JPH06236231A - Coordinate detecting device - Google Patents

Abstract

PURPOSE:To uniformize an attenuation factor and to improve coordinate detection accuracy by forming at least one of the two poles feeders in a loop shape or forming one of them to the loop-shaped feeder and the other to the Y-shaped feeder. CONSTITUTION:As the two feeders for detecting a coordinate on a position detecting plane designated by an operator by using a position indicator, both of Y-shaped and loop-shaped feeders are used. Namely, this device uses both of a Y-shaped feeder 31 as the feeder of the low attenuation factor for a position detecting member close to a point A and uses a loop-shaped feeder 41 as the feeder of the low attenuation factor for a position detecting member away from the point A. When one of two feeders is loop-shaped at least, the attenuation factor of the feeder for the position detecting member at a position away from a junction is lowered. When one of the feeders is loop-shaped and the other is Y-shaped, as a result, the attenuation factor of all the detecting members is uniformized.

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 used as an input device of a computer, and more particularly to a feeder line used as a sense line of an electromagnetic induction type coordinate detecting device, and more particularly to its shape and a coordinate detecting device using the same.

[0002]

2. Description of the Related Art A coordinate detecting device, which is usually called a digitizer tablet, has a coordinate detecting surface, detects a position designated by an operator on a coordinate detecting surface by a position indicator, and converts it into coordinate data. Then, the signal is transmitted to an external device such as a computer.

Position detection is performed by some physical interaction between the position indicator and the coordinate detection surface side. For example, position detection methods such as electrostatic induction, electromagnetic induction, and methods using light or ultrasonic waves have been proposed. Whatever the position detection method, so-called Cartesian coordinates (X
The position indicated by the position indicator is often read using (Y coordinate). In that case, the coordinate detection surface of the coordinate detection device may be configured by arranging members that emit some kind of electric signals or members that receive some electric signals in parallel in each of the XY directions at predetermined intervals.

For example, the coordinate detecting device disclosed in the "position detecting device" (Japanese Patent Laid-Open No. 63-307522) already proposed by the applicant of the present application includes a member for generating an alternating magnetic field in each of XY directions. However, a large number of sense lines, which are also members for detecting the alternating magnetic field, are arranged in parallel.

The above-mentioned “position detection device” proposed by the applicant
The principle of the invention disclosed in the embodiment will be briefly described. Time is divided into excitation of the X sense line, level detection of the X sense line, excitation of the Y sense line, and level detection of the Y sense line. The XY coordinates are alternately calculated. When exciting the X sense line, X
A high frequency current is applied to the sense line to generate an alternating magnetic field. The position indicator side is provided with a resonance circuit capable of resonating at the high frequency, and when the position indicator is placed at a certain position on the coordinate detection surface that the operator desires to input, the resonance causes the position indicator side of the position indicator side. An alternating magnetic field is also generated in the coil. Shortly thereafter,
The supply of high-frequency current to the X sense line is stopped, and this time X is generated by the alternating magnetic field returned from the coil on the position indicator side.
The voltage generated on the sense line is detected. The X coordinate is calculated by comparing which X sense line has the highest voltage level. Similar processing is performed for the Y coordinate.

A member arranged in parallel in each of the XY directions at a predetermined interval will be referred to as a position detecting member in the present application. This position detecting member is made of a capacitive member or an inductive member depending on the difference in the coordinate detecting method. In the above-mentioned prior art, the position detection member is composed of an inductive member, and has a function of generating an alternating magnetic field and a function of detecting an alternating magnetic field by time division.
In the present application, the term "position detecting member" is not limited to a member having a function of outputting a position detecting signal, and will be used. Similarly, even in the case of the electromagnetic induction type coordinate detecting device, in another device having a different coordinate detecting method, there may be a position detecting member having only one of the above-mentioned two functions, or other device such as electrostatic induction. This is because there is a similar situation in the coordinate detection method.

For example, in an electromagnetic induction type coordinate detecting device, an alternating magnetic field is generated by supplying a power source, that is, an alternating current transmission signal to an inductive member arranged in parallel on the coordinate detecting surface to indicate a position. There is also a device configured to detect the alternating magnetic field on the device side to detect the indicated position. In that case, a transmission signal is supplied to the position detection member, but the detection signal is not extracted from the position detection member,
The position detection signal is taken out from the position indicator side.

