JP2007128120A - Handwriting input system - Google Patents

Abstract

Provided is a handwritten handwriting input system that can accurately reproduce handwritten handwriting data, express the characteristics of a writer's final writing, and evaluate handwriting as data.
When a pen switch shifts from on to off, a function for continuously transmitting infrared signals and ultrasonic signals within a preset time period, and a transmission cycle of infrared signals and ultrasonic signals are continuously variable. The control means has an electronic pen having a function to enable, and at least one infrared receiver and two or more ultrasonic receivers, and the arrival of the infrared signal and the ultrasonic signal An infrared ultrasonic measurement unit for measuring a time difference, a coordinate calculation unit for calculating the position coordinate data of the electronic pen using the arrival time difference obtained from the infrared ultrasonic measurement unit, and a handwriting of the position coordinate data of the electronic pen A handwriting handwriting input system comprising a conversion processing unit for converting data.
[Selection] Figure 1

Description

  The present invention includes at least an infrared generation circuit including an infrared light emitting element, an ultrasonic generation circuit including an ultrasonic transmission element, a control means for controlling an infrared signal and an ultrasonic signal transmitted from these generation circuits, and a recording target The writing unit having a function capable of leaving a locus directly on the medium and a pen switch for detecting a contact state between the recording medium at the tip of the writing unit and depending on whether the pen switch is on or off An electronic pen for turning on / off transmission of infrared signals and ultrasonic signals, and at least one or more infrared light receivers and two or more ultrasonic receivers, the infrared signals and the ultrasonic signals An infrared ultrasonic measurement unit that measures the arrival time difference to the infrared light receiving unit or the ultrasonic reception unit, and the position coordinate data of the electronic pen using the arrival time difference obtained from the infrared ultrasonic measurement unit Coordinate calculating unit for calculating, as well as handwritten input system comprising a conversion processing unit for converting the position coordinate data of the electronic pen on the handwriting data.

In recent years, with the spread of computers, the pen position detection technology is a natural information input means for human beings, and the handwriting expresses personal features. It has been applied as an alternative input means.
As a pen position detection technique, for example, Patent Document 1 discloses a technique in which an electrode is laid on a writing surface and the position coordinates of the pen are detected by capacitive coupling with the pen. A position detection mechanism is incorporated in the writing surface, and the position of the pen can be detected. However, this technique is widely used for detecting the position coordinates by bringing a stylus into contact with an electronic tablet installed on a desk or a transparent electronic tablet installed on a computer screen.
However, when leaving a handwriting on the writing surface using a ballpoint pen, mechanical pencil, etc., the conductive carbon contained in the black ink or core is applied to the writing surface, so the position coordinate detection accuracy decreases. This is especially noticeable when the area is filled, and it is not suitable for leaving handwriting on the writing surface.

  On the other hand, as a technique capable of detecting, as data, the position coordinates of a pen on which a handwriting is actually recorded while recording the handwriting on paper or the like, for example, Patent Document 2 discloses an ultrasonic signal transmission unit and an infrared signal. Each time from when the electronic pen having the transmitter and the infrared signal transmitted from the infrared signal transmitter is received to when the ultrasonic signal transmitted from the ultrasonic signal transmitter is received at a plurality of locations Thus, there is disclosed an electronic pen position detection device that detects the position of the electronic pen based on each time. Incorporating a writable means such as a ballpoint pen or mechanical pencil into the electronic pen, and sending infrared signals and ultrasonic signals by contact with the recording medium at the tip of the pen, leaving handwriting on paper, etc. It is possible to obtain position coordinate data corresponding to.

  The handwriting handwriting input system captures the handwriting of the writer as data using a technology that records the handwriting on paper and detects the position of the pen, and displays the handwriting data on the screen, for example, or personal authentication Or use it for any purpose. For example, Patent Document 3 below proposes a system that can receive the same education as in the case of being gathered in an actual classroom even in a remote place using computer communication. The handwritten handwriting data used in such a system corresponds to the handwriting remaining on the paper, and its accurate reproduction, writing speed at the time of writing, writing pressure and character of the shape can be expressed, It was desired to be able to evaluate the writer's handwriting as data.

