JP2004302761A - Ultrasonic type coordinate input device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce power consumption in a pen and a fixed machine according to the state of the pen regarding an ultrasonic type coordinate input device. <P>SOLUTION: The ultrasonic type coordinate input device is constituted such that the state of pen 1 is decided by using a microcomputer inside the pen 1, transmission is performed by changing the interval of a plurality of infrared ray pulses according to the state of the pen 1 and ultrasonic signals are transmitted to the fixed machine 2 simultaneously only in the case that there is a state change, and an infrared ray synchronizing signal composed of one pulse is transmitted to the fixed machine 2 in the case that there is no state change. The fixed machine 2 detects the state of the pen 1 on the basis of the infrared ray signals transmitted from the pen 1, and interrupts the power of the ultrasonic reception part of the fixed machine 2 in the case of the state that the pen 1 is raised and a button is not depressed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate input device for inputting a trajectory when a character or a figure is handwritten on paper or the like with a pen into a computer, and in particular, to reduce power consumption by a pen and a fixed machine with a simple circuit configuration. The present invention relates to an ultrasonic coordinate input device that can be used.
[0002]
[Prior art]
The pen emits ultrasonic waves and electromagnetic waves such as infrared rays, and an infrared sensor and two or more ultrasonic sensors are fixedly arranged on the writing surface. The time from infrared reception to ultrasonic reception, that is, ultrasonic waves propagate in space A technique of measuring the distance between a pen and an ultrasonic sensor from time and obtaining two-dimensional coordinates of a pen on a writing surface by two or more ultrasonic sensors based on the principle of triangulation is disclosed in the following Patent Documents 1 and 2. , Patent Document 3 and Patent Document 4.
[0003]
In the input device described in Patent Literature 1, a user button is attached to a pen, and infrared light for synchronization is modulated by information of the button and transmitted to a receiving side. In the input device described in Patent Literature 2, when there are a plurality of pens, ID information for each pen is transmitted on a receiving side by being placed on infrared rays. Similarly, the input device described in Patent Document 3 also has pens of a plurality of colors, and transmits color information on infrared rays.
[0004]
On the other hand, Patent Literature 4 discloses that an infrared pulse is generated immediately after a pen down or only after a certain period of time has elapsed to measure a distance, and at other times, instead of generating an infrared pulse, the next pulse is received from the previous ultrasonic reception. The distance change is calculated by measuring the time until the reception of the ultrasonic wave, and taking the difference from the internally generated sampling period or the sampling period generated based on the intervals of multiple ultrasonic and infrared pulses. A technique is described in which a distance is obtained without an infrared ray by adding a distance change to the distance obtained when the infrared ray is present.
[0005]
[Patent Document 1]
U.S. Pat. No. 4,814,552
[Patent Document 2]
JP-A-3-71321
[Patent Document 3]
JP 2002-163070 A
[Patent Document 4]
JP 2001-236173 A
[0006]
[Problems to be solved by the invention]
Since the pen is driven by a battery, it is necessary to reduce the power consumed by the pen in order to extend the battery life. However, the techniques described in the above-mentioned Patent Documents 1, 2, and 3 disclose: Since infrared light is always modulated by pen information, there is a problem that power consumption for generating infrared light is large and battery life is short.
[0007]
Also, in the method described in Patent Document 4, since the infrared pulse is required only immediately after the pen down or only after a certain period of time has elapsed, the power consumed by the pen can be reduced. If the time bases are shifted between the pen side and the fixed machine side because they are not taken, there is a problem that the errors accumulate and increase.
[0008]
Therefore, using a highly accurate time base increases costs. Further, if a sampling period is generated based on a plurality of ultrasonic or infrared pulse intervals, a pulse interval measuring timer and a multiplier are required, which complicates the configuration and increases the cost.
[0009]
On the other hand, when the receiving side is fixedly connected to the computer, power can be supplied from the computer or its periphery, so that power consumption does not matter much. On the other hand, if the receiving side has a memory for storing coordinates and can be used without a computer nearby, it is convenient because it can be used in various places. However, for that purpose, the receiving side also needs to be driven by a battery, and in that case, the receiving side also needs to reduce power consumption. However, the technology described in each of the above patent documents does not consider power saving on the receiving side at all, and there is a problem that the battery life is shortened when used directly for battery driving.
[0010]
The present invention solves the above-mentioned problems of the prior art, and can reduce the power consumption of a pen and a fixed machine when inputting a locus of handwriting a character or a figure on paper or the like with a pen to a computer. It is an object of the present invention to provide a simple ultrasonic coordinate input device.
