JPH0573201A - Coordinate detecting device - Google Patents

Abstract

PURPOSE:To reduce the power consumption of a coordinate detecting device in its working state. CONSTITUTION:An energization control signal generating circuit 14 instructs an energization control circuit 16 to energize a signal detecting circuit 132 and a signal processing circuit 15 for a fixed time during which the switch state detected by a switch circuit 131 is turned on and then turned off. The circuit 14 also instructs the circuit 16 for energization if the switch state is turned off and then turned on again after a fixed time. Under such conditions, the energization is carried out just for a period necessary for measurement of the coordinates without causing any omission of the coordinates. Thus the power consumption of a coordinate detecting device can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate detecting device used in an information processing device capable of handwriting input.

[0002]

2. Description of the Related Art Conventionally, an information processing device such as a workstation or a personal computer has traditionally been provided with a display and a keyboard. In this way, with a device equipped only with a keyboard as an input device, there is no problem when inputting only code data such as characters and numbers, but when operating an application program or an information processing device. , It is necessary to remember all commands for operation (for example, commands such as FORMAT in the case of a personal computer of MS-DOS), and execute them by entering the command name from the keyboard when necessary. is there.

The method of inputting such a command can be easily performed by a person who is accustomed to the operation of the apparatus and is familiar with commands, but it is very difficult for a general person to process these information. This is one of the reasons why the device is shunned.

Recently, as a means for solving such a problem, a method of operating an information processing apparatus using a device called a pointing device such as a mouse or a trackball has been used.

Since the mouse and the trackball can point and select any position on the screen, the contents of the process and the object to be processed are displayed on the screen, and the process is performed by selecting them. be able to. With this method, it is not necessary to input each character of the command. Therefore, the operability is much better than that of an information processing apparatus having only a keyboard.

However, in the case of a mouse or a trackball,
Since the indirect method of moving the displayed mouse cursor to the position of the target object to give an instruction is used, it is still difficult to operate.

Therefore, in order to compensate for the poor operability of the mouse or the like, a display device such as a liquid crystal display and a coordinate detection device for inputting coordinate data (hereinafter referred to as a tablet).
By overlapping the above, an integrated display / input device in which the display position and the input position are matched has been developed.

When this integrated display / input device is used,
Unlike a mouse or the like, the displayed object can be directly pointed by a dedicated coordinate input pen (hereinafter referred to as a stylus pen), which has good operability.

Further, since the designated position and the display position are coincident with each other, when a character or a figure is handwritten directly on the screen, the handwriting can be displayed at the handwritten position, which is like writing on a paper with a pencil. Since it can be operated with a sense, it is easy for humans to operate.

[0010]

An information processing apparatus such as a personal computer or a workstation equipped with an integrated display input device in which a tablet and a display device are superposed and integrated is easy to carry because of its operability. , There is a demand to use it anywhere.

To meet this requirement, it is necessary to be able to drive the device with a battery. In the case of battery driving, a method for reducing power consumption has been considered in order to enable long-time driving without increasing the battery size more than necessary.

As for the tablet, when the stylus pen is not near the detection surface of the tablet or when the tablet is not used for a while, the sampling rate (the frequency of detecting the coordinates indicated by the pen tip of the stylus pen is indicated and It is considered and realized to reduce the power consumption by lowering the power consumption. However,
Still, there is a problem that the power consumption during operation is large.
The present invention has been made in view of the above points, and an object thereof is to provide a tablet (coordinate detection device) that can reduce power consumption during operation.

[0013]

DISCLOSURE OF THE INVENTION The present invention is directed to coordinate detecting means provided with a coordinate detecting surface to be scanned for coordinate detection, and position indicating means for indicating an arbitrary position on the coordinate detecting surface. And a signal detection processing unit that detects a scanning position on the coordinate detection surface indicated by the position indicating unit when energized, the position indicating unit indicates the position on the coordinate detecting surface. To the signal detection processing means for a fixed time after the end of the instruction, and when the position detection means again instructs the coordinate detection surface during the fixed time, A configuration including an energization control instruction means for continuously energizing and energization control means for energizing the signal detection processing means in response to an instruction from the energization control instruction means A. Furthermore, it is configured to include an energization control switching unit that switches the instruction from the energization control instruction unit to valid or invalid.

