JPH07239748A - Coordinate detection device - Google Patents

Abstract

PURPOSE:To evade wrong coordinate detection by supplying a conductive panel with intermittent constant-potential power source to one conductive panel and intermittently charging or discharging the other conductive panel to the constant- potential power source in a 1st or 2nd period. CONSTITUTION:In the 1st or 2nd period, to one conductive panel, a specific DC voltage is applied and to the other conductive panel the intermittent constant-potential electric power (e.g. Vcc or ground potential) is given. Namely, the high potential (Vcc) is applied to the electrode 24 of the lower conductive panel 22 in the 1st period in the order of Vcc, a TR3, the electrode 24 of the conductive panel 23, the electrode 23 of the panel 22, a TR4j, and the ground, and low potential (0V) is applied to the electrode 23 of the panel 22. In the 2nd period, the high potential (Vcc) is applied to the electrode 26 of the lower conductive panel 22 in the order of the Vcc, TR1j, the electrode 26 of the conductive panel 22, the electrode 27 of the panel 22, a TR2j, and the ground, and the low potential (0V) is applied to the electrode 27 of the panel 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate detecting device for detecting the coordinates of the position of characters or symbols displayed on a printed matter or a display screen, and more particularly to an electrode contact type (also referred to as voltage detecting type) coordinate detecting device. Regarding the device. The coordinate detection device
It is used to complement the keyboard operation of a computer or to realize a complete keyboardless. Among them, the electrode contact type coordinate detection device is of electrostatic coupling type, electromagnetic coupling type or piezoelectric effect type. compared,
It is occupying the mainstream in the future because it has a simple structure and can be manufactured at low cost.

[0002]

2. Description of the Related Art An electrode contact type coordinate detecting device (hereinafter simply referred to as "coordinate detecting device") "applies a DC voltage (E-volt for convenience) to two opposite sides of a rectangular panel having conductivity. , And the potential between the two sides is continuously measured, the gradient of the potential that changes linearly from E volt to 0 volt is obtained as it moves from one side to the other side. " Therefore, by measuring the potential between two sides of the panel at a pinpoint and comparing the magnitude of the potential with the potential gradient of the panel, the distance from one side or the other side of the measurement point (that is, 1 Axis coordinate) is detected.

Incidentally, in order to detect the X, Y orthogonal biaxial coordinates, the same operation may be performed between the other two opposite sides of the panel. By the way, the old type coordinate detection device had one panel and a pen-type dedicated probe for measuring the potential on the panel at a pinpoint, but recently, two panels are stacked. This eliminates the need for a dedicated probe.

That is, the coordinate detecting device to which the present invention is applied has a structure as shown in FIG. 5, in which two conductive panels 1 and 2 are arranged to face each other with a minute gap therebetween.
In the first period (T1), a predetermined DC voltage V _X is applied between two opposing sides (between the electrodes 3 and 4 in the figure) of the one conductive panel (the lower conductive panel 2 in the figure) in the X-axis direction. The first voltage applying means 5 to be applied and the second conductive panel (the upper conductive panel 1 in the figure) between the two opposite sides in the Y-axis direction (the electrodes 6 and 7 in the figure) in the second period (T2). Second voltage applying means 8 for applying a predetermined DC voltage V _Y during a period), a period 1A before the T1 (T1A) and a second period A before the T2.
During a period (T2A), a predetermined DC voltage V _C is applied between the two conductive panels 1 and 2 (between the electrodes 6 and 3 in the figure), and a predetermined interval between the T1A and the third applying means 9. Timing (t1a) and a predetermined timing (t2a) between the T2A and a predetermined timing (t1a) between the T1 and
In 1), the potential of the other conductive panel (in the figure, the potential V _(X) of the electrode 6) is detected, and at a predetermined timing (t2) between the above T2, the potential of the one conductive panel (the electrode in the figure). 4 potential V _(Y) ) for detecting the potential V _(Y) ), and two sheets based on the output D _{V (X)} of the potential detection unit 10 at the time t1a or t2a. The process of determining whether or not there is a contact between the conductive panels 1 and 2 (hereinafter referred to as “contact determination process”) is performed, and the outputs D _{V (X)} and D _V of the potential detecting means 10 at the times t1 and t2 are performed. A process of specifying the coordinates of the contact point between the two conductive panels 1 and 2 based on _{V (Y)} (hereinafter referred to as “coordinate specifying process”) is executed, and further, each of the periods T1A, T1, T
2A and T2 and respective timings t1a, t1, t2a
And respective timing signals S _T1A representing t2,
Processing means (for example, a microcomputer) 11 for generating S _T1 , S _T2A , S _T2 , S _t1a , S _t1 , S _t2a and S _t2
And with.

The first voltage applying means 5 comprises a pnp type bipolar transistor TR3 and an npn type bipolar transistor TR4, and TR3 and TR4 are the signals S.
_It is turned on when _T1 (and its inverted signal) is active, and TR4 is an inverted signal of signal S _T1A or signal S _T2A.
Also turns on when the inverted signal of is active. In addition, the second voltage applying means 8 includes a pnp-type bipolar transistor TR1 and an npn-type bipolar transistor TR.
2, TR1 and TR2 turn on when the signal _ST2 (and its inverted signal) is active.