[0011]
[Means for Solving the Problems]
In order to solve the above problems, the present invention modulates infrared rays only when the state changes when a signal indicating the pen state is put on the infrared rays generated from the pen, and otherwise modifies the minimum necessary for synchronization. It is configured to transmit infrared light. This reduces the power consumed by the pen.
[0012]
Furthermore, if the same infrared noise is generated externally with the minimum infrared signal required for synchronization, a malfunction may occur. Therefore, the present invention is configured so that the synchronization signal is detected only within the time error of the synchronization signal on the receiving side in accordance with the synchronization signal generated from the pen. As a result, it is possible to reduce a problem that synchronization is erroneously performed due to noise generated other than the time.
[0013]
Also, according to the present invention, the state of the pen is monitored on the receiving side, and when the pen is not touched, that is, when the coordinate is not input, the power supply to the ultrasonic receiving unit is stopped or the coordinate calculation is performed. The computer for power is turned off to reduce power consumption.
[0014]
Also, the reception of infrared rays or ultrasonic waves is performed at each sampling cycle, but if infrared rays or ultrasonic waves are received within that cycle, the ultrasonic waves or infrared rays do not come until the next sampling cycle. Therefore, the present invention is configured so that the power supply to these receiving circuits is stopped after receiving infrared rays or ultrasonic waves. With this configuration, power consumption can be further reduced.
[0015]
That is, the present invention provides a moving body that transmits or receives an ultrasonic wave and transmits an electromagnetic wave, a fixed body that receives or transmits an ultrasonic wave and receives an electromagnetic wave, and a moving body that transmits or receives an ultrasonic wave and the fixed body based on a propagation time of the ultrasonic wave. An ultrasonic coordinate input device comprising: means for determining a position of a moving body, wherein the moving body includes: means for detecting a state of the moving body; and Means for modulating an electromagnetic wave and outputting a modulated electromagnetic wave signal, wherein the means for outputting the modulated electromagnetic wave signal outputs an electromagnetic wave signal having a minimum power when the state of the moving object does not change. It is characterized by.
[0016]
In the ultrasonic coordinate input device, the electromagnetic wave may use infrared rays, and the means for modulating the electromagnetic waves may change an interval between a plurality of infrared pulses, and the electromagnetic wave signal having the minimum power may be one of the following. It is characterized in that it is an infrared pulse signal. This makes it possible to reduce the power consumption of the moving body based on the state of the moving body.
[0017]
Further, according to the present invention, in the ultrasonic coordinate input apparatus, the means for outputting a modulated electromagnetic wave signal provided in the moving body outputs an electromagnetic wave signal at a specific time interval, and the fixed body outputs the moving body. Means for generating a time interval equivalent to a specific time interval of the electromagnetic wave signal to be generated, and an electromagnetic wave signal output by the mobile object only for a specific time before a specific time before the mobile object may output the electromagnetic wave signal. Means for receiving the As a result, power consumption can be reduced, and an electromagnetic wave signal can be detected only within the time error range of the electromagnetic wave signal as a synchronization signal generated from a moving body, thereby preventing malfunction caused by externally generated noise. can do.
[0018]
Further, the present invention provides a moving object that transmits or receives an ultrasonic wave and transmits or receives an electromagnetic wave, a fixed body that receives or transmits an ultrasonic wave and receives or transmits an electromagnetic wave, and An ultrasonic coordinate input device comprising: means for determining a position of the moving body with respect to a fixed body, wherein the fixed body includes means for detecting a state of the moving body, and a state of the detected moving body. Means for reducing the power consumption of the fixed body by shutting off the power of the ultrasonic receiving circuit or the ultrasonic transmitting circuit of the fixed body, or by shutting off the power of the electromagnetic wave receiving circuit or the electromagnetic wave transmitting circuit based on It is characterized by having. Thereby, the power consumption of the fixed body can be reduced based on the state of the moving body.
[0019]
Further, the present invention provides a moving object that transmits or receives an ultrasonic wave and transmits or receives an electromagnetic wave, a fixed body that receives or transmits an ultrasonic wave and receives or transmits an electromagnetic wave, and An ultrasonic coordinate input device comprising: means for determining a position of the moving body with respect to a fixed body, wherein the moving body or the fixed body transmits ultrasonic waves or electromagnetic waves at a specific time interval, and Means for reducing the power consumption of the fixed body, wherein the means for reducing the power consumption of the moving body or the fixed body includes a remaining time of the specific time interval after the reception of the electromagnetic wave or the ultrasonic wave by the moving body or the fixed body. Is characterized by reducing power consumption. Thereby, the power consumption of the fixed body can be further reduced.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an outline of a first embodiment of the present invention. In the figure, 1 is a pen for inputting handwritten characters on a writing surface 3, 2 is a fixed machine that calculates the position of the pen 1 and monitors the state of the pen, and 3 is a handwritten character or figure written by the pen 1. Writing surface. Reference numerals 100 and 101 in the fixing machine 2 denote a first ultrasonic sensor and a second ultrasonic sensor for detecting ultrasonic waves transmitted from the pen 1, and 102 denotes an infrared sensor.