  In addition, as a method for detecting writing pressure, which is one of the features of handwriting, in Patent Document 4 below, a variable capacitor is disposed to change the capacitance in conjunction with the pen tip of an electronic pen, thereby generating ultrasonic waves. The circuit converts the writing pressure applied to the pen tip into the frequency of the ultrasonic signal by determining the frequency of the ultrasonic signal based on the combined capacitance of the ultrasonic element and the variable capacitor. A receiving device is disclosed that can detect the frequency of an ultrasonic signal received by an ultrasonic receiver and calculate pen pressure data applied to the pen tip. Can be obtained as a feature point of the handwriting.

JP-A-53-52133 JP 2005-174189 A JP 2002-156894 A JP 2004-164505 A

The handwriting is roughly divided into three states: first writing, sending, and last writing. The first writing refers to how to insert the pen at the beginning of writing, the feeding refers to how to send the pen from the first writing to the last writing, and the last writing refers to the state of how to put the pen (finishing). In order to be able to evaluate the writer's handwriting as data, the final writing is important as the part where the writer's characteristics are most likely to appear.
Although the method disclosed in Patent Document 2 can detect the position coordinate of the electronic pen, in terms of expressing the characteristics of the handwriting, the position coordinate data while the writing speed or the writing pressure exceeding a certain level is applied. Can only be obtained, that is, only the writing is expressed, and the final writing cannot be expressed.
Further, according to the method disclosed in Patent Document 4, the final stroke can be expressed by obtaining the writing pressure data which is one of the features of the handwriting, but the writing pressure is measured in the electronic pen. For this purpose, a variable capacitor is required. In other words, the electronic pen has a very complicated structure because a variable capacitor is added in addition to the infrared generation circuit, ultrasonic generation circuit, control means for controlling the transmission of infrared signals and ultrasonic signals, and the pen tip switch. In addition, there is a problem that the power consumption of the electronic pen increases.
The present invention has been made to solve the above-described problems, and takes in handwriting written on paper or the like as data using an electronic pen capable of writing, and features the handwriting with a simpler structure and less power consumption. The purpose is to obtain sufficient handwriting data so that the handwriting of the writer including the time of the final writing can be evaluated.

The present invention includes at least an infrared generation circuit including an infrared light emitting element, an ultrasonic generation circuit including an ultrasonic transmission element, a control means for controlling an infrared signal and an ultrasonic signal transmitted from these generation circuits, and a recording target Detects the contact state between the writing unit having a function capable of leaving a locus directly on the medium and the recording medium at the tip of the writing unit, and turns on the contact state and turns off the contact state. A function of continuing to transmit infrared signals and ultrasonic signals within a preset time when the pen switch shifts from on to off, and the transmission cycle of infrared signals and ultrasonic signals. An electronic pen provided with the function of making the variable continuously variable, and at least one infrared receiver and two or more ultrasonic receivers, the infrared signal and the Infrared ultrasonic measurement unit that measures the arrival time difference of the sound wave signal to the infrared light receiving unit or the ultrasonic wave reception unit, and the position coordinate data of the electronic pen using the arrival time difference obtained from the infrared ultrasonic measurement unit A handwriting handwriting input system comprising a coordinate calculation unit to calculate, and a conversion processing unit that converts the position coordinate data of the electronic pen into handwriting data, is a first gist,
2. The handwriting according to claim 1, wherein the transmission period of the infrared signal and the ultrasonic signal is changed to less than 1.0 times when the pen switch is turned on when the pen switch is turned on. The handwriting input system is the second gist,
The infrared ultrasonic measurement unit includes at least one infrared light reception unit and three ultrasonic reception units, and the ultrasonic reception unit is installed in a plane perpendicular to the recording medium surface. The handwritten handwriting input system according to claim 1 and 2 as a third gist,
The conversion processing unit performs conversion to handwriting data for each input of the position coordinate data, and has a display control means for displaying as handwriting on the screen, according to the change of the input period of the position coordinate data, The handwriting handwriting input system according to claim 1 or 2, wherein the handwriting handwriting input system according to claim 1 or 2 has a function of changing a handwriting.
The conversion processing unit includes display control means for performing conversion to handwriting data for each input of the position coordinate data and displaying it as handwriting on a screen, and changes the handwriting according to the position coordinate data. It has a function, The handwritten handwriting input system of Claim 3 characterized by the above-mentioned is made into a 5th summary.

