JPH04184521A - Coordinate detecting system - Google Patents

Abstract

PURPOSE:To accurately input the coordinates of an indicated position even when the indicated position moves by dividing a coordinate detecting surface into plural areas and measuring the coordinates of the indicated position by areas. CONSTITUTION:On a coordinate detecting surface 10, a large number of scanning lines composed of, for example, electrodes are arranged in both X- and Y-axis directions in the form of a matrix. The surface 10 is equally divided into plural blocks (12-1)-(12-n) in parallel with the Y-axis direction and the scanning lines arranged in parallel with the Y-axis direction are respectively connected to their corresponding shift registers (14-1)-(14-n) at every block. Then, after detecting the Y-coordinate by scanning surface 10 in the Y-axis direction from a starting point B-k in the block 12-k, the X-coordinate is detected by scanning the surface 10 in the X-axis direction from the starting point B-k. Therefore, since the coordinate measurement is performed by areas, the time interval for the coordinate measurement can be reduced and accurate coordinate values can be inputted against an indicated position even when the position indicated with a stylus pen 22 moves at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a coordinate detection method in a coordinate input device.

(Prior Art) Generally, in a coordinate input device, coordinate data indicating a position arbitrarily specified using a stylus pen or the like on a tablet surface is input. By using this coordinate input device, patterns such as characters and figures can be input by hand. Patterns such as characters and figures are expressed as a series of coordinate data input at certain times.

For example, in a coordinate input device using an electric field coupling method, a large number of electrodes are arranged in a matrix in the X-axis direction and Y-axis direction on the tablet, and by sequentially applying a predetermined voltage to each electrode, the tablet surface is The entire (coordinate detection surface) is scanned. In other words, to detect the coordinates specified by the stylus pen on the tablet surface, one point on the corner of the coordinate detection surface is used as the origin, scanning in the X-axis direction is performed from the origin, and then scanning in the Y-axis direction is similarly performed from the origin. It scans (may be in the Y-axis direction and then the X-axis direction) and determines one point on the coordinate detection surface from the detected coordinate values of the X-axis and Y-axis.

(Problem to be Solved by the Invention) As described above, in the conventional coordinate input device, the X
After scanning in the axial direction, scanning in the Y-axis direction is performed. Therefore, the position indicated by the stylus pen is
When moving quickly when drawing characters, etc., the time interval between detecting coordinates in the X-axis direction and Y-axis coordinates is long, so In some cases, the coordinate values determined by scanning in the Y-axis direction did not match the position originally indicated by the stylus pen.

The present invention has been made in view of the above points, and an object of the present invention is to provide a coordinate detection method that allows input of coordinates that accurately indicate a designated position on a coordinate detection surface.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a coordinate input device for inputting coordinates of an arbitrarily designated position on a coordinate detection surface, which divides the coordinate detection surface into a plurality of regions. The coordinates are measured in area units.

In addition, adjacent regions partially overlap.

Also, coordinates are measured only within the area near the input coordinates.

Further, only when coordinates are detected by determining coordinates Jl in one direction within the area, coordinate measurement in the other direction is performed.

(Function) According to such a method, the coordinate II determination is not repeatedly performed on the entire coordinate detection surface, but is performed on a region-by-area basis, so the time interval between coordinate measurements becomes narrower, and the designated position moves quickly. The exact coordinates corresponding to the indicated position will be input even if the specified position is correct.

Further, by partially overlapping adjacent regions, accurate coordinate input becomes possible even if a region near the boundary is specified.

In addition, when the position is indicated to the coordinate detection plane continuously, it can be predicted that the subsequent coordinates will be input in the vicinity of the previously input coordinates, so only within the area near the input coordinates. By performing coordinate measurements on
The time interval for coordinate measurements can be shortened.

Further, only when coordinates are detected by coordinate measurement in one direction within the region, coordinate measurement in the other direction is performed, so that the time interval between coordinate measurements can be shortened.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a diagram relating to a first embodiment. In FIG. 1, reference numeral 10 denotes a coordinate detection surface (tablet surface), on which a large number of scanning lines 24 (described later) made of, for example, electrodes are arranged in a matrix in the X-axis direction and the Y-axis direction. The coordinate detection plane IO is equally divided into a plurality of blocks 12-1 to 12-n in parallel to the Y-axis direction, as shown by broken lines in the figure.

On this coordinate detection plane 10, point A is taken as the origin that is the reference for coordinates.

Further, point B (B-2 to B-n) is set as the starting point for starting scanning in each block. (Point A and point B-1 are the same point)
The scanning lines 24 arranged parallel to the Y-axis direction correspond to shift registers 14-1 to 14- for each block.
n is connected. Shift registers 14-1 to 14-
n is for sequentially applying a constant voltage to the scanning lines 24 by inputting a clock signal. Each shift register 14-
1 to 14-n are connected to the decoder 16. The decoder 16 enables a control signal according to block selection data input from the controller 18, and controls the shift registers 14-1-14-n. The controller 18 is in charge of controlling the entire coordinate input device, and supplies block selection data, clock signals, etc. to the decoder 1B, and also inputs the coordinate value determination signal from the converter 20. A stylus pen 22 is connected to the converter 20. The converter 20 inputs the detection signal detected by the stylus pen 22 on the coordinate detection surface, converts this signal into a coordinate value determination signal, and outputs the signal to the controller 18. Note that the detection signal detected by the stylus pen 22 is induced between the tip of the stylus pen 22 and the scanning line to which voltage is applied.

