KR20000067478A - Position and Control Signal Input System using Ultrasonic - Google Patents

Abstract

PURPOSE: A position and control signal input system is provided to sense supersonic waves generated from a supersonic pen without using an expensive touch pad, and determine a current input position over a 2 dimension or 3 dimension space. CONSTITUTION: A position and control signal input system comprises a supersonic pen(30), a plurality of supersonic wave receivers(21,22,23), a modulator(40), a phase difference detector(50), an amplitude detector(60), a position determination unit(70), and an interface(80). The supersonic wave receivers(21,22,34), installed at a screen(10), receives the supersonic wave generated from the supersonic pen(20). The modulator(40) modulates the supersonic wave signals. The phase difference detector(50) detects phase differences among the modulated supersonic wave signals. The position determination unit(70) determines the position of the pen(30) on the screen(10) by using the phase differences and an output of the amplitude detector(60). The interface(80) transmits the output from the position determination unit(70) to a computer.

Description

Position and Control Signal Input System using Ultrasonic

The present invention relates to a position and control signal input system using ultrasonic waves, and more particularly, to a position and control signal input system using ultrasonic waves that can be implemented at a relatively low cost while increasing the size of an electronic blackboard.

Typically, a large monitor will be used to present the prepared material to those who attend the lecture or conference.

In addition, when the large monitor is used as an electronic blackboard, a transparent touch film is added to the display surface of the monitor to grasp the position currently indicated by the user.

That is, when the user directly touches the screen with a general input medium such as a pen, the user may determine the current contact position and perform a command displayed on the screen at the position.

In the copyboard, a method of identifying a location using a touch film includes a resistive contact method, a capacitance contact method, and a surface tension sensing method.

However, in the case of implementing the electronic blackboard using the touch film as described above, it is never advantageous in terms of cost.

Touch films are never easy to manufacture, they are also quite expensive, and are an obstacle to the enlargement of electronic blackboards.

In other words, since the monitor and the touch film themselves have limitations in size, there are various problems to increase the size.

Therefore, in view of the above problems, the present invention is simple to manufacture by detecting the ultrasonic waves generated by the ultrasonic pens by ultrasonic sensors without using the touch film to determine the current input position in two and three dimensions. In addition, an object of the present invention is to provide a position and control signal input system using ultrasonic waves, which implements a low-cost presentation device.

1 is a view showing a position and control signal input system using ultrasonic waves according to an embodiment of the present invention.

2 is a block diagram of an ultrasonic pen.

3 is a detailed block diagram of the ultrasonic wave generator of FIG. 2 and a waveform diagram of each block;

4 is a structural diagram of the reflector of FIG. 2 and a reflection state of ultrasonic waves;

5 is a diagram showing the progress of ultrasonic waves on an electronic blackboard;

6 is a detailed view of an ultrasonic receiver.

7 shows a state for confirming the position of the ultrasonic pen on the screen.

8 is a time chart for calculating a distance according to the time when the ultrasonic wave generated from the ultrasonic pen reaches the ultrasonic receiver.

9 is a view showing a position and control signal input system using ultrasonic waves according to another embodiment of the present invention.

10 is a view for explaining a state for identifying the position of the pen in the three-dimensional space by the received ultrasonic signal.

11 is a view for explaining the position and angle of the pen in the three-dimensional space.

12 is a view showing another embodiment of the ultrasonic generator.

13 is a view showing an example of an envelope generation state of the ultrasonic pen.

