JPH09282085A - Position information input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position information device which dissolves a drift phenomenon and can display an index on a precise position at still time. SOLUTION: A pointing device 1 has gyro sensors 2 and 3 for detecting the angular velocity of the directions of x and y-axes, amplifiers 4 and 5, a control means 6 incorporating an A/D converter 61 and a correction part 62 for correcting reference voltage, a data transmission module 7, right/left switches 8 and 9 and a power switch 11. The correction part 62 has a memory storing a program for controlling the operation of the pointing device 1 and a correction value counter. The correction part 62 corrects respective reference voltages so that respective reference voltages become actually equal to output voltage from the gyro sensors 2 and 3 when the pointing device 1 is still based on the output voltage from the gyro sensors 2 and 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position information input device.

[0002]

2. Description of the Related Art A mouse is known as a device for moving a cursor (pointer) displayed on a CRT screen of a personal computer or the like.

This mouse rolls a built-in sphere on a flat surface such as a rubber mat, converts the rolling direction and amount into an electric signal to detect the amount of movement, and rolls the sphere. Therefore, there is a constraint that the operation must be performed while it is in contact with the plane. Further, since the mouse and the personal computer are connected by a cord, there is a problem that the operation may be troublesome.

In order to solve such a drawback of the mouse, an input device capable of operating a pointing device using a gyro sensor in the air has been disclosed. This apparatus is incorporated in a pointing device, a set of vibration gyro sensors capable of detecting the displacement thereof, means for converting a detection signal detected by the sensor into position designation information, and the position designation information of a personal computer. And a transmission means for transmitting as input information to the CRT, the displacement of the pointing device is
It is configured to appear in correspondence with the movement of the cursor (pointer) on the screen.

However, this type of input device has the following drawbacks. Vibrating gyro sensor,
Because of its temperature dependence, its output voltage from the vibrating gyro sensor fluctuates with time even when the temperature of the pointing device rises immediately after the power is turned on, even when the pointing device is stationary. A phenomenon occurs, and as a result, the CRT is operated even if the operation of moving the cursor (pointer) is not performed.
The phenomenon that the cursor (pointer) on the screen flows (drift phenomenon) occurs.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a position information input device which can solve the above-mentioned conventional problem of drift phenomenon and display an index at an accurate position when stationary. To do.

[0007]

This and other objects are achieved by the present invention which is defined below as (1) to (13).

(1) Based on first and second sensors for detecting displacements in the X direction and the Y direction, which are orthogonal to each other, the voltages output from the first and second sensors, and a reference voltage. , Position information creating means for creating position information of the index displayed on the screen, transmitting means for transmitting the position information, and the position information input device when stationary,
A position information input device comprising: a correction unit that corrects the reference voltage so that the reference voltage becomes substantially the same as the voltage output from the first and second sensors.

(2) Position information input according to the above (1), which has a discrimination means for discriminating whether or not the position information input device is stationary based on the voltages output from the first and second sensors. apparatus.

(3) The determination means is configured to determine that the position information input device is moving when the amount of change in the voltage output from the first and second sensors exceeds a threshold value. The positional information input device according to (2) above.

(4) The position information input device according to (3), wherein the threshold value can be set to a plurality of values.

(5) The position information input device according to (4), wherein the threshold value is set to be larger when the power is turned on than in the normal operation.

(6) The correction means, at predetermined time intervals,
A voltage output from the first and second sensors,
The reference voltage is compared, and if they do not match, the reference voltage is shifted by one unit in a direction in which the voltage output from the first and second sensors approaches the reference voltage. The position information input device according to any one of (1) to (5), which enables the above.

(7) The correction means, at predetermined time intervals,
A voltage output from the first and second sensors,
The reference voltage is compared, and if they do not match, it is determined whether or not the voltages output from the first and second sensors are within a predetermined range, and the voltage is within the predetermined range. In this case, it is possible to shift the reference voltage by one unit in the direction in which the voltages output from the first and second sensors and the reference voltage approach each other. ) The position information input device according to any one of 1).

(8) The correction means, at predetermined time intervals,
A voltage output from the first and second sensors,
The reference voltage is compared, and when the number of times of detection of the deviations is accumulated a predetermined number of times, the reference voltage is adjusted so that the voltage output from the first and second sensors approaches the reference voltage. The position information input device according to any one of (1) to (5), which shifts by one unit.