[0021]
The tip of the pen 1 shown in FIG. 1 is a ballpoint pen, and can write on paper in the same manner as a normal ballpoint pen. There are a plurality of types of pens 1, such as a red pen A, a black pen B,..., Depending on the core color, and can be selected and written. When writing on paper, the stationary machine 2 can be used separately from the computer.
[0022]
FIG. 2 is a diagram illustrating transfer of handwriting data stored in the fixed machine 2 to a computer. After the writing is completed, as shown in FIG. 2, if the fixed device 2 is brought to a place where the computer 5 is located and connected to the computer 5, the handwriting data stored in the fixed device 2 can be transferred to the computer 5. .
[0023]
FIG. 3 is a diagram illustrating a configuration example of the pen according to the first embodiment of the present invention. In the figure, 11 is a battery, 12 is a drive circuit, 13 is a pen touch switch, 14 is an infrared LED, 15 is a cylindrical ultrasonic transmitter, and 16 is a pen tip.
[0024]
The pen 1 has a ballpoint pen core at the tip and a pen touch switch 13 for detecting contact between the core and the writing surface during writing. The tip is further provided with a cylindrical ultrasonic transmitter 15 and an infrared LED 14. The cylindrical ultrasonic transmitter 15 is made of a cylindrical piezoelectric film made of polyvinylidene fluoride. The cylindrical shape is obtained by setting the directivity to 360 degrees, so that the ultrasonic waves are transmitted in the same manner even when the pen 1 rotates, and the first ultrasonic sensor 100 and the second ultrasonic sensor 101 of the fixed machine 2 are formed. In order to reach.
[0025]
Three infrared LEDs 14 having a directivity of 120 degrees are arranged so that even when the pen 1 rotates, the infrared rays reach the infrared sensor 102 of the fixed unit 2 in the same manner.
[0026]
Further, the pen 1 is provided with a push button switch 17. For example, if the pen 1 is slightly floated in the air without pressing the button while writing, the locus at that time can be input. This function is used when it is desired to use the movement of the pen 1 between strokes in gesture input or signature authentication by the pen 1 or the like. Further, a battery 11 and a drive circuit 12 are mounted inside the pen 1.
[0027]
FIG. 4 is a diagram showing the internal configuration of the pen 1. The drive circuit 12 includes a microcomputer 121 for inputting the states of the pen touch switch 13, the push button switch 17, and the pen type switch 124. The microcomputer 121 operates the LED drive circuit 122 and the ultrasonic drive circuit 123 by operation to transmit infrared pulses from the infrared LED 14 and ultrasonic pulses from the ultrasonic transmitter 15 to the fixed machine 2. The operation of the microcomputer 121 will be described later.
[0028]
FIGS. 5A and 5B are diagrams illustrating a configuration example of the fixed machine 2. As shown in FIG. 5A, two ultrasonic sensors, a first ultrasonic sensor 100 and a second ultrasonic sensor 101, and one infrared sensor 102 are disposed on the front surface of the fixed machine 2. ing. The lower part of the main body of the fixing machine 2 is a paper fixing clip 21 that can fix the main body to paper. As shown in FIG. 5B, a battery 25 and a receiving circuit 20 are mounted inside the main body of the fixed machine 2.
[0029]
FIG. 6 is a diagram showing details of the internal configuration of the fixed machine 2 according to the first embodiment of the present invention. The fixing device 2 includes an infrared receiving unit 22 that receives an infrared pulse from the pen 1, an ultrasonic receiving unit 23 that receives an ultrasonic pulse from the pen 1, an infrared pulse that is received from the infrared receiving unit 22 and the infrared pulse that is received from the ultrasonic receiving unit 23. A timing generator 24 for measuring the sampling period and the ultrasonic propagation time based on the sound wave pulse, a microcomputer (microcomputer) 26 for reading the sampling period and the ultrasonic wave propagation time from the timing generator 24, the sampling period, and the ultrasonic wave propagation time The nonvolatile memory 27 to which data is written is provided.
[0030]
The infrared pulse transmitted from the pen 1 is received by the infrared sensor 102 in the infrared receiver 22, is appropriately amplified by the infrared amplifier 107, and is digitized by being compared with an appropriate threshold by the infrared comparator 108. Similarly, the ultrasonic pulse transmitted from the pen 1 is also received by the first ultrasonic sensor 100 and the second ultrasonic sensor 101 in the ultrasonic receiving unit 23, and the first ultrasonic amplifier 103 and the second ultrasonic amplifier 104 The first ultrasonic comparator 105 and the second ultrasonic comparator 106 digitize the signal by comparing it with an appropriate threshold. Reference numeral 109 denotes a power supply of the ultrasonic receiving unit 23.
