JPH0379728B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field to which the invention pertains] The present invention relates to a pen-touch type information input device,
In particular, the present invention relates to a pen-touch type information input device equipped with a signal detection pen with a built-in pen switch for checking whether the pen is in contact with a tablet or the like.

[Prior art and its problems]

Conventionally, tablet input devices, etc. have a
As shown in the figure, a signal detection pen 1 connected to an apparatus main body 60 via a cable 61 is equipped. Then, the tablet 6 provided on the top surface of the main body
When the pen 2 contacts a desired position and instructs information, the signal detecting pen 1 first emits a pen switch signal indicating that the pen has contacted, and in response, a scanning signal is supplied to the tablet 62. . When this scanning signal is supplied, the position coordinate signal of the contact area is detected by the signal detection pen 1, and predetermined electrical processing is performed on the device main body side based on the detected position coordinate signal. It is now possible to input information such as characters and figures, or input coordinates.

FIG. 2 shows a conventional signal detection pen used in a tablet input device. In this figure, a signal detection pen 1 includes a pen-shaped casing 5 in which a base 3 and a cap 4 are screwed onto a barrel 2.
A guide hole 6 is formed in the cap 3, and a detection rod 7 is slidably inserted into the guide hole 6.

This detection rod 7 is made of a conductive member, and when it comes into contact with the tablet 62 (see FIG. 1), it capacitively couples with the scanning electrode wire to detect a scanning signal.

This detected signal is subjected to signal processing such as amplification by an electric circuit 9 on a board 8 disposed inside the casing 5, and sent to the input device main body via a cable 61 inserted through the cap 4. It is becoming more and more common.

The signal detection pen 1 configured in this manner is further provided with a pen switch mechanism. This pen switch mechanism detects when the signal detection pen 1 is pressed against the tablet and outputs a pen touch signal, and performs an information input operation only when a pen touch is made.

To explain this pen switch mechanism, first, as mentioned above, the detection rod 7 is always urged forward by the spring 13 provided between the rear end of the detection rod 7, which is formed to be slidable, and the base plate 8. A stopper 14 fixed to the rear end comes into contact with the rear end surface of the cap 3 to prevent it from coming off.

An operating rod 15 is attached to this stopper 14. This action rod 15 extends parallel to the rear along the base plate 8, and has a pin 17 implanted at the end of a rotating plate 16 whose rear end is formed into an L-shape.
is connected to. The rotating plate 16 is rotatably incorporated into the base plate 8 by a pin 18 implanted therein.
When the rotary plate 16 is pressed or pulled by the action rod 15, the portion of the shielding portion 19 bent in the direction perpendicular to the plane of the drawing moves in the vertical direction in FIG. The optical paths of the light emitting/light receiving elements 20 and 21 are interrupted.

When the signal detection pen 1 comes into contact with the tablet and is pressed down, the detection rod 7 is pushed into the casing 5 against the elastic force of the spring 13. This stroke motion of the detection rod 7 causes the action rod 15 to push the rotary plate 16, and the light receiving element 21, which had been in a conductive state by receiving light from the light emitting element 20, is turned off. Based on this change in the output of the light receiving element 21, a switching circuit (not shown) mounted on the substrate 8 outputs a pen touch signal to the main body of the apparatus via the cable 61.

By the way, the above-mentioned conventional signal detection pen has a preamplifier for amplifying the detection signal inside the elongated casing.
Because it houses various parts such as the pen switch mechanism and switching circuit, the structure is complex, requires a lot of assembly time, and is expensive.Since it incorporates many parts, there is a limit to miniaturization, and it has to be thicker than a normal writing instrument. In addition, the cable connecting the signal detection pen and the main body of the device has a special specification consisting of at least four conductors: one for the detection signal, one for the pen switch signal, one for the power supply, and one for the ground.
For this reason, it is expensive, has a large outer diameter, and is difficult to reduce in weight.Furthermore, there are disadvantages in that the signal detection pen is prone to camera shake and has poor operability.

[Purpose of the invention]

The present invention has been made in view of the drawbacks of the prior art, and has a simple configuration and good operability by using the pen side signal line of the cable as both the detection signal sending line and the pen switch circuit wiring. The object of the present invention is to provide a pen-touch type information input device equipped with a signal detection pen.