(9) The position information input device according to (8), wherein the predetermined number of times can be set to a plurality of values.

(10) The position information input device according to (9), which is configured to set the predetermined number of times less when the power is turned on than in the normal operation.

(11) When the power is turned on, the reference voltage is corrected at a shorter time interval than during normal operation, and the reference voltage is corrected according to any one of the above (1) to (9). Position information input device.

(12) The position information is transmitted by wireless communication (1) to (11).
The position information input device according to any one of 1.

(13) The position information input device according to any one of (1) to (12), wherein the first and second sensors are angular velocity sensors.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The position information input device of the present invention will be described below in detail with reference to the preferred embodiments shown in the accompanying drawings. FIG. 1 and FIG. 2 respectively show a first example when the position information input device of the present invention is applied to a pointing device.
It is a block diagram and a perspective view showing the circuit configuration of an example.

As shown in these figures, the pointing device 1 is, for example, a C such as a personal computer.
This is a device for moving and operating an index such as a cursor (pointer) displayed on an RT screen, a liquid crystal screen, or a screen of a television (hereinafter, these are collectively referred to as "screen").

The pointing device 1 includes a gyro sensor (first angular velocity sensor) 2 for detecting an angular velocity in the x-axis direction (horizontal direction) and a gyro sensor (second angular velocity sensor) for detecting an angular velocity in the y-axis direction (vertical direction). Angular velocity sensor) 3, amplifiers (differential amplifiers) 4, 5, and control means 6
And a data transmission module (transmission means) 7, a left switch 8, a right switch 9, and a power switch 11.
These are housed in the casing 10 in a predetermined arrangement.

As shown in FIG. 2, the gyro sensor 2,
3 are installed in directions (x-axis direction and y-axis direction) orthogonal to each other, and displacements of the pointing device 1 in the x-axis direction and the y-axis direction can be detected as changes in angular velocity.

Examples of such gyro sensors 2 and 3 include those disclosed in Japanese Patent Laid-Open Nos. 2-51066 and 6-5075.
The vibration gyro sensor described in Japanese Patent No. 8 can be used. This vibrating gyro sensor has a columnar (for example, triangular prism or quadrangular prism) vibrating body. This vibrating body is formed of a constant elastic metal material such as an alloy of Ni, Fe, Cr, Ti or the like. A pair of piezoelectric elements for detection and a pair of piezoelectric elements for driving are provided in the center of the side surface of the vibrating body. The vibrating body is supported by the supporting member at its node point.

When a drive signal is applied to the piezoelectric element for driving the vibrating gyro sensor, the vibrating body bends and vibrates in a predetermined direction. In such a state, when the vibrating gyro sensor rotates about its axis, Coriolis force acts in a direction perpendicular to the vibrating direction. This Coriolis force changes the vibration direction of the vibrating body and changes the output voltage from the piezoelectric element for detection.

In this way, the gyro sensor 2 outputs a voltage corresponding to the angular velocity in the x-axis direction, that is, an analog signal, and the gyro sensor 3 outputs a voltage corresponding to the angular velocity in the y-axis direction, that is, an analog signal. Is output.

In this case, in this embodiment, when the angular velocity is 0 (stationary state) from each gyro sensor 2, 3,
A voltage of about 2.3 V is output, a voltage exceeding 2.3 V is output when the angular velocity is positive, and a voltage of less than 2.3 V is output when the angular velocity is negative. Actually, the output voltage from each of the gyro sensors 2 and 3 in the stationary state depends on the temperature, time, etc., and is 2.3 ±.
It fluctuates within a range of about 0.033V.

The control means 6 is usually composed of a microcomputer (CPU) and has an 8-bit A / D converter 61.
And a correction unit (correction means) for correcting the reference voltage described later.
62 and the like are built in. The main function of the position information creating means for creating the position information of the index displayed on the screen is achieved by the control means 6.

Further, the correction section 62 is a memory (ROM and RAM) (not shown) in which a program described later for controlling the operation of the pointing device 1 is stored.
And a correction value counter (not shown). The correction value counter is composed of a circulating up / down counter that returns to 0 at 256 so that it can count from 0 to 255.

A data transmission module 7, a left switch 8, a right switch 9 and a power switch 11 are connected to the control means 6 as described above. The data transmission module 7 converts the count data (count data corresponding to the movement amount of the pointing device 1) output from the control means 6 into transmission data according to a predetermined transmission format. As a transmission method, wireless communication is preferable, and for example, radio wave communication or infrared communication is possible.