Further, the third voltage applying means 9 is a pnp.
Type bipolar transistor TR5 (and TR4), and TR5 (and TR4) is turned on when signal S _T1A (and its inverted signal) or signal S _T2A (and its inverted signal) is active. R1 to R6 are resistors and V _CC
Is a DC power supply (for example, + 5V). In such a configuration, the process flow is as follows: “contact determination process” → “X coordinate (or Y coordinate) coordinate identification process” → “contact determination process” →
"Y-coordinate (or X-coordinate) coordinate specification processing" is performed, and this processing is sequentially repeated.

In the contact determination process in the period 1A (T1A) or the period 2A (T2A), the signal S _T1A or the signal S _T1A
T2A becomes active, and in response thereto, TR4 and TR5 of the third voltage applying means 9 are turned on. Therefore, a high potential (V _CC ) is applied to the upper conductive panel 1 via the path of “V _CC → TR5 → R6 → electrode 6”, and the lower conductive panel 2 is provided with “electrode 3 → The ground potential (0V) is applied via the path of "TR4 → ground". That is, V _{(X )} is kept at a high potential equivalent to V _CC .

In this state, a tool having a sharp tip such as a pen (unless otherwise specified, any tool having a smooth and sharp tip that does not damage the panel surface may be used; hereinafter referred to as a "pen" for convenience. ) Is used to press an arbitrary position of the upper conductive panel 1, the position of the upper conductive panel 1 is dented and comes into point contact with the lower conductive panel 2. Therefore, a closed circuit is formed in the route of “V _CC → TR5 → R6 → electrode 6 → upper conductive panel 1 → lower conductive panel 2 → electrode 3 → TR4 → ground”, and the upper conductive panel is formed. A potential given by the product of the value of the current flowing through the closed circuit and the value of the resistance between the electrodes 3 and 6 appears between the electrode 6 of 1 and the ground. This potential is the value of the resistance between the electrodes 6 and 3. Since V _CC is divided by the values of R6 and R6, if the value of R6 is made sufficiently large, it becomes a low potential substantially equivalent to the ground potential.

Therefore, a predetermined timing (t1a) during the first A period (T1A) or the second A period (T2A).
Alternatively, at t2a), if the magnitude of V _(X) is checked and it is a high potential equivalent to V _CC , it is determined that there is no contact with the pen, or if V _(X) is a low potential equivalent to 0 V, the pen is It is determined that there is contact with. Only when it is determined that there is contact, the result of the coordinate specifying process of the X coordinate or the Y coordinate performed thereafter is validated, and the output of incorrect coordinate information due to noise or the like is prohibited.

The first period (T1) or the second period (T
Upon entering 2), this time the signal S _T1 (and its inverted signal)
Alternatively, the signal S _T2 (and its inverted signal) becomes active, and in response thereto, TR3 and TR4 of the first voltage applying means 5 or TR1 and TR2 of the second voltage applying means 8 are turned on. Therefore, “V _CC → TR3 → electrode 4 of lower conductive panel 2 → electrode 3 of the same panel 2 → TR4 →
The electrode 4 of the lower conductive panel 2 via the “ground” path
Is applied with a high potential (V _CC ) and the electrode 3 of the panel 2 is applied with a low potential (0 V) (in the case of T1), or "V _CC "
→ TR1 → electrode 6 of the upper conductive panel 1 → the same panel 1
High potential (V _CC ) is applied to the electrode 6 of the upper conductive panel 1 and low potential (0 V) is applied to the electrode 7 of the same conductive panel 1 via the path of "electrode 7 → TR2 → ground". If).

Since the two conductive panels 1 and 2 are in point contact with each other at any position by the pressing of the pen, the conductive panels on the side to which the voltage is not applied (the upper side in the case of T1). In the case of the conductive panel 1 or T2, the potential of the contact point of the conductive panel on the side to which the voltage is applied, that is, one potential in the potential gradient appears on the lower conductive panel 2). .

Accordingly, the magnitude of V _(X) at a predetermined timing of the first period (T1) in (t1) is, from the electrode 4 of the lower conductive panel 2 (or the electrode 3) to the contact point Represents the distance (X coordinate), and also the second period (T2)
Since the magnitude of V _(Y) at a predetermined timing (t2) in the inside represents the distance (Y coordinate) from the electrode 6 (or electrode 7) of the upper conductive panel 1 to the contact point, these are combined. The X and Y coordinates of the pen contact point can be specified.

[0013]

However, in such a conventional coordinate detecting device, the first A period (T1
A) or the second A period (T2A), a voltage equivalent to V _CC is applied between the two conductive panels, and the same period (T1A or T2) is applied.
If the potential of the conductive panel on the high potential side at a predetermined timing (t1a or t2a) in A) is a low potential equivalent to 0V, it is determined that there is contact with the pen. (T1a or t2
The initial stage of the first period (T1) or the second period (T2) after the passage of a), specifically, the conductive panel 1 or 2
If the pen becomes non-contact in the transitional stage from the start of the application of the voltage V _X or V _Y to the panel to the stabilization of the potential gradient on the panel, there is no way to recognize this and the instability As a result of the coordinates being specified based on an incorrect potential gradient, there is a problem that the reliability of coordinate detection is greatly impaired.

