JP3007443B2 - Plotter control method and plotter device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plotter such as a pen plotter, and more particularly to a plotter control method and a plotter apparatus capable of reducing the amount of calculation in control processing of pen operation.

[0002]

2. Description of the Related Art Generally, in a pen plotter, drawing data sent from a host computer is, for example, a high-order C.
The image data is analyzed by a drawing data analysis unit configured by a PU (Central Processing Unit), converted into drawing vector data corresponding to the movement of the pen, and provided to a drawing control unit configured by, for example, a lower CPU. In this drawing control unit, the actual pen XY movement processing and pen up / down processing are performed based on the vector data.

When the movement of a pen along one straight line is considered, the processing time of the drawing data analysis unit is almost constant at, for example, several milliseconds regardless of the length of the line segment. Is the time until the movement of the pen is actually completed, and varies for example by several milliseconds depending on the contents of the drawing data.
A time from c to 1 sec is required. Therefore, except in the special case where many extremely short line segments continue,
The data processing time of the drawing data analysis unit is sufficiently shorter than the pen movement processing time of the drawing control unit.

For this reason, the drawing vector data converted by the drawing data analysis unit fills the buffer of the drawing control unit,
When the drawing control unit stops making a data request to the drawing data analysis unit, the drawing data analysis unit stops the data analysis and waits for a free space in the buffer of the drawing control unit. That is, the data analysis processing speed of the drawing data analysis unit is limited by the actual pen movement speed, which is substantially associated with the operation of the drawing control unit.

On the other hand, the restriction imposed by the actual pen moving speed is relaxed, the analyzed data is stored in a buffer provided in the drawing data analysis unit, and the analysis is performed in accordance with the data request timing from the drawing control unit. It has been considered that optimal data of the already processed data is sent to the drawing control unit.

Here, if the ordering for obtaining the optimum data among the data analyzed by the drawing data analysis unit is performed through all the drawing data, the most efficient drawing should be performed. To do this, it is necessary to analyze all drawing data. In this case, not only does the plotter stop during the processing (for example, for several seconds to several minutes), but also the amount of analyzed data becomes enormous, and a remarkably large capacity memory is required. Not a target.

[0007] Therefore, as a method conventionally performed or considered, there are a method based on bidirectional plotting and a method based on nearest point selection. These methods will now be described.

(1) Bidirectional plot When processing vector data indicating a drawing line segment obtained by analyzing given drawing data according to a given order, the end point of the next line segment vector data is processed. Then, an end point close to the current position (a reference position serving as a starting point of processing) is selected, and drawing is performed from the end point.

For example, as shown in FIG. 7, if vector data L1 to L5 of a line segment are sequentially given, the vector data L1 to L5 are sequentially drawn in the given order. At this time, the current position CP at the time when the vector data L1 is drawn from the end point L1a to the end point L1b is the end point L1b. When drawing the next vector data L2, the current position CP of the end points L2a and L2b (that is, L1b Is selected, and the vector data L2 is drawn starting from the end point L2b. For the next vector data L3, the end point L3a closer to the end point L2a of the vector data L2
3b is drawn. Similarly, the nearest end point of the line segment indicated by the next vector data is sequentially selected, and the vector data L4 and L5 are drawn in the given order.

In the above-described method based on bidirectional plotting,
Since the drawing is performed in accordance with the order of the given vector data and only the selection of the end point of each line segment is controlled, the calculation for the control is relatively simple, but the drawing time, the drawing efficiency, and the like depend on the order in which the vector data is provided. It depends greatly.

(2) Nearest point selection The end point closest to the current position is sequentially selected from both end points of a predetermined number of unprocessed vector data. That is,
In addition to the vector data of one line segment, the end point closest to the current position among the two end points of the vector data of a predetermined number of line segments is used as a starting point, and the vector data including the end point is preferentially drawn.

For example, as shown in FIG. 8, attention is paid to both end points of a predetermined number (in this case, four) of vector data L1 to L4 among unprocessed vector data, and an end point L4a closest to the current position is set as a starting point. , The vector data L4 including the end point L4a is preferentially drawn. When selecting data to be drawn next to the vector data L4, new vector data is added to the remaining vector data L1 to L3, and the current position at that time, that is, the vector data L4 is selected from both end points of the vector data. End point L4
Select the endpoint closest to b.