[0031]
The first ultrasonic sensor 100 and the second ultrasonic sensor 101 are also formed of a cylindrical piezoelectric film made of polyvinylidene fluoride. The digitized infrared pulse and ultrasonic pulse are sent to the timing generator 24, and various timings are generated. Operations of the timing generator 24 and the microcomputer 26 will be described later.
[0032]
Next, the operation at the time of actual pen writing will be described in detail. FIG. 7 is a diagram showing the state of the pen. Since the pen 1 has the pen touch switch 13, the push button switch 17, and the pen type switch 124, there are eight types of states according to ON / OFF of each switch. This state is assigned to S0 to S7 as shown in FIG. The infrared rays generated from the pen 1 are modulated based on these pen states. Although there are various modulation methods, in the embodiment of the present invention, in order to reduce power consumption as much as possible, two infrared pulses are generated from the pen 1 and infrared rays are modulated by changing the interval between the pulses according to the state. That is, for example, as shown in FIG._pIs changed in eight ways from 2 μs to 9 μs. The pulse width is, for example, 1 μs.
[0033]
FIG. 8 is a flowchart of the operation of the microcomputer of the pen 1. First, the states of the three switches are read out, and the current state of the pen 1 is determined from S0 to S7 (step S1). Next, it is determined whether the current state of the pen 1 is the same as the previous state (step S2). If the current state is the same as the previous state, there is no need to transmit the state of the pen 1, so that it is composed of one pulse. Transmit the ultrasonic signal at the same time as transmitting the infrared synchronization signal (step S3)
On the other hand, if it is different from the previous state, it is determined whether the current state is whether both the pen touch switch 13 and the push button switch 17 are OFF, that is, whether the pen is being used (step S4). If one or both of them are ON, information indicating the pen state is placed on the infrared signal, the infrared state signal is transmitted, and the ultrasonic signal is transmitted at the same time (step S5). Regardless of whether the signal transmission in step S3 or step S5 is performed, the process waits until the next sampling cycle (for example, until 10 ms elapses) (step S6), and returns to step S1.
[0034]
On the other hand, when both the pen touch switch 13 and the push button switch 17 are OFF, the pen 1 is not in use, and transmitting an infrared signal or an ultrasonic signal is a waste of power. Therefore, no signal is transmitted, and either the pen touch switch 13 or the push button switch 17 is pressed and turned on (step S7).
[0035]
FIG. 9 is a diagram illustrating an operation example when writing “f” using the pen 1. As shown in FIG. 9 (A), it is assumed that writing is performed from point 1 to point 6, pen 1 is raised, lowered again at point 10, written to point 13, and pen 1 is raised. The pen state at this time changes like the pen state shown in FIG. 9B according to the pen positions 1 to 14. Therefore, the state of S1 is output to the infrared ray only at the start of the strokes at points 1 and 10, and otherwise, only the infrared synchronization signal (one pulse) is output. At points 7 to 9 where the pen 1 is in the air, neither infrared light nor ultrasonic waves are output.
[0036]
The stationary machine 2 monitors the state of the pen 1 and is in the normal stationary machine power state while the pen is down, but when pen up is detected, no signal comes from the pen 1 anymore. Cut off. Therefore, as shown in FIG. 9B, when the pen position is between the points 7 and 9, the stationary machine power state is the power saving state. The infrared receiving unit 22 does not shut off the power to detect that the pen has been moved down next.
[0037]
Next, FIG. 10 shows an operation example when the push-button switch 17 is pressed during the writing of "f". For example, in the writing shown in FIG. 10A, it is assumed that the push button switch 17 starts to be pressed at the point 4 and has been pressed to the point 8. The pen state at this time is as shown in FIG. In this case, the points 4 and 7 are also output as infrared rays. Further, even when the pen tip is in the air, the output of infrared rays and ultrasonic waves continues at points 7 and 8 where the button is pressed. Therefore, the power supply of the ultrasonic receiving unit 23 is not cut off even in the fixed machine 2. At point 9, since both switches are turned off, no signal is output and the power is also shut off. Therefore, as shown in FIG. 9B, when the pen position is between the points 9 and 10, the stationary machine power state is the power saving state.
[0038]
Next, the operation of the timing generator 24 of the fixed machine 2 according to the first embodiment of the present invention will be described based on the internal configuration diagram of the fixed machine 2 of FIG. 6 and the timing chart of FIG.