[0014]

According to this structure, the signal detection processing means (stylus pen) is energized only for a certain period of time from the start of the position indication on the coordinate detection surface to the end of the indication, so that the power consumption is reduced. You can At this time, if an instruction is given again within a certain period of time, the power is continuously supplied. That is, in the case where the coordinates are input intermittently and continuously, the energization is continuously performed, so that the coordinates are not missing.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the coordinate detecting device according to the embodiment.

In FIG. 1, a coordinate detection plate 10 serves as a coordinate detection surface and is made of, for example, a glass plate,
The scanning lines 101 are arranged in a matrix (X direction, Y direction). In the embodiment, a tablet using the electrostatic induction method will be described as an example.

The drive circuit 11 is controlled by a control circuit 12 which will be described later, and the scanning lines 1 arranged in a matrix.
A predetermined voltage is sequentially applied to 01 to scan the coordinate detection surface.

The control circuit 12 controls the drive circuit 11 based on signals from the switch circuit 131 and the energization control circuit 16 of the stylus pen 13 described later. The control circuit 12 also inputs and receives data with the host device.

The stylus pen 13 is used for pointing on the coordinate detection surface of the coordinate detection plate 10.
The stylus pen 13 includes a switch circuit 131 and a signal detection circuit 132.

The switch circuit 131 is a signal "SW" indicating whether or not the pen tip is pressed by coming into contact with the coordinate detection surface (the pen down switch "S1" in the switch circuit 131 is turned on / off). Is output to the control circuit 12 and the energization control signal generation circuit 14. The signal detection circuit 132 detects a signal detected by the proximity of the scanning line 101 to which the voltage is applied and the pen tip to the signal processing circuit 1.
Output to 5.

The energization control signal generation circuit 14 outputs a signal "ON" for controlling the energization time to the energization control circuit 16 according to the signal "SW" from the switch circuit 131. The energization control signal generation circuit 14 controls the energization control circuit 16 according to an “Enable / Disable” signal (hereinafter referred to as “E / D” signal) from the host device. Here, the "E / D" signal is low level (Enable state).
In the case of, it operates to reduce the power consumption and "E / D"
When the signal is at a high level (Disable state), the operation is performed in the same manner as the conventional one.

The signal processing circuit 15 includes a signal detection circuit 132.
The signal detected by is amplified and filtered (high-frequency components are removed by the Low Pass Filter), then compared with a preset reference voltage, and when the reference voltage is exceeded, the control circuit 12 is informed of this fact. It outputs the indicated signal.

The energization control circuit 16 controls the power source V of the host device.
It is connected to IN and the "O
The supply of the power VDD to the signal detection circuit 132 and the signal processing circuit 15 is controlled according to the “N” signal.

FIG. 2 is a circuit diagram showing details of the energization control signal generation circuit 14, the energization control circuit 16 and the switch circuit 131 shown in FIG. In FIG. 2, the energization control circuit 1
6 is a transistor Q1, Q2, resistors R1, R2, R3
And performs a switching function of switching the supply of the power VDD to the signal detection circuit 132 and the signal processing circuit 15 according to the “ON” signal from the energization control signal generation circuit 14.

The switch circuit 131 includes a pen down switch "S1", a resistor R4, and "INV" (inverter).
Composed by. One end of the pen down switch "S1" is grounded, and the other end is connected to the input end of "INV". One end of the resistor R4 is connected to Vcc and the other end is "IN
V "input terminal. Therefore, switch "S1"
If is off, the signal a becomes high level and “IN
The output signal "SW" from "V" becomes low level. When the switch "S1" is in the ON state, the signal a becomes low level and the output signal "SW" from "INV" becomes high level.

The energization control signal generation circuit 14 uses the MM-1
(Retriggerable Monostable Multivibrator), MM-
2, OR-1 (OR gate), D-FF (flip-flop), and OR-2 (OR gate). MM-1 and MM-2 are R5, C1 and R, respectively.
6, a pulse having a time width determined by the values of C2 is output. Next, the basic operation of the embodiment will be described.

First, when the control circuit 12 receives a coordinate measurement start command from the host device, it outputs a signal (data, clock, etc.) for scanning the coordinate detection surface to the drive circuit 11.

