JP2977330B2 - 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 improving the efficiency 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.

[0003] When the movement of a pen along a single 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. 5, 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.

(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. 6, attention is paid to each end point of a predetermined number (four in this case) of vector data L1 to L4 among unprocessed vector data, and the 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.

[0012]

In the method (1) based on the bidirectional plot, 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 order in which the vector data is provided. For example, FIG.
In the case of drawing such data, the effect of the ordering is not so much obtained.

On the other hand, the above-mentioned method (2) based on nearest point selection
Can be expected to have a considerable effect on certain types of vector data groups. However, this method is basically a method of judging which vector data is to be selected and drawn next, based on a comparison of a plurality of vector data itself, and a sufficiently efficient drawing cannot be expected. .

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has as its object to provide a plotter control method and a plotter apparatus capable of performing efficient pen movement and contributing to shortening of drawing time. .

[0015]

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 optimal vector end point to be drawn and sequentially drawing vector data, at least two points from a processing start point for each end point of a predetermined number of undrawn vector data stored in the buffer means. A movement amount calculation step for calculating the total movement amount in the pen-up state required to draw the vector more than this, and a vector end point of the minimum movement amount based on the calculation result of the movement amount calculation step, An end point selecting step for selecting as a vector end point to be drawn, and a moving amount calculating step and an end point selecting step It is characterized by comprising the steps of repeating for each vector data rendering process.

A plotter device according to the present invention has a buffer means for storing drawing vector data based on sequentially given drawing data, and a processing starting point for each end point of a predetermined number of undrawn vector data stored in the buffer means. Moving amount calculating means for calculating the total moving amount in the pen-up state required to draw at least two vectors ahead of the vector, and a vector end point of the minimum moving amount based on the calculation result of the moving amount calculating means Endpoint selection means for selecting
It is characterized by comprising drawing control means for drawing successive vectors starting from the end point selected by the end point selecting means.

[0017]

According to the plotter control method and the plotter apparatus of the present invention, for each vector data processing, it is required to draw at least two or more vectors ahead of the processing start point for each end point of a predetermined number of undrawn vector data. The sum of the necessary movement amounts in the pen-up state is calculated, and the process of selecting the vector end point of the minimum movement amount as the vector end point to be drawn next based on the calculation result is repeated. In selecting the optimal vector end point to be drawn next based on the data and sequentially drawing the vector data, efficient pen movement can be performed and the drawing time can be shortened.

[0018]

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, a data group for each pen is used. And stored sequentially in the sort 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 start point are selected. Is transferred from the sort buffer 11 to the drawing control unit 13. The drawing control unit 13 operates the driving mechanism unit 14 according to the given data, and causes the pen to move and the pen to be moved up and down.

The sort processing unit 12 includes a movement amount calculation unit 15 for calculating a total movement amount in a pen-up state required to draw, for example, two vectors ahead of each end point of a 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).

In this embodiment, not only the current position, that is, the end point closest to the processing start point, but also a predetermined number of undrawn drawing vector data, one of line segments corresponding to each drawing vector data from the processing starting point. The sum of the distance to the end point of the line segment and the distance from the other end point of the line segment to one end point of the other vector data closest to the line segment, that is, the pen-up state required to draw the vector data two points ahead The total amount of movement is obtained, and the next endpoint corresponding to the shortest route and a line segment based on the drawing vector data are selected, and the next line segment is drawn with the selected endpoint as a starting point. . 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.

With reference to the flowchart shown in FIG. 2, the operation centering on the sort processing section 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, and in step S3 it is checked whether there is any data to be calculated in the sort buffer 11, and the sort buffer 11 should 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.
The vector end point selection and the total calculation of the pen-up movement amount in steps S4 and S5 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. When n = N is not satisfied, that is, n is less than N. At this time, n is incremented by 1 in step S7, and the process returns to step S3. If there is data to be calculated in the sorting buffer 11, the processing of steps S4 to S5 is repeated.
Similarly to the above, other vector endpoints are selected and the pen-up movement amount is calculated.

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 movement amount is selected in step S8, the process proceeds to step S9, and in step S9, it is determined whether there is one route with the minimum movement amount selected in step S8. . 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.

The processing of steps S2 to S7 is performed by the movement amount calculation unit 15 of the sort processing unit 12,
8 to S10 are performed by the endpoint selecting unit 16 of the sort processing unit 12.
Done in

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.

A specific example of the above processing will be described in more detail. As shown in FIG. 3, a case is considered in which the vector data corresponding to the line segments 1 to 5 is stored in the sorting buffer 11 in a state where the pen is at the current position, that is, the processing starting point 0.