[Summary of the invention]

In the present invention, a signal detection pen is provided which includes a signal detection rod that is slidably incorporated in the tip of the casing along the casing, and a pen switch attached to the signal detection rod. The main body of the apparatus is provided with a bias voltage applying means for inputting an output pen touch signal via a pen side signal line and outputting a scanning timing signal for the tablet based on the input pen touch signal. The pen switch is a normally closed switch whose one end is grounded and the other end is connected to the signal detection rod, and which opens when the signal detection rod is pressed down, and the signal detection rod is connected to the external output cable. A pen signal detection means is connected to the pen side signal line via a flexible wiring and separates and outputs the scanning timing signal from other signals from the pen side signal line, and the pen signal detecting means is detected by the signal detection rod and outputs the scanning timing signal together with the scanning timing signal. The main body of the device is equipped with position information detection means for separating the position coordinate signal on the tablet sent via the side signal line from other signals on the pen side signal line and outputting the signal. This aims to achieve the above-mentioned purpose.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on FIGS. 3 to 5.

In the embodiment shown in FIGS. 3 to 5, a signal detection rod 39 is installed at the tip of the casing 36 so as to be slidable along the casing 36;
Pen switch 4 attached to this signal detection rod 39
A signal detection pen 30 including 4 is provided. Further, a bias voltage applying means 50 (see FIG. 4) is provided which inputs the pen touch signal outputted from the signal detection pen 30 via the pen side signal line 47 and outputs a scanning timing signal for the tablet based on this signal. The device has a main body equipped with the following functions.

The pen switch 44 has one end grounded and the other end connected to the signal detection rod 39 in contact. The pen switch 44 is a normally closed switch whose contacts open when the signal detection rod 39 is pressed down.

The signal detection rod 39 is connected to a signal line for an external output cable via a telescopic wiring 49. The bias voltage applying means 50 is connected to the signal detection rod 3
It has a function of outputting a scan timing signal which operates in conjunction with the pressing operation of 9 and uses the rising edge of the output as a scan command signal. In addition, the signal detection rod 3
The above-mentioned device main body is equipped with a position information detection means 53 for inputting the position signal on the tablet detected by the tablet 9 through the pen side signal line, and for outputting it after separating it from other signals on the pen side signal line. ing.

To explain this in more detail, first, in FIG. 3, the signal detection pen 30 includes a conductive casing 36 consisting of a body 33 to which cylinders 31 and 32 are directly connected, a base 34 and a cap 35. An insulating layer 38 is installed in the guide hole 37 of the base 34, and a signal detection rod 39 made of a conductive member is slidably inserted into the guide hole 37. An electrically conductive stopper 40 is disposed at the inner opening of the guide hole 37. This stopper 4
0 is fixed approximately at the center of the signal detection rod 39. The end of the signal detection rod 39 inside the casing 36 (the right end in FIG. 3) is slidably guided by an insulating spring seat 41 fitted between the base 34 and the cylinder 31. It is structured like this.

A spring 42 is disposed between this spring seat 41 and the above-mentioned stopper 40, and the signal detection rod 39 is always urged forward (to the left in FIG. 3) by the tension of this spring 42. It is designed to be done.

An annular contact 43 is mounted on the inner side of the casing 36 of the base 34 so as to face the stopper 40 . When the stopper 40 moves forward (returns to its original position) under the force of the spring 42, the stopper 40 and the contact 43 come into contact and the pen switch 44 (see FIG. 4) is closed. The signal detection rod 39 is prevented from coming off. Here, as a material for the contact point 43, a carbon film member or conductive rubber with less chattering is used.

Inside the casing 36, a cable 45 inserted from the cap 35 extends to near the rear end of the signal detection rod 39. The distal end of the cable 45 inside the casing 36 is clamped by an insulating locking piece 46 fitted between the cylinders 31 and 32 and fixed on the central axis of the casing 36.

This cable 45 is a coaxial cable consisting of a pen-side signal line 47 as a common signal line and a ground wire 48, and the pen-side signal line 47 is connected to the signal detection rod 39 via a telescopic wiring 49 as described above. ing. On the other hand, the ground wire 48 is connected to the casing 36 to remove the influence of noise from the human body, etc., and is electrically connected to the signal detection rod 39 via the contact 43 and the stopper 40.

In the signal detection pen 30 configured in this way, when the signal detection pen 30 is not in contact with the tablet 62 (see FIG. 1), the signal detection rod 39 is moved forward (to the left in FIG. 3). In this case, the contact 43 in the signal detection pen 30 and the stopper 40 come into contact, the pen switch 44 is closed, and the signal detection rod 39 is grounded. At this time, the impedance between the pen side signal line 47 and the ground line 48 of the cable 45 is zero.