In the present invention, the final writing is distinguished from the writing representing the writing state (writing to the recording medium and the pen switch is on), and the pressure at which the tip of the writing unit touches the recording medium. In the wrinkled state of writing (the writing medium has been written but the pen switch is in the off state) and the non-writing state in which the writing part tip does not touch the recording medium thereafter, When the pen switch is switched from on to off, that is, from when the pressure applied to the tip of the writing section becomes lower than a certain level during writing, the infrared signal and the ultrasonic signal are continuously transmitted for a preset time. At the same time, by changing the transmission cycle of the infrared signal and ultrasonic signal within this time to the transmission cycle in the writing state, not only the writing state but also the handwriting information of the final writing can be acquired and the handwriting can be reproduced. Can . In addition, it is not necessary to add components such as a pen pressure detection circuit or a variable capacitor, which was necessary to acquire pen pressure information in the past. Can be obtained.
In particular, in the present invention, by shortening the transmission cycle at the time of final writing, it is possible to acquire detailed operation information at the tip of the writing part at the time of final writing and to accurately reproduce the handwriting.
In addition, by installing three ultrasonic receivers, the height position of the electronic pen from the recording medium can be detected, and the handwriting information of the writer at the end of writing can be acquired, and the handwriting can be accurately reproduced. The accuracy to do has increased dramatically.
Further, in the system of the present invention, the conversion processing unit has means for controlling the display of the handwriting, and the displayed handwriting is displayed according to the change of the input period of the coordinate data or the change of the height direction data. By having the function of changing (color change, density change, line width change, line length change), it is possible to accurately express, for example, “Tome”, “Hane”, “Harai” and the like, which are feature points of Japanese characters. In addition, for example, even when drawing a picture, the expressive power spreads.

An electronic pen includes an infrared generation circuit including an infrared light emitting element, an ultrasonic generation circuit including an ultrasonic transmission element, a control unit that controls infrared signals and ultrasonic signals transmitted from these generation circuits, and a recording medium. The writing unit has a function capable of directly leaving a locus on the head, and a pen switch for detecting a contact state of the tip of the writing unit with a recording medium. In the writing unit, a writable refill such as a ballpoint pen is inserted, and a handwriting can be recorded on a recording medium such as paper. The pen switch is turned on when the tip of the writing unit is in contact with the recording medium and a certain pressure is applied thereto, and is turned off below the certain pressure. The constant pressure may be adjusted so that the pen switch is turned off at a weak pressure such that the pen switch is turned on in a normal writing state and the tip of the writing part touches the recording medium, such as a faint state.
When the pen switch is turned on, the control means for controlling the transmission of the infrared signal and the ultrasonic signal gives a signal to the infrared generation circuit and the ultrasonic transmission circuit, and the infrared signal and the ultrasonic signal are continuously transmitted at a constant cycle. By transmitting, the position coordinates of the electronic pen in the writing state can be transmitted.
This control means also has a function of continuously transmitting the infrared signal and the ultrasonic signal within a preset time after the pen switch is turned off, and the transmission period of the infrared signal and the ultrasonic signal. By having the function of making it continuously variable, the position coordinates of the electronic pen at the time of final writing can be transmitted. The shorter the transmission cycle, the more detailed handwriting information can be obtained, but the power consumption of the electronic pen increases.

The infrared ultrasonic measurement unit receives an infrared signal from the electronic pen by at least one infrared light receiving unit, and receives an ultrasonic signal arriving late by at least two ultrasonic reception units. Measure the time from signal reception to ultrasonic signal reception. The infrared ultrasonic measurement unit measures the time each time there is an input from the electronic pen and sends it to the coordinate calculation unit.

The coordinate calculation unit converts the time measured by the infrared ultrasonic measurement unit into distance, converts it from the positional relationship of each ultrasonic reception unit to the position coordinate data of the electronic pen using the triangulation method, and performs infrared ultrasonic measurement Each time there is an input from the unit, the position coordinate data is transmitted to the conversion processing unit.