In the conventional nearest point selection method as described with reference to FIG. 6, 0 to ba to cd to fe to
It is drawn along the route of gh to ji, and the total amount of pen-up movement is 10 + 60 + 10 + 10 + 10 =
100 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 distance to each end point and the line segment are determined. The sum of the pen-up travel distance and the distance from the other endpoint of the to the next closest other endpoint is calculated. Here, for convenience, instead of the oblique movement distance, the longer one of the vertical and horizontal movement distances is used, and the shorter one is ignored, and the calculation is performed.

(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) + (e-c) = 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 = 70mm

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 data other than the data shown in FIG. 3 does not exist in the sort buffer 11 for easy understanding.)

When this is repeated, 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 the pen-up movement amount is calculated, 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. 4, when line segment data is stored in the order from line segment 1 to line segment 20, the line segment candidates to be initially subjected to distance calculation in the movement amount calculation are line segments 1 to 20. The line segment candidates for the second distance calculation are 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
This is to prevent the end point of the line segment 20 from being selected because the distance to the 19 line segments of to 19 is long.

By doing so, it is possible to prevent a drop 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 increase drawing efficiency.

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 line segment candidates to be subjected to the distance calculation in the distance calculation include the candidates ahead in order,
As shown in FIG. 4, it is desirable that the k-th line segment candidate to be subjected to distance calculation is (19 + k) line segments up to the line segment (19 + k).

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 distance from the processing start point is "0" is found, the calculation of the moving amount is stopped, and a line segment starting from the end point is selected to be drawn next.

If it is found that the final distance of the movement amount calculation, for example, the second distance in the above-described embodiment is shorter than a predetermined distance, before the accurate calculation of the distance, the predetermined distance is set to two. The distance is regarded as the second distance, and no more accurate calculation of the second distance is performed. The predetermined distance is
Usually, it is set to about half of the acceleration / deceleration distance. In many cases,
The amount of the second distance calculation is quite large, and if it turns out that the distance is short enough, rather than calculating the distance exactly,
It is more efficient to terminate the calculation earlier than in view of the relationship between the amount of calculation and the actual travel time.

Further, the present invention is applicable not only to a so-called flat bed type plotter in which a pen moves in both directions of XY, but also to a so-called paper moving type plotter in which a pen moves in one direction of XY and the drawing paper moves in the other direction. Can also be applied.

[0047]

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, For each vector data process, calculate the total amount of movement in the pen-up state required to draw at least two or more vectors ahead of the processing start point for each end point of a predetermined number of undrawn vector data, A plotter control method and a plotter apparatus that enable efficient pen movement and shortening of drawing time by repeating a process of selecting a vector end point having the minimum movement amount as a vector end point to be drawn next based on the calculation result. Can be provided.

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

FIG. 4 is a schematic diagram for explaining a calculation range of vector data used in the plotter device of FIG. 1;

FIG. 5 is a schematic diagram of drawing line segments for explaining a control operation called bidirectional plot in a conventional plotter device.

FIG. 6 is a schematic diagram of a drawing line segment for explaining a control operation referred to as 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.

Claims (4)

(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. In the method of controlling a plotter for drawing vector data, a pen-up required for drawing at least two or more vectors ahead of the processing start point for each end point of a predetermined number of undrawn vector data stored in the buffer means. A moving amount calculating step of calculating the total moving amount in the state, an end point selecting step of selecting a vector end point of the minimum moving amount as a vector end point to be drawn next based on a calculation result of the moving amount calculating step; Repeating the moving amount calculating step and the end point selecting step for each vector data drawing process; A plotter control method comprising: 2. The method according to claim 1, wherein the step of selecting the end point includes the step of selecting the vector end point of the oldest vector data among a plurality of vector end points having the minimum movement amount based on the calculation result of the movement amount calculation step. The plotter control method according to claim 1, wherein: 3. A buffer means for storing drawing vector data based on successively applied drawing data, and at least two points ahead of a processing start point for each end point of a predetermined number of undrawn vector data stored in the buffer means. Moving amount calculating means for calculating the total moving amount in the pen-up state required to draw the vector, and end point selecting means for selecting the vector end point of the minimum moving amount based on the calculation result of the moving amount calculating means. And a drawing control means for drawing successive vectors starting from the end point selected by the end point selecting means. 4. When there are a plurality of vector endpoints having the minimum movement amount based on the calculation result of the movement amount calculation means, the end point selection means includes means for selecting the vector end point of the oldest vector data. Claim 3
A plotter device according to claim 1.