[0039]
The infrared pulse digitized by the infrared comparator 108 is first input to a pulse width detection timer 110 and a pulse interval detection timer 113 in the timing generator 24, and the pulse width and the pulse interval are respectively measured by these. The pulse width determination unit 111 determines whether the measured pulse width is 1 μs. The pulse interval determination unit 114 determines whether the pulse interval is also 2 to 9 μs.
[0040]
Of course, in practice, the pulse width and the pulse interval between the pen 1 and the fixed machine 2 may slightly deviate, so that the deviation should be allowed. By observing the width and interval, erroneous detection due to noise or the like is prevented. If all the judgments are correct, the pulse is regarded as a normal pulse from the pen 1 and the first logical product 112 is turned on. The window timer 115 is triggered by the rising edge of the first logical product_WON during
[0041]
In the second logical product 118, the pulse on the rear side of the two pulses is cut out by the logical product of the output of the window timer 115 and the infrared pulse. At the falling edge of this pulse, the interrupt generation timer 116, the sampling period timer 117, and the power-off timer 119 are triggered, and the interrupt generation delay time T_i, Sampling period T_S, Power OFF setting time T_fIs measured. At the same time, the first distance detection timer 125 and the second distance detection timer 126 for detecting the ultrasonic distance also start measuring.
[0042]
The outputs of the first ultrasonic amplifier 103 and the second ultrasonic amplifier 104 have waveforms as shown in FIG. 11, but are digitized by the first ultrasonic comparator 105 and the second ultrasonic comparator 106, respectively. The first distance detection timer 125 stops at the output pulse of the first ultrasonic comparator 105, and the ultrasonic propagation time t₁Is measured. Similarly, the second distance detection timer 126 stops at the output pulse of the second ultrasonic comparator 106, and the ultrasonic propagation time t₂Is measured.
[0043]
On the other hand, after the interrupt generation timer 116 is triggered, the interrupt generation delay time T_iWhen the time elapses, it is certain that the ultrasonic wave has arrived, so the microcomputer 26 is interrupted by the interrupt generation timer 116. Interrupt occurrence delay time T_iIs determined from the writing range. For example, in the case of a writing range of A4 size, the maximum distance between the pen 1 and the fixing device 2 is about 366 mm on a diagonal line. Since the speed of the ultrasonic wave is about 331 m / s (0 ° C.) to 347 m / s (25 ° C.), the maximum propagation time is 1.1 ms. Therefore, the interrupt occurrence delay time T_iIs set to 1.2 ms, if it is within the writing range, the ultrasonic wave arrives before the interruption occurs, and the first distance detection timer 125 and the second distance detection timer 126 should have stopped.
[0044]
After the interruption, the microcomputer 26 outputs the pulse interval t from the pulse interval detection timer 113._PAnd the ultrasonic wave propagation time t from the first distance detection timer 125 and the second distance detection timer 126.₁, T₂Is read. The microcomputer 26 writes the read data to the external nonvolatile memory 27. After writing the data, the microcomputer 26 enters the sleep state, consumes low power, and waits for the next interrupt.
[0045]
On the other hand, the measurement is performed by the sampling cycle timer 117 until immediately before the next sampling cycle. The falling timer of the sampling period timer 117 triggers the window timer 115 again. Then, the next single infrared pulse is detected by the window timer 115.
[0046]
Sampling period T_SAnd the window timer period T measured by the window timer 115_WIs determined by the time accuracy of each of the pen 1 and the fixed machine 2. If each has a highly accurate time base, T_SIs as close as possible to the specified sampling period, and T_WCan be as close as possible to the actual pulse width of 1 μs, but an accurate time base is expensive, and it is necessary to provide a margin in order to reduce the price.
[0047]
For example, if the sampling cycle is 10 ms and there is a time base error of ± 0.1% between the pen 1 and the fixed machine 2, an error of about 10 μs occurs. Therefore, in such a case, T_S= 9990 μs, T_W= 21 μs. Since only the infrared pulse that arrives during this 21 μs is received, malfunction can be prevented even if infrared noise occurs elsewhere, for example, as shown in FIG. That is, assuming that infrared noise is generated randomly, the probability of malfunctioning by 0.2% can be reduced by the above-described window cutout processing.
[0048]
On the other hand, the power OFF set time T_fIs set to a time longer than the sampling period, for example, 11 ms. Therefore, the power-off timer 119 is normally retriggered by the next trigger before the time is measured, and is not turned off. However, when no signal is received from the pen 1 due to pen-up or the like, since the infrared pulse is not cut out by the window timer 115, the operation of the power-off timer 119 is completed and turned off. Thereby, the power supply 109 of the ultrasonic receiving unit 23 is cut off, and the power consumption is reduced. When the pen pulse is returned and the infrared pulse comes again, the ultrasonic receiving unit 23 is turned on.