FIG. 6 is an operation waveform diagram (for the sake of convenience, an operation waveform diagram of the period 1A and the first period) for explaining the above problem. In this figure, the upper waveform represents changes in the potential (V _(X) ) of the conductive panel 1, and the lower waveform represents contact (H level) and non-contact (L level) of the pen.
Further, the upper and lower solid lines represent the case where the pen is not in contact after the judgment of the pen contact, and the broken lines represent the case where the pen is in the non-contact after the judgment (when the above problems occur).

The time point a is the start point of the period 1A (T1A), that is, the period for determining the presence / absence of pen contact. At this starting point a, when the pen is in contact, the two conductive panels 1 and 2 are in a conductive state with each other, and “V _CC → TR5
→ R6 → Electrode 6 → Conductive panel 1 → Conductive panel 2 → Electrode 3 → TR4 → Ground ", a current flows, and the potential V _(X) of the conductive panel 1 has a predetermined time constant (two conductive sheets _). (Provided by the capacitance and resistance of the sex panels 1, 2) gradually approaching the ground potential.

Therefore, at the time of about the end of T1A,
Potential V at (corresponding to the above timing t1a)_(X)
The value of is always the ground potential as long as the pen is in contact.
It will show a considerable low potential. Then end of T1A
At the same time, the first period (T1) is started. At this T1
Is a predetermined direct current between the electrodes 3 and 4 of the lower conductive panel 2.
Voltage V_XIs applied and the potential gradient between the electrodes 3 and 4 is sufficient.
After waiting for stabilization, the potential V of the upper conductive panel 1 _(X)
To detect.

The potential gradient between the electrodes 3 and 4 stabilizes at a point d when a certain time has elapsed from the starting point C of T1, but the detected potential V _(X) when the contact state of the pen is maintained is ,
As shown by the waveform of the solid line, it completely matches with one potential in the potential gradient between the electrodes 3 and 4. Therefore, V _(X) at an appropriate time point after time point D (for example, time point E; corresponding to the above timing t1) is V _(X)
Distance from (or electrode 4) to contact point of pen (X coordinate)
Is accurately represented.

On the other hand, when the pen becomes non-contact at the initial stage of T1, for example, when the pen becomes non-contact at the time point between the time points c and d, the potential gradient at this time point is reached. , That is, the potential V in the potential gradient before reaching the stable state
_{Since (X)} is fixed, there is a problem that the error indicated by Δ _X cannot be avoided when the coordinates of the time point e are specified. [Purpose] Therefore, the present invention is to connect the conductive panel on the voltage non-application side intermittently to a predetermined constant-potential power supply in the first period T1 or the second period T2, so that the conduction during the same period is increased. The discharge path or charge path of the opacity panel is secured so that it can be determined even if the pen is not in contact at the initial stage of the synchronization (transition period of the potential gradient), and incorrect coordinates can be specified. It is intended to avoid the above and improve the reliability of coordinate detection.

[0019]

The invention according to claim 1 is
A first voltage application for applying a predetermined DC voltage between two conductive panels that are arranged opposite to each other with a minute gap therebetween and two opposite sides of one conductive panel in the X-axis direction in the first period. Means, second voltage applying means for applying a predetermined DC voltage between the two opposite sides of the one conductive panel in the Y-axis direction in the second period, and first voltage applying means before the first period. A third voltage applying means for applying a predetermined DC voltage between the two conductive panels in a period A and a period 2A prior to the second period, and during the first period and the second period. And a connecting means for intermittently connecting the other conductive panel to a predetermined constant-potential power supply, and a predetermined timing (t1 during the period 1A).
a) and a predetermined timing (t2 during the second A period).
a) and a predetermined timing (t1 _(i) ; i is 1, 2, 3, ...) During the first period and when the other conductive panel is not connected to a predetermined constant potential power source. To detect the potential of the other conductive panel, and
During a period of time and when the other conductive panel is not connected to a predetermined constant potential power source (t2).
_(i) ) a potential detecting means for detecting the potential of the other conductive panel, and two sheets based on the output of the potential detecting means at the predetermined timing (t1a) or the predetermined timing (t2a). A process for determining the presence or absence of contact between the conductive panels is executed, and a time-series change at the predetermined timings (t1 _(i) and t2 _(i) ) is obtained, and the change is not larger than a predetermined amount. In this case, a process of executing the process of specifying the coordinates of the contact point between the two conductive panels based on the output of the potential detecting means at each of the predetermined timings (t1 _(i) and t2 _(i) ) And means.