The above-described method based on nearest point selection is basically a method of judging which vector data is to be selected and drawn next by comparing a plurality of vector data itself. A considerable effect can be expected for the group.

[0014]

In any of the above-described methods, the pen movement amount between the current position, that is, the processing start position and the end point of each vector data, or between the end points of each vector data is obtained. The closest endpoint is selected. In the movement amount calculation in this case, the movement amount in the X direction and the movement amount in the Y direction between these two points are obtained based on the coordinate information of the two points for which the movement amount is to be obtained, and the movement in the X direction is obtained. The amount of movement between the two points is calculated by taking the square root of the sum of squares of the two from the amount and the amount of movement in the Y direction.

For this reason, the calculation of the movement amount in selecting the closest end point requires a large amount of calculation and time, and the load on the control CPU is large. This means
The more serious the number of vector data for which the movement amount is to be calculated, the more serious the problem becomes.

The present invention has been made in view of such circumstances, and reduces the amount of calculation and the calculation time for determining the drawing order, enables efficient drawing control, and reduces the drawing time. It is an object of the present invention to provide a plotter control method and a plotter device that can contribute.

[0017]

According to a plotter control method of the present invention, drawing vector data based on sequentially provided drawing data is temporarily stored in a buffer means, and a next step is performed based on the vector data stored in the buffer means. In a plotter control method for selecting an optimum vector end point to be drawn and sequentially drawing vector data, a maximum movement in a plurality of drive axis directions for each end point of undrawn vector data stored in the buffer means. A movement amount calculation step for calculating the movement amount in the pen-up state from the processing start point by using the amount instead of the actual movement amount, and a vector end point of the minimum movement amount based on the calculation result of the movement amount calculation step Is selected as a vector endpoint to be drawn next .

The plotter device according to the present invention comprises a buffer means for storing drawing vector data based on sequentially provided drawing data, and a plurality of driving axis directions for each end point of undrawn vector data stored in the buffer means. the maximum movement amount using, instead of the actual moving amount, the process starting point
Moving amount calculating means for calculating a moving amount in a pen-up state from the camera, and a minimum moving amount based on a calculation result of the moving amount calculating means.
The vector end point of the momentum is the vector end point to be drawn next.
It is characterized with end point selection means for selecting, in that it comprises a drawing control means for sequentially drawing the next vector selection by end point in this end point selection means as a starting point Te.

[0019]

According to the plotter control method and the plotter apparatus of the present invention, the maximum movement amounts in the directions of a plurality of drive axes are used instead of the actual movement amounts in the movement amount calculation for selecting the vector end point to be drawn next. Based on the vector data stored in the buffer means, the most suitable vector endpoint to be drawn next is selected, and when performing sequential vector data drawing, the calculation amount of calculation for selecting the next vector endpoint to be drawn And the calculation time can be reduced, and efficient drawing control can be performed.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a main part of a plotter device according to an embodiment of the present invention. The drawing data supplied from the host computer is analyzed and converted into drawing vector data by, for example, a drawing data analysis unit (not shown). When a plurality of pens are used, the drawing data is collected into a data group for each pen. Then, the data is sequentially stored in the sorting buffer 11 for each pen. The drawing vector data stored for each pen in the sorting buffer 11 is processed for each pen as described below.

The drawing vector data stored in the sorting buffer 11 is sequentially processed by the sorting unit 12 by a predetermined number, and vector data to be drawn next and an end point serving as a drawing starting point are selected. The vector data starting from the selected end point is stored in the sorting buffer 1.
1 to the drawing control unit 13. The drawing control unit 13 operates the driving mechanism unit 14 according to the given data,
Pen movement and pen up / down are performed.

The sort processing unit 12 includes a movement amount calculation unit 15 for calculating the total movement amount in the pen-up state required to draw, for example, two vectors ahead of each end point of the predetermined number of vector data, This movement amount calculation unit 15
And an end point selection unit 16 for selecting the end point and the vector data that minimize the total amount of movement in the pen-up state among the end points calculated in (1).

