JP2004062729A - Pen-character input device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To duplicate highly faithful pen-characters by providing a digitizer with high pen pressure precision. <P>SOLUTION: In this pen-character input device being a digitizer connected to a control part provided with an arithmetic unit and using a signal input pen, the control part sends a rectangular wave to the digitizer, the signal input pen detects the amount of capacitive coupling on the basis of a distance between the signal input pen and a digitizer panel, and the control part operates to prepare pen pressure data. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Industrial applications]
The present invention measures the distance between the surface of the digitizer and the input pen in an electrostatic capacitance type digitizer, and converts the distance into X, Y, and Z coordinates. This system estimates the weight applied to the pen tip of the input pen from the three-dimensional data, converts the weight into pen pressure data, and enables input of brush characters.
[0002]
[Prior art]
Conventionally, in a pen pressure measuring method using a digitizer, a spring is built in an input pen, and the spring is compressed according to the pressure applied to the pen tip. Based on this principle, it is general that the distance in which the spring is contracted is used as the pen pressure, and the line width is determined according to the pen pressure to represent a brush character.
[0003]
[Problems to be solved by the invention]
Therefore, in the above-mentioned conventional technique, the variation in the load characteristics of the spring built in the pen directly appears in the pen pressure. In order to enhance the writing pressure accuracy, the variation in the load characteristics of the springs is suppressed, or the variation characteristics of the individual springs are measured and corrected by a program. In any case, the above-mentioned method is costly and man-hour, and is not practical. Therefore, the present invention is to reproduce a brush character with high fidelity by providing a digitizer with high writing pressure accuracy.
[0004]
[Means for Solving the Problems]
A digitizer connected to a control unit provided with an arithmetic unit and using a signal input pen, wherein the control unit sends a rectangular wave to the digitizer, and the signal input pen is coupled to the digitizer board based on a distance from the digitizer board. Is detected by the signal input pen, and the control unit performs arithmetic processing to create pen pressure data.
[0005]
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The digitizer of the present invention is a coordinate input device using an electrostatic capacitance coupling method, and uses a property of passing an AC signal, which is the property of a capacitor, but not a DC signal, and detects the signal with a pen through the digitizer board. A method of converting a received signal into coordinate data is employed.
Accurate data on both handwriting and pen pressure is needed to faithfully reproduce brush characters. In order to obtain the above data, the handwriting can be accurately converted to two-dimensional data of XY coordinates with a conventional digitizer.
Next, the pen pressure is mounted on the pen tip of the digitizer, the tip of the brush is measured, and the sink of the tip is measured, and the pen pressure is converted into the pen pressure according to the sink distance.
[0006]
[Action]
The handwriting can be composed of two-dimensional coordinate data of the XY axes and the pen pressure can be composed of three-dimensional coordinate data of the Z axis, and the brush character is faithfully reproduced by attaching the tip of the brush to the pen tip.
[0007]
【Example】
The structure and operation principle of this digitizer will be described. First, a rectangular wave is generated from the control substrate 1 to drive the transparent electrode 2 provided on the digitizer. When the pen tip 4 of the input pen 3 is brought into contact with the digitizer board surface 5, the glass 6 functions as a dielectric. Capacitive coupling occurs between the transparent electrode 2 and the pen tip 4 of the input pen 3, a signal is detected by the input pen 3, and the signal is amplified by the amplifier circuit 7. The control board 1 establishes two-dimensional coordinate data by the CPU performing arithmetic processing from the received signal level.
[0008]
Next, also in the state of FIG. 2 showing the state where the pen tip 4 floats from the digitizer board 5, capacitive coupling occurs between the transparent electrode 2 and the pen tip 4 as in the above-described embodiment, and the signal is input to the input pen 3. Can be detected. However, in this state, the received signal level is lower than the contact state between the digitizer board 5 and the pen tip 4. The flying distance is calculated by the CPU provided on the control board 1 according to the level of the received signal level, and is established as three-dimensional coordinate data.
[0009]