Next, in order to input information, use the signal detection pen 3.
0 to the tablet 62, the signal detection rod 3
9 is slid backward (to the right in Fig. 3), and the contact point 43
The stopper 40 is separated, the pen switch 44 is opened, and the signal detection rod 39 becomes electrically floating (see FIG. 4). At this time, there is a high impedance between the pen side signal line 47 of the cable 45 and the ground line 48, and the signal detection rod 39 and the scanning electrode line 63 of the tablet 62 (see FIG. 4) are capacitively coupled.
It becomes possible to detect the position coordinate signal.

As shown in FIG.
Resistor for multiplying 7 by a predetermined bias voltage V ₀
A bias voltage applying means 50 consisting of R ₁ , R ₂ and a power source 55 is provided. In this case, in this embodiment, R ₁ is 9 [MΩ] and R ₂ is 1 [MΩ].

Then, the pen switch 44 closes and the cable 4
When the impedance of 5 becomes zero, the resistance
Since R ₂ is short-circuited, the voltage v of the pen side signal line 47 with respect to ground is always zero. On the other hand, when the pen switch 44 opens and the impedance becomes "high level," a voltage V ₀ determined by the voltage division ratio of the resistors R ₁ and R ₂ is applied to the pen side signal line 47, and v=V ₀ . Therefore, from the voltage change of the pen side signal line 47,
Changes in the impedance of the cable, ie, opening and closing of the pen switch 44, can be detected. Furthermore, if the signal detection rod 39 discards the position coordinate signal e from the tablet 62 in this state, the position coordinate signal e will be superimposed on the bias voltage V ₀ of the side signal line 47.

An impedance conversion circuit 51 connected to the pen-side signal line 47 is provided on the output side of the bias voltage application means 50, so that the voltage V ₀ of the pen-side signal line 47 is output as is in a low output impedance state. It has become. On the output side of this impedance conversion circuit 51, a pen signal detection means 52 and a capacitor 53 for cutting DC components are further provided.
A and position information detection means 53 consisting of an amplifier 53B are connected.

Of these, the pen signal detecting means 52 DC amplifies the voltage v of the pen side signal line 47, and generates a pen touch signal PSW (containing scan command and scan timing information) that changes in steps from zero to V ₀ '. It is mainly composed of a DC amplifier with the function of outputting. In this case, the gain of the DC amplifier is set to be large, so that it immediately saturates with respect to a very small signal.
Therefore, even if the position coordinate signal e arrives, its output, that is, the level of the pen touch signal PSW, hardly changes. This pentouch signal RSW is sent to a tablet controller (not shown) in the main body of the apparatus, and scanning of the tablet 62 is performed after a predetermined delay time has elapsed from the rise of the pentouch signal.

On the other hand, the detection signal PSIG of a predetermined level riding on the bias voltage V ₀ of the pen side signal line 47 is sent to the position information detection means 53 including a capacitor 53A and an amplifier 53B. Then, the signal portion is detected by the capacitor 53A and the amplifier 5
The signal is sent to 3B, where it is amplified to a predetermined level. The detection signal PSIG containing this position information is sent to the tablet controller within the main body of the device. Then, the positional coordinates of the contact point of the signal detection pen 30 are specified from the detection timing.

Here, a further embodiment of the embodiment shown in FIG. 4 will be described with reference to FIGS. 6 to 9.

In the specific example shown in FIGS. 6 to 9, the impedance conversion circuit 51 provided on the output side of the bias voltage applying means ₅₀ is constructed around a voltage follower 511. or,
The amplifier 53B of the position information detecting means 53 is mainly composed of an operational amplifier ₅₃₁ , and further, the pen signal detecting means 52 is mainly composed of a comparator ₅₂₁ .

In FIG. 6, first, a signal I in which a position coordinate signal e and a pen touch signal _PT are superimposed as shown in FIG. 7 is input to the positive input terminal of the voltage follower ₅₁₁ . Here, setting a practical case, the signal level of the new position coordinate signal e is sufficiently smaller than that of the pen touch signal _PT . and,
In the case of this FIG. 6, this voltage follower 5
At the output stage of 1 ₁ , the same waveform as the waveform of the input stage is reduced in impedance and outputted at v ₀ [v].