The power switch 11 is operated when the pointing device 1 is started, and the power switch 11 is turned on.
As a result, power is supplied to various parts of the device from a power source (battery) not shown.

The left switch 8 and the right switch 9 are switches for giving a predetermined command to the position of the cursor (pointer) on the screen. For example, when the left switch 8 is clicked, an icon is selected on the screen. When the right switch 9 is clicked, the selection of an icon is canceled or the like.

Next, the operation of the pointing device 1 will be described. With this pointing device 1,
The gyro sensor 2 outputs a voltage corresponding to the angular velocity in the x-axis direction, that is, an analog signal. This analog signal is input to the amplifier (differential amplifier) 4, and the difference value from the reference value is amplified by the amplifier 4 and input to the control means 6.

The control means 6 samples the amplified analog signal every 30 ms and converts the analog signal into a digital signal by the A / D converter 61. Hereinafter, the value represented by this digital signal is referred to as a “detection value”.

The detected value is an integer of 0 to 255,
The detected value “128” corresponds to the output voltage 2.3V from the gyro sensor 2. The detected value is "255" when the output voltage from the gyro sensor 2 is equal to or higher than a predetermined value (upper limit value), and is "255" when the output voltage from the gyro sensor 2 is equal to or lower than the predetermined value (lower limit value). It becomes "0". It should be noted that one interval (1 div) of the detection value (A / D conversion value)
When converted into the voltage after being amplified by the amplifier 4, 11.
It is about 8 mV.

Similarly to the above, the gyro sensor 3 outputs a voltage corresponding to the angular velocity in the y-axis direction, that is, an analog signal, and this analog signal is input to the amplifier (differential amplifier) 5 and the amplifier 5 outputs it. , The difference value from the reference value is amplified and input to the control means 6. Then, the control means 6 samples the amplified analog signal every 30 msec and converts the analog signal into a digital signal by the A / D converter 61.

The control means 6 obtains the angular velocities in the x-axis direction and the y-axis direction, respectively, based on the digital signal (detection value) and a corrected reference voltage (voltage when the angular velocity is 0) described later. Based on these angular velocities, count data (position information) in the x-axis direction and the y-axis direction corresponding to the amount of movement of the cursor (pointer) in the x-axis direction and the y-axis direction are obtained, respectively.

The count data in the x-axis direction and the count data in the y-axis direction are respectively sent by the data transmission module 7.
It is converted into transmission data (signal) of a system according to a predetermined format for radio waves or infrared communication (wireless communication).
Then, the signal is transmitted from the data transmission module 7.

A receiving side device (not shown) such as a personal computer or a television receiver receives the signal transmitted from the data transmitting module 7, and the cursor displayed on the screen based on the received signal. The (pointer) is moved in a predetermined direction at a predetermined speed, that is, in a direction and speed corresponding to the movement of the pointing device 1, or is made to stand still.

As described above, the gyro sensors 2, 3
The voltage, that is, the analog signal output from the device increases or decreases depending on temperature and time. Therefore, the pointing device 1 detects the voltage output from the gyro sensors 2 and 3, and based on this voltage, at rest (when the angular velocity is 0
The reference voltage, that is, the reference voltage is substantially the same as the voltage output from the gyrosensors 2 and 3 when the pointing device 1 is stationary. to correct.

The correction of the reference voltage will be described below.
In addition, the correction of the reference voltage for the gyro sensor 2,
Since the correction of the reference voltage for the gyro sensor 3 is performed by the same method, the correction of the reference voltage for the gyro sensor 2 will be representatively described.

FIG. 3 is a flow chart showing the control operation of the control means 6 of the pointing device 1. Less than,
A description will be given based on this flowchart. This program is executed when the power switch 11 is turned on. When the pointing device 1 is used, it is preferable that the pointing device 1 is stationary and the power switch 11 is turned on, or the pointing device 1 is once stopped after the power switch 11 is turned on.

When the power switch 11 is turned on, initialization is performed (step 101). That is, this step 10
At 1, the count value k of the correction value counter is set to 128, the correction value dif is set to 0, and the initial reference voltage ref is set.
Read. These correction value dif and initial reference voltage r
Each ef is stored in a memory (RAM) (not shown) built in the control means 6. In this case, the sum of the initial reference voltage ref and the correction value dif (ref + dif)
Is the reference voltage (corrected reference voltage).

