JPH0786802B2 - Coordinate detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to a coordinate detection device for detecting coordinates on a plane plate by an electrostatic induction method.

(Prior Art) Generally, as a coordinate detection device by the electrostatic induction method,
The one shown in the figure is known.

In this device, the detection line 2 and the detection line 3 are arranged so as to be orthogonal to each other in the x direction and the y direction in the flat glass plate 1.

The x-direction detection line 2 and the y-direction detection line 3 are each driven by a predetermined drive circuit (not shown), and at a certain time point, a voltage is sequentially applied to only one detection line.

The stylus pen 4 is connected to a voltage detection circuit (not shown), and by detecting the electrostatic induction voltage,
It is possible to input a predetermined position on the glass plate 1.

FIG. 5 is a diagram showing a configuration of a main part of this coordinate detecting device, in which detection lines 2a, 2b ... Are arranged in the glass plate 1 in the x direction (the same applies to the y direction), and detection is performed at a certain point. The state where a voltage is applied to the line 2b is shown.

The stylus pen 4 points near the detection line 2b.

In this case, the capacitance between the detection line 2b and the input stage of the sense amplifier 5 in the stylus pen 2 is C ₀ , and the capacitance between the input stage of the sense amplifier 5 and the ground is C _1. The output E ₁ of the sense amplifier 5 can be represented by E ₁ = K · {C ₀ / (C ₀ + C ₁ )} · E ₀ (where K represents the amplification factor of the sense amplifier 5).

The output E ₁ of the sense amplifier 5 is “0” when the detection line 2b is not driven and, for example, the detection line 2a is driven.

Therefore, the pointing position of the stylus pen 4 can be detected from the output E ₁ of the sense amplifier 5 and the information indicating which detection line is being scanned.

(Problems to be Solved by the Invention) By the way, in general, the coordinate designation by the stylus pen is suitable for the designation of fine coordinates, but is not suitable for the designation of rough coordinates. It is convenient in terms of operability if the operator can give a rough coordinate instruction with a finger, but on the contrary, the coordinate instruction with a finger cannot give a fine coordinate instruction.

That is, although the coordinate designation by the stylus pen and the coordinate designation by the finger have properties that should be properly used in some cases, the conventional electrostatic coordinate detection device described above can detect the coordinate designation by the stylus pen. However, there is a problem that the coordinate instruction by the operator's finger cannot be detected.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a coordinate detecting device having a high degree of freedom, which is capable of detecting not only a coordinate pointing by a stylus pen but also a coordinate pointing by an operator's finger.

[Configuration of the Invention] (Means for Solving Problems) A coordinate detecting device according to the first invention is a flat plate, a plurality of detection lines arranged in the flat plate, and the detection lines sequentially. A drive circuit that applies a voltage, a stylus pen that detects a change in the electrostatic induction voltage between the detection line and itself, and a detection line to which a voltage is applied at a certain point among the detection lines. It is provided with detection means for detecting a change in electrostatic induction voltage between adjacent detection lines, and switching means for switching between voltage detection by the stylus pen and voltage detection by the detection means according to an instruction.

A coordinate detecting device according to a second aspect of the present invention is a plane plate, a plurality of first detection lines arranged in the plane plate, and a plurality of second detection lines arranged so as to be adjacent to the detection lines. Detection line, a drive circuit that sequentially applies a voltage to the first detection line, a stylus pen that detects a change in electrostatic induction voltage between the first detection line and itself, and a voltage at a certain time point. Means for detecting a change in the electrostatic induction voltage between the first detection line to which is applied and the second detection line adjacent thereto, voltage detection by the stylus pen, and voltage detection by the detection means And switching means for switching between and according to the instruction.

(Operation) In the first aspect of the present invention, the electrostatic induction voltage between the stylus pen and each detection line is detected, and between the detection line to which the voltage is applied at a certain time and the detection line adjacent to the detection line. The detection of the electrostatic induction voltage of can be switched arbitrarily.

