JPH0484212A - Information input device - Google Patents

Abstract

PURPOSE:To more accurately specify a detection position by processing a reception signal from the electrode lines of a tablet with a signal reception means having amplifiers and signal-noise discriminators. CONSTITUTION:When a pen 2 irradiating a pulse signal is abutted on the desired position of the tablet 3, a waveform by a static capacitance is induced to the electrode lines 4 and 5. The waveform is divided into an X-coordinate position signal and a Y-coordinate position signal by an X-switching circuit 11 and a Y-switching circuit 12 in the reception means 10 and they are processed by respective amplifiers 13 and 14 and the signal-noise discriminators 15 and 16. Then, they go to signals corresponding to position information. Thus, the pen becomes light in weight and an operation is facilitated with such constitution. Noise is removed and the detection position can more accurately be specified.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to information input devices for graphics, characters, etc., and particularly to a pen-touch type information input device of a simplified stylus pen type. .

(Prior art and its problems) Various bench-touch information input devices have been proposed and used in the past, but most of the capacitive coupling methods apply pulses sequentially to electrode wires placed on a digitizer. The pulse was detected using a signal detection pen that was electrostatically coupled to the electrode wire to which the pulse was applied. As shown in Japanese Patent Publication No. 52-23739, Japanese Patent Publication No. 53-19494, and Japanese Patent Publication No. 53-37163, filed by the applicant, in this state, an amplifier circuit is housed inside the signal detection pen. Moreover, the S/N ratio is poor due to external noise and the like.

Furthermore, the inside of the pen is complicated, and the pen itself is heavy, so that when a single position information signal is amplified, noise is directly amplified, causing fluctuations in the position information.

(Means for Solving the Problems) The present invention has been made in view of the above conventional problems, and includes a transmitting circuit for generating position information, a signal pen for emitting a signal from the transmitting circuit, and a signal pen for emitting a signal from the transmitting circuit. , a tablet having an electrode line arranged along a coordinate axis for receiving a signal from the signal pen, an amplifier III for amplifying the received signal from the electrode line of the tablet, and a signal for removing noise from the signal from the amplifier. - A noise discriminator is proposed.

(Function) In the information input device of the present invention, a pulse signal from a pulse transmitting circuit in the tablet body is irradiated from the pen to the instruction S (pen) that approaches or comes into contact with a desired position on the tablet. By passing the capacitively coupled signal through a signal-to-noise discriminator, a more accurate detection position is specified.

(Example) A detailed description will be given below based on an example shown in the attached drawings. FIG. 1 is a schematic block diagram of the information input device of the present invention, and FIG. 2 is a waveform diagram.

Reference numeral 1 indicates means for transmitting a pulse as a signal, reference numeral 2 indicates a pen as a signal transmitting means, and reference numeral 3 indicates a pen as a signal transmitting means.
indicates a tablet, and reference numeral 10 indicates a signal receiving means.

A signal sending pen 2 is connected to the signal sending means 1 from an oscillation circuit 6 that generates pulses, and a pulse is applied from a conductor at the tip of the pen 2 to an electrode wire 4.5 of the tablet 3.

Tablet 3 has multiple electrodes, just like conventional tablets! 4.5 is also placed in the X and Y axis directions, each electrode! 4 and 5 are connected to an X switch 11 and a Y switch 12, respectively. The signal receiving means 10 includes amplifiers 13, 14, a signal-noise discriminator and an analog signal for distinguishing between the amount of positional information and noise.
A digital conversion circuit is housed and connected to the control circuit 20.

Note that the signal receiving means 10 also accommodates the oscillation circuit of the oscillation means 1 described above.

Next, the operation will be explained. In the initial state,
The output of the oscillation circuit 6 of the oscillation means 1 in the signal reception means 10 has a pulse waveform as shown in A in FIG. 2, and is applied to the pen 2 as a signal transmission means through the signal transmission cable 7. The light is irradiated (output) from the conductor at the tip of this pen 2.

Here, the electrode wires 4 and 5 of the tablet 3 are connected to the signal receiving means 1.
It is connected to each of the X and Y switching circuits 11 and 12 in 0, and the X coordinate,
Each Y coordinate is sequentially scanned.

When the pen 2 is held in the operator's hand and touches a desired position on the tablet 3, a waveform as shown in FIG. 2C is induced in the electrode wires 4 and 5 at the position where the pen 2 touches. be done.

This induced waveform is generated by the X switching circuit 11. Y switching circuit 1
2, the signal is divided into an X-coordinate position signal and a Y-coordinate position signal, which are amplified by respective amplifiers 13.14, resulting in a waveform as shown in 2nd @D, which is then passed through a signal-to-noise discriminator 15.16.
The noise is removed by the signal-to-noise discriminators 15 and 16, resulting in a signal corresponding to the position information as shown in FIG. It is processed as position information in the circuit 20 and sent to a computer (not shown). Signal-noise discriminators include signal differentiation circuits, integration circuits, filters, and arithmetic circuits.

Although there are comparison circuits, etc., this example uses an arithmetic circuit,
The purpose is achieved by extracting only the noise from the input signal and subtracting the extracted noise from the input signal to perform discrimination.

In this embodiment, switch information for the pen 2 is not particularly mentioned, but the switch information can be turned on by bringing the pen 2 into contact with the tablet 3 as necessary.

It is also possible to arrange a switch that turns off.

Furthermore, various circuits can be employed in the signal-to-noise discriminator.

(Effects of the Invention) Since the present invention has the above configuration, the pen is light and easy to operate, and noise is removed, making it easy to identify signals, especially when the signals are adjacent. It is something that becomes.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, with FIG. 1 being a schematic block diagram and FIG. 2 being a waveform diagram. DESCRIPTION OF SYMBOLS 1... Signal transmission means, 2... Pen, 3... Tablet, 4.5... Electrode wire, 6... Oscillation circuit, 10.
...Signal receiving means, 11.12...X, Y switching circuit, 13゜14...Amplifier. 15゜16...Signal-noise discriminator. 17...Analog-digital conversion circuit, 20...Control circuit

Claims (1)

[Claims] (1) A transmitting circuit for generating position information, a signal pen for emitting signals from the transmitting circuit, a tablet on which electrode lines are arranged along coordinate axes for receiving signals from the signal pen, and a tablet for receiving signals from the signal pen. An information input device comprising: an amplifier that amplifies a received signal from an electrode wire of a tablet; and a signal-noise discriminator that removes noise from the signal from the amplifier.