Further, in the electromagnetic induction type coordinate detecting device, among the position detecting members arranged in the XY directions, a transmission signal is supplied to the position detecting members arranged in the X direction to alternate. A magnetic field is generated to excite the resonance circuit provided in the position indicator, and the alternating magnetic field generated by the inductive member of the excited resonance circuit is reversed to detect the position arranged in parallel in the Y direction on the position detection surface side. There is also a configuration in which detection is performed by a member.

Of course, there is a structure in which an alternating magnetic field is generated on the position indicator side and a position detecting member provided on the position detecting surface side is configured to take out a signal for position detection.

Now, the concept of a power supply line will be defined. It goes without saying that the position detecting member described above is provided in an organic relationship with other circuits provided in the coordinate detecting device. As described above, in the case of the electromagnetic induction method, the position detecting member has one of the two functions of generating an alternating magnetic field and detecting the alternating magnetic field, or has both functions by time division. In general, not only the electromagnetic induction method but also a general coordinate detection device has two functions, that is, a function of performing some physical action by receiving a transmission signal and a function of converting into an electric signal by receiving some physical action. It is considered to have at least one of these functions. Here, some of the physical actions are not only due to changes in magnetic field, but also light, sound waves,
Those related to ultrasonic waves and changes in electric field are included.

When the position detecting members perform some physical action by being supplied with a transmission signal, the circuits connected to these position detecting members have a property as a transmission signal supplying circuit. Further, when the position detecting members have a function of converting into an electric signal by receiving some physical action, a circuit connected to these position detecting members processes the electric signal to calculate coordinates. It has the property of a circuit.

Focusing on the conducting wire directly connected to the position detecting member, when the position detecting member receives a transmission signal and performs some physical action, it functions as a transmission signal supplying line. When the position detecting member has a function of converting it into an electric signal by receiving some physical action, it has a function as a signal line for sending the electric signal to the processing circuit. In the present application, regardless of which of the above-mentioned functions the conducting wire directly connected to the position detecting member has, it will be referred to as a power feeding wire. This is because even if it has a function as a signal line, it can be considered that an electric signal is supplied to the reception signal processing circuit side.

In the present application, the power supply line means a conducting wire directly connected to the position detecting member. What is the position detection member?
It is a member arranged in parallel in each of the XY directions orthogonal to the coordinate detection surface with a predetermined interval.

The shape of the power supply line which has been conventionally used will be described with reference to FIGS.

FIG. 8 is a diagram showing a balanced type feed line using only the Y-shape. In the conventional example shown in FIG. 8, the position detecting member is a U-shaped sense line, that is, an inductive position detecting member. X sense lines 11 and 12, which are position detecting members,
The 13, 14 and Y sense lines 21, 22, 23, 24 are arranged in parallel on the coordinate detection surface of the coordinate detection device at predetermined intervals in the respective XY directions. For the sake of understanding, FIG. 8 shows that adjacent sense lines are not overlapped with each other, but they are usually overlapped with each other.

A feed line is connected to each sense line, but in FIG. 8, the feed line is Y-shaped. That is, the Y-shaped power supply lines 81 and 82 are provided. Here, the Y-shape means that it is connected to the transmission signal supply circuit or the reception signal processing circuit at the center point of the L-shaped power supply line having a shape having two branches. B, C, D, and E are electrical connection points between the Y-shaped power supply line 81 and the X sense lines 11, 12, 13, and 14, respectively. F, G, H, and I are electrical connection points of the Y-shaped power supply line 81 and the Y sense lines 21, 22, 23, and 24, respectively. K, L, M, N are Y-shaped power supply lines 82
And the X sense lines 11, 12, 13, and 14 respectively. O, P, Q, and R are Y-shaped power supply line 82 and Y
It is an electrical connection point with each of the sense lines 21, 22, 23, 24.

