JPH02148213A - Handwritten character input device - Google Patents

Abstract

PURPOSE:To simply input a handwritten character, without using a coordinate input board, and also, in a sense of writing a character on paper with a usual writing tool by providing a pen means containing two acceleration sensors. CONSTITUTION:An electronic pen 10 contains an (x) acceleration sensor 11, a (y) acceleration sensor 12 and a pen switch 13. A state of a movement of a pen point of the electronic pen 10 is always detected as (x) direction acceleration and (y) direction acceleration by the acceleration sensors 11, 12, and supplied to a device body 20 through a cable 30. A handwriting tracking processing part 23 derives successively a position of the electronic pen 10, based on a result of this detection and tracks writing of the pen point. In such a way, a handwritten input of a character, etc. can be executed simply in a sense of writing a character on paper with a usual writing tool, and also, since a coordinate input board such as a tablet, etc. is not required, the constitution can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a character input device for inputting handwritten characters and the like.

(Prior Art) Conventionally, character input devices for inputting handwritten characters have generally included a coordinate input device using an electrostatic or electromagnetic tablet.

With this type of character input device, the user is required to write large characters on the tablet with an electronic pen (stylus pen) due to the accuracy of position detection of the tablet. For this reason, with conventional character input devices, it is difficult to input characters smoothly as if writing on paper with a normal writing instrument such as a pencil or a ballpoint pen.

(Problems to be Solved by the Invention) As mentioned above, conventional handwritten character input devices require a dedicated coordinate input board such as a tablet, and when inputting characters on this board, characters are written on paper using a regular writing instrument. There was a problem that I could not type smoothly.

Therefore, the problem to be solved by the present invention is to make it possible to easily input characters by hand without using a coordinate input board and with the same feeling as writing characters on paper with a normal writing instrument.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a pen means for handwriting characters, etc., and a first acceleration for detecting an acceleration of the pen means in a first direction. a pen means having a built-in sensor and a second acceleration sensor for detecting acceleration in a second direction perpendicular to the first direction; A handwriting tracing means is provided which sequentially calculates the positions in the first and second directions and determines the handwriting of the pen means based on the calculation results, and the handwriting found by the handwriting tracing means is handwritten using the pen means. The present invention is characterized in that it is input as the shape of a character or the like.

(Function) According to the above configuration, when a character or the like is handwritten using the pen means, the movement of the pen means at that time is
Since the acceleration sensor detects the acceleration in the first and second directions, the handwriting tracing means sequentially inputs the detected acceleration and, based on this acceleration, determines the position of the pen means at the time when the acceleration is detected. By repeating the process to obtain the information, it becomes possible to input the handwriting of the pen means as a shape of a character or the like handwritten using the same means.

(Embodiment) FIG. 1 is a block diagram of a handwritten character input device according to an embodiment of the present invention, and FIG. 2 is an external perspective view of the handwritten character input device of FIG. In FIG. 2, 10 is an electronic pen used for handwriting characters, etc., and 20 is an electronic pen 1.
30 is a cable for electrically connecting the electronic pen 10 and the device main body 20.

As shown in FIG. 1, the electronic pen 10 includes an X acceleration sensor it, an X acceleration sensor 12, and a pen switch 13. As shown in the cross-sectional view of FIG. 3, the X-acceleration sensor II and the X-acceleration sensor 12 detect the acceleration ax in the direction indicated by the symbol a of the electronic pen 10 (the (t), and the
(t) of the pen shaft 4 of the electronic pen 10.
1 and are arranged in mutually orthogonal directions. The pen switch 13 also includes an electrode 43 forming the tail end of the pen tip 42 of the electronic pen 10, as shown in the cross-sectional view of FIG.
3, and an electrode 44 provided facing away from the pen tip 4.
2 to the outside of the electronic pen 10 (to the left in the figure). The pen nib 42 is the same pen nib 42
When pressure is applied toward the inside of the electronic pen 10 (the pen shaft 41 thereof), the electronic pen 10 moves inside the electronic pen 1o (toward the right in the figure) against the biasing force of the spring 45. When the pressure exceeds a predetermined value, the electrode 43 comes into contact with 71+44, and the pen switch 1
3 turns on.

As shown in FIG. 1, the device main body 20 is an analog device that inputs the detection results of the X acceleration sensor 11 and the /Interface (IF) with built-in digital converter (not shown)
) 21, an interface (IF) 22 for inputting the on/off state of the pen switch 13 of the electronic pen 1o via the cable 3o, and a handwriting tracking processing unit 23 for tracing the handwriting of the electronic pen 10. . The device main body 20 further includes a timer 24 that is activated by the handwriting tracking processing section 23 and generates an interrupt to the processing section 23 at predetermined time intervals.
, and a bitmap memory (hereinafter referred to as handwriting memory) 25 for recording the handwriting tracing results of the handwriting tracing processing section 23.

Next, the operation of an embodiment of the present invention will be explained in FIGS. 4(a) and 4(b).
) will be explained with reference to the flowchart.

When a user attempts to enter a desired character by handwriting by operating the electronic pen IO, first place the pen tip 42 of the electronic pen 10 on an object to be written such as an arbitrary piece of paper or a board, and then press the electronic pen IO. Make it still. In this state, the user presses the writing target with the pen tip 42 and moves the pen tip 42 into the pen shaft 41 of the electronic pen IO against the biasing force of the spring 45, thereby forming the tail end of the pen tip 42. By bringing the electrode 43 into contact with the electrode 44, the pen switch 13 is turned on. In this state, the user moves the electronic pen 10 while holding it in a fixed direction, for example, to handwrite desired characters.

The movement of the electronic pen 10 (the pen tip 42) during handwriting is monitored by the X acceleration sensor 11 inside the electronic pen 10. X direction acceleration ax (t), y by the X acceleration sensor 12
The directional acceleration ay (t) is constantly detected and supplied to the interface 21 via the cable 30. The interface 21 converts the acceleration detection results of the X acceleration sensor 11 and the X acceleration sensor 12 into digital values at predetermined time intervals and supplies the digital values to the handwriting tracking processing section 23 .

Now, when the pen switch 13 is turned on, this fact is notified to the handwriting tracing processing section 23 via the cable 30 and the interface 22. As a result, the handwriting tracking processing section 23
As shown in the flowchart of FIG. 4(a), the timer 24 is activated (step St), and a counter (not shown) for counting the off period of the pen switch 13 is activated.
0'' (step S2). This counter is, for example, a software counter using a register (or a specific area of memory).

When the timer 24 is activated by the handwriting tracing processing section 23, it generates an interrupt (timer interrupt) to the handwriting tracing processing section 23 at a predetermined time interval (Δt). Whenever an interrupt from the timer 24 occurs, the handwriting tracking processing unit 23 performs the process shown in FIG.
Execute the process shown in the flowchart b). That is, the handwriting tracking processing section 23 uses the X acceleration sensor 11 . Y acceleration sensor 12
Input the digital values indicating the acceleration detection results aX(t), ay(t) of The relative position of (x-0, y-0) is calculated according to the following equation (step 511).

y-5", vy (t) dt S:o(aY (t) d t 10v Oy) d
t...(2) Above (1), (In formula 21,
vx (t), vy (t) are electronic pen 1 at time t
The speeds in the x and y directions of the nib 42 of the electronic pen 10 at time to, vox, and voy are the speeds (initial speeds) in the x and y directions of the nib 42 of the electronic pen 10 at time to. In this example, vex, vQy
is 0. Therefore, the handwriting tracking processing unit 23 calculates the X value of the pen tip 42 of the electronic pen 10 at time t according to the following equation (3).

The y position will be calculated. Note that the time t is obtained by counting the number of interrupts C from the timer 24 after the timer 24 is started (t−tO×c·Δt).

When the handwriting tracking processing unit 23 executes step SLI, it examines the contents of the on/off state notification from the interface 22 and determines whether or not the pen switch 3 is in the on state (step 512). If YES, the handwriting tracking processing unit 23 determines that the user is in the process of writing a meaningful character part (a character part to be recorded as handwriting) with the electronic pen 10, and sets the counter to "0". Along with clearing, step Sll
X calculated by

Write “1” at the position in the handwriting memory 25 indicated by the y position (
Step S13 514), waits for the next interrupt from the timer 24.

On the other hand, if the determination in step SL2 is No,
That is, when the pen switch I3 is in the off state (this is
- When inputting characters that cannot be written by hand, the electronic pen l
When the pen tip 42 of O is simply moved from a stroke in the same character to the next stroke to be written, or when inputting one character is completed, etc., the handwriting tracking processing section 23 sets the counter. +1 step 515), and it is determined whether the value of this counter is greater than or equal to a predetermined value N (
Step 51B). If the counter value is not N or more, the handwriting tracking processing unit 23 temporarily moves the pen tip 42 of the electronic pen 10 to the writing target in order to simply move from a stroke in the same character to the next stroke to be written. Therefore, it is determined that the pen switch 13 is in the OFF state, and the pen switch 13 waits for the next interrupt from the timer 24. On the other hand, if the counter value is N or more, that is, pen switch 1
If the off state of 3 continues for a long time until the counter value becomes N or more, the handwriting tracking processing unit 23 determines that the handwritten input of one character is completed, stops the timer 24, and starts the next one. Waits for the pen switch 13 to be turned on for inputting one character.

At this time, the tracking memory 25 stores information about the pen tip 42 during the period of handwriting input of one character performed using the electronic pen IO (while pressing the writing target with a predetermined pressure or more).
Handwriting is recorded. The handwriting recorded in the handwriting memory 25 indicates the shape of a character input by hand. Therefore, by comparing this handwriting with a standard pattern and character recognition, it becomes possible to input it into a word processor, computer, etc.

[Effects of the Invention] As detailed above, according to the present invention, when a character or the like is handwritten using a pen means, the movement of the pen means at that time is detected in the form of acceleration by two acceleration sensors built into the pen means. Based on this detection result, the position of the pen means is sequentially determined and the handwriting of the tip of the pen means is traced, so that handwritten input of characters etc. using the pen means can be performed using a normal writing instrument. It is as easy as writing on paper, and the configuration can be simplified because a coordinate input board such as a tablet is not required.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of a handwritten character input device according to an embodiment of the present invention, FIG. 2 is an external perspective view of the handwritten character input device of FIG. 1, and FIG. FIG. 4, which is a sectional view of the essential parts of the electronic pen 10, is a flowchart for explaining the operation. 10...electronic pen, ll...X acceleration sensor, 12
...X acceleration sensor, 13...pen switch, 20
...Device body, 23...Handwriting tracking processing section, 24...
- Timer, 25... Handwriting memory, 30... Cable, 42... Pen tip. Applicant's agent Patent attorney Takehiko Suzue

Claims (3)

[Claims] (1) A pen means used for handwriting characters, etc.; a first acceleration sensor built in the means for detecting acceleration of the pen means in a first direction; and a first acceleration sensor of the pen means. A second acceleration sensor built in the means for detecting acceleration in a second direction orthogonal to the direction, and the first and second acceleration sensors of the pen means based on the detection results of the first and second acceleration sensors. handwriting tracing means that sequentially calculates positions in two directions and performs handwriting tracing processing to determine the handwriting of the pen means based on the calculation results; 1. A handwritten character input device characterized in that the handwritten character input device is configured to input the shape of a handwritten character using a handwritten character. (2) The pen means further includes a built-in switch that is turned on only during a period when pressure of a predetermined value or more is applied to the tip of the pen means, and the handwriting tracking means is activated when the switch is turned on. The handwritten character input device according to claim 1, wherein the handwritten character input device is configured to start the handwriting tracing process. (3) When the switch is temporarily turned off within a predetermined period of time during execution of the handwriting tracing process, the handwriting tracing means ignores the handwriting of the pen means during that time, and the handwriting tracing means ignores the handwriting of the pen means during that time, 3. The handwritten character input device according to claim 2, wherein the handwritten character input device is configured to determine that input of one character has ended and end the handwriting tracing process when the off state of the handwritten character exceeds the predetermined time.