The signal output from this voltage follower 51 ₁ is then input to the negative terminal side of the comparator 52 ₁ . Here, it is compared with a reference voltage v ₁ that is separately input in advance to the positive terminal side. When v ₀ > v ₁ , the output of the comparator 52 ₁ becomes 0 [v] as shown in FIG. 8 (this signal becomes PWS). On the other hand, this comparator ₅₂₁ has a resistor connected to its positive terminal input side.
Hysteresis is provided in Ra and Rb. Therefore, only when the input voltage drops to v ₁ ', its output becomes
It's starting to go back to _v2 . In this case, the position coordinate signal e is sufficiently smaller than the pen-touch signal _PT , and therefore falls within the hysteresis of the comparator 52 ₁ . Therefore, the comparator 52 ₁ does not respond to this position coordinate signal e.
The range of the hysteresis is determined.

Further, the output of the voltage follower 51 ₁ mentioned above is sent to the position information detection means 53 at the same time as it is sent to the comparator 52 ₁ .
And, regarding this position information detection means 53,
The DC component of the input signal to the operational amplifier ₅₃₁ is first separated by the capacitor 53A. Therefore, a differential waveform of rising and falling DC levels appears in the output, but the rising edge is a waveform in the opposite direction and is cut off by the diode _D1 . Furthermore, since the falling edge occurs after the coordinate position signal is determined, there is no relation. As a result, the PSIG signal shown in FIG. 9 is output, and is sent to the tablet controller as described above.

In this way, in this embodiment, the switch signal and the position information detection signal on the tablet surface are sent from the signal detection pen 30 to the main body through the same common signal line, so the number of signal lines is reduced from, for example, four compared to the conventional one. In use, this can be reduced to two,
Therefore, the pen can be made lighter and smaller, and the pen switch 44 inside the signal detection pen 30 can be made lighter and smaller.
Since the contact material is made of carbon or the like, the life of the contact can be extended, chattering can be reduced, and the switch mechanism can be simplified.

Here, when the pen touch signal PSW rises, a pulse A as shown by the dotted line A in FIG.
However, as mentioned above, since the scanning of the tablet is delayed by a predetermined time, this pulse A does not specify the location in question.

〔Effect of the invention〕

As described above, according to the present invention, the switch signal and the position information detection signal on the tablet surface are sent from the signal detection pen to the main body of the device using the same common signal line, so the number of signal lines on the pen side can be reduced. For example, the conventional use of four rods can be reduced to two, and the structure is such that the signal detection rod and external output cable are always connected, so the detected position information can be transmitted to the device with high sensitivity. Since the scanning signal for the tablet is output only while the signal detection rod is being pressed down, it is possible to effectively eliminate malfunctions of the entire device. It is possible to provide an unprecedented and excellent pen-touch type information input device in which the structure of the detection pen is simplified and miniaturized, and the cable is also lightened, thereby significantly improving operability and productivity.

[Brief explanation of drawings]

FIG. 1 is an external perspective view showing how a tablet input device equipped with a signal detection pen is used, FIG. 2 is a sectional view showing an example of a conventional signal detection pen, and FIG. 3 is a summary of an embodiment of the present invention. FIG. 4 is a block diagram showing an example of the circuit on the main body side of the device connected to the signal detection pen;
5 is an explanatory diagram of the operation of FIG. 4, FIG. 6 is a circuit diagram showing a specific example of FIG. 4, and FIGS. 7 to 9 are explanatory diagrams each showing the operation of each part of FIG. 6. . 30...Signal detection pen, 36...Casing,
39...Signal detection rod, 40...Stopper, 43
...Contact, 44...Pen press down confirmation switch, 4
5...Cable, 47...Pen side signal line, 48...
...Earth wire, 49...Extensible wiring, 50...
Bias voltage application means, 52... pen signal detection means, 53... position information detection means.

Claims (1)

[Claims] 1. A signal detection pen is provided at the tip of the casing and includes a signal detection rod that is slidably incorporated along the casing, and a pen switch attached to the signal detection rod, and a device main body equipped with a bias voltage applying means for inputting a pen touch signal output from a detection pen via a pen side signal line and outputting a scanning timing signal for the tablet based on the pen touch signal, One end of the switch is grounded and the other end is connected to the signal detection rod, and is a normally closed switch that opens when the signal detection rod is pressed down, and the signal detection rod is connected to a pen side signal line for an external output cable. a pen signal detecting means for separating and outputting the scanning timing signal from other signals on the pen side signal line; The pen-touch type information is characterized in that the main body of the device is equipped with a position information detection means that separates the position coordinate signal on the tablet sent through the signal line from other signals on the pen side signal line and outputs the signal. input device. 2. The pen touch type information input device according to claim 1, wherein a contact member of a pen switch equipped with the signal detection pen is formed of an annular carbon film member. 3. The pen touch type information input device according to claim 1, wherein a contact member of a pen switch equipped with the signal detection pen is formed of conductive rubber.