JPH0944299A - Handwritten input display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To freely perform a handwritten input from any direction while using a cordless input pen by detecting the top end position of the pen for inputting handwriting onto a display panel, and sending a driving signal to a drive circuit part corresponding to the detected signal. SOLUTION: An input pen 2 has a signal generator inside and generates a search signal from its top end. A position detection part 3 of the input pen 2 is respectively connected to the x-axis direction electrode group and y-axis direction electrode group of a display panel 1 and respectively detects the electrodes having the strongest search signal from the input pen 2 in the x-axis direction electrode group and y-axis direction electrode group. A drive circuit part 7 impresses a signal for display to the x-axis direction electrode group and y-axis direction electrode group of the display panel 1. Then, a signal processing part 10 sends the detected signal from the detection part 3 of the input pen 2 to the drive circuit part 7. Thus, the handwritten input onto the display panel 1 can be freely performed from either direction while using the cordless input pen 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a handwriting input display device. More specifically, the present invention relates to a handwriting input display device that enables handwriting input with a cordless input pen.

[0002]

2. Description of the Related Art A conventional handwriting input display device is disclosed in, for example, Japanese Patent Laid-Open No. 4-195624 or Japanese Patent Laid-Open No. 5-127.
As disclosed in Japanese Patent No. 801, a liquid crystal display panel (hereinafter referred to as an LCD panel) having a coordinate input panel, an input pen for handwriting input, and a control device for controlling the LCD panel by a signal received from the input pen. It consists of Such a handwriting input device is shown in FIG.

In FIG. 5, reference numeral 21 denotes an LCD panel, 22
a and 22b are an x-axis direction driver, a y-axis direction driver, 23 is an electronic pen, 24 is an amplifier, 25 is a detection circuit, 26 is a coordinate detection counter, 27 is a coordinate detection controller, 28 is a display controller, and 29 is an MPU. Is. In this device, a capacitance detection circuit is built in the tip of the electronic pen 23, and a scanning signal for position detection is applied from the x-axis direction driver 22a and the y-axis direction driver 22b of the LCD panel 21. The tip of the electronic pen 23 is L
LCD panel 21 by tracing on CD panel 21
A change in the above capacitance is detected. The change in the capacity is detected by the detection circuit 25, the position of the electronic pen 23 is specified by the coordinate detection counter 26 and the coordinate detection controller 27, the display data signal is sent to the display controller 28, and the MPU 29 displays the display data. The signal and the scanning signal for position detection are combined and sent to the LCD panel 21 for liquid crystal display. That is, the x-axis direction driver 22
A detection signal is input via the a and y axis direction drivers 22b, the tip of the electronic pen 23 detects the timing, and the coordinates of the pen tip are determined.

[0004]

In the handwriting input / display device having the above-mentioned configuration, the detection circuit is connected to the electronic pen, the position of the pen tip is detected from the capacitance change read by the tip of the electronic pen, and the coordinate detection controller is used. The coordinates in the x-axis and y-axis directions are read. Therefore, the cord is always connected to the electronic pen, and the cord is connected to the LCD panel 21 via the detection circuit or the like via the cord, and the cord becomes an obstacle during use, which is difficult to use.

SUMMARY OF THE INVENTION It is an object of the present invention to solve such a problem and to provide a handwriting input display device which is capable of handwriting input from any direction using a cordless input pen and which is easy to use. .

[0006]

According to the handwriting input display device of the present invention, a plurality of x-axis direction electrode groups and y are provided at predetermined intervals along the x-axis direction and the y-axis direction.
A display panel having an axial direction electrode group, an input pen having a signal generator inside to generate a search signal from the tip, and an input pen connected to the x axis direction electrode group and the y axis direction electrode group of the display panel, respectively. The position detection unit of the input pen for detecting the electrode having the strongest search signal from the pen in the x-axis direction electrode group and the y-axis direction electrode group, and the x-axis direction electrode group and the y-axis direction electrode group of the display panel. And a drive circuit section for applying a display signal, and a signal processing section for sending a drive signal corresponding to the detection signal from the position detection section to the drive circuit section.

[0007] The position detector is configured to detect the x-axis direction and the y-axis direction.
An x-axis direction changeover switch and a y-axis direction changeover switch which can be switched and connected to each electrode of the axial direction electrode group, and each electrode in the x-axis direction inputted by the x-axis direction changeover switch and the y-axis direction changeover switch, respectively. And y
An x-axis direction detection circuit and a y-axis direction detection circuit that detect the maximum electrode of the high-frequency signal from the input pen among the respective electrodes in the axial direction, and signals from the x-axis direction detection circuit and the y-axis direction detection circuit. Therefore, it is preferable that the coordinate detection controller specifies the x-axis direction electrode and the y-axis direction electrode at the position of the input pen, because the position of the pen tip of the input pen can be easily detected.