The conversion processing unit is preinstalled with a conversion processing program and activated, and receives the position coordinate data of the electronic pen transmitted from the coordinate calculation unit. In the writing state, the electronic pen continuously transmits an infrared signal and an ultrasonic signal at a constant cycle, so that the conversion processing unit receives the position coordinate data of the electronic pen at a constant cycle. Further, when the period for receiving the position coordinate data changes, the conversion processing unit determines that the state has shifted to the blurred state.
When three ultrasonic receivers are provided, the height from the recording medium surface to the ultrasonic transmitting element at the time when the pen switch is turned on from the off position of the electronic pen in the direction perpendicular to the recording medium surface is determined. The initial value of the origin of the height is set as the initial value, and then the height of the lowest point obtained in the written state is set as the origin and the update is continued. And In addition, the writing processing end height is set in advance in the conversion processing unit. If the pen switch is on, the pen switch is turned from on to off, and within this height, the writing state or the blurred state, if the writing end height is not less than Judged as non-written. At this time, the writing end height may be set arbitrarily by the writer in comparison with the actual handwriting.
The conversion processing program has a function that allows you to edit the line thickness, color, etc. of handwriting data. In the writing state, the specified handwriting is displayed on the screen, and when it becomes blurred, the density change and line width change The features of the final writing can be displayed finely or stored in a storage device up to a position where the handwriting with a non-writing state is reached.

Hereinafter, the present invention will be described in more detail with reference to examples.
In FIG. 1, an example of the handwriting handwriting input system of this invention is shown. The infrared signal and the ultrasonic signal transmitted from the electronic pen 1 are respectively received by the ultrasonic receiver 3 and the infrared light receiver 4 of the receiver 2, and the time from the reception of the infrared signal to the reception of the ultrasonic signal is determined by the receiver 2. It is measured by an infrared ultrasonic measurement unit (not shown). A coordinate calculation unit (not shown) in the receiving device 2 converts each measured time into a distance, and converts it into position coordinate data of a two-dimensional or three-dimensional electronic pen using a triangulation method. The obtained position coordinate data is sent from the receiving device 2 to the computer 6 through the communication cable 5. In this embodiment, the receiving device 2 and the computer 6 are connected by a USB cable. A conversion processing program is preinstalled in the computer 6 and activated. The conversion processing program converts the position coordinate data into handwriting data and displays it as handwriting data on the screen of the computer 6 or a storage device. Or you can save it.

Example 1:
FIG. 2 is a copy of the structure of the tip of the electronic pen. The pen switch 11 of the electronic pen is normally off, and a certain pressure (for example, 50 g or more) is applied to the tip of the writing portion, and the spring 12 supporting the tip is contracted to a certain length 13 (for example, 0.2 mm). ) It will turn on when you move. When the pen switch is turned on, the infrared light emitting element 14 and the ultrasonic wave transmitting element 15 start transmitting signals at a constant cycle.
In general, the writing speed tends to be higher at the time of character writing (shaded state) in the “Hane” and “Harai” portions than at the time of character writing (writing state) in other portions. The writing speed in the faint state varies depending on the writer's habit, the type of character, the size, etc., but may reach a speed about 1 to 3 times the normal writing state. From this, when the pen switch shifts from on to off, the number of position coordinate data points that can be acquired in a blurred state will be reduced unless the transmission period of the infrared signal and ultrasonic signal is shortened corresponding to this writing speed. Features are harder to catch.
In other words, when the pen switch shifts from on to off, the transmission period of the infrared signal and the ultrasonic signal is less than 1.0 times, more preferably 0.3 times or less compared to the writing state, so that the blurring state is Detailed motion information at the tip of the writing part can be acquired, and the handwriting can be accurately reproduced.