<Description of the code | symbol about the principal part of drawing>

10,100: screen

21,22,23,210,220,230: ultrasonic receiver

30,300: ultrasonic pen 31: housing

32: power supply unit 33: ultrasonic generator

33-1: Ultrasonic Oscillator 33-2: Modulator

33-3: reference signal generator 34: ultrasonic guide

35 reflector 36 transmission window

37: pressure sensor 38: ball

40,400: demodulator 50: phase difference detector

500: trajectory detector 60,600: amplitude detector

610: tilt information detection unit 70,700: positioning unit

80,900: Interface 800: Lookup Table

Position and control signal input system using the ultrasonic wave according to an embodiment of the present invention for achieving the above object, the ultrasonic pen for generating an ultrasonic signal; A plurality of ultrasonic receivers provided in elements of a screen to receive ultrasonic signals generated from the ultrasonic pens; A demodulator for demodulating each of the ultrasonic signals received from the plurality of ultrasonic receivers; A phase difference detector for detecting a phase difference between the demodulated signals; An amplitude detector for detecting an amplitude of each demodulated signal; A positioning unit that determines the position of the ultrasonic pen on the screen by the output of the phase difference and amplitude detection unit; And an interface unit for connecting output data of the positioning unit to a computer.

The ultrasonic pen has a pen shaped housing; A power supply unit supplying power to the ultrasonic wave generation unit when a signal is applied from the pressure sensor; An ultrasonic generator for generating an ultrasonic signal having a predetermined frequency when power is supplied; An ultrasonic guide for guiding the generated ultrasonic waves to a position of a reflector; A reflector for reflecting the ultrasonic wave guided by the ultrasonic wave guide in a desired direction; And a transmission window formed along the circumference of the housing to transmit ultrasonic waves reflected by the reflector to the outside of the housing.

The ultrasonic generator includes an ultrasonic oscillator for oscillating an ultrasonic wave having a predetermined frequency; A reference signal generator for generating a reference signal of a predetermined waveform; The modulator is configured to receive the ultrasonic wave and the reference signal and modulate it.

One embodiment of the present invention configured as described above will be described in detail with reference to FIGS. 1 to 8.

A plurality of ultrasonic receivers 21, 22, and 23 capable of receiving ultrasonic waves are provided at elements of a predetermined position of the screen 10. In the present invention, the receivers are positioned at both upper edges and lower centers of the screen 10. An example is demonstrated.

As shown in FIG. 2, the ultrasonic pen 30 generating ultrasonic waves for determining a position is provided with a pen-shaped housing 31, and a ball 38 is provided under the housing 31. Is held on the screen 10 by holding the ultrasonic pen 30, the ball 38 is in contact with the contact sensor 37.

The touch sensor 37 accordingly applies a contact signal to the power supply unit 32, thereby supplying power to the ultrasonic wave generator 33.

At this time, instead of having a ball 38 in the lower portion of the ultrasonic pen 30, a button is provided at a predetermined portion of the side surface of the housing 31, so that the power supply unit 32 causes the ultrasonic generator 33 by the button when the user uses it. The power can be applied to.

The ultrasonic generator 33 generates a modulated ultrasonic signal when power is applied from the power supply unit 32. As shown in FIG. 3A, the ultrasonic oscillator 33-1 is constant as shown in FIG. 3B. The ultrasonic wave having a frequency is oscillated, and the reference signal generator 33-3 generates a triangular wave having a predetermined frequency as shown in FIG. 3C.

In this case, the reference signal may be a signal of various forms such as a square wave or a sinusoidal wave in addition to the triangle pie.

The modulator 33-2 receives the ultrasound signal generated from the ultrasonic oscillator 33-1 and the reference signal generated from the reference signal generator 33-3 to perform modulation as shown in FIG. 3D.

The ultrasonic signal modulated by the above process is guided to the position of the reflector 35 through the ultrasonic guide 34.

The induced ultrasonic signal is reflected by the reflector 35 to spread to the side of the ultrasonic pen 30, the reflector 35 is formed in a conical shape, as shown in Figure 4a, shown in Figure 4b As described above, when the ultrasonic signal is induced from the upper side, the ultrasonic signal is diffused to the side by the inclined surface of the reflector 35.

Of course, by adjusting the angle of the inclined surface of the reflector 35 it is possible to determine the diffusion range of the ultrasonic signal to be spread.

4C is a diagram illustrating a reflected state of the ultrasonic signal, in which the plane wave of the ultrasonic signal incident from the upper side is converted into a cylindrical wave and diffused to the surroundings.