It is preferable that the signal generator is a high frequency oscillator and the search signal is a high frequency signal because a simple oscillator is less susceptible to noise.

If the high-frequency oscillator is one type of oscillator selected from the group consisting of RC oscillator, LC oscillator and LCR oscillator, it can be formed in a small size with low power consumption.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a handwriting input display device of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a handwriting input display device of the present invention, FIG. 2 is an equivalent circuit diagram showing the capacitance between electrodes of a display panel, and FIG. 3 is a diagram showing the magnitude of a signal detected by each electrode. FIG. 4 is an explanatory diagram showing an example of changes, and FIG. 4 is an equivalent circuit diagram of an example of a high frequency oscillator.

As shown in the block diagram of one embodiment of the handwriting input display device of the present invention, the position of the display panel 1, the input pen 2 for handwriting input, and the position of the tip of the input pen 2 are shown. It comprises a position detecting section 3 for detecting, a drive circuit section 7 for driving the display panel 1, and a signal processing section 10 comprising an MPU or the like for sending a drive signal according to a detection signal from the position detecting section 3 to the drive circuit section 7. ing.

The display panel 1 is composed of, for example, an LCD panel. In the case of an LCD panel, the display panel 1 has a normal LCD structure. For example, as shown in FIG. A liquid crystal material 15 is injected into a gap between one transparent substrate 11 provided with a plurality of transparent electrode groups 12 along it and the other transparent substrate 13 provided with a plurality of electrode groups 14 along the y-axis direction. It is formed by As a result, a display panel is formed in which dot-matrix pixels are formed at the intersections of the electrodes of the upper and lower transparent substrates, and a capacitance C as shown in FIG.
₁ , C ₂ , C ₃ are formed. An alignment film (not shown) is provided on the surface of the transparent electrode, and a polarizing plate (not shown) is provided on the outside of the transparent substrate.

The input pen 2 includes, for example, an RC oscillator (see FIG. 4 (a)) and an LC oscillator (see FIG. 4 (b)) including a resistor R, a capacitor C, and a coil L as shown in FIG.
It has a signal generator consisting of a high-frequency oscillator with a simple structure such as, a battery, etc., and generates a search signal such as a high-frequency signal from its tip with a single pencil-shaped pen that is not connected to an external circuit by a lead wire. It is structured to

The position detecting section 3 includes an x-axis direction changeover switch 4
a, y-axis direction selector switch 4b, x-axis direction detection circuit 5
It is composed of an a, y axis direction detection circuit 5b and a coordinate detection controller 6, and the changeover switches 4a, 4b are respectively x
A detection circuit 5 that switches each electrode of the electrode group in the axial direction and the y-axis direction to detect a search signal from the input pen 2.
a and 5b are sequentially connected. This changeover switch 4a, 4b
For example, an IC such as an analog switch can be used. Each of the x-axis direction detection circuit 5a and the y-axis direction detection circuit 5b includes, for example, as shown in FIG. 3A, an operational amplifier OP and a resonance coil L ₀ whose one end is connected to ground, and is amplified by the operational amplifier OP. Read the signal. This amplified signal is transferred to the changeover switches 4a, 4
By sequentially switching with b, as shown in FIG. 3B, signals of different magnitudes are obtained by the electrodes. Therefore, the largest signal among the detection signals of each electrode is detected. In FIG. 3B, A ₁ , A ₂ and A ₃ respectively represent electrodes at the positions shown in FIG. The coordinate detection controller 6 formed of an IC or the like identifies which electrode the electrode having the largest signal is, and sends the information to the signal processing unit 10.

The drive circuit unit 7 is the same as that used in a normal LCD or the like, and an x-axis direction driver 8a for driving an x-axis direction electrode, a y-axis direction driver 8b for driving a y-axis direction electrode, and a display signal. Display controller 9 for applying
The pixel touched by the pen tip of the input pen 2 is turned on by a signal sent from the signal processing unit 10 based on the position information from the position detection unit 3 described above.