FIG. 3 is a conceptual diagram of handwriting data in a “splash” state, which is one of the feature points of Japanese characters, as an example of accurate handwriting data. FIG. 3A shows an actual handwriting on the paper surface, and writing is performed at a constant speed from the start of writing to the end of writing. FIG. 3B is a conceptual diagram when the transmission cycle when the pen switch shifts from on to off is, for example, 0.3 times the writing state. FIG. 3C is a conceptual diagram when the transmission cycle when the pen switch transitions from on to off is, for example, 0.8 times that in the writing state.
Along with the writing operation, the coordinate data 16 to 19E are position coordinates output from the electronic pen. By changing the transmission cycle from the electronic pen when the pen switch is switched from on to off, the writing state represented by the coordinate data 16, 17 and the last writing represented by the coordinate data 18, 19, 19E are divided. .
When shifting from the written state to the faint state, when there is input of data whose transmission cycle has changed, it is determined that the point 17 immediately before the point 18 where the change has occurred is the starting point of the faint state. Thereafter, calculation is performed as handwriting until the position coordinates are not input from the coordinate calculation unit.
When displaying on the screen, the conversion processing unit applies gradation from the blurred start point 17 to the last point 19E of the position coordinate input so that, for example, the start point is 100% density and the last point is 0% density. The feature points of the final writing can be reproduced in detail.
If you lower the multiple of the transmission period in the faint state, you can obtain detailed operation information at the tip of the writing part in the faint state, and you can accurately reproduce the handwriting, but the number of infrared and ultrasonic signal transmissions As power consumption increases, power consumption increases.

Example 2:
FIG. 4 is a schematic diagram of the second embodiment. In the present embodiment, three ultrasonic receivers 3-1, 3-2 and 3-3 are provided. The ultrasonic receiving unit 3-1 and the ultrasonic receiving unit 3-2 are installed on the same plane as the recording medium, and an ultrasonic signal transmitted from the electronic pen is transmitted to the ultrasonic receiving unit 3-1, The position coordinate data of the handwriting written on the recording medium can be detected from the time difference reaching 3-2. The ultrasonic receiving unit 3-3 is installed away from the ultrasonic receiving unit 3-2 in a direction directly above the recording medium surface, and the ultrasonic wave transmitted from the electronic pen is transmitted to these ultrasonic receiving units. The height of the electronic pen from the recording medium can be measured from the time difference that has reached 3-2 and the ultrasonic wave receiving unit 3-3. Although the calculation of the height is complicated, the ultrasonic receiving unit 3-3 does not have to be directly above the ultrasonic receiving unit 3-2.

  5A to 5C are diagrams for specifically explaining the positional relationship of the electronic pen according to the present embodiment. FIG. 4A shows the relationship in the height direction between the tip of the writing part and the surface of the recording medium such as paper in the writing state. The pen switch is turned on, and the infrared signal and the ultrasonic signal are continuously transmitted at a constant cycle. In the conversion processing unit, since the position coordinate data is input at a constant cycle, it can be determined that the writing state is normal.

FIG. 4B shows the relationship in the height direction in the blurred state. The transition from the state (a) to the state (b) is a time when the pen switch for detecting the contact state of the tip of the writing part with the surface of the recording medium has transitioned from on to off, and a preset time ( For example, the infrared signal and the ultrasonic signal are continuously transmitted for 0.5 seconds. The conversion processing unit calculates the height of the electronic pen (the height of the ultrasonic element built in the electronic pen) from the measurement results of the ultrasonic receiving units 3-2 and 3-3. As a result, when it is higher than the origin and within a writing end height (for example, 2 mm), it can be determined that the camera is in a blurred state.

The position shown in FIG. 6C represents a non-writing state (the writing medium is not written and the pen switch is off). When the height of the electronic pen is higher than the writing end height (for example, 2 mm), it is not displayed as handwriting. However, the trajectory at the end of writing can be accurately reproduced by converting to handwriting data and calculating until the input of position coordinate data from the coordinate calculating unit is completed in the arithmetic processing unit.