According to the second aspect of the invention, a minute gap is provided.
And two conductive panels placed opposite each other during the first period
A predetermined straight line is provided between two opposite sides of one conductive panel in the X-axis direction.
A first voltage applying means for applying a flow voltage and a second period
Between the two opposite sides of the other conductive panel in the Y-axis direction,
Second voltage applying means for applying a flow voltage, and the first period
Before period 1A and before period 2
During the period 2A, a predetermined direct contact is made between the two conductive panels.
Third voltage applying means for applying a flow voltage, and the first period
In the meantime, disconnect the other conductive panel to the specified constant potential power supply.
A first connecting means for connecting continuously, and during the second period
One of the conductive panels is intermittently connected to a specified constant potential power source.
Second connecting means for connection, and predetermined during the period of the first A
Timing (t1a) and the predetermined time during the period 2A
Timing (t2a) and during the first period and
The other conductive panel is connected to a predetermined constant potential power source.
Predetermined timing (t1_(i)I is 1,
2, 3, ...) to detect the potential of the other conductive panel
Together with the one of the conductive layers during the second period.
Predetermined when the channel is not connected to the prescribed constant potential power supply
Timing (t2 _(i)) The potential of one conductive panel
And a predetermined timing (t
1a) or the predetermined timing (t2a).
2 conductive panels based on the output of the potential detecting means.
The process of determining whether there is contact between the
The predetermined timing (t1_(i)And t2_(i)) Time series
If the change is not larger than a predetermined amount, seeking a line change
The predetermined timing (t1_(i)And t2_(i))
Based on the output of the potential detection means at each time point of
Performs processing to identify the coordinates of the contact points between conductive panels.
And a processing means for processing.

[0021]

According to the invention of claim 1 or 2, a predetermined direct current voltage is applied to one conductive panel during the first period or the second period, and the other conductive panel is intermittently applied. A constant potential power supply (eg V _CC or ground) is provided. Therefore, since the other conductive panel is intermittently discharged or charged toward the constant potential power source, for example, when the pen becomes non-contact in the initial stage of the same period, the other conductive panel of the other conductive panel is discharged. A time-series change appears in the electric potential due to discharge or charge, and the non-contact / contact of the pen at the initial stage (transition period of the electric potential gradient) during the synchronization is accurately determined depending on the presence or absence or the magnitude of this change.

[0022]

Embodiments of the present invention will now be described with reference to the drawings.
To do. 1 to 4 show one embodiment of the coordinate detecting device according to the present invention.
It is a figure which shows an example. First, the configuration will be described. Figure 1 Smell
Therefore, the coordinate detection device of the present embodiment is arranged with a minute gap.
The two conductive panels 21 and 22 arranged facing each other, and the first
During the period (T1), one of the conductive panels (lower conductive in the figure)
Characteristic panel 22; the same applies hereinafter) between two opposite sides in the X-axis direction (Fig.
Then, between the electrodes 23 and 24), a predetermined DC voltage V_XApply
Same as the first voltage applying means 25 for the second period (T2).
Between two opposite sides of one conductive panel 22 in the Y-axis direction (in the figure,
Is a predetermined DC voltage V between electrodes 26 and 27)_YTo apply
The second voltage applying means 28 and the first A before T1
Period (T1A) and period 2A before T2
In (T2A), between the two conductive panels 21 and 22 (see FIG.
Then, between the electrode 29 and the electrode 23 or the electrode 27),
Current voltage V_CThird voltage applying means 30a, 30 for applying
b and the predetermined timing (t1a) between T1A and
And a predetermined timing (t2a) between T2A and
Predetermined timing (t1_(i)I is 1,
2, 3, ...) and a predetermined timing between the above T2
(T2_(i)), The potential of the other conductive panel 21 (V_(X)
/ V _(Y)) Detecting potential (for example, A / D conversion)
31) and at the time of the t1a or the t2a
Based on the output of the potential detecting means 31, two conductive panels are
Processing for determining the presence or absence of contact between the rule 21 and 22 (contact determination
Processing) and at the same time t1_(i)And t2
_(i)Of the output of the potential detecting means 31 at each time point of
When the deviation on the line is less than or equal to the reference value, the potential detection means 31 outputs
Contact point between two conductive panels 21, 22 based on force
Perform the process (coordinate specification process) to specify the coordinates of
In each of the periods T1A, T1, T2A and T2, and
Timing t1a, t1_(i), T2a and t2_(i)The table
Each timing signal S_T1A, S_T1, S_T2A, S
_T2, S_t1a, S_{t1 (i)}, S_t2aAnd S_{t2 (i)}To generate
And a processing means (for example, a microcomputer) 32
In addition, the point of this embodiment is that the first period
During the second period (T2) and during the second period (T2).
The channel 21 is connected to a predetermined constant potential power source (ground potential in the figure).
Ru V_CCConnection means 3 for connecting intermittently to
3 is provided.

The connecting means 33 connects the collector to the electrode 29a of the upper conductive panel 21 and connects the emitter to the ground potential, which is an npn type bipolar transistor TR6.
This TR6 is for forcibly setting the potential of the upper conductive panel 21 to the ground potential when a predetermined control signal S _{cont applied} to the base is active.

The predetermined control signal S_contIs the first period
Within the period (T1) or the second period (T2), and before
Signal S_{t1 (i)}Or S_{t2 (i)}Is inactive,
Signals that become active intermittently at equal or unequal intervals
And its generation place is S _T1, S_T2, S_{t1 (i)} And S
_{t2 (i)}In order to synchronize with
Yes.