Therefore, the ultrasonic signal reflected by the reflector 35 is diffused to the outside of the housing 31 through the transmission window 36, where the transmission window is located at the position of the housing 31 where the reflector 35 is located. It is formed along the circumference of the side surface so that the ultrasonic signal penetrates and diffuses outward.

FIG. 5 illustrates a state in which ultrasonic signals diffused from the ultrasonic pen 30 on the screen 10 are diffused on the screen 10. When the ball 38 contacts the screen 10, the ultrasonic pen 30 Ultrasonic signal is diffused with a relatively constant height through the transmission window (36).

6 shows a detailed view of the ultrasonic receiver 21, in which ultrasonic signals diffused along the plane of the screen 10 are collected by the accumulator 21-1, and in the ultrasonic detector 21-2, FIG. The received ultrasonic signal is converted into an electrical signal.

Therefore, the demodulator 40 demodulates the electric ultrasonic signals input from the ultrasonic receivers 21, 22, and 23 and provides them to the phase difference detector 50 and the amplitude detector 60.

The phase difference detector 50 may detect the difference in phase from the respective ultrasonic signals to calculate the distance between the ultrasonic pen 30 and the ultrasonic receivers 21, 22, and 23, and the amplitude detector 60 may detect each ultrasonic signal. The accuracy can be calculated by weighting the signal with the maximum amplitude of the reference signal from.

That is, in order to prevent confusion with reference signals adjacent to each other, as shown in FIG. 3D, weighting is performed on the largest amplitude of the ultrasonic signals to detect phase differences for each period of the reference signal, which is illustrated in FIG. 8. As

8 shows that the ultrasonic signal received by the ultrasonic receiver 21 arrives at a distance d1 from the ultrasonic pen 30, and the ultrasonic signal received by the ultrasonic receiver 22 has a distance d2 from the ultrasonic pen 30. Arriving, the case in which the ultrasonic signal received by the ultrasonic receiver 23 has arrived at a distance of d3 from the ultrasonic pen 30.

The distances d1, d2, and d3 correspond to the ultrasonic pen 30 and the ultrasonic receiver for the same signal when the ultrasonic pen 30 and the ultrasonic receivers 21, 22, and 23 are synchronized with RF signals or light that are sufficiently faster than the ultrasonic waves. The distance can be calculated by the time difference between 21, 22, and 23, and the intersection point of the circle formed by these values becomes the position of the ultrasonic pen 30.

In the case of the present invention, it is possible to determine the position of the ultrasonic pen 30 without a separate synchronization process.

The positioning unit 70 converts the time at which the ultrasonic wave generated from the ultrasonic pen 30 is received by each of the ultrasonic receivers 21, 22, and 23 into a distance, and the angle from each of the ultrasonic receivers 21, 22, and 23. A parabola-shaped line is formed according to the distances d1, d2, and d3, and the A portion (that is, the portion where aa and bb meet), which is an intersection point of the line, is determined as the position of the ultrasonic pen 30, and the position data is transferred to the interface 80. ) To the computer.

The principle side of this is explained in more detail.

The line on which the ultrasonic pen may be determined is determined by the time difference or the phase difference calculated by the time difference between the ultrasonic signals arriving at the two ultrasonic receivers 21 and 23.

That is, if there is no phase difference between the ultrasonic signals arriving from the two ultrasonic receivers 21 and 22, a line perpendicular to the straight line connecting the two ultrasonic receivers 21 and 22 ( ) Becomes the same phase difference trajectory, and the ultrasonic receiver 21 If the phase is earlier than the ultrasonic receiver 22, a parabolic line like aa is formed.

Also, if there is no phase difference between the ultrasonic signals arriving from the two ultrasonic receivers 21 and 23, a line perpendicular to the straight line connecting the two ultrasonic receivers 21 and 23 ( ) Becomes the same phase difference trajectory, and the ultrasonic receiver 21 If the phase is earlier than the ultrasonic receiver 23, a parabolic line like bb is formed.

