JPH0277825A - Hand-written character input display device - Google Patents

Abstract

PURPOSE:To display a character with a curve close to a hand-written character by representing input coordinates as a vector and comparing the vector with its last vector, and performing fine processing between the two coordinate points according to the comparison result. CONSTITUTION:Coordinate data is inputted from an XY coordinate input device 1 to an input controller 2 and a vector discriminating device 5 converts the coordinate variation into vector variation. The curve part is sampled finely and new coordinate points a' - h' are set among coordinate points (a) - (i) to display the part finely. Here, the directional angle of the vector is calculated from the inputted coordinate values. Then a straight line is drawn roughly corresponding to a part where variation in the direction of the vector is small and finely corresponding to a part where the variation is large to display a character close to a hand-written character on a CRT display device 4 and a decrease in processing speed can be suppressed small.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a handwritten character input/display device that allows handwritten characters to be input and displayed during video conferences, video calls, and the like.

[Conventional technology]

Fig. 5 is a block connection diagram showing a conventional handwritten character input/display device. An input control device 3 that calculates the amount of change is a CR that displays an image (character) that approximates the handwritten character on the CRT display 4 according to the calculation result.
This is a T display processing device. Next, the operation will be explained. First, handwritten characters are input to the XY coordinate input device 1 using a light ben or the like, and the handwritten characters are input to the input control device 2 as XY coordinate value data. Here, the coordinate value data is
As shown in Fig. 6, samples are taken every certain period of time TI''Tq, and the coordinate values and the amount of change in these values are calculated.Here, for example, the input state when the hiragana ``tsu'' is input manually is shown in Figure 6. According to this, if the starting point is a (X, Y) and the coordinate point after a certain time is b (ΔxI+Δy+), ΔxI+Δy
I is the amount of change from the previously sampled coordinate point a. These coordinate points are then transferred to the CRT display processing device 3.
By inputting , and drawing a straight line between the coordinate points, it is possible to approximately represent the handwritten characters as described above. Here, FIG. 7 shows the input coordinate points a''-i connected by straight lines.

[Problem to be solved by the invention]

Since the conventional handwritten character input/display device is configured as described above, as shown in FIG. There were problems in that each straight line did not form a smooth circular arc, resulting in characters that were far different from handwritten characters. This invention was made in order to solve the above-mentioned problems, and it is a handwritten character display device that can approximate the curved parts of characters with straight lines and display arcs as smoothly as possible as a whole. The purpose is to obtain.

[Means to solve the problem]

The handwritten character input/display device according to the present invention samples j+ handwritten data based on the handwritten characters input to the XY coordinate input device at regular intervals using the input control device, and calculates the XY coordinate value and the amount of change thereof. Based on these, the handwritten characters are approximately displayed on the CRT display. In particular, based on the coordinate values obtained from the input control device, the vector discriminator calculates the vector of the straight line connecting each coordinate point. If the magnitude and direction angle are determined, and the direction angle exceeds the set value, set at least one pre-calculated coordinate point between the two coordinate points that make up the vector, and draw a straight line on the CRT display. The configuration is such that an approximate display is performed.

[For use]