FIG. 2 shows a specific cross-sectional structure of the two conductive panels 21 and 22. ITO is formed on the lower surface of a transparent and elastic sheet 34 such as a PET (polyester) film.
A film 3 having flexibility and conductivity such as (indium oxide)
5 to form the upper conductive panel 21, and further, a flexible and conductive film 37 such as ITO is formed on the transparent substrate 36 such as glass to form the lower conductive panel 22. Make up. In addition, 38 is an insulating and flexible spacer, and 39 is, for example, an insulating thick double-sided adhesive tape that joins the ends of the two conductive panels 21 and 22.

The first voltage applying means 25 includes the electrode 23 or
The same number of pnp type bipolar transistors as the number of electrodes 24
Dista TR3_j(J is 1 to the number of electrodes; the same applies below) and np
n-type bipolar transistor TR4_jConsists of TR
Three_jAnd TR4_jIs the signal S_T1(And its inverted signal)
Turns on when active and TR4_jIs the signal S
_T1AAlso turns on when the inverted signal of is active.

The second voltage applying means 28 is composed of the electrodes 2
6 or the same number of electrodes 27 as the number of electrodes of pnp type bipolar transistors TR1 _j and npn type bipolar transistors TR2 _j , and TR1 _j and TR2 _j are turned on when the signal S _T2 (and its inverted signal) is active. At the same time, TR2 _j also turns on when the inverted signal of the signal S _T2A is active.

Further, the third voltage applying means 30a, 30
b is a pnp-type bipolar transistor TR5 (and TR4j of the first voltage applying means 25 and TR2 _{j of} the second voltage applying means 28), and TR5 (and TR4).
_j and TR2 _j ) are turned on when the signal S _T1A (and its inverted signal) or the signal S _T2A (and its inverted signal) is active.

R21, R22 _j , R23 _j , R2
4 _j , R25 _j, and R26 are resistors, and V _CC is a DC power supply (for example, +5 V). In such a configuration, the flow of processing is the same as in the conventional example at the beginning, from "contact determination processing" to "X.
The process is “coordinate (or Y coordinate) coordinate specifying process” → “contact determination process” → “Y coordinate (or X coordinate) coordinate specifying process”, which is sequentially repeated.

In the contact determination process in the first A period (T1A) or the second A period (T2A), the signal S _T1A or the signal S _T1A is _{detected.
T2A} becomes active, and in response thereto, TR5 (and TR4 _j or TR of the third voltage applying means 30a, 30b) is activated.
2 _j ) is turned on. Therefore, "V _CC → TR5 →
The conductive panel 21 on the upper side via the path of R6 → electrode 29 ”
Is applied with a high potential (V _CC ), and the lower conductive panel 22 passes through a path of “electrode 23 (or electrode 27) → TR4 _j (or TR2 _j ) → ground” to the ground potential (0
V) is given.

That is, the potential V _(X) / V _(Y) of the upper conductive panel 21 at this time is maintained at a high potential equivalent to V _CC . In this state, using the pen, the upper conductive panel 2
When an arbitrary position of 1 is pushed, the position of the upper conductive panel 21 is dented, and the lower conductive panel 22 is point-contacted.

Therefore, "V _CC → TR5 → R6 → electrode 2
9 → upper conductive panel 21 → lower conductive panel 22
→ electrode 23 (or electrode 27) → TR4 _j (or TR
A closed circuit is formed in the path of “2 _j ) → ground”, and a low potential substantially equivalent to the ground potential appears between the electrode 29 of the upper conductive panel 21 and the ground. That is, the potential V _(X) / V _(Y) of the upper conductive panel 21 at this time changes to a low potential equivalent to the ground potential.

Therefore, at a predetermined timing (t1a) during the first A period (T1A) or the second A period (T2A).
Alternatively, at t2a), V _(X) / V is detected by the potential detecting means 31.
The size of _(Y) is examined, and if there is a high potential equivalent to V _CC , it is determined that there is no contact with the pen, and if it is a low potential that corresponds to 0 V, it is determined that there is contact with the pen. Upon entering the first period (T1) or the second period (T2), the signal S _T1 (and its inverted signal) or the signal S _T2 (and its inverted signal) becomes active and responds to this. First voltage applying means 25
TR3 _j and TR4 _j or TR1 _j and TR2 _{j of} the second voltage applying means 28 are turned on.

Therefore, "V _CC → TR3 _j → electrode 24 of the conductive panel 22 → electrode 23 of the panel 22 → TR4 _j
A high potential (V _CC ) is applied to the electrode 24 of the lower conductive panel 22 and a low potential (0 V) is applied to the electrode 23 of the same panel 22 via the path of "→ ground" (in the case of T1). Alternatively, “V _CC → TR1 _j → electrode 26 of conductive panel 22 →
A high potential (V) is applied to the electrode 26 of the lower conductive panel 22 via a path of “electrode 27 of the panel 22 → TR2 _j → ground”.
_CC ) also causes a low electric potential (0
V) is given (for T2).