Therefore, the intersection A of these two parabola-type lines a-a and b-b becomes the position of the ultrasonic pen 30.

The computer accordingly checks the position of the ultrasonic pen 30 on the screen 10 and executes the command at that position.

On the other hand, the frequency of the ultrasonic wave and the maximum frequency of the reference signal is determined by the following equation (1).

Accordingly, as shown in FIG. 8A, the phase difference between the ultrasonic signals arriving later may be obtained based on the ultrasonic signals arriving first.

As a result, when the signal between the ultrasonic pen 30 and the ultrasonic receiver is in phase, the radius of the ultrasonic pen 30 may be determined from the time difference between the ultrasonic signals detected by the ultrasonic receivers 21, 22, and 23. The trajectory of the circle is formed, and the intersection of the trajectory of the circle obtained from each of the ultrasonic receivers 21, 22, 23 becomes the position of the ultrasonic pen 30.

One embodiment of the present invention described above relates to the process and operation of identifying the position on the screen 10, that is, the two-dimensional plane, the operation process of identifying the position in the three-dimensional space according to another embodiment of the present invention Explain.

First, a position and control signal input system using ultrasonic waves according to another embodiment of the present invention, an ultrasonic pen for generating an ultrasonic signal; A plurality of ultrasonic receivers provided in elements of a screen to receive ultrasonic signals in a three-dimensional space generated from the ultrasonic pens; A demodulator for demodulating each of the ultrasonic signals received from the plurality of ultrasonic receivers; A trajectory detector for detecting a 3D trajectory from each of the demodulated signals; An amplitude detector for detecting an amplitude difference of each demodulated ultrasonic signal; A position determination unit which grasps the position from the screen to the ultrasonic pen by the overlapping positions of the three-dimensional trajectories, and determines the position of the screen indicated by the user based on the inclination data for each amplitude difference; A lookup table having tilt angle data for an amplitude difference of each signal; And an interface unit for connecting output data of the positioning unit to a computer.

Operation according to another embodiment of the present invention configured as described above will be described in detail with reference to FIGS. 9 to 11.

When the ultrasonic pen 300 is positioned in a three-dimensional space to generate an ultrasonic signal, the ultrasonic pens 210, 220, and 230 located at the edge elements of the screen 100 receive the electrical signals to the demodulator 400. Will print.

The demodulator 400 demodulates the electrical signal of the ultrasonic signal and then provides the signal to the locus detector 500 and the amplitude detector 600, respectively. The locus detector 500 demodulates as shown in FIG. 10. The position of the ultrasound pen 300 in the 3D space is determined from the received ultrasound signal.

That is, when the phase difference of the ultrasonic signals received by each of the ultrasonic receivers 210, 220, and 230 is determined, a three-dimensional surface such as a, b, and c may be formed according to the distance of the parabola type trajectory in the space drawn by the phase difference. The portion B, which is the intersection point of the trajectory of each parabola type, becomes the position of the ultrasonic pen 300.

In other words, as described above with reference to FIG. 7, the parabola-shaped lines are formed in two dimensions, but the three-dimensional parabola-shaped faces are generated in three dimensions, whereby the intersection points B where the respective surfaces meet are located at the position of the ultrasonic pen 300. To be.

The intersection point, that is, the portion where the ultrasonic pen 300 is positioned is positioned at a distance of D on the three-dimensional space from the screen 100 as shown in FIG. 11.

However, when a person points to a specific portion of the screen 100 at that position, the position may change as much as the tilt of the ultrasound pen 300.

In other words, in the two-dimensional plane, the area where the ultrasonic pen contacts the screen may be the position of the ultrasonic pen, but in the three-dimensional space, the position indicated by the user on the screen may be changed by tilting together with the position of the ultrasonic pen. It is.

Therefore, as shown in FIG. In the case of indicating the upward direction at an angle, the final position indicated by the user is the P position on the screen 100.

The inclination of the ultrasonic pen is detected by the amplitude detector 600, and the difference in the amplitude of the ultrasonic signals received by the ultrasonic receivers 210, 220, and 230 occurs according to the tilt of the ultrasonic pen 300.