The moving amount calculating section 15 calculates the moving amounts in the X and Y directions corresponding to the moving amount in the pen-up state to be obtained, that is, the X moving amount and the Y moving amount respectively.
A Y-movement calculating unit 17, a maximum value extracting unit 18 for extracting a larger moving amount of the X-moving amount and the Y-moving amount,
And a total for calculating the total amount of movement in the pen-up state required to draw, for example, two vector data points ahead for each end point of the predetermined number of vector data using each movement amount extracted by the maximum value extraction unit. It has a movement amount calculation unit 19.

In this embodiment, instead of simply finding the current position, ie, the end point closest to the processing start point, for a predetermined number of undrawn drawing vector data, one of the line segments corresponding to each drawing vector data from the processing start point The sum of the movement amount to the end point of the line and the movement amount from the other end point of the line segment to one end point of the other vector data closest to the end point, that is, the pen-up state required to draw the vector data two points ahead The total amount of movement in the is determined, the next endpoint corresponding to the route with the shortest route and a line segment based on the drawing vector data are selected, and the next line segment is accordingly selected from the selected endpoint as a starting point. Draw. From the end point of the line segment to be drawn at this time, the same processing as described above is repeated for a predetermined number of undrawn drawing vector data. By doing so, it is possible to effectively reduce unnecessary pen-up movement that occurs because there is no other line segment to be drawn near the end point of the end point of the line segment starting from the closest end point. In this case, as each of the above-mentioned movement amounts, only the larger one of the X movement amount and the Y movement amount corresponding to the X component and the Y component of the movement amount is used for each movement amount. By using the individually selected X movement amount or Y movement amount instead of the actual movement amount for the total movement amount and end point selection processing, the calculation processing of the movement amount is greatly simplified.

With reference to the flowchart shown in FIG. 2, the operation centering on the sort processing unit 12 of the apparatus shown in FIG. 1 will be specifically described. The drawing vector data obtained based on the drawing data supplied from the host computer is sequentially stored in the sorting buffer 11 in step S1. This operation is performed as needed until there is no image data.

In step S2, the vector data counter (variable) n is set to 1. In step S3, it is confirmed whether or not there is data to be calculated in the sort buffer 11, and the sort buffer 11 is to calculate. If there is data, the process proceeds to step S4. In step S4, the line segment end point, that is, the vector end point of the drawing vector data is selected in accordance with the data order in the sort buffer 11, and in step S5, the pen-up movement amount calculation from the processing start point (current position) is performed.

In the pen-up movement amount calculation in step S5, as described above, the pen movement amount (pen-up movement amount) from the current position to the selected vector end point and another vector closest to the other end point of the vector. The sum with the pen movement amount to the end point (pen-up movement amount) is calculated.
However, in this case, the pen movement amount is, for each pen movement, an X movement amount in the X direction and a Y movement amount in the Y direction.
The larger movement amount of the movement amount is extracted and used as the movement amount in the pen movement.

The details of the calculation of the movement amount in step S5 will be described with reference to FIG. An X movement amount and a Y movement amount between the processing start point and the vector end point selected in step S4 of FIG. 2 are obtained (step S51). The X movement amount and the Y movement amount obtained in step S51 are compared (step S51).
52), if (X movement amount) ≧ (Y movement amount), select the X movement amount as the first movement amount with respect to the selected vector end point; if (X movement amount) <(Y movement amount), Y The moving amount is selected as the first moving amount for the selected vector end point (step S53).

Next, the X movement amount between the other end point of the vector, that is, the vector end point and the other vector end point, and Y
The movement amount is obtained (step S54). Step S54
(Step S55). If (X movement amount) ≧ (Y movement amount), the X movement amount is set as a candidate for the second movement amount with respect to the selected vector end point. If (X movement amount) <(Y movement amount), Y
The moving amount is selected as a second moving amount candidate for the selected vector endpoint (step S56). Step S5
The processing of 4 to S56 is performed for all other vector endpoints (step S57). The smallest value among the second movement amount candidates obtained in this way is selected as the second movement amount (step S58). The first movement amount selected in step S58 and the second movement amount selected in step S58 are summed (step S59).