[0049]
When the microcomputer 26 is later connected to the computer 5 (FIG. 2) such as a personal computer (PC), the microcomputer 26 stores the pulse interval t indicating the pen state stored in the nonvolatile memory 27._P, Ultrasonic propagation time t indicating the distance₁, T₂To your computer. The coordinates of the pen 1 are calculated by a personal computer (PC). The distance from the pen 1 to the first ultrasonic sensor 100 and the second ultrasonic sensor 101 is represented by a distance r.₁, R₂And the sound velocity is V
r₁= V × t₁
r₂= V × t₂
It is.
[0050]
When the first ultrasonic sensor 100 is set as the origin and the second ultrasonic sensor 101 has a coordinate system of (W, 0), the coordinates (x, y) of the pen 1 are as follows.
x²+ Y²= R₁ ²
(X-W)²+ Y²= R₂ ²
Therefore, if x and y are solved,
x = (r₁ ²-R₂ ²+ W²) / 2W
y = (r₁ ²-X²)^1/2
, The pen coordinates are obtained.
[0051]
FIG. 12 is a diagram illustrating details of the internal configuration of the fixed machine 2 according to the second embodiment of the present invention. In the second embodiment of the present invention, unlike the first embodiment, the interruption of the power supply 109 of the ultrasonic wave receiving unit 23 is performed by the interrupt generation timer 116 instead of the power off timer 119. That is, after an infrared signal and an ultrasonic signal come within the sampling period, the microcomputer 26 is interrupted and the power supply 109 of the ultrasonic receiving unit 23 is turned off. FIG. 13 shows a timing chart at this time. 11 differs from FIG. 11 only in the ultrasonic receiving unit power supply 109.
[0052]
In the above-described first embodiment of the present invention, the power supply 109 of the ultrasonic receiving unit 23 is turned off by pen-up or the like. However, in the second embodiment of the present invention, after the ultrasonic wave is detected, Since the power supply 109 is turned off even during the sampling period until the next detection, the power consumption can be further reduced.
[0053]
However, in the case of a power supply circuit in which it takes time to stabilize after the power is turned on, the second embodiment of the present invention is not appropriate, and is implemented using the first embodiment. . Also in the first embodiment of the present invention, when an ultrasonic signal is received after the power is turned on by an infrared pulse and is stabilized, there occurs a problem that the position of the first point at the time of pen down cannot be obtained. . However, the pen 1 does not normally move immediately after the pen down, so that there is no practical problem even if one point immediately after the pen down does not come out.
[0054]
In the above description, it has been described that the infrared rays and the ultrasonic waves are transmitted from the pen 1, but these relationships may be interchanged.
[0055]
For example, it is also possible to transmit infrared rays from the fixed machine 2 side, transmit ultrasonic waves from the pen 1 when the pen 1 receives infrared rays, and obtain the pen coordinates from the time from the infrared transmission to the ultrasonic reception on the fixed machine 2 side. It is. In this case, low power consumption of the fixed machine 2 can be achieved by detecting the pen-up on the fixed machine 2 side and stopping the infrared rays transmitted from the fixed machine 2 side. In this case, when the pen is down, it is possible to transmit the pen down to the fixed machine 2 by generating an ultrasonic wave without receiving the infrared light on the pen 1 side, and the fixed machine 2 restarts the infrared transmission. Just do it.
[0056]
After receiving the infrared ray, the pen 1 may shut off the power supply of the infrared ray receiving circuit until immediately before the next sampling cycle. Similarly, after receiving the ultrasonic wave on the fixed machine 2 side, the power supply of the ultrasonic wave receiving circuit may be cut off until the next sampling cycle.
[0057]
Also, the ultrasonic wave is transmitted from the fixed machine 2 side, and when the pen 1 receives the ultrasonic wave, the pen 1 transmits the infrared ray, and the fixed machine 2 side can obtain the pen coordinates from the time from the transmission of the ultrasonic wave to the reception of the infrared ray. It is possible. Also in this case, low power consumption of the fixed machine 2 can be achieved by detecting the pen-up on the fixed machine 2 side and stopping the ultrasonic wave transmitted from the fixed machine 2 side. In this case, when the pen is down, it is possible to transmit the pen down to the fixed machine 2 by generating infrared rays without receiving the ultrasonic wave on the pen 1 side, and the fixed machine 2 resumes the ultrasonic transmission. You can do it.