That is, as illustrated in FIG. 13, the envelope of the ultrasonic signal generated at the end of the ultrasonic pen 300 is detected by the ultrasonic receivers 210, 220, and 230, and the tilt is determined based on the amplitude.

Therefore, as illustrated in FIG. 11, when the ultrasonic pen 300 is inclined upward and instructed, the ultrasonic receivers 210 and 230 detect envelopes of ultrasonic signals generated from the ends of the ultrasonic pen 300. The inclination of the ultrasound pen 300 is determined based on the difference between the amplitude of the signal received at 230 and the amplitude of the signal received at the ultrasound receiver 210.

If the amplitude of the ultrasonic signal received by the ultrasonic receiver 210 is greater than the amplitude of the ultrasonic signal received by the ultrasonic receiver 230, the indicated position of the ultrasonic pen 300 is in an upward direction, and the difference in amplitude is This is the degree of tilt.

Therefore, the amplitude detector 600 detects a difference in amplitude of a signal received by each of the ultrasonic receivers 210, 220, and 230, and the data about the difference in amplitude is provided to the position determiner 700.

The position determining unit 700 determines the position of the user's instruction on the screen 100 by the output of the trajectory detector 500 and the amplitude detector 600. The position of the pen 300 is determined, and the angle data is read from the lookup table 800 based on the amplitude difference provided from the amplitude detection unit 600.

In the lookup table 800, the angle data of the slope with respect to the mutual amplitude difference of each ultrasonic signal is stored in advance.

As a result, since the positioning unit 700 knows the position from the screen 100 to the ultrasonic pen 300 and the angle data of the ultrasonic pen 300, the positioning unit 700 can accurately determine the indicated position P of the screen 100. will be.

Therefore, the positioning unit 700 determines the P position on the screen 100 as an instruction position of the ultrasonic pen 300, and transmits the position data to the computer through the interface 900.

The computer accordingly checks the position of the ultrasound pen 300 instruction on the screen 100 and executes the command at that position.

Position and control signal input system using the ultrasonic wave according to another embodiment of the present invention, the ultrasonic pen for generating a signal for the ultrasonic signal and the tilt detection value; A plurality of ultrasonic receivers provided in elements of a screen to receive ultrasonic signals in a three-dimensional space generated from the ultrasonic pens; A demodulator for demodulating each of the ultrasonic signals received from the plurality of ultrasonic receivers; A trajectory detector for detecting a 3D trajectory from each of the demodulated signals; A tilt information detector for detecting only a tilt detection value from the demodulated ultrasonic signal; A position determination unit which grasps the position from the screen to the ultrasonic pen by the overlapping positions of the three-dimensional trajectories, and determines the position of the screen indicated by the user according to each tilt detection value; And an interface unit for connecting output data of the positioning unit to a computer.

The description of the overlapping parts of one embodiment and the other embodiments of the present invention is excluded.

The inclination of the ultrasonic pen 300 may determine the position indicated by the inclination value detected by the inclination sensor as well as the amplitude of the ultrasonic signal.

To this end, the ultrasound pen 300 includes a tilt detection sensor 33-4 capable of detecting a tilt as shown in FIG. 12, and modulates the tilt detection value together with the ultrasonic wave oscillated by the ultrasonic oscillator 33-1. In section 33-2, modulation is performed.

Therefore, the ultrasonic signal having the modulated slope value is received and demodulated by the ultrasonic receivers 210, 220, 230 and the demodulator 400, and then provided to the tilt information detector 610.

The inclination information detector 610 detects only the inclination value included in the ultrasound signal and provides the inclination value to the positioning unit 700. The positioning unit 700 outputs the trajectory detection unit 500 and the inclination information detection unit 610. As a result, the position of the indication on the screen 100 can be accurately determined.

As described above, the present invention detects the ultrasonic wave generated from the ultrasonic pen to determine the current input position in 2D and 3D, so that the manufacturing process and structure are simple, and the low-cost copyboard is realized, and the size of the screen is respected. There is no effect.