The vector end point selection and the sum calculation of the pen-up movement amount in steps S4 and S5 in FIG. 2 are performed for both end points of the selected vector data.
After the total calculation of the pen-up movement amount in step S5, it is determined in step S6 whether or not the data counter n is a predetermined number N of drawing vector data.
That is, when n is less than N, n is set to 1 in step S7.
Increment and return to step S3. If there is data to be calculated in sort buffer 11, steps S4 to S4 are executed.
The processing of S5 is repeated, and another vector endpoint is selected and the pen-up movement amount is calculated in the same manner as described above.

If it is determined in step S6 that n = N, that is, if n has reached N, the flow advances to step S8 to calculate the minimum movement from the pen-up movement amount for each vector endpoint calculated so far. A quantity route is selected. In addition,
If it is determined in step S3 that there is no data to be calculated in the sort buffer 11, that is, if there is no more data to be calculated in the sort buffer 11 in a state where n does not reach N, step S8 immediately follows from step S3. , And the path with the minimum movement amount is selected from the pen-up movement amount for each vector endpoint calculated so far.

After the route with the minimum moving amount is selected in step S8, the process proceeds to step S9, and in step S9, it is determined whether or not the single route with the minimum moving amount selected in step S8 is one. . If it is determined in step S9 that there are a plurality of routes with the minimum movement amount, step S10
Selects the path including the oldest vector data from the plurality of paths, and proceeds to step S11. If it is determined in step S9 that there is only one route with the minimum movement amount, the process also proceeds to step S11.

Steps S2 to S7 in FIG.
Is performed by the movement amount calculation unit 15 of the sort processing unit 12, and the processing of steps S8 to S10 is performed by the end point selection unit 16 of the sort processing unit 12. Further, the processing of steps S51 and S54 in FIG. 3 is performed by the XY movement amount calculating unit 17, and the processing of steps S52, S53, S55 and S56.
Is performed by the maximum value extracting unit 18, and the processing in steps S57 to S57 is performed.
The process of S59 is performed by the total movement amount calculation unit 19.

In step S11, according to the route selected in step S8 or S10, the sort buffer 1
1 to the drawing control unit 13. The drawing control unit 13 performs a line segment drawing process starting from the selected vector end point. After the processing in step S11, the vector data that has been subjected to the drawing processing is deleted from the sorting buffer 11 in step S12, and it is determined in step S13 whether there is no vector data in the sorting buffer 11.

In step S13, the sort buffer 11
Is determined to have vector data, the process returns to step S2, and the same processing as described above is repeated until there is no more vector data in the sorting buffer 11. Step S
If it is determined in step 13 that there is no vector data in the sort buffer 11, the processing is terminated, and the processing shifts to the next processing, for example, processing of other pen data.

The above processing will be described in more detail with reference to a specific example. As shown in FIG. 4, a case is considered in which the vector data corresponding to the line segments 1 to 5 is stored in the sort buffer 11 in a state where the pen is at the current position, that is, the processing starting point 0.

In the method based on nearest point selection as described with reference to FIG. 8, 0 to ba to cd to fe to gh
Are drawn along the path of ｊ to ji, and the total movement amount of the pen-up is 10 + 60 + 10 + 10 + 10 = 100 in the case shown.
mm.

On the other hand, in the method of the present embodiment, in order to obtain the first point, the end points of the line segments 1 to 5 are selected in order of the end points a to j from the vector data, and the movement amount to each end point and the line The sum of the pen-up movement with the movement from the other endpoint of the minute to the next closest other endpoint is calculated.

When calculating the movement amount, for example, a line segment 2
Considering the case (1), as shown in FIG. 5, the movement amount of O to c is Oc, its X direction component is Oc _x , and its Y direction component is Oc.
c _Y , the movement amount of d to f is df, and its X-direction component is d
Supposing f _x and its Y-direction component to be df _Y , strictly speaking, the movement amount RDc with respect to the end point c of the line segment 2 is expressed by Equation 1.

[0040]

[Number 1] RDc = Oc + df = (Oc X 2 + Oc Y 2) 1/2 + (df X 2 + df Y 2) 1/2 = (10 2 +20 2) 1/2 + (0 + 10 2) 1/2 = 32.36

However, the calculation of equation (1) is very complicated, and requires a large amount of calculation and time. Therefore, in the present embodiment, the calculated movement amount SDc is obtained according to Equation 2, and this is used for the calculation instead of the above-described movement amount RDc.