Here, the initial reference voltage ref is output from the gyro sensor 2 immediately after the power switch 11 is turned on, amplified by the amplifier 4, and A / D converted by the A / D converter 61. , That is, the detected value.

After step 101, as described above, the analog signal output from the gyro sensor 2 and amplified by the amplifier 4 is converted into a digital signal by the A / D converter 61 (step 102). This digital signal, that is, the detected value A _N sampled this time (N is a natural number)
Is a memory (RA not shown) built in the control means 6.
M).

Next, the detected value A _N sampled this time
It is determined whether is a correction target value (step 103). In step 103, the previously sampled detection value A _N-1
And whether the absolute value of the difference from the detected value A _N sampled this time is less than or equal to a predetermined threshold value (threshold value = 1 in this embodiment), that is, −1 ≦ A _N −A _N−1. It is determined whether or not ≦ 1, and if −1 ≦ A _N −A _N−1 ≦ 1, it is set as a correction target value, and −1> A _N −A _N−1 , or 1 <A _N −A. _In the case of _N-1 , it is considered not to be the correction target value.

Here, when N = 1, that is, when it is determined whether the detected value A ₁ is a correction target value, A ₀ = r
ef. By this step 103, when the pointing device 1 is in the moving state, the pointing device 1 is excluded so as not to shift to the following correction routine.

When it is determined in step 103 that the value is the correction target value, the reference voltage (ref + dif)
It is determined whether the difference from the detected value A _N sampled this time is 0, that is, whether A _N − (ref + dif) = 0 (step 104). By this step 104, the case where there is no fluctuation in the output voltage from the gyro sensor 2 at rest, that is, the case where no correction is necessary, is eliminated.

At step 104, A _N- (ref
+ Dif) ≠ 0, A _N − (ref +
It is determined whether or not dif)> 0 (whether the sign of the difference is positive), that is, whether or not the drift direction is the ascending direction (step 105). In step 105, A _N − (re
When it is determined that f + dif)> 0, it is determined whether the detected value A _N sampled this time is within the correction target width (step 106).

In step 106, 35≤A _N ≤221
If 35 ≦ A _N ≦ 221, the correction target width is set, and if 34 ≧ A _N or 222 ≦ A _N , the correction target width is not set. In addition, the above "3
5 ”is the output voltage from the gyro sensor 2.
The voltage "221" corresponds to the output voltage from the gyro sensor 2 of about 2.333V. The output voltage from the gyro sensor 2 when the angular velocity is 0 is usually included in the detection value range of 35 to 221 and fluctuates within this range.

Here, the reason why it is judged in step 106 whether or not it is within the correction target width is, for example, when the pointing device 1 is moved so that the detected value A _N becomes the maximum (255) ( The minimum detected value A _N (0)
The same applies when a moving operation is performed so that
≦ A _N −A _N−1 ≦ 1 and A _N − (ref + dif) ≠
Since the condition of 0 is satisfied and the correction process described later is performed, it is necessary to eliminate this and to make an output voltage exceeding the fluctuation range of the output voltage from the gyro sensor 2 when the angular velocity is 0 as a correction target. Because there is no.

When it is determined in step 106 that the correction target width is within the correction target width, the correction value counter count value k
Is incremented by 1 (k = k + 1) (step 1
07). Next, it is determined whether k = 0 (whether k overflows to the upper side) (step 108).

When it is judged in step 108 that k ≠ 0, step 114 described later is executed, then the process returns to step 102, and step 102 and subsequent steps are executed again. In step 105, A _N
When it is determined that − (ref + dif) <0, it is determined in the same manner as described above whether the detected value A _N sampled this time is within the correction target width (step 110).

When it is determined in step 110 that the correction target width is within the correction target width, the count value k of the correction value counter is set to 1
Decrement (k = k-1) (step 11
1). Next, it is determined whether k = 0 (whether k overflows to the lower side) (step 112).

When it is judged in step 112 that k ≠ 0, step 114 to be described later is executed, then the process returns to step 102, and step 102 and subsequent steps are executed again. Further, when it is determined in step 103 that the value is not the correction target value, when it is determined that A _N − (ref + dif) = 0 in step 104, or when it is determined that it is not within the correction target width in step 106 or 110. Is the step 114 described later.
Is executed, and then the process returns to step 102 and the steps after step 102 are executed again.

