JPH05282094A - Handwriting input device - Google Patents

Abstract

PURPOSE:To freely vary thickness of a line by writing pressure of a pen by detecting pressure from the pen applied to an input panel, varying width of a line or size of a point in a graphic in accordance with magnitude of this pressure and displaying it on a display. CONSTITUTION:When an input pen 11 is brought into contact with an input panel 6, a constant-current outputted from the input pen 11 is converted to an analog signal of coordinate data by each operational amplifier 13 of an input coordinate detecting part 7 and a writing pressure detecting part. Also, a voltage detected by each piezoelectric element 12 due to contact is detected by each operational amplifier 13' and converted to an analog signal of writing pressure data. Those data are converted to digital data and transferred to a CPU. The CPU derives a center position of the input pen 11 from the digital coordinate data, and also, derives writing pressure by adding digital writing pressure data, calculates a center position of dots on a liquid crystal display and the number of dots, that is, line width from these values, and controls the liquid crystal display.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input device with a display, and more particularly to a handwriting input device capable of inputting handwritten figures, characters and symbols.

[0002]

2. Description of the Related Art A display and an input panel are combined to display a graphic from the input panel on the display to check the contents, or a communication device is added to add and correct the original graphic sent from the other party and send it back. Such a handwritten character input device is configured as shown in FIG. 1, for example.

In FIG. 1, a CPU (Central Processing Unit) 1
Performs control processing of each part of this handwriting input device,
The display control of the LCD drive unit 5 for driving the display (hereinafter referred to as LCD) 4 using liquid crystal is performed based on the position data of the pen input from the coordinate detection unit 7. ROM
A (read only memory) 2 stores a control processing program executed by the CPU 1, data necessary for processing, etc., and a RAM (random access memory) 3
Stores various information unique to this handwriting input device. The LCD 4 is a display for displaying handwritten input characters and figures. In the above, CPU1, ROM
2, RAM 3, LCD drive unit 5, coordinate detection unit 7 is a CPU
Information is transmitted via the bus 8.

[0004]

As described above, in the conventional handwriting input device, only the coordinates of the pen input are detected and displayed on the display with a uniform line width. In this way, it is impossible to express a variety of information in which the line width naturally changes according to the emotion of the creator. Therefore, the display of a sentence created by a conventional handwritten character input device is often unnatural, which is not preferable.

Therefore, the present invention provides a handwriting input device capable of displaying thick lines that the creator wants to emphasize.

[0006]

In order to solve the above-mentioned problems, the handwriting input device according to the present invention is such that the line thickness is automatically increased when the pen pressure of the pen is large.

That is, according to the present invention, the position of the pen added to the input panel is detected, and characters are displayed on the display.
In a handwriting input device that displays a figure, the pressure from a pen applied to an input panel is detected, and the line width or point size of the figure (including characters and symbols) is detected in accordance with the detected pressure. A handwriting input device is obtained which is characterized in that it is displayed on a display by changing the height.

[0008]

Therefore, according to the present invention, when the document creator makes an effort to write, a thick line is naturally displayed on the display.

[0009]

FIG. 2 shows the configuration of an embodiment of the present invention. In FIG. 2, the CPU 1 performs the control processing of each unit of the handwriting input device, and the position data of the input pen 11 from the coordinate detecting unit 7 and the writing pressure data from the writing pressure detecting unit 9 provided especially in the present invention. , Which drives the LCD 4 on the basis of these data.
The display of the drive unit 5 is controlled. ROM2 is CP
The control processing program executed by U1 and data necessary for processing are stored. The RAM 3 stores various information unique to this handwriting input device. LCD4
Is a device for displaying handwritten input characters and figures. CP
The U1, the ROM2, the RAM3, the LCD driving unit 5, and the multiplex data selector 10 (the coordinate detecting unit 7 and the writing pressure detecting unit 9) transfer information via the CPU bus 8.

FIG. 3 shows an input panel 6 and an input coordinate detecting section 7.
FIG. 3 is a diagram showing an example of configurations of a writing pressure detection unit 9 and a multiplex data selector 10. The input panel 6 has a structure in which a transparent and uniform resistor is applied on the glass surface, and a constant current supplied from the input pen 11 is provided on the four sides of the electrodes X1,
This is a resistance division method in which the coordinate position is obtained by detecting with X2, Y1 and Y2, and the ratio of the above currents. Piezoelectric elements 12 for detecting writing pressure are attached to the lower four corners of the input panel 6. The input coordinate detector 7 and the writing pressure detector 9 are composed of operational amplifiers 13 and 13 ', respectively, and detect a current or a voltage to generate a voltage signal. The multiplex data selector 10 includes an analog multiplexer 14 that selects and outputs one of a plurality of analog signals, a sample hold 15 that samples the analog signal and maintains the signal at that time, and an A / D converter 16. The constant current source 17 is a power source for supplying a constant current to the input pen 11 regardless of load fluctuation.

When the input pen 11 is brought into contact with the input panel 6, the constant current output from the input pen 11 changes the input pen 1
1 and the respective electrodes X1, X2, Y1, and Y2 are shunted to the respective electrodes in inverse proportion to the resistance ratio of the transparent resistor (not shown), and the operational amplifiers 13 of the input coordinate detecting section 7 and the writing pressure detecting section 9 are divided. Are converted into analog signals representing coordinate data. Also,
The voltage detected by each piezoelectric element 12 by the contact is detected by each operational amplifier 13 'and converted into an analog signal representing writing pressure data. One of the total eight analog signals thus obtained is selected by the analog multiplexer 14, sampled by the sample hold 15, and
The / D converter 16 converts the digital data signal. The digital data output from the multiplex data selector 10 in this way is sent to the CPU 1 via the CPU bus 8.
Be transmitted to.

The CPU 1 is 4 obtained from the CPU bus 8.
The center position of the input pen 11 is obtained from one digital coordinate data, the writing pressure is obtained by adding four digital writing pressure data, and the central position of the dots and the number of dots on the LCD 4 to be driven are calculated from these values. (Line width) is calculated and CPU
It is sent to the LCD drive unit 5 via the bus 8. LCD drive unit 5
Controls the LCD 4 using the sent signal.

[0013]

As described above, according to the present invention, since the line thickness can be freely changed by the pen pressure, a variety of information such as the habit of the creator of the document, psychological information, etc. Can be displayed, and a handwriting input device with a very natural display function can be realized.

[Brief description of drawings]

FIG. 1 is a configuration example of a conventional handwriting input device.

FIG. 2 is a block diagram of a handwriting input device according to an embodiment of the present invention.

FIG. 3 is a diagram showing a configuration and a circuit diagram from an input panel to a multiplex data selector in the present invention.

[Explanation of symbols]

 1 CPU (Central Processing Unit) 2 ROM (Read Only Memory) 3 RAM (Random Access Memory) 4 LCD (Liquid Crystal Display) 5 LCD Driving Section 6 Input Panel 7 Input Coordinate Detection Section 8 CPU Bus 9 Pen Pressure Detection Section 10 Multiplex Data Selector 11 Input Pen 12 Piezoelectric Element 13, 13 'Operational Amplifier 14 Analog Multiplexer 15 Sample Hold 16 A / D Converter 17 Constant Current Source

Claims (1)

[Claims] 1. A handwriting input device for detecting a position of a pen applied to an input panel to display characters and figures on a display, detecting pressure from the pen applied to the input panel, and detecting the detected pressure. A handwriting input device characterized by changing the width of a line or the size of a point of a figure (including characters and symbols) in accordance with the size of the display and displaying it on the display.