FIG. 2 is an enlarged view of the connecting portion between the shift register 14 and the scanning line 24. It is shown that a plurality of scanning lines 24 arranged in the corresponding block 12 are connected to the shift register 14.

Note that scanning lines are also arranged parallel to the X-axis direction.

However, in the first embodiment, it is not divided into a plurality of blocks in the Y-axis direction.

FIG. 3 is a diagram relating to the second embodiment. In the second embodiment, blocks 12-1=12-n of the coordinate detection surface 10 are partially overlapped. In other words, the ends of adjacent blocks are overlapped, and the overlapping regions 26-1 to 2B-(n
-1) is provided. The configuration of other parts is the same as that of the first embodiment, so a description thereof will be omitted.

Next, the operations of the first embodiment and the second embodiment will be explained.

In the coordinate input enabled state, the controller 18 performs scanning in the X-axis direction and Y-axis direction for each block.

For example, as shown in FIG. 4, a case will be described in which a line C is drawn by the stylus pen 22. Conventionally, since the time interval between scanning in the Y-axis direction and the X-axis direction is long, after the Y-coordinate CIY is detected, the X-coordinate C2X is detected by scanning in the X-axis direction. Therefore, the required coordinates are C2 (C2X, CIY), which is significantly different from the originally specified position. On the other hand, in the present invention, first, in block 12-k (K is arbitrary), the Y-axis direction is scanned from the starting point B-k to detect the Y coordinate CIY, and then the X-axis direction is scanned from the starting point B-k. X coordinate C
Detect IX. As a result, the required coordinates are C1(
CIX, CIY), and the error from the original indicated position can be extremely reduced. In addition, the coordinate f of the real cavity
rX (position on the coordinate detection plane 10) is obtained by converting a coordinate value based on the starting point to a value based on the origin.

By scanning in this manner, even if the position indicated by the stylus pen 22 moves quickly, the accurate coordinates of the indicated position can be detected.

The second embodiment is different from blocks I2-1 to I2-1 in the first embodiment by providing an area that overlaps with adjacent blocks.
This is to improve the difficulty in detecting the coordinates on the boundary line of 12-n. As a result, blocks 12-1 to 12-n
It is also possible to accurately detect coordinates near the boundary line.

FIG. 5 is a diagram relating to the third embodiment. In the third embodiment, in the same way as in the X-axis direction shown in the first and second embodiments,
It is equally divided into a plurality of blocks 28-1 to 281 in the axial direction as well. The scanning lines arranged parallel to the X axis in each block 28-1 to 281 are connected to corresponding shift registers 30-1 to 30-m for each block. The shift registers 30-1 to 301 sequentially apply a constant voltage to the scanning lines in response to input of a clock signal from the controller 18. Each shift register 30-1 to 30-1 is connected to a decoder 32. The decoder 32 enables a control signal according to the Y-axis block selection data input from the controller I8, and controls the shift registers 30-1 to 301. Note that from the controller 18 to the decoder 16
, X-axis block selection data is output.

Next, the operation of the third embodiment will be explained.

In the third embodiment, when coordinates are input, the subsequent coordinate detection is performed for blocks (target blocks) in the vicinity of the detected coordinates, thereby reducing the time required for scanning in the X-axis direction and scanning in the Y-axis direction. The aim is to shorten the time interval. For example, as shown in Figure 6, if a dot on the coordinate detection plane IO is detected on the 18th day, the point expected to be detected by the next coordinate measurement will be determined according to the drawing speed. The maximum travel distance is expected to be within a circle with radius R. Therefore, instead of measuring the coordinates from the origin, it is only necessary to scan the target block within the circle (indicated by the broken line in the figure), reducing the time interval from detecting the X coordinate to detecting the Y coordinate. can do.

In the state shown in FIG. 6, scanning of the X and Y coordinates starts from the starting point E of the target block and is performed only within the target block. This operation will be explained with reference to the flowchart shown in FIG.

First, based on the initial drawing speed V,
The maximum movement distance radius R from the previously detected coordinate position to the next coordinate expected to be detected is calculated. According to this radius R, a target block to be scanned during the coordinate 17 determination process is set.

Here, in order to simplify the explanation, in the X-axis direction and the Y-axis direction, as shown in FIG.
It is assumed that blocks 1-Y6 are set.

First, in the case of the first coordinate measurement, the coordinates of the X1 block in the Y-axis direction are measured (steps 81 to S3).