When the drive circuit 11 receives the signal from the control circuit 12, the drive circuit 11 scans the scanning line 101 arranged on the detection surface from the end (applies a predetermined voltage). At this time, if the pen tip of the stylus pen 13 is near the scanning line 101 being scanned, the signal detection circuit 132 inside the stylus pen 13 can detect the signal induced from the scanning line 101. The signal detected by the signal detection circuit 132 increases as the distance between the scanning line 101 being scanned and the pen tip of the stylus pen 13 decreases.

Therefore, as the scanning line 101 is scanned from the end, the signal detected by the signal detection circuit 132 gradually increases, and becomes the largest when the distance between the stylus pen 13 and the scanning line 101 becomes the smallest. The value is obtained.

The signal processing circuit 15 includes a signal detection circuit 132.
The signal detected in step S3 is received, amplified and filtered, and compared with a preset reference voltage. As a result, when the detected signal exceeds the reference voltage, a signal indicating this is output to the control circuit 12.

When the control circuit 12 receives a signal from the signal processing circuit 15 that the reference voltage has been exceeded, the scanning line 10
The time from the start of the scan to 1 until the detected signal exceeds the reference voltage is measured.

This makes it possible to detect the distance from the end (origin) of the coordinate detection surface to the position indicated by the pen tip of the stylus pen 13. Perform this measurement operation in the X-axis direction and Y
The position (coordinates) of the stylus pen 13 on the plane can be detected by performing the operation in the axial direction.

Whether or not the pen tip of the stylus pen 13 is in contact with the coordinate detection surface can be detected by the switch circuit 131 (the pen down switch "S1") built in the stylus pen 13.

The switch circuit 131 is the stylus pen 1
Even if the pen tip of 3 is not on the coordinate detection surface, a signal is generated only when the pen tip is pressed. Therefore, the control circuit 12
Determines whether the pen tip is on the detection surface by checking the measured coordinate values.

In response to a coordinate measurement command from the host device,
When the coordinate measurement is performed and the measurement is completed, the control circuit 12
Generates an interrupt signal to the host device. When the host device receives the interrupt from the tablet,
Import the detected coordinate data.

When the measurement cannot be performed (the stylus pen 13 is away from the detection surface of the tablet) for a certain period of time and the coordinate data cannot be detected, the control circuit 12
Reduces the power consumption of the tablet by reducing the sampling rate for scanning the coordinate detection surface.

Further, in a tablet having an auto sampling function (coordinates are automatically measured in the tablet at fixed time intervals and an interrupt is generated at each measurement to request coordinate acquisition), the state in which measurement cannot be performed for a fixed time period is impossible. Then, the power consumption can be reduced by automatically lowering the sampling rate.

All of these are intended to reduce power consumption when the tablet is not used. The coordinate detection device of the present invention operates so as to reduce power consumption even during operation.

Next, using the timing charts shown in FIGS. 3 and 4, the power consumption is reduced, that is, the switch circuit 1
According to the state of the switch S1 of 31, the signal detection circuit 13
2 and the operation of turning on / off the power supply to the signal processing circuit 15 will be described. Here, "E /
It is assumed that the "D" signal is at a low level (Enable state).

First, when the switch S1 is off, the "SW" signal output from the switch circuit 131 is off (low level in FIG. 3). In this state, no signal is added to the D-FF,
The "ON" signal goes low, turning off the transistor Q2 in the communication control circuit 16. As a result, the transistor Q1 is also turned off, and nothing is output to VDD, which is a power source for the signal detection circuit 132 and the signal processing circuit 15.

From this state, when the switch S1 is turned on, the "SW" signal becomes high level (the rising edge of the "SW" signal in FIG. 3), and the output "ON" signal from the OR-2 also becomes high level. Therefore, the transistors Q2 and Q1 of the energization control circuit 16 are turned on, and power is supplied to the signal detection circuit 132 and the signal processing circuit 15. This enables coordinate measurement.

Next, when the switch S1 is turned off, "S
The MM-1 operates at the falling edge of the "W" signal, and the time width defined by the values of R5 and C1 (for example, T = 0.45 ×).
A high active pulse of R5 × C1) is output to the Q output (see signal b in FIG. 3).