Further, in the second aspect of the invention, the electrostatic induction voltage between the stylus pen and each detection line is detected, and the first detection line to which the voltage is applied at a certain point and the second detection line adjacent thereto. The detection of the electrostatic induction voltage between and can be switched arbitrarily.

Therefore, in any of the inventions, by operating the switching means, it is possible to select the instruction input with the stylus pen and the instruction input with the finger as necessary.

(Example) Hereinafter, the detail of the Example of this invention is described based on drawing.

FIG. 1 is a diagram showing the configuration of an embodiment of the first present invention.

In this embodiment, the detection line is placed in the flat glass plate 6 in the x direction.
7a, 7b, ... Are arranged, and a detection line (not shown) is also arranged in the y direction orthogonal to this. This point is common to the conventional coordinate detecting device shown in FIG.

Each of the detection lines 7a, 7b ... Is connected to a power source via switches 8a, 8b ... And these switches 8a, 8b ... Are sequentially opened and closed by a drive circuit (not shown).

The detection lines 7a, 7b ... Are connected to the terminal S _{1 of the} selector 11 via the switches 9a, 9b ... And the sense amplifier 10.

Terminal S _{2 of} selector 11 is connected to the stylus pen and
S ₃ is connected to the voltage detection circuit.

Next, the operation of this device will be described.

First, when this device is made to function as a coordinate detection device using a stylus pen, the terminals S ₃ and S ₂ of the selector 11 are connected.

Then, the switches 9a, 9b ... Are all opened, and the switches 8a, 8b.

And the stylus pen is near the detection line 7b, the switch 8b for this detection line 7b is closed,
When a voltage is applied to 7b, the electrostatic induction voltage is detected by the voltage detection circuit, and the coordinates of the pointing position of the stylus pen are detected.

Next, when this coordinate detecting device is used as a touch panel, the terminals S ₃ and S ₁ of the selector 11 are connected.

Then, the switches 8a, 8b ... Are sequentially opened and closed by the drive circuit, and the switch of the detection line adjacent to the detection line in which the switch is closed is closed by the drive circuit.

For example, when the switch 8b is closed, the switch 9a adjacent thereto is closed.

Here, the capacitance between the detection line 7a and the detection line 7b when the operator's finger is not on or near the glass surface is always a constant value C ₀ , and the electrostatic capacitance between the detection line 7a and the ground is constant. Capacity
Output voltage of sense amplifier 10 when C ₁ and power supply voltage are E ₀
E ₁ is constant as E ₁ = K · {C ₀ / (C ₀ + C ₁ )} · E ₀ (where K is the amplification factor of the sense amplifier).

On the other hand, when the operator's finger is on or near the glass surface, the capacitance between the detection line 7a and the detection line 7b changes from C ₀ to C ₂ , so the output of the sense amplifier 10 The voltage E ₁ changes to E ₁ = K · {C ₂ / (C ₂ + C ₁ )} · E ₀ . If this voltage is detected by the voltage detection circuit, it is possible to detect the pointing position by the finger.

FIG. 2 is a diagram showing a state of the glass plate in the second embodiment of the present invention.

In this embodiment, a plurality of sub detection lines 14 are provided in the glass plate 12 in parallel with the detection lines 13 in the x direction, and a plurality of sub detection lines 16 are provided in parallel with the detection lines 15 in the y direction.

FIG. 3 is a diagram showing the configuration of the main part of this embodiment, in which the detection lines 13a, 13b ...
4b and are arranged alternately.

A voltage is sequentially applied to the detection lines 13a, 13b ... By a drive circuit (not shown).

The sub-detection lines 14a, 14b ... Are connected to the terminal S _{1 of the} selector 19 via the switches 17a, 17b ... And the sense amplifier 18.

The terminal S _{2 of the} selector 19 is connected to the stylus pen.

The terminal S _{3 of the} selector 19 is connected to the voltage detection circuit.

Next, the operation of the apparatus of this embodiment will be described.

First, when this device is made to function as a coordinate detecting device using a stylus pen, the terminals S ₃ and S ₂ of the selector 19 are connected.

Then, the switches 17a, 17b ... Are all opened, and a voltage is sequentially applied to the detection lines 13a, 13b.