[0058]
Also, the infrared rays transmitted from the pen 1 may be modulated only when the pen state changes. Further, on the pen 1 side, after receiving the ultrasonic wave, the power supply of the ultrasonic receiving circuit may be cut off until the next sampling cycle. Similarly, after receiving the infrared ray on the fixed machine 2 side, the power supply of the infrared ray receiving circuit may be cut off until the next sampling cycle.
[0059]
As can be understood from the above, the features of the embodiment of the present invention are as follows.
[0060]
(Supplementary Note 1) A mobile body and a fixed body are provided, an electromagnetic wave is transmitted from the mobile body to the fixed body, and an ultrasonic wave is transmitted and received between the mobile body and the fixed body. An ultrasonic coordinate input device for determining a position of the moving body with respect to the fixed body based on a propagation time,
The moving object is
Means for detecting the state of the moving object;
Means for modulating the electromagnetic wave based on the detected state of the moving body and outputting a modulated electromagnetic wave signal,
The means for outputting the modulated electromagnetic wave signal outputs an electromagnetic wave signal having a minimum power among a plurality of types of signal patterns when the state of the moving body does not change.
An ultrasonic coordinate input device, characterized in that:
[0061]
(Supplementary Note 2) In the ultrasonic coordinate input device according to Supplementary Note 1,
The moving body has a pen shape,
The means for detecting the state of the moving body detects whether the state is a writing state or a non-writing state.
An ultrasonic coordinate input device, characterized in that:
[0062]
(Supplementary note 3) In the ultrasonic coordinate input device according to supplementary note 1,
The electromagnetic wave is infrared light;
The means for modulating the electromagnetic wave changes an interval between a plurality of infrared pulses according to a state of the moving body,
The electromagnetic wave signal having the minimum power is one infrared pulse signal.
An ultrasonic coordinate input device, characterized in that:
[0063]
(Supplementary Note 4) In the ultrasonic coordinate input device according to Supplementary Note 1,
The means for outputting a modulated electromagnetic wave signal provided in the moving body outputs the electromagnetic wave signal at a specific time interval,
The fixed body is
Means for generating a time interval corresponding to a specific time interval of the electromagnetic wave signal output by the moving object;
Means for receiving an electromagnetic wave signal output by the moving object only during a specific time before a specific time before the moving object may output an electromagnetic wave signal.
An ultrasonic coordinate input device, characterized in that:
[0064]
(Supplementary Note 5) Having a moving body and a fixed body, transmitting and receiving an electromagnetic wave and transmitting and receiving an ultrasonic wave between the moving body and the fixed body, An ultrasonic coordinate input device for determining a position of the moving body,
The fixed body is
Means for detecting a state of the moving object;
The power of the ultrasonic receiving circuit or the ultrasonic transmitting circuit of the fixed body is cut off or the power of the electromagnetic wave receiving circuit or the electromagnetic wave transmitting circuit is cut off based on the detected state of the moving body, so that the fixed body is fixed. Equipped with means for reducing power consumption
An ultrasonic coordinate input device, characterized in that:
[0065]
(Supplementary note 6) In the ultrasonic coordinate input device according to supplementary note 5,
The moving body has a pen shape,
The means for detecting the state of the moving body detects whether the state is a writing state or a non-writing state,
The means for reducing the power consumption of the fixed body reduces the power consumption of the fixed body when the detected state of the moving body is a state without writing.
An ultrasonic coordinate input device, characterized in that:
[0066]
(Supplementary Note 7) The mobile communication device has a moving body and a fixed body, and transmits and receives an electromagnetic wave and an ultrasonic wave between the moving body and the fixed body. An ultrasonic coordinate input device for determining a position of the moving body,
One of the mobile unit and the fixed unit includes a unit that transmits an ultrasonic wave or an electromagnetic wave at a specific time interval,
The other of the movable body and the fixed body includes means for reducing power consumption by shutting off a power supply of an electromagnetic wave or ultrasonic wave reception circuit for the remaining time of the specific time interval after reception of the transmitted electromagnetic wave or ultrasonic wave. Prepare
An ultrasonic coordinate input device, characterized in that:
[0067]
【The invention's effect】
According to the present invention, the power consumption of the pen can be reduced with a relatively simple circuit configuration without using a high-precision and expensive time base. Also, the power consumption of the fixed machine can be reduced. As a result, the battery life when the battery is driven can be extended.
[Brief description of the drawings]
FIG.
FIG. 1 is a diagram illustrating an outline of a first embodiment of the present invention.
FIG. 2
FIG. 4 is a diagram illustrating transfer of handwriting data stored in a fixed machine to a computer.
FIG. 3
FIG. 3 is a diagram illustrating a configuration example of a pen.
FIG. 4
FIG. 3 is a diagram illustrating an internal configuration of a pen.