FIG. 6 is an example showing a conceptual diagram of position coordinate data at the time of final writing.
FIG. 6A shows the position coordinates when Japanese characters “Large” are written. FIG. 6B is a conceptual diagram that reproduces the movement of the electronic pen in a three-dimensional space when the portion 41, which is the feature point of the final writing, is written.
The coordinate data 20 to 24 are position coordinates output from the electronic pen along with the writing operation. Depending on the height of the electronic pen, the writing state up to the coordinate data 21, the blurred state of the coordinate data 22 whose height coordinate is less than the writing end height a, and the coordinate data 23 whose height coordinate is the writing end height a or more. It can be divided into up to 24 non-writing states.
When shifting from the written state to the blurred state, when the height data of the height origin or higher is input, the point 21 immediately before the point 22 where the change has occurred is determined as the starting point of the blurred state. Thereafter, calculation is performed as handwriting until the position coordinates are not input from the coordinate calculation unit.
The conversion processing unit calculates the trajectory of the electronic pen up to the last point 24 of the position coordinate input, calculates at which point the writing end height a is reached, and creates a virtual writing end point 25. When displayed on the screen, the gradation from the start point 21 of the blurred state to the virtual writing end point 25 is subjected to gradation such that the origin is 100% density and the writing end height a is 0% density, for example. The point can be reproduced finely.
The end point does not necessarily have to be higher than the writing end height a, and even if it is within the writing end height a, the handwriting can be similarly reproduced by using the extrapolation method. In addition, after the electronic pen is in a faint state, even when returning to the writing state while the transmission of the infrared signal and the ultrasonic signal is continued, the faint state may be similarly expressed.

The conceptual diagram of a handwritten handwriting input system. The figure which copied the structure of the tip of an electronic pen. The conceptual diagram of the feature point of a handwritten character. The schematic diagram of one Example of this invention. Conceptual diagram of the height of the writing part tip from the recording medium surface Conceptual diagram of position coordinate data at the end of writing

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic pen 2 Receiver 3 Ultrasonic receiver 4 Infrared light receiver 5 Communication cable 6 Computer 11 Pen switch 12 Spring 13 Amount of movement until the pen switch is turned on 14 Infrared light emitting element 15 Ultrasonic transmitter 16, 17, 18 , 19, 19E Position coordinates output from the electronic pen 3-1 Ultrasonic receiver 3-2 Ultrasonic receiver 3-3 Ultrasonic receiver 20, 21, 22, 23, 24 Position coordinates output from the electronic pen 25 Virtual Writing End Point 30 Writing State 31 Faint State 33 Non-Writing State 41 Feature Points

Claims (5)

At least an infrared generation circuit including an infrared light emitting element, an ultrasonic generation circuit including an ultrasonic transmission element, a control means for controlling an infrared signal and an ultrasonic signal transmitted from these generation circuits, and directly on a recording medium A pen switch that detects a contact state between a writing unit having a function capable of leaving a locus and a recording medium at a tip of the writing unit, and turns on a contact state and turns off a contact state. When the pen switch shifts from on to off, the function of continuing the transmission of the infrared signal and the ultrasonic signal within a preset time and the transmission cycle of the infrared signal and the ultrasonic signal are continuously set. The control means has an electronic pen having a variable function, and at least one or more infrared light receivers and two or more ultrasonic receivers, and the infrared signal and the ultrasonic signal. Infrared ultrasonic measurement unit for measuring the arrival time difference to the infrared light receiving unit or the ultrasonic reception unit, and coordinates for calculating the position coordinate data of the electronic pen using the arrival time difference obtained from the infrared ultrasonic measurement unit A handwriting handwriting input system comprising: an arithmetic part; and a conversion processing part for converting the position coordinate data of the electronic pen into handwriting data. 2. The handwriting according to claim 1, wherein the transmission period of the infrared signal and the ultrasonic signal is changed to less than 1.0 times when the pen switch is turned on when the pen switch is turned on. Handwriting input system. The infrared ultrasonic measurement unit includes at least one infrared light reception unit and three ultrasonic reception units, and the ultrasonic reception unit is installed in a plane perpendicular to the recording medium surface. The handwritten handwriting input system according to claim 1 or 2. The conversion processing unit performs conversion to handwriting data for each input of the position coordinate data, and has a display control means for displaying as handwriting on the screen, according to the change of the input period of the position coordinate data, The handwritten handwriting input system according to claim 1 or 2, wherein the handwriting handwriting input system has a function of changing the handwriting. The conversion processing unit includes display control means for performing conversion to handwriting data for each input of the position coordinate data and displaying it as handwriting on a screen, and changes the handwriting according to the position coordinate data. The handwritten handwriting input system according to claim 3, which has a function.

Images