Here, the two conductive panels 21 and 22
Is in point contact with the pen at any position by the pressing of the pen, the potential of the contact point of the conductive panel 22 on the side to which the voltage is applied, That is, one potential in the potential gradient appears.
Therefore, the potential V of the upper conductive panel 21 at the predetermined timing (t1 _(i) ) during the first period (T1).
The magnitude of _(X) / V _(Y) represents the distance (X coordinate) from the electrode 23 (or electrode 24) of the lower conductive panel 22 to the contact point, and also in the second period (T2). The magnitude of the potential V _(X) / V _(Y) of the upper conductive panel 21 at a predetermined timing (t2 _(i) ) is lower than that of the lower conductive panel 2.
Since the distance (Y coordinate) from one electrode 26 (or electrode 27) to the contact point is represented, the X and Y coordinates of the pen contact point can be specified by combining these.

FIG. 3 is a schematic flow chart showing the contact determination process and the X coordinate (or Y coordinate) coordinate specifying process in this embodiment. This flow is as follows:
(B) data collection unit, (c) post pen contact determination unit,
It is roughly divided into (d) data processing and deviation calculation unit, (e) data abnormality determination unit, and (f) panel charging / discharging unit, which is the point of this embodiment. In the following, the operation of detecting the X coordinate will be described, and the Y coordinate will be indicated with [].

In (a), first, at step P ₁ , the signal S
_T1A and its inversion signal [S _T2A and its inversion signal] are activated, and after waiting for a predetermined time α in step P ₂ , the signal S _t1a [S _t2a ] is activated in step P ₃ . That is, this pre-pen contact determination unit (a)
TR5 and TR4 of the third voltage applying means 30a, 30b
_j [TR2 _j ] is turned on, a high potential equivalent to V _CC is applied to the upper conductive panel 21, and a low potential equivalent to 0 V is applied to the lower conductive panel 22, and this state is kept for a predetermined time. α After the potential of the upper conductive panel 21 has sufficiently risen, the potential V _(X) / of the upper conductive panel 21 is continuously increased.
V _(Y) is measured, and if the measured value is a high potential equivalent to V _CC , the non-contact of the pen is determined, and if the measured value is a low potential equivalent to 0 V, the contact of the pen is determined.

[0038] In the following (b), first, and activates the signal S _T1 and the inverted signal [S _T2 and the inverted signal] in step P _4, after waiting a predetermined time β in step P _5, Step P ₆ Signal S _{t1 (i)} [S _{t2 (i)} ] is activated to activate the potential V _(X) / V of the upper conductive panel 21.
Measure _(Y) . That is, this data collection unit (b)
Is TR3 _j and TR4 of the first voltage applying means 25.
_j [TR1 _j and TR2 _{j of} the second voltage applying means 28]
Is turned on, a predetermined DC voltage V _X [V _Y ] is applied to the lower conductive panel 22, and this state is kept for a predetermined time β.
Continuously, the X direction of the lower conductive panel 22 [Y direction]
After the potential gradient of 1 is sufficiently stabilized, the potential V _(X) / V _(Y) of the upper conductive panel 21 is measured.

Here, the measurement is of i during T1 [T2] period.
When the maximum value is n, it is repeated about n / 3 times. For example
If n = 24, the first step P₆Execution of i
= 1 to i = 8, that is, S_{t1 (1)}, S_{t1 (2)}, S
_{t1 (3)}, ……, S_{t1 (8)}[S _{t2 (1)}, S_{t2 (2)}, S
_{t2 (3)}, ……, S_{t2 (8)}] Signal becomes active
Therefore, 8 data are collected at one time.

Next, the point of this embodiment is (f).
Is executed when it is determined that i = n is not satisfied in the final step P ₇ of (b). In the panel charging / discharging unit (f), first, the signal S _cont is activated in step P ₈ , and the predetermined time γ is waited in step P ₉ .
In step P ₁₀ , the signal S _cont is deactivated, and in step P ₁₁ , the signal S _cont is again waited for a predetermined time δ, and then the above (b)
Return to step P ₆ of.

That is, in this panel charging / discharging section (f), TR6 of the connecting means 33 is switched every time the signal S _{t1 (i )} [S _{t2 (i)} ] is activated eight times during the period T1 [T2]. This is to turn on for the time γ and connect the upper conductive panel 21 to the ground potential. More specifically, if n = 24 and the number of measurements in step P ₆ is 8, T1 During the [T2] period, the discharging operation of the upper conductive panel 21 (the charging operation when the constant-potential power supply is V _CC ) is intermittently executed at least twice.

In (c), first, in step P ₁₂ , the signal S
_T1A and its inverted signal [S _T2A and its inverted signal] are activated, and after waiting for a predetermined time α in step P ₁₃ , the signal S _t1a [S _t2a ] is activated in step P ₁₄ . That is, the subsequent pen contact determination unit (c)
The TR5 and TR4 _j [T of the third voltage applying means 30a and 30b are the same as the above-mentioned pre-pen contact determination section (a).
R2 _j ] is turned on and a high potential equivalent to V _CC is applied to the upper conductive panel 21 and a low potential equivalent to 0 V is applied to the lower conductive panel 22, and this state is continued for a predetermined time α. Then, after the potential of the upper conductive panel 21 rises sufficiently, the potential of the upper conductive panel 21 V _(X) / V _(Y)
Is measured, and if the measured value is a high potential equivalent to V _CC, the non-contact of the pen is determined, and if the measured value is a low potential equivalent to 0 V, the contact of the pen is determined.