FIG. 5
It is a figure showing the example of composition of a fixed machine.
FIG. 6
FIG. 3 is a diagram illustrating details of an internal configuration of the fixed machine.
FIG. 7
It is a figure showing the state of a pen.
FIG. 8
4 is a flowchart of a microcomputer operation of the pen.
FIG. 9
It is a figure which shows the operation example at the time of writing "f" using a pen.
FIG. 10
It is a figure which shows the operation example at the time of writing "f" using a pen.
FIG. 11
It is a figure showing a timing chart.
FIG.
It is a figure which shows the detail of the internal structure of the fixed machine of 2nd Embodiment.
FIG. 13
FIG. 9 is a diagram illustrating a timing chart according to the second embodiment.
[Explanation of symbols]
1 pen
2 Fixed machine
3 Writing surface
5 Computer
11 Battery
12 Drive circuit
13 pen touch switch
14. Infrared LED
15 Ultrasonic transmitter
16 pen tip
17 push button switch
20 Receiver circuit
21 Paper fixing clip
22 Infrared receiver
23 Ultrasonic receiver
24 Timing generator
25 batteries
26 microcomputer
27 Non-volatile memory
100 first ultrasonic sensor
101 second ultrasonic sensor
102 Infrared sensor
103 1st ultrasonic amplifier
104 2nd ultrasonic amplifier
105 first ultrasonic comparator
106 second ultrasonic comparator
107 infrared amplifier
108 infrared comparator
109 power supply
110 pulse width detection timer
111 Pulse width judgment unit
112 First logical product
113 Pulse interval detection timer
114 Pulse interval judgment unit
115 Window timer
116 Interrupt generation timer
117 Sampling period timer
118 Second logical product
119 Power OFF timer
121 microcomputer
122 LED drive circuit
123 ultrasonic drive circuit
124 pen type switch
125 1st distance detection timer
126 Second distance detection timer

Claims (5)

It has a moving body and a fixed body, transmits electromagnetic waves from the moving body to the fixed body, and transmits and receives ultrasonic waves between the moving body and the fixed body, based on the propagation time of the ultrasonic wave. An ultrasonic coordinate input device for determining a position of the moving body with respect to the fixed body,
The moving object is
Means for detecting the state of the moving object;
Means for modulating the electromagnetic wave based on the detected state of the moving body and outputting a modulated electromagnetic wave signal,
The ultrasonic coordinate input device, wherein the means for outputting the modulated electromagnetic wave signal outputs an electromagnetic wave signal having a minimum power among a plurality of types of signal patterns when the state of the moving body does not change. The ultrasonic coordinate input device according to claim 1,
The electromagnetic wave is infrared light;
The means for modulating the electromagnetic wave changes an interval between a plurality of infrared pulses according to a state of the moving body,
The ultrasonic coordinate input device, wherein the electromagnetic wave signal having the minimum power is one infrared pulse signal. The ultrasonic coordinate input device according to claim 1,
The means for outputting a modulated electromagnetic wave signal provided in the moving body outputs the electromagnetic wave signal at a specific time interval,
The fixed body is
Means for generating a time interval corresponding to a specific time interval of the electromagnetic wave signal output by the moving object;
Means for receiving an electromagnetic wave signal output by the moving object only during a specific time before a specific time before the moving object may output an electromagnetic wave signal, an ultrasonic coordinate input device comprising: . It has a moving body and a fixed body, and transmits and receives electromagnetic waves and ultrasonic waves between the moving body and the fixed body, whereby the moving body moves with respect to the fixed body based on the propagation time of the ultrasonic wave. An ultrasonic coordinate input device for obtaining a position,
The fixed body is
Means for detecting a state of the moving object;
On the basis of the detected state of the moving body, the power of the ultrasonic receiving circuit or the ultrasonic transmitting circuit of the fixed body is cut off, or the power of the electromagnetic wave receiving circuit or the electromagnetic wave transmitting circuit is cut off, thereby consuming the fixed body. An ultrasonic coordinate input device comprising means for reducing electric power. It has a moving body and a fixed body, and transmits and receives electromagnetic waves and ultrasonic waves between the moving body and the fixed body, whereby the moving body moves with respect to the fixed body based on the propagation time of the ultrasonic wave. An ultrasonic coordinate input device for obtaining a position,
One of the mobile unit and the fixed unit includes a unit that transmits an ultrasonic wave or an electromagnetic wave at a specific time interval,
The other of the movable body and the fixed body includes means for reducing power consumption by shutting off a power supply of an electromagnetic wave or ultrasonic wave reception circuit for the remaining time of the specific time interval after reception of the transmitted electromagnetic wave or ultrasonic wave. An ultrasonic coordinate input device comprising:

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