As described above, the capacitors C ₁ , C ₂ and C ₃ shown in FIG. 2 are formed between the electrodes of the display panel. In FIG. 2, (a) is an equivalent circuit diagram showing the inter-electrode capacitance of each pixel when seen in a plan view, and (b) is an equivalent circuit diagram showing the inter-electrode capacitance of each pixel when seen in a cross section. C ₁ is the x-axis direction of the transparent substrate 11. The capacitance between the electrodes, C ₂ is the capacitance between the electrodes of the transparent substrate 13 in the y-axis direction, C ₃
Indicates the capacitance between the electrodes of the upper and lower transparent substrates 11 and 13, respectively. Since such a capacitance is formed in each pixel, when a high-frequency signal is emitted from a high-frequency oscillator having a simple structure as shown in FIG. 4, a high-frequency voltage is generated at its electrode terminal, and FIG. x) as shown in a)
When connected to the axial direction detection circuit 5a, the operational amplifier OP
An amplified signal is obtained, and each electrode of the electrode group is switched by the x-axis direction changeover switch 4a.
The detection signal as shown in (b) is obtained, and the input pen 2 is placed at the electrode number A ₁ where the largest detection signal is obtained.
You can see that there is a pen tip. Similarly, regarding the electrode in the y-axis direction, the electrode number for which the largest detection signal is obtained can be detected, and the pixel with the pen tip can be specified.

In the above embodiment, a high-frequency oscillator having a simple structure such as an RC oscillator composed of R, C and L and an LC oscillator was used as a signal generator incorporated in the input pen. An oscillator can be used.

According to the present invention, since the search signal is generated from the pen tip of the input pen, the magnitude of the search signal received by each electrode is the largest at the electrode close to the pen tip of the input pen and is far from the pen tip. The electrode becomes smaller. for that reason,
The position of the pen tip of the input pen can be determined by detecting the signal of each electrode that receives the search signal emitted from the pen tip of the input pen and detecting the electrode with the largest signal in both the x-axis direction and the y-axis direction. Can be specified. By sending a display signal based on the position information from the signal processing unit to the drive circuit unit, the position of the pen tip of the input pen can be displayed.

By using a high frequency signal as the search signal, a large signal appears at the electrode end together with the capacitance between the adjacent electrodes and between the electrodes of the upper and lower substrates, and the electrode having the maximum signal can be easily detected. .

[0021]

According to the present invention, since the position detecting portion of the input portion is provided only on the display panel side and the signal generator is built in the input pen, the input pen is connected by the cord. There is no need to use the input pen in a free state, and a handwriting input display device that is very easy to use can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a handwriting input display device of the present invention.

FIG. 2 is an explanatory diagram showing a capacitance between electrodes of the display panel of FIG.

FIG. 3 is a circuit diagram showing an example of the detection circuit of FIG. 1 and a diagram showing an example of signals at that time.

FIG. 4 is an equivalent circuit diagram showing an example of a high frequency oscillator.

FIG. 5 is a block diagram of an example of a conventional handwriting input display device.

[Explanation of symbols]

 1 display panel 2 input pen 3 position detection unit 4a x-axis direction changeover switch 4b y-axis direction changeover switch 5a x-axis direction detection circuit 5b y-axis direction detection circuit 6 coordinate detection controller 7 drive circuit unit 10 signal processing unit

Claims (4)

[Claims] 1. A display panel having a plurality of x-axis direction electrode groups and a plurality of y-axis direction electrode groups provided at predetermined intervals along the x-axis direction and the y-axis direction, and a signal generator inside. Then, an input pen for generating a search signal from the tip and electrodes connected to the x-axis direction electrode group and the y-axis direction electrode group of the display panel and having the strongest search signal from the input pen are respectively connected to the x-axis direction electrode group. And a position detection unit of the input pen for detecting in the y-axis direction electrode group, a drive circuit unit for applying a display signal to the x-axis direction electrode group and the y-axis direction electrode group of the display panel, and the position detection unit. And a signal processing section for sending a drive signal corresponding to the detection signal to the drive circuit section. 2. The x-axis direction changeover switch and the y-axis direction changeover switch, wherein the position detecting section can be switched and connected to each electrode of the electrode group in the x-axis direction and the y-axis direction, and the x-axis direction changeover switch. And the electrodes in the x-axis direction and the y-axis direction input switches, respectively.
An x-axis direction detection circuit and a y-axis direction detection circuit that detect the maximum electrode of the high-frequency signal from the input pen among the respective electrodes in the axial direction, and signals from the x-axis direction detection circuit and the y-axis direction detection circuit. 2. The handwriting input display device according to claim 1, further comprising a coordinate detection controller that specifies an x-axis direction electrode and a y-axis direction electrode at the position of the input pen. 3. The signal generator is a high frequency oscillator,
The handwriting input display device according to claim 1, wherein the search signal is a high frequency signal. 4. The handwriting input display device according to claim 3, wherein the high frequency oscillator is one type of oscillator selected from the group consisting of an RC oscillator, an LC oscillator and an LCR oscillator.