JPH0115089B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a handwritten figure transmission device that encodes and transmits sample point coordinates of a handwritten figure.

Conventionally, there has been a device of this type as shown in FIG. In the figure, 1 is an input section for handwritten figures such as doublets, 2 is a stroke detection section that detects strokes from changes in pen up and down signals among the signals obtained from this figure input section 1, and 3
4 is an encoding unit that adds identification codes indicating the beginning and end of each stroke based on the results of the stroke detection unit 2, and encodes the sample point coordinates of the handwritten figure; 4 is the detection result of the stroke detection unit 2; 5 is a decoding unit that decodes the received figure data; 6 is a figure that displays sample point coordinates of the handwritten figure decoded in the decoding unit 5; This is the display section.

The following operation will be explained. Among the signals related to the sample point coordinates of the handwritten figure input by the figure input unit 1, a change in the signal indicating the up and down of the pen is detected in the stroke detection unit 2,
A stroke is detected. Next, sample point coordinates are encoded on a stroke-by-stroke basis. As the encoding method, a differential PCM encoding method is used in which the starting point of the stroke is displayed in absolute coordinates, and points in the middle of the stroke are displayed in relative coordinates with respect to the immediately preceding sample point. Overall, as shown in FIG. 2, identification codes h and e indicating the beginning and end of the stroke s are added to each stroke. The communication control section 4 switches between transmission and reception on a stroke-by-stroke basis based on the results of the stroke detection section 2. Since this device alternately performs transmission and reception in half-duplex communication, it uses a reception switching method based on carrier detection.
That is, when no data is input from the graphic input section 1, it waits in reception mode, and when a carrier is detected, it demodulates the data. When data is input from the graphic input unit 1, if a carrier has not been sent from the other party, the carrier is sent, a communication link is established for switching between transmission and reception, and after the communication link is established, the data is The block is completed at each end of the stroke, transmission is stopped, and the mode is switched to reception mode. Here, as shown in Figure 2b, the transmission and
To switch reception, a time c is required for establishment of the communication link. The decoding unit 5 decodes the received data d to obtain sample point coordinates of the handwritten figure, and displays the sample point coordinates on the figure display unit 6. 7 is
It is a communication line.

Since the conventional handwritten figure transmission device is configured as described above, it is necessary to switch between transmission and reception for each stroke, which increases the proportion of time required to establish a communication link. The disadvantage was that the transmission efficiency deteriorated.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and it measures the time from the end of a stroke to the start of the next new stroke, and if the time interval is within a predetermined time, Handwritten figure transmission that can be efficiently transmitted by treating strokes as the same block, dividing the strokes into separate blocks when the time interval is longer than a predetermined time, and switching between transmission and reception in block units. The purpose is to provide equipment.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 3, 1 is a handwritten figure input section such as a tablet, 2 is a detection section that detects strokes from changes in pen up and down signals among the signals obtained from this figure input section 1, and 8 is the above-mentioned stroke. A stroke interval measurement section 9 measures the time from the end of a stroke to the start of the next new stroke based on the detection result of the detection section 2; and 9 indicates that the stroke time interval is less than a predetermined value based on the result of the stroke interval measurement section 8. In some cases, multiple strokes are treated as the same block and combined into one block, and if the time interval between strokes is greater than a predetermined value, the strokes are divided into separate blocks and code is applied to each block. 4 is a communication control unit that switches transmission/reception for each block; 7 is a communication line;
5 is a decoding section that decodes data received through the communication line 7; 6 is a figure display section that displays sample point coordinates of the handwritten figure obtained in the decoding section 5;

Next, the operation will be explained.

Among the signals inputted from the graphic input section 1, the continuity of strokes is detected in the stroke detection section 2 from changes in signals related to the up and down movement of the pen. The stroke interval measuring section 8 measures the time from the end of a stroke to the beginning of the next stroke. If the time interval between strokes measured by the stroke interval measuring section 8 is within a predetermined time interval, the block encoding section 9
These strokes are regarded as the same block and encoded. The communication control unit 4 transmits and transmits each block based on the output of the block encoder 9.
Switch reception.

In FIG. 4, a shows a pen stroke generation state inputted from the graphic input section 1. In FIG. The time interval t ₁ between the stroke s1 and the stroke s2 is measured in the stroke interval measuring section 8,
Since it is smaller than the predetermined time T, the stroke s1
and stroke s2 are considered to be the same block. Similarly, since the interval t ₂ between stroke s2 and stroke s3 is also smaller than T, they are considered to be the same block. Since the interval _t3 between stroke s3 and stroke s4 is greater than the predetermined time T, they are treated as different blocks. Therefore, stroke s1 to stroke s
The three strokes of 3 are encoded as one block b. Then, as shown in FIG. 4b, for each block b, the time c required to establish a communication link for switching between transmission and reception, and identification codes h and e indicating the start and end of the block are added. Furthermore, d
1, d2, and d3 are data in which strokes s1, s2, and s3 are encoded.

On the other hand, the signal sent through the communication line 7 is received through the communication control section 4, and is received by the decoding section 5.
The sample point coordinates are determined and displayed on the graphic display section 6.

As described above, according to the present invention, the time interval is measured for each stroke, and if the stroke interval is within a predetermined time, those strokes are considered to be the same block, and if the stroke interval exceeds the predetermined time, they are Since the blocks are divided into separate blocks and each block is encoded and switched between transmission and reception, the proportion of time required for switching is smaller than when switching between transmission and reception on a stroke-by-stroke basis. This has the effect of enabling efficient communication.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing a conventional handwritten figure transmission device, FIG. 2 is an explanatory diagram of encoding in the conventional handwritten figure transmission device, and FIG. 3 is a configuration diagram showing a handwritten figure transmission device according to an embodiment of the present invention. 4 are explanatory diagrams of block encoding by the apparatus of FIG. 3. DESCRIPTION OF SYMBOLS 1... Graphic input section (tablet), 2... Stroke detection section, 4... Communication control section, 5... Decoding section, 6... Graphic display section, 8... Stroke interval measuring section, 9... Block Encoding part. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1 In a handwritten figure transmission device that encodes and transmits the sample point coordinates of a handwritten figure input from a tablet, there is a stroke detection unit that detects strokes based on changes in signals indicating up and down of the pen, and a time interval between strokes. a stroke interval measurement unit that determines whether or not the stroke interval is within a predetermined time interval; and a stroke interval measuring unit that determines whether the stroke interval is within a predetermined time interval; A block encoding unit divides the strokes into separate blocks and adds and encodes commands to indicate the start and end of each block, a communication control unit switches transmission and reception for each block, and a communication control unit processes the received data. A handwritten figure transmission device comprising: a decoding section that performs decoding; and a figure display section that displays sample point coordinates of the handwritten figure obtained in the decoding section.