Next, in (d), first, in step P ₁₅ , the average value of the i pieces of data collected by the data collecting section (b) is calculated. The average value calculation performed here is data processing for increasing the reliability of data, but is not necessarily limited to average value processing. In short, any method can be used as long as it can eliminate or suppress the influence of noise or the like. Then, the i pieces of data deviation calculated in step P _16, or above the pre-pen contact determination unit in step P ₁₇ (a) and both determination results of the post-pen contact determination unit (c) is a contact not If YES, then in step P ₁₈ , the deviation obtained in step P ₁₆ is compared with the reference value. And
If both of these steps P ₁₇ and P ₁₈ are YES,
In step P ₁₉ , the detected data is normal, and either one is NO.
To determine the abnormality of the detection data in step P ₂₀ For.

If the pen maintains the contact state at all stages of the T1 [T2] period, the above data collecting section (b)
The values of the i data groups collected in (1) are almost the same, and if the variations are ignored, they converge to a deviation of zero or a very narrow width in the vicinity thereof. However, when the pen becomes non-contact in the initial stage of the same period, the i data groups are responsive to the operation of the above charging / discharging unit (f), and every 8 continuous data units. Gradually decrease the value (in case of discharge;
Increase if charging).

Therefore, it is clear that the deviation in this case is a value other than zero. Therefore, if the deviation is compared with an appropriate reference value, the non-contact of the pen during the transient period of the potential gradient can be accurately determined. It is possible to make a determination, avoid output of incorrect coordinate detection information, and improve the reliability of coordinate detection. Here, the operation of this embodiment will be described with reference to FIG. In this figure, the upper waveform shows the potential (V _(X) / V _(Y) ) change of the conductive panel 21, and the lower waveform shows the contact (H level) and non-contact (L level) of the pen. There is. Further, the upper and lower solid lines represent the case where the pen does not become non-contact after the judgment of the pen contact, and the broken lines represent the case where the pen becomes non-contact after the judgment.

Time point a'is the start point of the period 1A (T1A), that is, the period for determining the presence or absence of pen contact. At this starting point a ', when the pen is in contact, the two conductive panels 21 and 22 are in conduction with each other, and "V _CC
→ TR5 → R6 → Electrode 29 → Conductive panel 21 → Conductive panel 22 → Electrode 23 → TR4 _j → Ground ”, a current flows, and the potential V _(X) / V _(Y) of the conductive panel 21 is predetermined. Gradually approaching the ground potential along the time constant (given by the capacitance and resistance of the two conductive panels 21 and 22).

Therefore, the potential V at the time point b ′ (corresponding to the above timing t1a) near the end of T1A.
The value of _(X) / V _(Y) always shows a low potential equivalent to the ground potential as long as the pen is in contact. Then
At the same time as the end of T1A, the first period (T1) is started.
At this T1, the electrodes 23, 2 of the lower conductive panel 22 are
A predetermined DC voltage V _X is applied between the two electrodes 23, 24
After waiting for sufficient stabilization of the potential gradient between them, the potential V _(X) / V _(Y) of the upper conductive panel 21 is detected. Both electrodes 2
The potential gradient between Nos. 3 and 24 stabilizes at a time d'after a certain time has elapsed from the starting time C'of T1, but the detection potential V _(X) / V _(Y when the contact state of the pen is maintained. ₎ Completely coincides with one potential in the potential gradient between the two electrodes 23 and 24, as indicated by the solid waveform.

Therefore, an appropriate time point after the time point d '(time point e'; corresponding to the above timing t1 _(i) )
V _(X) / V _(Y) in (3) accurately represents the distance (X coordinate) from the electrode 23 (or electrode 24) on the X coordinate axis to the contact point of the pen. On the other hand, if the pen becomes non-contact in the initial stage of T1, for example, the time point between the time points c and d '
If the pen becomes non-contact with, the potential V _(X) / V _(Y) is fixed by the potential gradient at this point, that is, the potential gradient before reaching the stable state. In the example, the potential V _(X) / V _(Y) of the upper conductive panel 21 is discharged for a predetermined time (γ) at an appropriate time point T ', C'in the period of T1, so that the discharge operation is performed in accordance with the discharge operation. V _(X) / V _(Y) can be gradually decreased, and the non-contact of the pen during the transient period of the potential gradient can be detected based on this potential change.

In the above embodiment, the non-contact of the pen is determined by the deviation of the data, but the present invention is not limited to this, and the magnitude of the data may be compared on the time axis. The invention can also be applied to the prior art mentioned at the beginning. That is,
TR2 may be turned on several times during the first period (T1), and TR4 may be turned on several times during the second period (T2). The ON time is a predetermined time γ.