[0042]

## EQU2 ## SDc = MAX (Oc _X , Oc _Y ) + MAX (df _X , df _Y ) = Oc _X + df _Y = 20 + 10 = 30

That is, instead of the movement amount Oc, MAX (O
c _X, with Oc _Y), instead of the moving amount df MAX (d
f _X, using df _Y). As described above, the maximum value of the moving amount in the X direction component and the Y direction component, that is, MAX (X
(Movement amount, Y movement amount) is used instead of the actual movement amount. In an actual plotter device, in many cases, the maximum movement speed in the X direction and the maximum movement speed in the Y direction in pen operation are usually substantially equal, and if they are equal, the time required for pen movement is the X movement amount and the Y movement amount. Depends on the larger amount of movement. Therefore, as described above, MAX (X movement amount, Y
(Movement amount) can be used in place of the actual movement amount.

The movement amount calculated as described above is as follows. (0-a) + (bc) = 40 + 20 = 60 mm (0-b) + (ac) = 10 + 60 = 70 mm (0-c) + (df) = 20 + 10 = 30 mm (0-d) + (Ce) = 60 + 10 = 70 mm (0-e) + (f-d) = 20 + 10 = 30 mm (0-f) + (ec) = 60 + 10 = 70 mm (0-g) + (h-f) ) = 20 + 10 = 30 mm (0-h) + (g-e) = 60 + 10 = 70 mm (0-i) + (j-h) = 20 + 10 = 30 mm (0-j) + (i-g) = 60 + 10 = 70 mm

Of these, the path having the end points c, e, g, and i as the first points is the shortest path of 30 mm, and the first, that is, the oldest end point c is the first point.

Next, the same calculation is performed for the line segments 1, 3 to 5 with the other end point d of the line segment 2 having the end point c as one end, and the end point f is selected. (In this case, it is assumed that there is no data other than the data shown in FIG. 4 in the sort buffer 11 for easy understanding.)

By repeating this, 0 to cd to fe to
The routes gh to ji to ba are selected, and the total pen-up movement amount in this case is 20 + 10 + 10 + 10 + 3.
0 = 80 mm, which indicates that the method is improved over the method based on the nearest point selection.

In the above description, when calculating the pen-up movement amount, as shown in FIG.
Assuming that the number of vector data as a candidate for the second line is 20, the number of vector data as a second candidate is increased by one to 21. That is, in FIG. 6, when the line segment data is stored in the order from line segment 1 to line segment 20, the first line segment candidates to be subjected to the first movement amount calculation in the movement amount calculation are line segments 1 to 20. In addition, the line segment candidates to be subjected to the second movement amount calculation are the line segments 1 to 21.

This is because the twentieth line segment 20 is closest to the current position (processing start point), and the next line segment 21 is also close to the line segment 20. 1
Since the movement amount to 19 line segments of ~ 19 is long, the line segment 20
This is to prevent the end point from being no longer selected.

By doing so, it is possible to prevent a decrease in drawing efficiency due to useless pen-up movement due to no line segment near the other end point of the closest end point, and to increase the drawing efficiency with a simple calculation. be able to.

Note that in order to obtain a more optimal route, 3
What is necessary is just to calculate the pen-up movement amount up to the vector data beyond this one. In this case, the candidates for the line segments to be calculated for the movement amount are sequentially included in the candidates, and as shown in FIG. 6, the candidates for the k-th line segment to be calculated for the movement amount are line segments ( It is desirable to have (19 + k) line segments up to 19 + k).

Further, if the following processing is added to the sort processing including the movement amount calculation and the end point selection, the amount of calculation related to the sort processing can be reduced. When a line segment having an end point whose movement amount from the processing start point is “0” is found,
The movement amount calculation is stopped, and a line segment starting from the end point is selected to be drawn next.

If it is found before the accurate calculation of the movement amount that the final movement amount of the movement amount calculation, for example, the second movement amount in the above-described embodiment is shorter than the predetermined movement amount, the predetermined movement amount is calculated. The movement amount is regarded as the second movement amount,
No more accurate calculation of the second movement amount is performed. The predetermined movement amount is usually set to about half of the movement amount corresponding to the acceleration / deceleration distance. In many cases, the amount of the second movement amount calculation is quite large, and if it is known that the movement amount is sufficiently short, it is better to terminate the calculation earlier than to calculate the movement amount exactly. Efficiency is high in view of the relationship with the actual travel time.

