 is changed every time new X data or Y data is input from the buffer Ax (23x) to the buffer Bx (24x) to the buffer Cx (25x).
In order, buffer Ay (23y) → buffer By (24y) →
The data is transferred in the order of the buffer Cy (25y). Therefore, _assuming that coordinate data input continuously is P _n , P _{n + 1} , P _{n + 2} , the second
The data is fetched into each buffer as shown in the figure. Also, CPU22
Has arithmetic means and executes the following arithmetic operation each time data is newly updated to determine data.

That is, | Ax data−Bx data | = d ₁ | Ay data−By data | = d ₂ | Bx data−Cx data | = d ₃ | By data−Cy data | = d ₄ Is calculated, and the absolute value of the difference between adjacent data of the continuous three data for X and Y is calculated. Next, it is determined whether or not the sum of the difference data between X and Y (d ₁ + d ₂ , d ₃ + d ₄ ) is equal to or less than the correlation distance value L. The correlation distance L is set to be large enough that all data is not determined to be invalid data even if the moving speed of the stylus B is high. If the sum of the difference data is within the correlation distance value L, the absolute value of the difference of the sum (| d ₁ + d ₂ − (d ₃ +
d ₄ ) It is determined whether or not |) is equal to or less than the adjacent correlation distance ΔL. Then, d ₁ + d ₂ ≦ L, d ₃ + d ₄ ≦ L, | d ₁ + d ₂ − (d ₃ +
d ₄ ) When | ≦ ΔL is satisfied, control is performed so that the data in the buffers Cx (25x) and Cy (25y) is loaded into a data memory (not shown).

Hereinafter, the operation of the above configuration will be described. When the stylus B is moved on the tablet board A, the X data and the Y data at each point (P ₁ , P ₂ ,. Input to means D.

Here, as shown in FIG. 6 (a), when data including two consecutive erroneous data (P ₄ , P ₅ ) due to the influence of noise or the like is input, P ₄ or P ₄ is included in the arithmetic expression. contains _{P 5 (P 2, P 3} , P 4), (P 3, P 4, P 5), (P 4, P 5, P 6), (P 5, P 6,
Since the value of d ₁ + d ₂ or d ₃ + d ₄ in P ₇ ) is equal to or greater than the correlation distance value L, P ₂ , P ₃ , P ₄ , and P ₅ are determined to be invalid data, and P ₁ , P ₆ , P ₇
Is determined as valid data. Therefore, the data P ₄ and P ₅ mis consecutive two is eliminated.

Also, as shown in FIG. 6 (b), when data is input in which the moving speed of the stylus B is high and the interval between adjacent points is wide, the values of d ₁ + d ₂ , d ₃ + d ₄ increase. Even if the moving speed is high, the correlation distance value L is set to be large enough that the positive data is not regarded as invalid data, so that all data is not determined to be invalid data. And d ₁ +
the value of d ₂ and d ₃ + d ₄ is increased in direct proportion to the moving speed, the value of d ₁ + d ₂ and d ₃ + d ₄ is substantially identical to undergo the influence of noise or the like in order to vary both. If there is erroneous data due to noise or the like irrespective of the moving speed of the stylus B, the value of | d ₁ + d ₂ − (d ₃ + d ₄ ) | is greater than or equal to the adjacent correlation distance value ΔL. Erroneous data is determined to be invalid data. The buffer Cx (25x) and the buffer Cy (25x) determined to be valid data by the above operation
The data _{Pn of} y) is taken into a data memory (not shown).

In the above embodiment, the coordinate data is represented by the X component and the Y component.
Although the calculation is performed separately for the components, it is preferable to perform the calculation in a vector so that more precise determination can be performed.

Further, in this embodiment, whether or not the absolute values of two adjacent difference data are both within the relative distance value L and the absolute value of the difference between the two difference data are determined by the adjacent relative distance value ΔL.
Although the two-stage determination of whether or not the number is within the range is performed, only one of them may be adopted. By adopting only the former, when two erroneous data continue, these can be eliminated as invalid data. By employing only the latter, erroneous data due to noise or the like can be purely removed regardless of the moving speed of the stylus B.

Furthermore, in this embodiment, the coordinate data P _n , P _{n + 1} , and P _{n + 2} input continuously are calculated, and P _n is configured as valid or invalid, but P _{n + 1} , or P _{n + 2} may be determined to be valid or invalid, or two or more of these data may be determined to be valid or invalid.

[Effects of the Invention] As described above, the present invention has the following effects.

According to the first aspect, in the position detecting device for detecting the position of the position indicating member on the coordinate plate at predetermined time intervals and obtaining the movement trajectory data, the arbitrary coordinate data P _n , P continuously inputted _{For n + 1} and P _{n + 2} | P _{n + 2} −P _{n + 1} | = D ₁ , | P _{n + 1} −P _n |
= Calculates the equation D _2, and the coordinate data _{P n, P n + 1,} P n + 2 in at least one valid data when D ₁ and D ₂ is both within relative distance value L, so Since the data processing means is configured to determine invalid data when the error data is not present, there is an effect that even when two erroneous data continue, these can be eliminated as invalid data.

According to the second aspect, in the position detecting device for detecting the position of the position indicating member on the coordinate plate at predetermined time intervals and obtaining the movement trajectory data, the arbitrary coordinate data P _n , P _{For n + 1} and P _{n + 2} || P _{n + 2} −P _{n + 1} | − | P _{n + 1} −P _n || =
The formula of ΔD is calculated, and when ΔD is within the adjacent correlation distance value ΔL, at least one of the coordinate data P _n , P _{n + 1} , and P _{n + 2} is regarded as valid data. Since the data processing means is configured to judge, the effect is that purely erroneous data due to noise or the like can be eliminated regardless of the moving speed of the position indicating member.

According to the third aspect, in the position detecting device for detecting the position of the position indicating member on the coordinate plate at predetermined time intervals and obtaining the movement trajectory data, the arbitrary coordinate data P _n , P continuously inputted _{For n + 1} and P _{n + 2} | P _{n + 2} −P _{n + 1} | = D ₁ , | P _{n + 1} −P _n |
= D ₂ is calculated and || P _{n + 2} −P _{n + 1} | − | P _{n + 1} −P _n || = ΔD
When both D ₁ and D ₂ are within the relative distance value L and ΔD is within the adjacent relative distance value ΔL, at least the coordinate data P _n , P _{n + 1} , and P _{n + 2} are calculated. The data processing means is configured to determine one as valid data and to discriminate it as invalid data when not, so that if two erroneous data continue, they can be eliminated and regardless of the moving speed of the position indicating member. Only erroneous data due to noise or the like can be eliminated purely, and the results of | P _{n + 2} −P _{n + 1} | = D ₁ and | P _{n + 1} −P _n | = D ₂ indicate the movement speed of the position indicating member. If the correlation distance L is set large enough that all data will not be invalid data even if the moving speed is high, erroneous data due to noise or the like can be eliminated purely and D ₁ or D ₂ can be affected by the correlation distance. When the value is equal to or larger than the value L, it is possible to eliminate the case where two erroneous data are consecutive. There is an effect that that.

[Brief description of the drawings]

FIGS. 1 to 6B show an embodiment of the present invention.
FIG. 2 is a circuit diagram of the data generating means, FIG. 2 is a circuit block diagram of the data processing means, FIG. 3 is a waveform diagram of each part, FIG. 4 is a cross-sectional view of the tablet board, FIG. 7 (a) and (b) are diagrams showing a movement locus and an input point, FIGS. 7 to 8 (c) show a conventional example, FIG. 7 is a configuration diagram of a data processing means, and FIG. a),
(B), (c) is a figure which shows a movement locus and an input point, respectively. A: tablet board (coordinate board), B: stylus (position indicating member), C: data generating means, D: data processing means.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Motoichi Ishihara 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Takaaki Koizumi 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo No. Sony Corporation (56) References JP-A-60-114924 (JP, A) JP-A-60-175191 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G06F 3/03 G06F 3/033-3/037

Claims (2)

(57) [Claims] 1. A position indicating member capable of freely moving on a coordinate plate, data generating means for generating coordinate data of the position indicating member on the coordinate plate, and a coordinate data generated by the data generating means. Data processing means for selecting the correct and invalid ones and sending out the valid coordinate data, detecting the position of the position indicating member at predetermined time intervals, and moving the locus data of the position indicating member. In the position detecting device for obtaining the coordinate data, coordinate data inputted continuously
With respect to P _n , P _{n + 1} , and P _{n + 2} , the following expression is calculated: || P _{n + 2} −P _{n + 1} | − | P _{n + 1} −P _n || = ΔD When ΔD is within the adjacent correlation distance value ΔL, at least one of the coordinate data P _n , P _{n + 1} , and P _{n + 2} is determined as valid data, and otherwise, it is determined as invalid data. A position detecting device characterized by the above-mentioned. 2. A position indicating member which can be freely moved on a coordinate plate, data generating means for generating coordinate data of the position indicating member on the coordinate plate, and effective data from the coordinate data generated by the data generating means. Data processing means for selecting the correct and invalid ones and sending out the valid coordinate data, detecting the position of the position indicating member at predetermined time intervals, and moving the locus data of the position indicating member. In the position detecting device for obtaining the coordinate data, coordinate data inputted continuously
For P _n , P _{n + 1} , and P _{n + 2} , the expression of | P _{n + 2} −P _{n + 1} | = D ₁ , | P _{n + 1} −P _n | = D ₂ is calculated and || P _{n + 2} −P _{n + 1} | − | P _{n + 1} −P _n || = Δ
The formula of D is calculated, and when both D ₁ and D ₂ which are the previous calculation results are within the correlation distance value L and ΔD which is the later calculation result is within the adjacent correlation distance value ΔL, the coordinate data P is calculated. _n , P _{n + 1} , P
A position detecting device characterized in that at least one of _{n + 2} is determined as valid data, and otherwise, it is determined as invalid data.