Claims (7)

An ultrasonic pen for generating an ultrasonic signal; A plurality of ultrasonic receivers provided in elements of a screen to receive ultrasonic signals generated from the ultrasonic pens; A demodulator for demodulating each of the ultrasonic signals received from the plurality of ultrasonic receivers; A phase difference detector for detecting a phase difference between the demodulated signals; An amplitude detector for detecting an amplitude of each demodulated signal; A positioning unit that determines the position of the ultrasonic pen on the screen by the output of the phase difference and amplitude detection unit; Position and control signal input system using the ultrasonic wave, characterized in that consisting of an interface unit for connecting the output data of the positioning unit to a computer. The method of claim 1, wherein the ultrasound pen housing; An ultrasonic generator which is located inside the housing and generates an ultrasonic signal having a predetermined frequency when power is supplied; Position and control signal input system using ultrasonic waves, characterized in that the transmission window for transmitting the ultrasonic waves generated from the ultrasonic generator to the outside of the housing. The method of claim 1, wherein the ultrasound pen A housing in the form of a pen; A power supply unit supplying power to the ultrasonic wave generation unit when a signal is applied from the pressure sensor; An ultrasonic generator for generating an ultrasonic signal having a predetermined frequency when power is supplied; An ultrasonic guide for guiding the generated ultrasonic waves to a position of a reflector; A reflector for reflecting the ultrasonic wave guided by the ultrasonic wave guide in a desired direction; And a transmission window formed along a circumference of the housing and configured to transmit ultrasonic waves reflected by the reflector to the outside of the housing. The ultrasonic generator of claim 2 or 3, wherein the ultrasonic wave generator An ultrasonic oscillator for oscillating ultrasonic waves having a predetermined frequency; A reference signal generator for generating a reference signal of a predetermined waveform; Position and control signal input system using the ultrasonic wave, characterized in that consisting of a modulator for receiving the ultrasonic signal and the reference signal and modulates it. An ultrasonic pen for generating an ultrasonic signal; A plurality of ultrasonic receivers provided in elements of a screen to receive ultrasonic signals in a three-dimensional space generated from the ultrasonic pens; A demodulator for demodulating each of the ultrasonic signals received from the plurality of ultrasonic receivers; A trajectory detector for detecting a 3D trajectory from each of the demodulated signals; An amplitude detector for detecting an amplitude difference of each demodulated ultrasonic signal; A position determination unit which grasps the position from the screen to the ultrasonic pen by the overlapping positions of the three-dimensional trajectories, and determines the position of the screen indicated by the user based on the inclination data for each amplitude difference; A lookup table having tilt angle data for an amplitude difference of each signal; Position and control signal input system using the ultrasonic wave, characterized in that consisting of an interface unit for connecting the output data of the positioning unit to a computer. An ultrasonic pen for generating a signal for the ultrasonic signal and the tilt detection value; A plurality of ultrasonic receivers provided in elements of a screen to receive ultrasonic signals in a three-dimensional space generated from the ultrasonic pens; A demodulator for demodulating each of the ultrasonic signals received from the plurality of ultrasonic receivers; A trajectory detector for detecting a 3D trajectory from each of the demodulated signals; A tilt information detector for detecting only a tilt detection value from the demodulated ultrasonic signal; A position determination unit which grasps the position from the screen to the ultrasonic pen by the overlapping positions of the three-dimensional trajectories, and determines the position of the screen indicated by the user according to each tilt detection value; Position and control signal input system using the ultrasonic wave, characterized in that consisting of an interface unit for connecting the output data of the positioning unit to a computer. 7. The ultrasonic pen of claim 6 wherein A tilt detection sensor capable of detecting a tilt; An ultrasonic oscillator for oscillating an ultrasonic signal; Position and control signal input system using the ultrasonic wave, characterized in that consisting of a modulator for receiving the signal corresponding to the slope and the ultrasonic signal to modulate it.