The vector discriminator in this invention vectorizes the input coordinates, compares the direction angle of the vector with, for example, the direction angle of the previous vector, and as a result of this comparison, detects a change of more than a certain value between these two vectors. When there is a problem, by processing the coordinates between two coordinate points in detail and connecting the newly processed coordinate point to the above two coordinate points to make a straight line approximation,
To enable the display of characters with curves similar to handwritten characters.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 5 is a vector discriminator, which calculates the magnitude and direction of the vector of a straight line connecting the angular coordinate points based on the coordinate values obtained from the input control device 2, and if the direction angle exceeds the set value , at least one coordinate point on a pre-calculated circular arc is found between the two coordinate points forming the vector, and is displayed as a straight line approximation on the CRT display. Note that other blocks that are the same as those shown in FIG. 5 are designated by the same reference numerals, and redundant explanation thereof will be omitted. Next, the operation will be explained. First, the XY coordinate input device 1
The input of coordinate data to the input control device 2 is the same as in the conventional system, but in the present invention, the number of coordinates input in a certain period of time is twice that of the conventional system, as shown in FIG. However, if all of these coordinates are displayed, it takes time to process the coordinates and display them, making it impossible to display handwritten characters. Therefore, the vector discriminator 5 converts the coordinate change into a vector change, samples the curved part more finely, and converts the new coordinate points a° to h° into the previous coordinate points a w
i, and display only that part in detail. Therefore, first, the direction angle θ of the vector is calculated from the input coordinate values (using equation 11.) Now, as shown in Figures 2 and 3, the vector 1θ1
When θt1≦θ7, coordinate point b′ is ignored and a straight line is drawn between coordinates t and c. Here, 07 is a reference value (tolerable change value of vector vector) for determining the size of the curve. On the other hand, in the part B where the curve shown in Fig. 2 is drawn, the direction is θ.
4, then 1θ3-θ41≦θゎ, so
Lines de, ee' passing through the newly set coordinate point e',
e' f is subtracted. This situation is shown in Figure 4. In this way, by roughly drawing straight lines for parts where the vector direction changes little, and by drawing finer straight lines for parts where there is a lot of change, characters that are closer to handwritten characters can be displayed on the CR7 display 4. Decrease in processing speed can also be kept small. In addition, in the above embodiment, by increasing the number of input coordinate points,
The case where the curve of a character is displayed smoothly is explained, but by setting the vector discriminator 5 shown in FIG. Without increasing the number of coordinate points, smooth characters similar to those obtained by increasing the number of coordinate points can be displayed on the CR7 display 4 by a certain interpolation calculation. That is, according to this, in the vector discriminator 5, when the change in the vector direction of the straight line connecting the input coordinate points is large, the interpolation function is activated and the calculation shown below is performed. For example, by Hek, the direction of the interpolation vector θ
A is calculated using equation (2). Here, the magnitude of the interpolation vector is half of ef, the direction θi of the interpolation vector is determined from this formula, and since its magnitude is half of ef, the coordinate point e° is calculated,
decide. In this way, even if the number of input coordinate points is small, smooth characters can be displayed on the CR7 display 4, and the same effect as in the above embodiment can be obtained.

【Effect of the invention】

As described above, according to the present invention, a vector discriminator is provided to determine the magnitude and direction angle of the vector of a straight line connecting each coordinate point from the coordinate values obtained from the input control device, and set the direction angle. If the value exceeds, create a vector 2
At least one pre-calculated coordinate point between the two coordinate points is calculated and displayed as a linear approximation on the CRT display, so the number of coordinate point input data can be
This has the effect of allowing curved portions of handwritten characters to be displayed smoothly on a CRT display.

[Brief explanation of the drawing]

FIG. 1 is a block connection diagram showing a handwritten character input/display device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a basic handwritten character input method according to this explanation, and FIG. 3 is a diagram showing the distance between each coordinate point. A vector diagram showing the direction angle of a straight line vector connecting , Figure 4 is a display of handwritten characters when the input method shown in Figure 2 is applied to a part of handwritten characters, and Figure 5 is a conventional handwritten character input display FIG. 6 is an explanatory diagram showing a conventional handwritten character input method, and FIG. 7 is a conventional handwritten character display diagram. ■ is an XY coordinate input device, 2 is an input control device, 3 is a CRT
A display processing device, 4 a CRT display, and 5 a vector discriminator. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Patent applicant Mitsubishi Electric Corporation Figure 2 Figure 4 T273 ” T5 Ice Obe T6 f・B h9'T''' T8

Claims (1)

[Claims] an XY coordinate input device for inputting handwritten characters in XY coordinates; an input control device for sampling the input handwritten data at regular intervals to obtain XY coordinate values and changes therein; In a handwritten character input display device comprising a CRT display processing device that linearly approximates and displays the handwritten character on a CRT display based on the amount, a straight line connecting each coordinate point is provided based on the coordinate values obtained from the input control device. The magnitude of the vector and its directional angle are determined, and if the directional angle exceeds a set value, at least one pre-calculated coordinate point is determined between the two coordinate points that make up the vector, and the above CRT display is displayed. 1. A handwritten character input/display device characterized by being provided with a vector discriminator that displays a linear approximation of a handwritten character.