The MM-2 operates at the trailing edge of this pulse and outputs a low active pulse that can be cleared by the D-FF. At this time, if the switch is turned on only once, the "SW" signal is already at a low level, so a low active pulse is output from the OR-1 gate (see signals c and d in FIG. 3), and D- Clear FF,
Stop the supply to VDD (see signal ON and VDD in Figure 3).

In the case of inputting coordinates intermittently (switch S1 is turned on / off continuously in a short time), as in the case of inputting characters by online character recognition, As shown in 4.

As shown in FIG. 3, first, the switch S1
When is turned on again after turning off from on, the "SW" signal is at the high level. Therefore, nothing is output from the OR-1 gate (signal d in FIG. 4).
Signal), the “ON” signal continuously becomes high level (see signal ON in FIG. 4), and the supply to VDD becomes continuous. Therefore, the problem of the followability of the coordinate measurement due to turning on / off the power supply (coordinate omission occurs because the power supply takes time) is eliminated.

Next, the energization control circuit 16 is disabled.
The case will be described. En of the energization control circuit 16
Able / Disable can be switched only by the OR-2 gate. When it is disabled,
Since the "E / D" signal from the host device is at the high level, the "ON" signal from the OR-2 gate is at the high level regardless of the output of the D-FF. For this reason,
The transistors Q2 and Q1 of the energization control circuit 16 are turned on and V
Power is supplied to the DD. In this way, since the same use as before can be performed, the software or the like in the conventional coordinate detecting device can be used as it is.

In this way, when the switch S1 requiring coordinate measurement is on, the signal detection circuit 132 and the signal processing circuit 15 are energized, and a certain time or more has passed since the switch S1 was turned off. In some cases, energization is stopped. As a result, the minimum required power supply is enough.
Low power consumption can be achieved.

The energization control circuit 1 for controlling power supply
Since 6 can be enabled / disabled, normal operation can be performed when it is not necessary to reduce power consumption (for example, when battery driving is not required).

Although the tablet using the electrostatic induction method has been described as an example in the above embodiment, other methods such as an electromagnetic induction method and a pressure sensitive method may be used. Further, the energization control circuit 16 has been described using the configuration using the transistor, but other devices such as a relay and an FET may be used.

Similarly, the energization control signal generation circuit 14 has a D-
FF and Monostable Multivibrator (MM-1, MM-
Although 2) is used for the description, other devices may be used or software may be used for control.

[0051]

As described above, according to the present invention, the power supply is stopped when the coordinate measurement is not necessary even during the operation (the pen down switch S1 is off), so that the power consumption can be reduced. Can be done. Further, by adding a circuit for switching a circuit for controlling power supply to valid or invalid, normal operation can be performed when it is not necessary to reduce power consumption.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a coordinate detection device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing details of an energization control signal generation circuit 14, an energization control circuit 16, and a switch circuit 131 shown in FIG.

FIG. 3 is a timing chart showing changes in signals when the pen down switch S1 is turned on / off.

FIG. 4 is a timing chart showing changes in signals when the pen down switch S1 is continuously turned on / off.

[Explanation of symbols]

10 ... Coordinate detection plate, 101 ... Scan line, 11 ... Drive circuit,
12 ... Control circuit, 13 ... Stylus pen, 131 ... Switch circuit, 132 ... Signal detection circuit, 14 ... Energization control signal generation circuit, 15 ... Signal processing circuit, 16 ... Energization control circuit.

Claims (2)

[Claims] 1. A coordinate detecting means provided with a coordinate detecting surface to be scanned for coordinate detection, a position indicating means for indicating an arbitrary position on the coordinate detecting surface, and the above-mentioned by being energized. In a coordinate detection device having a signal detection processing means for detecting a scanning position on the coordinate detection surface indicated by a position indication means, a fixed time after the instruction is completed after the position indication means indicates the coordinate detection surface. Only to instruct to energize the signal detection processing means, and to instruct energization to the signal detection processing means continuously when the position instructing means reinstructs the coordinate detection surface during the certain time. A coordinate detecting apparatus comprising: a control instruction unit; and an energization control unit that energizes the signal detection processing unit according to an instruction from the energization control instruction unit. 2. The coordinate detecting apparatus according to claim 1, further comprising energization control switching means for switching an instruction from the energization control instruction means to valid or invalid.