As described above, step 102 and subsequent steps are repeatedly executed, and when it is determined that k = 0 in step 108, the correction value dif is incremented by 1 (dif = dif + 1), and the correction value counter counts. The value k is initialized (k = 128) (step 109). In this step 109, the reference voltage (ref + dif) becomes 1
It is corrected by the unit.

FIG. 4 is a timing chart for explaining the correction of the reference voltage. This timing chart shows the case where the voltage (analog signal) output from the gyro sensor 2 rises almost in proportion to the time when the pointing device 1 is stationary.

For example, as shown in the figure, when the voltage output from the gyro sensor 2, that is, the analog signal rises with time, the initial reference voltage ref
= 128, correction value dif = 0, that is, reference voltage ref
In the state of + dif = 128, the detection value of 128 times is “12.
9 ”, the correction value dif = 1, that is, the reference voltage r
It is corrected to ef + dif = 129. Similarly, in the state of the reference voltage ref + dif = 129, when the detected value of 128 times is “130”, the correction value dif = 2, that is, the reference voltage ref + dif = 130 is corrected.

As described above, in the present embodiment, the reference voltage is corrected when k is added / subtracted a plurality of times and k = 0 (when k overflows). That is,
When the number of times of detecting the deviation between the detected value and the reference voltage is accumulated a predetermined number of times, the reference voltage is shifted by one unit. This allows
When the pointing device 1 is moved, the adverse effect of the correction of the reference voltage can be suppressed when calculating the movement amount of the cursor (pointer). Therefore, the amount of movement of the cursor (pointer) can be accurately obtained, which allows the cursor (pointer) to be accurately and surely moved to an appropriate position.

Further, the gyro sensor 2 based on the drift
Since the rising speed and the falling speed of the output voltage from are relatively small, there is no problem even if correction is performed at relatively long time intervals as described above. In the present invention, the cumulative number (predetermined number) may be set to a plurality of values.

In the step 112, k =
If it is determined to be 0, the correction value dif is decremented by 1 (dif = dif−1), and the count value k of the correction value counter is initialized (k = 128) (step 11).
3). In step 113, the reference voltage (ref + di
f) is corrected by one unit.

After step 109 or 113, the count data is output (step 114). In this step 114, as described above, the angular velocity is calculated based on the detected value A _N sampled this time and the corrected reference voltage (ref + dif), and the moving amount of the cursor (pointer) is determined based on the angular velocity. Find the corresponding count data. Then, the data transmission module 7 converts the count data into a signal according to a predetermined format for radio wave or infrared communication, and transmits the signal.

After step 114, the process returns to step 102, and steps 102 and subsequent steps are executed again. As described above, the detection value is sampled at a cycle of 30 msec, and the correction routine is repeated until the output voltage from the gyro sensor 2 stabilizes, and when the output voltage stabilizes, the correction routine is exited.

The correction of the reference voltage for the gyro sensor 3 is performed by the same method as the correction of the reference voltage for the gyro sensor 2 described above. In this case, the same processing as steps 102 to 113 is performed by the gyro sensor 3
As a process for correcting the reference voltage related to step 114, the process goes before step 114. In the present invention, the threshold value may be set to a plurality of values.

As described above, according to the pointing device 1, the output voltage from the gyro sensors 2 and 3 when the pointing device 1 is stationary (when the angular velocity is 0) becomes the reference voltage. Each reference voltage is corrected. Therefore, when the pointing device 1 is stationary, the gyro sensors 2, 3
The cursor (pointer) displayed on the screen remains stationary regardless of whether or not the output voltage from the device changes. Therefore, when stationary, the cursor (pointer) can be continuously displayed at the correct position.

Further, in the pointing device 1, since the drift phenomenon does not occur due to the correction of the reference voltage, that is, the data processing (processing on software), the structure is simple. Then, without improving the gyro sensor or the like, it is possible to realize a pointing device in which the drift phenomenon does not occur by using the existing gyro sensor.

Next, a second embodiment in which the position information input device of the present invention is applied to a pointing device will be described. The description of common points with the first embodiment will be omitted, and the main differences will be described. The circuit configuration of the pointing device according to the second embodiment is the same as that of the pointing device 1 according to the first embodiment described above, except for the difference in the control program, and a description thereof will be omitted.