In addition to the so-called flat-bed type plotter in which the pen moves in both XY directions, the so-called paper moving type plotter in which the pen moves in one of the XY directions and the drawing paper moves in the other direction. It can be implemented in a similar manner.

In the above-described embodiment, when the optimal vector end point to be drawn next is selected based on the vector data stored in the buffer means and the vector data is sequentially drawn, each vector data processing must be performed. For each end point of a predetermined number of undrawn vector data, the total amount of movement in the pen-up state required to draw at least two vectors ahead of the processing start point is calculated, and based on the calculation result, In the case of performing efficient drawing control by repeating the process of selecting the vector end point of the minimum movement amount as the vector end point to be drawn next, the maximum movement amount in the direction of a plurality of drive axes (coordinate axes of the drive system) is determined. Although the case where the calculation for obtaining the optimum route is performed using the moving amount instead of the moving amount has been described, the method based on the bidirectional plot described with reference to FIG. A movement-distance calculation in the process according to the closest point selected as described with communication, may be used in place of the plurality of drive shaft maximum movement amount (the coordinate drive system) direction of the actual movement amount.

[0056]

As described above, according to the present invention, when the next optimal vector end point to be drawn is selected based on the vector data stored in the buffer means, and the vector data is drawn sequentially, The maximum amount of movement in a plurality of drive axes is used in place of the actual amount of movement in the calculation of the amount of movement for selecting the vector endpoint to be drawn next, thereby reducing the amount of calculation and the time required for efficient drawing. It is possible to provide a plotter control method and a plotter device that enable control and contribute to shortening of a drawing time.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a main part of a plotter device according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a control operation of the plotter device of FIG. 1;

FIG. 3 is a flowchart for explaining a movement amount calculation operation in control of the plotter device of FIG. 1;

FIG. 4 is a schematic diagram of drawing line segments for explaining a specific operation of the plotter device of FIG. 1;

FIG. 5 is a schematic diagram for explaining arithmetic processing in the plotter device of FIG. 1;

FIG. 6 is a schematic diagram for explaining a calculation range of vector data used in the plotter device of FIG. 1;

FIG. 7 is a schematic diagram of a drawing line segment for explaining a control operation called a bidirectional plot in a conventional plotter device.

FIG. 8 is a schematic diagram of a drawing line segment for explaining a control operation called nearest point selection in a conventional plotter device.

[Explanation of symbols]

1-5 line segment, 11 sort buffer, 12 sort processing unit, 13 drawing control unit, 14 drive mechanism unit, 15
Movement amount calculation unit, 16: end point selection unit, 17: XY movement amount calculation unit, 18: maximum value extraction unit, 19: total movement amount calculation unit.

Claims (2)

(57) [Claims] 1. An image processing apparatus according to claim 1, wherein the drawing vector data based on the sequentially provided drawing data is temporarily stored in a buffer means, and an optimum vector end point to be drawn next is selected based on the vector data stored in the buffer means. a method of controlling a plotter for drawing vector data, the respective end points of the vector data that has not been drawn stored in the buffer means, using instead of the maximum amount of movement of the plurality of drive axis actual moving amount, processing A movement amount calculation step for calculating a movement amount in a pen-up state from the starting point, and a minimum movement amount based on a calculation result of the movement amount calculation step
An end point selecting step of selecting the vector end point as a vector end point to be drawn next . 2. A buffer means for storing drawing vector data based on sequentially given drawing data; and a maximum moving amount in a plurality of drive axis directions for each end point of undrawn vector data stored in the buffer means. A moving amount calculating means for calculating a moving amount in a pen-up state from the processing start point by using the moving amount instead of the moving amount; and a vector of a minimum moving amount based on a calculation result of the moving amount calculating means. A plotter apparatus comprising: an end point selecting means for selecting an end point as a vector end point to be drawn next; and a drawing control means for drawing successive vectors starting from the end point selected by the end point selecting means. .