It was confirmed how the received signal level changed with the tip 8 of the brush attached to the pen tip of the input pen 3 shown in FIG. The distance between the input pen 3 and the digitizer board 5 is defined as Z1, based on the state in which the tip 8 of the brush just contacts the digitizer board 5, and the received signal level at that time is also defined as a reference value. When the tip 8 does not contact the digitizer board 5 at Z0, it is considered that there is no writing pressure and no character is written. In the state of Z2 or Z3 in which pressure is applied to the tip 8, the received signal level also changes according to the digitizer board 5 and the tip 8. The material of the tip of the brush attached to the tip of the input pen 3 described in the present embodiment may be an artificial or natural material.
According to this principle, three-dimensional coordinate data can be determined, and a brush character can be input according to the pen pressure.
[0010]
In the board structure of the digitizer 9 shown in FIG. 4, a transparent conductive transparent electrode is deposited on the back surface of the glass plate. At the four corners, there are electrode terminals for inputting signals from the CPU provided on the control board 1, and ABCD is determined clockwise from the left. Each is connected to the port ABCD of the CPU.
[0011]
In the coordinate detection method of the digitizer 9 shown in FIG. 5, the terminal of the port A of the CPU provided on the control board 1 is connected to the electrode A, and the electrode C is connected to GND. The CPU drives port A with a rectangular wave of about 20 KHz. Then, a current flows from the terminal A to the terminal C, and the resistance of the transparent electrode is uniformly deposited, so that the signal level increases in proportion from the terminal C to the terminal A.
[0012]
When the input pen 3 makes contact with the board surface 5 of the digitizer 9, a signal can be detected by the capacitive coupling method, and the magnitude of the received signal is measured by an ADC built in the CPU provided on the control board 1. Since this measured value is equal to the voltage dividing resistance of A and C, the position where the input pen 3 abuts the board 5 of the digitizer 9 is obtained as the ratio between the points A and C. In the same manner, the ratio is obtained from the points B and D, from the points / C, from the points A, from the points / D and B, and the two-dimensional data coordinates of the exact XY axes in which the input pen 3 abuts the board 5 of the digitizer 9 Can be established.
[0013]
Subsequently, the signal detection method in a state in which the input pen 3 shown in FIG. 6 is floated from the board 5 of the digitizer 9 is performed in the same procedure as that at the time of contact, but the received signal is divided by the drive signal, and only the signal size is obtained. Rather than the signal ratio. Similarly, two-dimensional coordinates of the input pen that has been measured and floated four times can be established. In addition, by dividing the magnitude of the received signal at the time of flying by the magnitude of the received signal at the time of contact, the flying distance can also be calculated from data in which the signal attenuation rate is registered in advance by the flying distance.
[0014]
By applying this principle and writing characters on the board 5 of the digitizer 9 with the input pen 3 having the tip 8 of the brush attached to the input pen 3 as shown in FIG. The tip 8 of the brush attached to the sun sinks, accurate three-dimensional coordinate data can be detected, and a brush character corresponding to the writing pressure of the brush can be reproduced.
[0015]
【The invention's effect】
As described above, according to the present invention, by using a real brush for the pen pressure measuring method, each individual character can be faithfully reproduced without penalty of the brush touch.
At the same time, since there is no need to use springs with many variations in the pen pressure measurement method, there is no need for sorting costs or correction man-hours, and costs can be reduced.
[Brief description of the drawings]
[Fig. 1] Digitizer structure and operating principle [Fig. 2] Received signal when pen tip floats [Fig. 3] State of input pen with brush tip attached [Fig. 4] Digitizer board structure [Fig. 5] ] Digitizer signal detection method [Fig. 6] Signal detection when the input pen is floating above the board [Fig. 7] Mechanism for converting to pen pressure

Claims (2)

A digitizer connected to a control unit provided with an arithmetic unit and using a signal input pen, wherein the control unit sends a rectangular wave to the digitizer, and the signal input pen transmits the signal input pen to the digitizer board based on a distance from the digitizer board. Is detected by the signal input pen, and the control unit performs an arithmetic process to generate writing pressure data. The brush character input device according to claim 1, wherein the pen tip of the signal input pen is a tip of a brush.

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