As a modification of the Y-shape, it is conceivable that the conductor is composed of one line segment and is connected to the transmission signal supply circuit or the reception signal processing circuit at the center point. This should be called a T-shape rather than a shape, but in the present application, this is also called a Y-shape.
This modified shape can be used in a one-dimensional coordinate detection device or a two-dimensional coordinate detection device of the type in which the X sense line and the Y sense line are separately connected to the transmission signal supply circuit or the reception signal processing circuit.

In FIG. 8, it is drawn as if it is connected to an amplifier, assuming that the received signal detected by the sense line is sent to the processing circuit. In the balanced type feeder line, the amplifiers are connected at points A and B in FIG. Here, the balanced type refers to a case where a bridge circuit is applied so that voltage detection is accurately performed.

FIG. 9 is a diagram showing an unbalanced feeder line using only the Y-shape. What is different from that shown in FIG. 8 is that
This is how to connect to the amplifier at point A. Since a balanced circuit is generally expensive, an unbalanced circuit may be used for cost reduction. In that case, measures are taken to reduce the impedance by increasing the line width of the power supply line.

[0020]

This Y-shaped feed line supplies a uniform transmission signal to both the X sense line and the Y sense line, or from both the X sense line and the Y sense line. In order to achieve the purpose of making the level of the electric signal uniform and sending it to the processing circuit, it has reached a certain extent.

However, since the power feed line is a distributed constant circuit, when considering the attenuation rate of each of the plurality of X sense lines and Y sense lines provided, it is considered to be a transmission signal supply circuit or a reception signal processing circuit. There is a drawback in that the attenuation rate from each sense line to the reception signal processing circuit and the attenuation rate from the transmission signal supply circuit to each sense line are different depending on how close the distance is to the connection point. Figure 8
As for the Y-shaped power supply line 81 drawn in FIG. 3, the attenuation rate for the X sense line 11 and the attenuation rate for the X sense line 14 differ due to the difference in the lengths of the line segment AB and the line segment AE. .

This means that when the power supply line is connected to the transmission signal supply circuit, the transmission signal of a uniform level is not supplied to each sense line, and the power supply line is connected to the reception signal processing circuit. In that case, the received signal level becomes non-uniform depending on the location, resulting in a decrease in coordinate detection accuracy.

This will be described with reference to experimental data.
FIG. 10 is a diagram showing signal levels when only the Y-shape is used. In FIG. 10A, the horizontal axis represents the distance from the connection point of the transmission signal supply circuit or the reception signal processing circuit of the power supply line to each sense line. The right side is the X sense line and the left side is the Y sense line. The vertical axis represents the level of the voltage signal detected by the X sense line or the Y sense line. As the distance increases, the attenuation rate increases, and the level increases toward the center. This situation also applies to the power supply line shown in FIG. The graph is exaggerated for convenience of explanation.

It is an object of the present invention to solve this problem and provide a uniform level of transmitted signal at different locations,
Another object of the present invention is to provide a feeder line capable of detecting a received signal of a uniform level even at different positions.

[0025]

In order to achieve the above object, the coordinate detecting device according to the present invention receives a position indicator and a transmission signal to perform a physical action on the position indicator. Alternatively, a position detection surface, which is a member that generates an electric signal by receiving a physical action from the position indicator or that performs both of them, is arranged side by side at a predetermined interval in the position detection direction, A power supply line, which is a conductor provided to connect each position detection member and the transmission signal supply circuit or the reception signal processing circuit, is provided, and the reception signal detected by the position indicator or the position detection member is processed. Thus, in the coordinate detection device configured to detect the coordinates on the position detection surface designated by the operator with the position indicator, the power supply line is composed of a two-pole power supply line. At least in one consists loop shape.

One of the two-pole power supply lines can be formed in a loop shape and the other in a Y shape.

The position detecting members may be arranged side by side in each of the XY directions which are two orthogonal directions.

The position indicator is connected to the transmission signal supply circuit so as to perform the function of the alternating magnetic field generating means, and the position detecting members are so arranged that the position detecting members perform the function of the alternating magnetic field detecting member. Can be connected to the reception signal processing circuit by the power supply line.