Next, the correction of the reference voltage will be described.
In addition, the correction of the reference voltage for the gyro sensor 2,
Since the correction of the reference voltage for the gyro sensor 3 is performed by the same method, the correction of the reference voltage for the gyro sensor 2 will be representatively described. FIG. 5 is a flowchart showing the control operation of the control means 6 of the pointing device. Hereinafter, description will be made based on this flowchart.

This program is executed when the power switch 11 is turned on. When the power switch 11 is turned on,
A timer (not shown) built in the control means 6 is started (step 201). This timer time is preset to a predetermined value. The timer time is
For example, it is about 5 to 10 seconds.

Then, initialization is performed (step 20).
2). That is, in this step 202, the count value k of the correction value counter is set to 128, the correction value dif is set to 0, and the initial reference voltage ref is set to a predetermined value. These correction value dif and initial reference voltage ref are
Each is stored in a memory (RAM) (not shown) built in the control means 6. In this case, the initial reference voltage re
The sum (ref + dif) of f and the correction value dif is the reference voltage (corrected reference voltage). The initial reference voltage r
The value of ef is preferably around 128 (corresponding to 2.3 V), and is set to 128, for example.

After step 202, it is judged whether or not the timer has expired (whether or not the power is turned on) (step 20).
3). If it is determined in step 203 that the timer has not expired, the power-on parameters (m, n) are set (step 204).

In this step 204, the threshold value m = m for the correction target value determination in step 207 described later.
₁ , the addition / subtraction value n = n ₁ to the correction value counter in steps 211 and 215 described later is set. In this case, m ₁ and n ₁ are larger than m ₂ and n ₂ described later, respectively. In particular, m ₁ is set to a value that allows a shift to the correction routine even when the pointing device is held by hand and kept stationary. In addition, in this embodiment, n, that is, n ₁ and n ₂ is 12 respectively.
It is a divisor of 8. Note that m ₁ is preferably about 2 to 8, and is set to 5, for example. Further, n ₁ is preferably about 2 to 8, and is set to 8, for example.

If it is determined in step 203 that the timer has expired, the parameters (m, n) for normal operation are set (step 205).
In this step 205, the threshold value m for correction target value determination in step 207, which will be described later, is set to m = m ₂ , and the addition / subtraction value n = n ₂ to the correction value counter in steps 211 and 215, which will be described later. Note that m ₂ is preferably about 1 to _{2, and} is set to 1, for example. N ₂ is 1
It is preferably about 2 to 2, for example, 1.

After step 204 or 205, as described above, the output from the gyro sensor 2 and the amplifier 4
The analog signal amplified in step A is converted into a digital signal by the A / D converter 61 (step 206). This digital signal, that is, the detected value A _N sampled this time
(N is a natural number) is stored in a memory (RAM) (not shown) built in the control means 6.

Next, the detected value A _N sampled this time
It is determined whether is a correction target value (step 207). In step 207, the previously sampled detection value A _N-1
And whether or not the absolute value of the difference between the detected value A _N sampled this time is m or less, that is, whether or not −m ≦ A _N −A _{N− 1} ≦ m, and −m ≦ A _N −A in the case of _N-1 ≦ m is a correction target _{value, -m> a N -A N-} 1 or m <a _N, -
In the case of A _N-1 , it is not a correction target value.

Here, when N = 1, that is, when it is determined whether the detected value A ₁ is a correction target value, A ₀ = r
ef. Since m ₁ > m ₂ , in step 207, when the power is turned on (when m = m ₁ is set), it is more than in normal operation (when m = m ₂ is set). It is easy to determine that “the detected value A _N is the correction target value”. For example, when the pointing device is held by hand, a minute movement (angular velocity) at that time is detected by the gyro sensor 2, so that a normal operation (m =
(when set to m ₂ ), usually -m> A _N -A
The _N-1 or m <A _N -A _{N- 1,} but when the power is turned on (m
= When set to m ₁₎ is also slightly moving the pointing device becomes _{-m ≦ A N -A N-1} ≦ m.

In step 207, when the pointing device 1 is in the moving state, the pointing device 1 is excluded so as not to proceed to the following correction routine. If it is determined in step 207 that the value is the correction target value, the reference voltage (ref
+ Dif) and the difference between the detected value A _N sampled this time is 0, that is, A _N − (ref + dif) = 0
It is determined whether or not (step 208).