Further, the measurement of V _(X) or V _{(Y )} during the first period (T1) or the second period (T2) is performed by the unstable period of the potential gradient, the ON period of TR2 or TR4, and ,
It may be repeated at an appropriate timing excluding the period from the OFF transition of TR2 or TR4 until the time δ elapses. Therefore, TR2 functions as a first connecting unit that intermittently connects the other conductive panel 1 to a predetermined constant potential power source during the first period (T1), and TR4 is
It functions as a second connecting unit that intermittently connects one conductive panel 2 to a predetermined constant potential power supply during the second period (T2).

[0051]

According to the invention of claim 1 or claim 2, during the first period or the second period, an intermittent constant potential power supply (for example, V _CC or ground) is intermittently provided to the other conductive panel. The other conductive panel is intermittently discharged or charged toward the constant potential power supply. Therefore, for example, when the pen becomes non-contact in the initial stage of the same period, the potential of the other conductive panel changes in time series due to discharging or charging. Since it is possible to accurately determine the non-contact / contact of the pen in the initial stage (transition period of the potential gradient) during the same period, it is possible to avoid erroneous coordinate detection and improve the reliability of coordinate detection.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment.

FIG. 2 is a structural diagram of a conductive panel.

FIG. 3 is an operation flow of an embodiment.

FIG. 4 is an operation waveform diagram of one embodiment.

FIG. 5 is a configuration diagram of a conventional example.

FIG. 6 is an operation waveform diagram of a conventional example.

[Explanation of symbols]

 TR2: first connecting means TR4: second connecting means 1, 2: conductive panel 5: first voltage applying means 8: second voltage applying means 9: third voltage applying means 10: potential detecting means 11: processing means 21, 22: conductive panel 25: first voltage applying means 28: second voltage applying means 30a, 30b: third voltage applying means 31: potential detecting means 32: processing means 33: connecting means

Claims (2)

[Claims] 1. Two conductive panels (21, 22) arranged to face each other with a minute gap therebetween, and a predetermined interval between two facing sides of one conductive panel in the X-axis direction in a first period. First voltage applying means (2 for applying a DC voltage)
5), second voltage applying means (28) for applying a predetermined DC voltage between two opposing sides of the one conductive panel in the Y-axis direction during the second period, and before the first period. Third voltage applying means (3) for applying a predetermined DC voltage between the two conductive panels during the first A period and the second A period prior to the second period.
0a, 30b) and connecting means (3) for intermittently connecting the other conductive panel to a predetermined constant potential power source during the first period and the second period.
3), a predetermined timing (t1a) during the first A period, a predetermined timing (t2a) during the second A period, and a predetermined constant during the first period and the other conductive panel. The potential of the other conductive panel is detected at a predetermined timing (t1 _(i) ; i is 1, 2, 3, ...) When not connected to the potential power source, and during the second period and A potential detecting means (3) for detecting the potential of the other conductive panel at a predetermined timing (t2 _(i) ) when the other conductive panel is not connected to a predetermined constant potential power source.
1) and the potential detection means (31) at the predetermined timing (t1a) or the predetermined timing (t2a).
Processing for determining the presence / absence of contact between the two conductive panels based on the output of the above, and determining the time series change of the predetermined timings (t1 _(i) and t2 _(i) ). When the change is not larger than a predetermined amount, the contact between the two conductive panels is made based on the output of the potential detecting means (31) at each of the predetermined timings (t1 _(i) and t2 _(i) ). A coordinate detecting device comprising: a processing means (32) for executing a process for specifying the coordinates of a point. 2. Two conductive panels (1, 2) arranged to face each other with a minute gap therebetween, and a predetermined interval between two facing sides of one conductive panel in the X-axis direction in the first period. First voltage applying means (5) for applying a DC voltage, and second voltage applying means (5) for applying a predetermined DC voltage between two opposite sides of the other conductive panel in the Y-axis direction during the second period. 8) and a third voltage for applying a predetermined DC voltage between the two conductive panels in a period 1A prior to the first period and a period 2A prior to the second period. Applying means (9) and first connecting means (TR2) for intermittently connecting the other conductive panel to a predetermined constant potential power source during the first period.
And second connection means (TR4) for intermittently connecting the one conductive panel to a predetermined constant-potential power supply during the second period.
And a predetermined timing (t1a) during the period of the first A, a predetermined timing (t2a) during the period of the second A, and a predetermined constant potential power source during the first period and the other conductive panel. The potential of the other conductive panel is detected at a predetermined timing (t1 _(i) : i is 1, 2, 3, ...) When not connected to Potential detecting means (1) for detecting the potential of one conductive panel at a predetermined timing (t2 _(i) ) when the conductive panel is not connected to a predetermined constant potential power source.
0) and the potential detection means (10) at the predetermined timing (t1a) or the predetermined timing (t2a).
Processing for determining the presence / absence of contact between the two conductive panels based on the output of the above, and determining the time series change of the predetermined timings (t1 _(i) and t2 _(i) ). When the change is not larger than the predetermined amount, the contact between the two conductive panels is made based on the output of the potential detection means (10) at each of the predetermined timings (t1 _(i) and t2 _(i) ). A coordinate detecting device comprising: a processing unit (11) for executing a process of specifying the coordinates of a point.