In order for each of the position detecting members to function as the alternating magnetic field generating means, each of the position detecting members is connected to the transmission signal supply circuit by the power supply line, and the position indicator functions as the alternating magnetic field detecting means. The position indicator can be connected to the reception signal circuit.

In order for the position detecting member to perform the two functions of the alternating magnetic field generating means and the alternating magnetic field detecting means by time division, a switching means is provided at the other end of the power supply line of the two poles, and each position detecting member is provided. Can be connected to both the transmission signal supply circuit and the reception signal processing circuit via the bipolar feed line and the switching means.

Of the position detecting members arranged in parallel in the two directions orthogonal to each other, the position detecting members arranged in parallel in the first direction are arranged in the first direction so as to perform the function of the alternating magnetic field generating means. The respective position detecting members provided are connected to the transmission signal supply circuit by the first two-pole power supply line, and the position detecting members arranged in parallel in the second direction are arranged to perform the function of the alternating magnetic field detecting means. Each position detecting member arranged in parallel in two directions is connected to a reception signal processing circuit by a second bipolar power supply line, and both position detecting members are electromagnetically coupled by the position indicator. You can

[0032]

By making at least one of the two power supply lines loop-shaped, it works as if the attenuation factor of the power supply line for the position detection member far from the connection point is lowered.

Making one loop-shaped and the other Y-shaped serves to make the attenuation rate uniform for all position detecting members.

When the position indicator and the position detecting member are formed of an inductive member, there is a great demand for making the attenuation rate uniform, so that the function of the loop shape is large.

When the power supply line is connected to both the transmission signal circuit and the processing circuit, the attenuation factor becomes uniform in both cases.

[0036]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a diagram showing a balanced type feed line using a loop type. The same parts as those in the conventional example shown in FIG. As shown in the figure, the loop-shaped power supply line 43 forms a closed loop passing through the connection point A with the transmission signal supply circuit or the reception signal processing circuit, and the connection point with the position detection member (sense line) is A. By providing it on the far side, the sense line closer to A is configured to reach A through a longer portion. The loop type power supply line 44 is similarly configured.

Considering the attenuation rate of the loop-type feeder line 43, the attenuation rate between the point B and the point A is the level from the point B to the point C by rotating C, D and E in the clockwise direction. It is a value obtained by dividing the combined level of the levels from B to F by turning F, G, H, I counterclockwise until reaching point A by the level at point B.

In the embodiment using two loop type feeders,
The above-mentioned drawbacks of the conventional example are eliminated. This can be known from the experimental data shown in FIG. FIG. 5 is a diagram showing a signal level when a loop-shaped power supply line is used. The effect of reducing the attenuation rate in the far portion is eliminated by eliminating the defect that the attenuation rate is small near the point A and is higher as the distance is greater, which the conventional example shown in FIG. 10 has.

This also applies to the unbalanced feeder line using the loop type shown in FIG.

As described above, by using the loop-shaped power supply line, although the effect of lowering the attenuation rate for the position detecting member far from the point A can be obtained, on the contrary, the attenuation of the position detecting member close to the point A is attenuated. The result is higher rates. Further, in the unbalanced embodiment shown in FIG. 6, the impedance on the ground side is high, which causes noise. The situation during this period is shown in FIG.

In order to solve this problem, the embodiment shown in FIG. 1 uses both Y-shaped loop-shaped feeder lines. That is, a Y-shaped power feed line 31 that is a power feed line with a small attenuation rate for the position detection member near the point A and a loop-shaped power feed line 41 that is a power feed line with a low attenuation rate for the position detection member far from the point A. And are used together.

It is shown in FIG. 2 that this leads to a uniform detection level. The solid line in FIG. 2A shows the level only in the loop form. The broken line indicates the level based on the Y shape only. The alternate long and short dash line shows the detection level in the case where both Y-shaped loop-shaped feeders are used. Just the two have been combined to achieve evenness. The graph of FIG. 2A is exaggerated.

FIG. 3 is a diagram showing an unbalanced feeder line using both Y-shaped loops. Although it is almost the same as the balanced type embodiment shown in FIG. 1, the thickness of the Y-shaped power supply line 42 is adjusted to be thick in order to lower the impedance on the ground side and reduce noise. .