This step 208 eliminates the case where there is no fluctuation in the output voltage from the gyro sensor 2 at rest, that is, the case where no correction is necessary. In step 208, A _N − (ref + dif) ≠ 0
If it is determined that A _N − (ref + dif)> 0 (whether the sign of the difference is positive or not), that is, it is determined whether the drift direction is the ascending direction (step 209).

At step 209, A _N- (ref
When it is determined that + dif)> 0, it is determined whether the detected value A _N sampled this time is within the correction target width (step 210). In step 210, 35 ≦ A _N ≦ 22
It is determined whether or not 1, and if 35 ≦ A _N ≦ 221, it is within the correction target width, and if 34 ≧ A _N or 222 ≦ A _N , it is not within the correction target width.

When it is determined in step 210 that the correction target width is within the correction target width, the count value k of the correction value counter is set to n.
Increment (k = k + n) (step 21
1). Then, it is determined whether k = 0 (whether k overflows to the upper side) (step 212).

When it is judged in step 212 that k ≠ 0, step 218 described later is executed, then the process returns to step 203, and step 203 and subsequent steps are executed again.

In step 209, A _N
When it is determined that-(ref + dif) <0, it is determined whether the detected value A _N sampled this time is within the correction target width in the same manner as described above (step 214). When it is determined in step 214 that the width is within the correction target width, the count value k of the correction value counter is decremented by n (k
= K-n) (step 215).

Next, it is determined whether k = 0 (whether k overflows downward) (step 216).
When it is determined in step 216 that k ≠ 0,
Perform step 218, which will be described later, and then execute step 2
Returning to step 03, the steps from step 203 are executed again.

If it is determined in step 207 that the value is not the correction target value, in step 208 it is determined that A _N- (ref + dif) = 0, or in step 210 or 214 that it is not within the correction target width. If so, step 218 described below
Is executed, and then the process returns to step 203, and the steps after step 203 are executed again.

As described above, step 203 and subsequent steps are repeatedly executed, and when k = 0 is determined in step 212, the correction value dif is incremented by 1 (dif = dif + 1), and the correction value counter counts. The value k is initialized (k = 128) (step 213). In this step 213, the reference voltage (ref + dif) becomes 1
It is corrected by the unit.

In step 216, k =
If it is determined to be 0, the correction value dif is decremented by 1 (dif = dif-1), and the count value k of the correction value counter is initialized (k = 128) (step 21).
7). In step 217, the reference voltage (ref + di
f) is corrected by one unit. When the power is turned on, the addition / subtraction value n = n ₁ (> n ₂ ) to the correction value counter is set, so that k = 0 is set relatively early and the reference voltage is corrected.

After step 213 or 217, the count data is output (step 218). In this step 218, as described above, the angular velocity is obtained based on the detected value A _N sampled this time and the corrected reference voltage (ref + dif), and the moving amount of the cursor (pointer) is determined based on the angular velocity. Find the corresponding count data. Then, the data transmission module 7 converts the count data into a signal of a predetermined method for radio wave or infrared communication, and transmits the signal.

After step 218, the process returns to step 203, and step 203 and subsequent steps are executed again. As described above, the detection value is sampled at a cycle of 30 msec, and the correction routine is repeated until the output voltage from the gyro sensor 2 stabilizes, and when the output voltage stabilizes, the correction routine is exited.

The correction of the reference voltage for the gyro sensor 3 is performed by the same method as the correction of the reference voltage for the gyro sensor 2 described above. In this case, the same processing as steps 206 to 217 is performed by the gyro sensor 3
Step 218 is entered as a process for correcting the reference voltage related to.

As described above, according to the pointing device of the second embodiment, the cursor (pointer) is continuously displayed at the correct position when the pointing device is stationary, like the first embodiment described above. The structure is simple. And in this second embodiment,
When the power is turned on (at the time of activation), the threshold value m for correction target value determination is set to m ₁ (> m ₂ ), so in step 207, shift to the “Yes side”, that is, the correction routine. Easy to do. Further, when the power is turned on, the addition / subtraction value n to the correction value counter is set to n ₁ (> n ₂ ), so that k = 0 is set relatively early and the reference voltage is corrected.