Then, as in the conventional case, the coordinates of the pointing position of the stylus pen are detected from the output voltage of the sense amplifier (not shown) in the stylus pen and the information indicating which detection line is being scanned.

On the other hand, when this device is used as a touch panel, the terminals S ₃ and S ₁ of the selector 19 are connected.

The switches 13a, 13b ... Are sequentially controlled to be opened / closed by the drive circuit, and the switches 17a, 17b ... for the sub-detection lines 14a, 14b ... Adjacent to the detection lines 13a, 13b. To be done.

For example, when a voltage is applied to the detection line 13a, the switch 17a for the sub detection line 14a adjacent to the detection line 13a is opened. And the detection line 13a and the sub detection line when the operator's finger is not near the detection line 13a and the sub detection line 14a
The capacitance with 14a is always a constant value C ₀ , the capacitance between the sub-detection line 14a and ground is C ₁ , and the power supply voltage is E.
_{Assuming 0} , the output voltage E ₁ of the sense amplifier 18 is constant as E ₁ = K · {C ₀ / (C ₀ + C ₁ )} · E ₀ (where K is the amplification factor of the sense amplifier).

On the other hand, when the finger is in the vicinity of the detection line 13a and the sub detection line 14a, the capacitance between the detection line 13a and the sub detection line 14a changes from C ₀ to C ₂ , so that the sense amplifier The output voltage E _{1 of} 18 changes to E ₁ = K · {C ₂ / (C ₂ + C ₁ )} · E ₀ .

By detecting this voltage by the voltage detection circuit, the position pointed by the finger can be detected.

Thus, in the first embodiment of the invention, detection of the electrostatic induction voltage between the stylus pen and each detection line, and detection between the detection line to which the voltage is applied at a certain point and the detection line adjacent thereto The detection of the electrostatic induction voltage can be arbitrarily switched. Further, in the embodiment of the second invention, the electrostatic induction voltage between the stylus pen and each detection line is detected, and the electrostatic induction voltage between the detection line to which the voltage is applied at a certain point and the sub-detection line is detected. The voltage detection can be switched arbitrarily.

[Advantages of the Invention] As described above, the coordinate detection device of the present invention can detect not only the coordinate designation by the stylus pen but also the coordinate designation by the operator's finger, and has a high degree of freedom.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a main part of one embodiment of the first invention, FIG. 2 is a perspective view showing a state of a glass plate in one embodiment of the second invention, and FIG. FIG. 4 is a diagram showing a configuration of a main part of an embodiment, FIG. 4 is a perspective view showing a state of a glass plate in a conventional coordinate detection device, and FIG. 5 is a diagram showing a configuration of a main part of the conventional coordinate detection device. . 1,6,12 …… Glass plate 2,7,13 …… Detection line (in x direction) 3,15 …… Detection line (in y direction) 4 …… Stylus pen 5,10,18 …… Sense amplifier 8 , 9, 17 …… Switch 14, 16 …… Sub detection line 19 …… Selector

Claims (2)

[Claims] 1. A flat plate, a plurality of detection lines arranged in the flat plate, a drive circuit for sequentially applying a voltage to the detection lines, and an electrostatic induction voltage between the detection line and itself. A stylus pen for detecting a change in the detection line, and a detection unit for detecting a change in the electrostatic induction voltage between the detection line to which a voltage is applied at a certain time and the detection line adjacent to the detection line,
A coordinate detecting device comprising: switching means for switching the voltage detection by the stylus pen and the voltage detection by the detection means according to an instruction. 2. A flat plate, a plurality of first detection lines arranged in the flat plate, a plurality of second detection lines arranged so as to be adjacent to these detection lines, A drive circuit that sequentially applies a voltage to one detection line, a stylus pen that detects a change in electrostatic induction voltage between the first detection line and itself, and a first voltage that is applied at a certain time point. Detection means for detecting a change in the electrostatic induction voltage between the detection line and the second detection line adjacent thereto, and switching means for switching between the voltage detection by the stylus pen and the voltage detection by the detection means according to an instruction. A coordinate detection device comprising: