JPH0525148B2 - - Google Patents

Description

[Detailed description of the invention]

(Technical Field) The present invention relates to an online handwritten character recognition device. (Background Art) A conventional online handwritten character recognition device is shown in FIG. In Fig. 1, 1 is a tablet, 2 is a pen, 3 is a recognition section, 4 is a control section, 5 is a display section, and 6 is a printing section. , write characters on paper, send the strokes moment by moment to the recognition unit 3, recognize the characters written on the tablet 1, and send the strokes to the recognition unit 3.
The characters recognized by the control unit 4 are sent to the display unit 5 for display, and after being edited or proofread by the scribe using the keyboard unit (not shown), the characters are sent to the printing unit 6.
The configuration was such that the output was output to . Therefore, the tablet 1 as an input unit,
A display unit 5 is required as a temporary output unit,
When attempting to construct an inexpensive device, the price increases, and a major drawback is that it is impossible to provide an inexpensive online handwritten character recognition device beyond a certain limit. In addition, since the input section and output section are separated,
The scribe must alternate between looking at the place to write and the place to display the output, which, unlike writing on paper, is extremely uncomfortable and not only makes the scribe tired. However, a major drawback was that the input speed was slow. Furthermore, due to physical limitations in the arrangement of sensors for input, due to the shape of the sensors, etc., the sensor arrangement is limited to 3 to 4 sensors/mm, and the resolution does not improve as it is, resulting in difficulty in recognizing input characters or symbols. There was a drawback that the rate did not increase. (Problems to be solved by the invention) An object of the present invention is to solve the above-mentioned drawbacks.
The purpose is to provide an online handwritten character recognition device that combines the functions of a tablet 1 as an input device with a display section 5 as an output device, and its features include a matrix of cells each consisting of a light emitting diode and a light receiving transistor. At least 2
The interface surface that constitutes the character frame above,
The first light emitting device is sequentially selected and assigned.
a counter and a drive circuit for emitting light within a time period of The elongated pen and the signal from the light-receiving transistor within the allotted second time period are converted from analog to digital, the digital output level is checked, and the instantaneous value of the counter at the time when the digital output level exceeds the reference level; means for more accurately detecting the inside of the pitch between the light receiving transistors based on the level of the signal from the light receiving transistors; a recognition unit that recognizes a pattern drawn by the pen having the reflective mirror; means for displaying a pattern of characters or symbols recognized by It is an online character recognition device that operates on the input/output board. (Structure and operation of the invention) FIG. 2 is a block diagram showing an embodiment of the present invention, and 7 is a block diagram showing a light-emitting diode and a light-receiving transistor arranged alternately and densely on one plane with the light-emitting surface and the light-receiving surface facing upward. an interface surface having a width for inputting and outputting a plurality of characters of at least two characters; 8, a counter (hereinafter referred to as X-C) for selecting a line in the X direction of the interface surface 7;
9 decodes the output of (X-C)8 and returns the specified
A decoder driver (hereinafter referred to as
-C), 11 is a decoder driver (hereinafter referred to as Y-D) for driving the light emitting diode in the Y direction, and 12 is a light receiving circuit for receiving signals from the light emitting transistor in the Y direction (hereinafter referred to as Y-S). and 13 is a pen having at its tip a hemispherical reflecting mirror with an area that covers an area of one pair of light emitting diodes and light receiving transistors;
7 is an AD conversion circuit that converts the analog output value of the light receiving circuit 12 into a digital value, and 18 is a level check circuit that compares and checks the output value of the AD conversion circuit 17 with a predetermined reference value using the digital value. , the maximum value within the second time period that exceeds the reference value is sent to the register 19-1, and at the same time a sample pulse is sent. 14 receives the sample pulse (X-C)8, (Y
-C) A sample circuit that samples 10 values, 1
9-1 and 19-2 are registers that hold the maximum value of the AD-converted digital value of the light-receiving transistor output at the second time in the AD conversion circuit 17 and level check circuit 18; holds AD conversion data sampled at the same timing by the sample circuit 14,
19-2 is a register that holds previous timing information sampled by 19-1, that is, AD conversion data of the output of the adjacent light-receiving transistor. 20 is the register 19-1 and 19-2.
This is a ROM (read only memory) that has the output of the address as its address, and stores the table shown in Table 1.

[Table] Here, Vm is the sample timing at which the values of (X-C)8 and (Y-C)10 detected by the level check circuit 18 are sampled.
Indicates the AD conversion data value held in register 19-1, and Vn is the value held in register 19-1 at the next timing when Vm is sampled.
It shows the AD conversion data value, and at this time the Vm has been transferred to the register 19-2. represents the pitch dimension of the light receiving transistor arranged on the interface surface 7, and X(n) and Y(n) represent the counter (X-C) 8 when the sample pulse is output from the level check circuit 18. and (Y-
C) X direction and Y direction corresponding to a count value of 10
Indicates position data in direction. 21 is the above correction
The output of the ROM 20 and (X-C)8 and (Y-C)10 sampled by the sample circuit 14
15 is a font memory having character information in the form of dots;
Reference numeral 16 is constructed like a matching circuit for checking the match between the X and Y information of the dot pattern in the font memory 15 and the values of (X-C)8 and (Y-C)10. The printing section 6 shown in FIG. 1 has the same function in FIG. 2 as well. Further, in FIG. 1, the control section 4 simply transfers or edits data, and since it has little relevance to the present invention, a description thereof will be omitted. Here, details of the interface surface 7 are shown in FIG. Figure 3 shows 300 pairs of light-emitting diodes and light-receiving transistors arranged in a one-to-one ratio.As shown in Figure 3, 30 pairs are arranged in the X direction, and 10 pairs are arranged in the Y direction.
Groups are arranged. The anode of the light emitting diode and the collector of the light receiving transistor are interconnected to the X-ray, led out from X-1 to X-30, and connected one-to-one to (X-D) 9 in FIG. Further, the cathode side of the light emitting diode is interconnected to the Y line, led out from the line Y-1 to Y-10, and connected one-to-one to (Y-D) 11 in FIG. 2. Also, (X
-D) A current is drawn to the line selected by 9, and a current flows into the line selected by (Y-D) 11. Since they are arranged on a matrix, at a certain point (X-D) 9 and (Y-D)1
Only the light emitting diode at one point on the matrix selected by 1 can emit light. next,
The emitters of the light-receiving transistors are interconnected in the same Y direction, led out from the line YS-1 to YS-10, and connected one-to-one to (YS-12) in FIG. The operation of this device will be explained in detail below.
While (X-C)8 counts 1, (Y-C)1
0 is configured to count 10. Therefore, in order to sample input data, the light emitting diodes emit light sequentially from the top left to the bottom, and when the light emitting diode at the bottom left emits light, the top light emitting diode in the second row from the left emits light, and so on. . Here, the light emission timing and light reception timing of each light emitting diode will be explained. Fig. 4 is a diagram showing the light emission timing of the light emitting diode and the waveform of each part. If the count period of (Y-C)10 is a in Fig. 4, then the time shown in Fig. 4b is required for input data sampling. (X-D) 9 and (Y-D) 11 are controlled so that they emit light. Note that the timings b and c with respect to a in FIG. 4 are generated by a timer function or the like included in a control section (not shown). c is a timing waveform that displays the recognition result at the first time; d, e;
is the output waveform of the light receiving circuit 12, f is the output waveform of the AD conversion circuit 17, and g is the counter (Y-C).
10 states, Y(n), Y(n+1) are
The count value at time n and n+1 is shown. Now, when the pen 13 is placed on the top surface of the interface surface 7, the pen 13 is
At the timing when the light emitting diode at the position where 3 is placed emits light, the light is reflected and received by the paired light receiving transistor. At this time, the light receiving circuit 12
The waveform shown in FIG. 4 d is outputted, and is further AD converted as shown in FIG. The level check circuit 18 recognizes that the pen 13 is on, and the count value Y(n) of the counter (Y-C) 10 at that time n is sampled by the sample circuit 14, and at the same time, the AD conversion data is sampled. A value Vm exceeding the reference value SL is set in the register 19-1.
Furthermore, at the next time point n+1, the reflected light reflected by the reflector of the pen 13 is also received by the light receiving transistor adjacent to the light receiving transistor at the position where the pen 13 is placed, and the output of the light receiving circuit 12 is The waveform shown in Figure 4 e is output, and AD converted as shown in Figure 4 f in the AD conversion circuit 17, and this value is
If Vn is larger than the reference value SL, it is assumed that the pen 13 is turned on and the simultaneous counter (Y-C)
10 count value Y(n+1) is sample circuit 1
At the same time, the AD conversion value Vn
is set in register 19-1, and the sampled Vm is simultaneously transferred to register 19-2. Here, the address of the ROM 20 is connected by the registers 19-1 and 19-2, so if the bits of the AD conversion circuit are 4 bits, the registers 19-1 and 19-2 each have a bit length of 4 bits. This is sufficient, and an 8-bit address for the ROM 20 will suffice. Furthermore ROM20
As shown in Table 1, the memory contents are AD conversion data Vm at the n time point and AD conversion data Vm at the n+1 time point with respect to the pitch between the light receiving transistors.
Value proportional to AD conversion data Vn
By storing Vn/Vm+Vn as a table, the pitch between the light-receiving transistors can be
It becomes possible to divide with a resolution proportional to the bit length of the registers 19-1 and 19-2.
As a result, the counter value Y(n) of the counter (Y-C) 10 sampled by the sample circuit 14
, the output value of the ROM20 is
Vn/Vm+Vn is added by an adder 21 and sequentially output to the recognition unit 4. The counter (X-C) 8 is also controlled in the same manner by changing the scan direction and counting (X-C) 8 30 times while counting (Y-C) 10 once. The switching is controlled by the X-Y switching signal 22. Therefore, when a character is written on the interface surface 7, the locus (pattern) of the character is sampled moment by moment in the sample circuit 14 and further stored in the ROM.
Since the values corrected by the adder 20 and the adder 21 are sent out, the position can be detected with sufficient accuracy even with a small number of sensors. Thereafter, the character type of the character is recognized by the recognition unit 4. Now, to explain a case where the interface surface 7, which is made up of 300 pairs of light emitting diodes and light receiving transistors, inputs and outputs two characters, for example, when inputting the characters "handwritten character recognition",
I have just finished inputting the character ``hand'' on the left half of the interface surface 7, and I am about to enter the character ``calligraphy'' on the right half of the interface surface 7, so I move the pen 13 to the right half of the interface surface 7. When placed in the area, the recognition unit 3 regards the input to the left half of the interface surface 7 as complete, recognizes the character "hand", and transmits the information to the font memory 15. The font memory 15 outputs a dot pattern corresponding to the character "hand",
A matching circuit 16 detects a match between the position of the dot pattern and the data of (X-C)8 and (Y-C)10.
If there is a match, the point corresponding to the display position of the dot pattern of the character "hand" is
When C)8 and (Y-C)10 indicate, (X-D)
9 and (Y-D) 11, the light emitting diode corresponding to the dot pattern position of the character "hand" is driven. In this way, a standardized pattern of the characters ``hand'' is displayed. In the same manner, by starting to write the character ``bun'' on the left side of the interface surface 7, a dot pattern corresponding to the character ``sho'' that has already been written is output on the right side of the interface surface 7. ,
Erase the dot pattern corresponding to the character "hand" on the left side of the interface surface 7 in the following steps.
It is used as an input section and an output section one after another. As explained above, in the embodiment, the interface surface 7 is connected to the pen 13 having a reflective mirror at the tip.
In addition to being used as an input tablet, it can also be used as a display unit for outputting recognition results. In addition, in terms of time, the light emission timing is divided into the time when it is used as an input part and the time when it is used for display, and by shortening the light emission time used as an input part and lengthening the light emission time used for display, it is possible to emit light at the time of input. Reduces flickering to the eyes of
Furthermore, the light emitted during display can be clearly confirmed with the eye due to an afterimage phenomenon. Conventionally, input and output were performed using separate devices, which resulted in poor operability and the ability to increase operating speed. The scribe has the advantage of being able to input data while confirming whether or not the data has been entered correctly, and as a result of improved operability, operation speed is also improved. Next, in FIG. 2, the interface surface 7 and its peripheral circuits (X-C) 8, (X-D) 9, (Y
-C) 10, (Y-D) 11, (Y-S) 12,
The AD conversion circuit 17, level check circuit 18, registers 19-1, 19-2, ROM 20, adder 21, matching circuit 16, etc. have been described as separate units because they are functionally different, but these are
It is easy to manufacture it as a single LSI, and when configured as a single LSI, the number of connection points is significantly reduced, making it inexpensive and compact. In the explanation of the above embodiment, when inputting ends on the left side, which constitutes a character frame for two characters, and inputting on the right side starts, the dot pattern of the recognition result of the character inputted on the left side is moved to the left side of the interface surface 7. display,
In the explanation, the dot pattern of the recognized character is displayed after inputting one character after another, but in addition to displaying the dot pattern of the recognized character using the font memory 15, the trajectory of the character or symbol being input is also displayed. It is also possible to display directly. By directly displaying the trajectory of the characters or symbols being input, the scribe can be aware of the form in which the characters or symbols he or she has input into the online handwritten character recognition device, so the recognition unit 3 can prevent mistakes. When the scribe's writing habits are recognized, the scribe's writing habits are clearly fed back to the scribe himself, which also has the effect of promoting the scribe's learning effect. Further, although the light emitting diode on the interface surface 7 in the above embodiment is shared with the light receiving transistor for input and display purposes in a time-sharing manner, it is of course possible to implement and use it as a separate device. Furthermore, in this case, by using an infrared light emitting diode for input and using an optical filter or the like that passes only the infrared region for the light receiving transistor, it is also possible to clearly distinguish it from the one for display. (Effects of the Invention) As described above, according to the present invention, since the output characters are displayed on the input tablet, the input speed is fast.
An online character recognition device that is accurate and has a high recognition rate is obtained.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional online handwritten character recognition device, Fig. 2 is a block diagram showing an embodiment of the present invention, Fig. 3 is a detailed view of the interface surface 7, and Fig. 4 is a diagram of a light emitting diode. FIG. 6 is a diagram showing light emission timing and waveforms of various parts after the light receiving transistor. 1...tablet, 2...pen, 3...recognition unit, 4...
Control unit, 5... Display unit, 6... Printing unit, 7... Interface surface, 8... X-ray selection counter, 9... X-ray decoder driver, 10... Y-ray selection counter, 11
...Y-line decoder driver, 12...Y-line light receiving circuit,
13... Pen having a reflective mirror at the tip, 14... Sample circuit, 15... Font memory, 16... Match circuit, 17... AD conversion circuit, 18... Level check circuit, 19-1, 19-2... Register, 20... Pitch Correction ROM, 21...Adder, 22...X, Y
switching signal.

Claims (1)

[Scope of Claims] 1. An online system comprising a flat interface surface into which the trajectory of a character pattern drawn by a pen is input, a recognition unit that recognizes the character pattern, and means for displaying the recognized pattern on the interface surface. In the character recognition device, the interface surface has an array of cells each consisting of a pair of light emitting diodes and a light receiving transistor arranged in a matrix, the pen is elongated and has a reflecting mirror at the tip, and the pen is elongated and has a reflecting mirror at the tip, and the pen is slender and has a reflecting mirror at the tip. Detection results are obtained by detecting the output of a counter and drive circuit that sequentially emit light within a first time period in each period, and a light receiving transistor for reflected light from the pen at a second time period that does not overlap with the first time period within the period. An online character recognition device comprising: a correction means for correcting and applying the corrected information to the recognition unit. 2. The correction means stores a table for interpolating the output of the light receiving transistor according to the cell pitch.
The online character recognition device according to claim 1, characterized in that it includes a ROM.