Therefore, when the power is turned on, the reference voltage can be corrected even if the pointing device is held by hand, that is, even if the pointing device is slightly moved or vibrated, and it is relatively short. The reference voltage can be corrected with time.

The position information input device of the present invention is, for example, an index (pointer) on the TV screen for setting various functions such as TV volume, channel selection (channel selection), mode switching, image quality adjustment, and timer setting. ) Is moved and the switch such as the left switch 8 and / or the right switch 9 is clicked according to the position of the index,
It is suitable to be applied to a system that sets the various functions. The position information input device of the present invention has been described above based on the illustrated configuration example, but the present invention is not limited thereto.

[0094]

As described above, according to the position information input device of the present invention, it is possible to prevent the drift phenomenon, that is, the movement of the index, when the position information input device is stationary. The index can be displayed at the correct position. And in the position information input device of the present invention,
Since the drift phenomenon does not occur due to the data processing, the structure is simple.

Further, when the power is turned on, if the threshold for determining whether or not the position information input device is stationary is set to be larger than that during normal operation, the power is turned on. The reference voltage can be corrected even when the position information input device is slightly moved or vibrated when it is turned on (during start-up) (for example, the position information input device is held by hand).

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a first embodiment when a position information input device of the invention is applied to a pointing device.

FIG. 2 is an external perspective view showing the first embodiment.

FIG. 3 is a flowchart showing a control operation of a control means in the first embodiment.

FIG. 4 is a timing chart for explaining correction of a reference voltage in the present invention.

FIG. 5 is a flowchart showing the control operation of the control means in the second embodiment.

[Explanation of symbols]

 1 pointing device 2 gyro sensor 3 gyro sensor 4 amplifier 5 amplifier 6 control means 61 A / D converter 62 correction unit 7 data transmission module 8 left switch 9 right switch 10 casing 11 power switch 101-114 steps 201-218 steps

Claims (13)

[Claims] 1. A first sensor and a second sensor, which detect displacements in the X direction and the Y direction, respectively, which are orthogonal to each other, and voltages output from the first and second sensors,
Based on the reference voltage, position information creating means for creating position information of the index displayed on the screen, transmitting means for transmitting the position information, when the position information input device is stationary, the reference voltage, A position information input device comprising: a correction unit that corrects the reference voltage so that the reference voltage is substantially the same as the voltage output from the first and second sensors. 2. The position information input device according to claim 1, further comprising a determination unit that determines whether or not the position information input device is stationary based on the voltages output from the first and second sensors. 3. The determination means is configured to determine that the position information input device is moving when the amount of change in the voltage output from the first and second sensors exceeds a threshold value. The position information input device according to claim 2. 4. The position information input device according to claim 3, wherein the threshold value can be set to a plurality of values. 5. The position information input device according to claim 4, wherein the threshold value is set to be larger when the power is turned on than in the normal operation. 6. The correction means compares the voltage output from the first and second sensors with the reference voltage at predetermined time intervals, and if they do not match, the first and second sensors are compared. The position information input device according to claim 1, wherein the reference voltage can be shifted by one unit in a direction in which the voltage output from the second sensor and the reference voltage approach each other. . 7. The correction means compares the voltage output from the first and second sensors with the reference voltage at predetermined time intervals, and if they do not match, the first and second sensors are compared. It is determined whether the voltage output from the second sensor is within a predetermined range, and if the voltage is within the predetermined range, the voltage output from the first and second sensors and the The position information input device according to any one of claims 1 to 5, wherein the reference voltage can be shifted by one unit in a direction closer to the reference voltage. 8. The correction means compares the voltage output from the first and second sensors with the reference voltage at predetermined time intervals, and when the number of times of detecting the deviation is accumulated a predetermined number of times. 6. The position information input device according to claim 1, wherein the reference voltage is shifted by one unit in a direction in which the voltages output from the first and second sensors and the reference voltage approach each other. . 9. The position information input device according to claim 8, wherein the predetermined number of times can be set to a plurality of values. 10. When the power is turned on, the
The position information input device according to claim 9, wherein the predetermined number of times is set to be small. 11. When the power is turned on, the
The position information input device according to claim 1, wherein the reference voltage is corrected at short time intervals. 12. The position information input device according to claim 1, wherein the position information is transmitted by wireless communication. 13. The position information input device according to claim 1, wherein the first and second sensors are angular velocity sensors.