In this scan, the Y coordinate of each Xn block is measured. If no coordinates are detected, repeat the measurement (
Step S4). If coordinates are detected in step S4, the detected Y coordinate value is stored in a register within the controller 18, for example (step S5). Then, the coordinates of the X1 block in the X-axis direction are measured (step S6). Here, if the coordinates are not detected (step S7), the block to be measured is changed and the process moves to step S3, where the Y-axis coordinate of the X2 block is measured. In this way, by sequentially scanning the X-axis coordinate and the Y-axis coordinate block by block from the direction of the origin, the time interval from detecting the Y-axis coordinate to detecting the X-axis coordinate is shortened.

In this way, when the X-axis coordinate is detected in step S6, the X-axis coordinate measured in block units is converted into the coordinate measured from the origin (step S9). That is,
Since the X-axis coordinate value detected by scanning in the X-axis direction is a value determined by scanning from the starting point of each block, this value is converted into a coordinate value with the origin as a reference. The conversion method is that for blocks with the same coordinate width, the X-axis coordinate value detected in the n-th block is the X-axis coordinate width of one block.If the desired coordinate value from the origin is N, then N - (n −1) X L + K −(1)
becomes.

In this way, the spot detected by the first measurement is determined from the X-axis coordinate and the Y-coordinate (step S10). The X-axis and Y-axis coordinate values of the detected point A are stored in a register (steps S11 and S12).

The measurement at the second point tJ is performed on the target block with point A as a reference. First, a target block located within a maximum movement distance radius R based on a preset drawing speed (2) centered on point A (coordinates saved in step S12) is calculated (step S13). As shown in FIG. 6, when point A is detected within block (X5.Y4), the target block is (X4~
X6. Y3 to Y5). Then, the Y-axis coordinate is measured from the starting point of the target block (middle point E in FIG. 6) (step S14). As a result, when coordinates are detected, the detected Y-axis coordinates are saved in the register (
Step S15.51B). Next, the X-axis coordinate is measured from the starting point of the target block (step S17). As a result, if coordinates are detected (step 5ll
i) Convert the X-axis coordinates and Y-axis coordinates to coordinates from the origin. Step 5L9): X-axis.

Save the Y-axis coordinates in the register (step S20゜5)
12). Subsequent points are detected by scanning the target block based on the coordinates saved in step S12 in the same manner as described above. Note that step 515,
In Sll+, if the coordinates are not detected,
The process moves to step S2.

In this way, by dividing the coordinate detection plane IO into a plurality of blocks and performing coordinate measurement for each block,
Since the time interval between coordinate detection in the axial direction and the Y-axis direction is shortened, the error between the original position indicated by the stylus pen 22 and the detected coordinates can be made extremely small. In particular, by providing an area that overlaps with adjacent blocks, coordinates near the boundary line can also be accurately detected. Furthermore, by scanning only blocks within a predetermined range from the detected coordinates, the scanning time in the X-axis and Y-axis directions can be shortened, and the Y-axis coordinate can be detected after the X-axis coordinate is detected. The time interval until the coordinates are detected is shortened, and accurate coordinate detection can be performed.

In addition, in the third embodiment, the size of the target block is
Although the setting is based on the preset maximum moving distance radius R, the drawing speed V may be measured during the processing process and the setting may be made according to this drawing speed V. Also,
In the third embodiment, an overlapping area is not provided in adjacent blocks, but a configuration in which an overlapping area is provided as in the second example can also be adopted.

[Effects of the Invention] As described above, according to the present invention, the coordinate detection plane is divided into a plurality of regions and the coordinates of the designated position are measured in units of regions, thereby narrowing the time interval of coordinate measurements. Therefore, accurate coordinates can be input even if the indicated position is moving.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a coordinate detection plane according to the first embodiment of the present invention, FIG. 2 is an enlarged view of the connecting portion between the shift register and the scanning line shown in FIG. 1, and FIG. FIG. 4 is a diagram for explaining the operation of coordinate detection; FIG. 5 is a diagram showing a coordinate detection surface according to the third embodiment of the present invention; FIG. 7 is a diagram for explaining the operation of the third embodiment, and FIG. 7 is a flowchart showing the operation procedure of coordinate detection. 10... Coordinate detection plane, 12.28... Block (area), 14, 30... Shift register, 16.32.
...Decoder, 1g...Controller, 20...Converter, 22...Stylus pen, 24...Scanning line,
2B...IYI multi-domain. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 7 Prisoner (Part 1) Figure 7 (Part 2)

Claims (4)

[Claims] (1) A coordinate input device for inputting the coordinates of an arbitrarily designated position on a coordinate detection plane, characterized in that the coordinate detection plane is divided into a plurality of regions and the coordinates are measured in units of regions. method. (2) The coordinate detection method according to claim 1, characterized in that adjacent regions partially overlap. (3) The coordinate detection method according to claim 1 or 2, characterized in that the coordinates are measured only in a region near the input coordinates. (4) Coordinates according to claim 1, 2, or 3, characterized in that only when coordinates are detected by coordinate measurement in one direction within a region, coordinate measurement in the other direction is performed. Detection method.