[0045]

Since the present invention is configured as described above, it is possible to make the attenuation factor of the power supply line uniform, and to improve the coordinate detection accuracy.

In particular, by using both the Y-shape and the loop shape together, the effect of uniformization is further enhanced.

Further, particularly in the case where the power supply line also functions as a transmission signal supply line for the position detection member and a signal line for transmitting a detection signal from the position detection member to the reception signal processing circuit, the effect of this uniformization is obtained. Is remarkably obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a balanced feed line using both Y-shaped loop types.

FIG. 2 is a diagram showing signal leveling.

FIG. 3 is a diagram showing an unbalanced feeder line using both Y-shaped loops.

FIG. 4 is a diagram showing a balanced type feed line using a loop type.

FIG. 5 is a diagram showing a signal level when a loop-shaped power supply line is used.

FIG. 6 is a diagram showing an unbalanced feeder line using a loop type.

FIG. 7 is a diagram showing an impedance distribution of a loop type power supply line.

FIG. 8 is a diagram showing a balanced feed line using only a Y shape.

FIG. 9 is a diagram showing an unbalanced power supply line using only a Y shape.

FIG. 10 is a diagram showing a signal level when only a Y-shape is used.

[Explanation of symbols] 11,12,13,14 X-sense line 21,22,23,24 Y-sense line 31,32,81,82,83,84 Y-shaped feeder line 41,42,43,44,45 , 46 loop type power supply line

Claims (7)

[Claims] 1. A position indicator and a physical signal are applied to the position indicator by receiving a transmission signal, or an electric signal is generated by receiving a physical action from the position indicator. Position detecting members, which are members for performing both of these, are provided to connect the position detecting surface formed by arranging the position detecting members side by side at a predetermined interval in the position detecting direction, and the position detecting members and the transmission signal supply circuit or the reception signal processing circuit. And a power supply line that is a conducting wire, by processing a signal detected by the position indicator or the position detection member,
In a coordinate detection device configured to detect coordinates on a position detection surface designated by an operator with a position indicator, the power supply line is composed of a bipolar power supply line, at least one of which is a loop shape. A coordinate detection device comprising: 2. The coordinate detection device according to claim 1, wherein one of the bipolar feed lines has a loop shape and the other has a Y shape. 3. The coordinate detecting device according to claim 1, wherein the position detecting members are arranged in parallel in each of XY directions which are two orthogonal directions. 4. The position indicator is connected to a transmission signal supply circuit so as to perform the function of the alternating magnetic field generating means, and each position detecting member functions so as to function as the alternating magnetic field detecting member. The coordinate detection device according to claim 1, 2 or 3, wherein a detection member is connected to the reception signal processing circuit through the power supply line. 5. The position detecting members are connected to a transmission signal supply circuit by the power supply line so that the position detecting members can function as the alternating magnetic field generating means, and the position indicator functions as the alternating magnetic field detecting means. The coordinate detecting apparatus according to claim 1, 2 or 3, wherein the signal received by the position pointing device is transmitted to a reception signal circuit as much as possible. 6. The position detecting member is provided with switching means at the other end of the two-pole power supply line so that the position detecting member can perform the two functions of the alternating magnetic field generating means and the alternating magnetic field detecting means by time division. 4. The coordinate detecting device according to claim 1, 2 or 3, wherein a detection member is connected to both the transmission signal supply circuit and the reception signal processing circuit via the bipolar power supply line and the switching means. 7. Among the position detecting members arranged in parallel in the two directions orthogonal to each other, each position detecting member arranged in parallel in the first direction serves to function as an alternating magnetic field generating means. The position detection members arranged in parallel with each other are connected to the transmission signal supply circuit by the first two-pole power supply line, and the position detection members arranged in parallel in the second direction perform the function of the alternating magnetic field detection means. Each position detecting member arranged in parallel in the second direction is connected to the reception signal processing circuit by a second bipolar power feed line, and both position detecting members are electromagnetically coupled by the position indicator. The coordinate detection device according to claim 1, 2 or 3, characterized in that.