JPH0390397A - Writing brush driving control method of writing brush plotter - Google Patents

Abstract

PURPOSE:To suppress the fluctuation of writing pressure and to perform good printing by a method wherein the correction based on the distance detection data with the surface of printing paper of control data for controlling the driving of a writing brush in a Z-direction by a non-contact distance detection means is performed in a stroke unit and the distance detection data is detected at the time of the printing of the previous stroke. CONSTITUTION:Distance detection data is sent to a distance detection data memory means and also sent to an initial stroke correction quantity determining means 18. The correction quantity determined by the initial stroke correction quantity determining means 8 is sent to a correction driving control means 12 to correct the control data in a Z-direction in the control data of the first stroke from a control data memory means 14 and a drive apparatus 1 is driven on the basis of this corrected control data to perform the printing of the first stroke. At the time of the printing of the first stroke, the distance with the surface of printing paper is detected by a non-contact type distance detection means 6 and distance detection data for determining the correction quantity of the second stroke being the next stroke is sent to the distance detection data memory means 7.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a plotter, and particularly to a plotter that uses a writing brush as a writing instrument and continuously drives the writing brush in three directions of X, Y, and Z with respect to printing paper. The present invention relates to a method for controlling the drive of a writing brush in a writing brush plotter, which continuously changes writing pressure to draw writing characters.

(Prior art) In conventional plotters, the drive control of the writing instrument was performed continuously in the horizontal front, back, left and right directions with respect to the printing paper, that is, in the X and Y directions, but in the vertical direction, that is, in the Z direction.
The direction of the writing instrument was controlled in two positions, either by bringing the tip of the writing instrument into contact with the surface of the printing paper or by pulling it away.

As mentioned above, when the control in the Z direction is two-position control, even if a brush is used as a writing instrument, the pressure of the pen against the printing paper surface is constant, so only characters of a constant thickness can be drawn, and it is difficult to draw brush letters. was difficult.

On the other hand, if the brush is continuously driven and controlled in the Z direction in the same way as in the A brush plotter with such a configuration has recently been developed because it allows drawing.

As mentioned above, with a brush plotter, the thickness of the characters is determined by the pressure of the brush against the printing paper, so in order to draw the desired characters with uniform quality, it is necessary to draw the characters in the X and Y directions, but especially in the Z direction. , it is necessary to have a configuration that allows accurate drive control.

For this reason, we have improved the dimensional accuracy of the mechanism in the Z direction and the flatness of the base, and also installed the printing paper by vacuum suction to the base surface to prevent the printing paper from floating. Measures are being taken to eliminate the contributing factors.

(Problem to be Solved by the Invention) However, no matter how many measures are taken to remove the factors that change the pen pressure in the Z direction as described above, it is impossible to completely eliminate this. This results in an increase in the cost of the device.

The present invention was devised in view of the above-mentioned circumstances, with the purpose of providing a drive control method in the Z direction that can suppress fluctuations in pen pressure and perform good printing without making the device particularly high precision. It is what was done.

(Means for Solving the Problems) That is, the present invention provides a method for detecting the surface of a printing paper detected by a non-contact distance detection means attached to an X-Y drive device which is a horizontal drive means of a brush holding means for holding a brush. Based on the distance detection data, which is the distance between The correction is performed based on the correction amount determined by the initial stroke correction amount detection means from the distance detection data detected, and from the second stroke onward, the next stroke correction amount determination means is performed based on the distance detection data detected during printing of the previous stroke. The re-stroke printing is performed based on the correction amount determined by the re-stroke printing when the re-stroke printing determination means determines that re-printing is necessary by comparing the distance detection data for the printing stroke and the distance detection data for the next stroke. This is a brush drive control method for a brush plotter, characterized in that the method is performed based on a correction amount determined by a restroke printing correction amount determining means from distance detection data for a print stroke and the next stroke.

(Function) The present invention is configured as described above, and its function is such that the correction based on the distance detection data of the control data for controlling the drive of the brush in the Z direction to the printing paper surface by the non-contact distance detection means is Since it is performed in units of units, and the distance detection data was detected during printing of the previous stroke, the correction is extremely accurate, and if it is determined that the correction is insufficient, an appropriate correction amount can be applied. Since re-printing is performed, it is possible to easily print with good quality.

(Example) A block diagram showing the basic configuration of the present invention is shown in FIG.

The drive device 1 includes a Z drive device 3 that drives the brush holding means 4 that holds the brush 5 in the Z direction perpendicular to the printing paper.
It is configured to be attached to an X-Y drive device 2, which is a driving means for driving the left and right and front and rear X-Y directions parallel to the printing paper.

The X-Y drive device 2 includes a non-contact distance detection means 6 such as an optical type for detecting the distance from the print paper surface during printing and correcting the height of the brush 5 based on this distance detection data. is installed.

12 is a correction drive control means for driving and controlling the drive device 1 while correcting the height of the writing brush 5; 13 is a character arrangement that determines the printing position on the printing paper, the number of characters to be printed, the size of the characters to be printed, etc. The determining means 14 is a control data storage means for storing control data for each printed character.

7 is a distance detection data storage means for storing the distance detection data detected by the non-contact distance detection means 6, and 8 is an initial stage for determining the stroke correction amount based on the distance detection data of the printing point before starting printing. The stroke correction amount determination means 9 includes distance detection data that is used to determine the correction amount when printing a stroke, and distance detection data that is detected during stroke printing and that determines the correction amount for printing the next stroke. This is a restroke printing determination means that compares the two data and determines whether or not reprinting is to be performed based on the magnitude of the difference between both data.

Reference numeral 10 denotes a next stroke correction amount that determines the correction amount for printing the next stroke based on the distance detection data during stroke printing when the restroke printing determining means 9 determines that there is no need for reprinting. is a means of decision,
Reference numeral 11 also includes the distance detection data used as a basis for determining the correction amount of stroke printing and the distance detection data detected during stroke printing when it is determined that reprinting is necessary by the restroke printing determination means. This is a re-stroke printing correction amount determining means for determining the correction amount for re-stroke printing.

The printing operation of the brush plotter configured as described above while performing height correction will be described next.

First, to start printing, the X-Y drive device 2 is driven under the control of the correction drive control means 12 based on the determination by the character arrangement determination means 13, and the non-contact distance detection means 6 detects the character frame range of a predetermined printing position. The distance to the printing paper surface is detected at the distance detection point inside.

The distance detection data described above is stored in the distance detection data storage means 7.
It is also sent to the initial stroke correction amount determining means 8.

The correction amount determined by the initial stroke correction amount determining means 8 is sent to the correction drive control means 12, and the Z-direction control data of the first stroke control data from the control data storage means 14 is corrected. Based on this corrected control data, the drive device is driven to perform printing of the first stroke.

When printing this first stroke, the non-contact distance detection means 6 detects the distance to the printing paper surface, and the distance detection data for determining the correction amount for the next stroke, the second stroke, is stored. It is sent to means 7.

The distance detection data for the first stroke and the distance till detection data for the second stroke stored in the distance detection data storage means 7 are sent to the restroke printing determination means 9, which compares both data and determines whether the difference is small. , when it is determined that printing of the first stroke was performed with an appropriate correction amount, the distance detection data for the second stroke is sent to the next stroke correction amount determining means 10.

The second stroke determined by the next stroke correction amount determining means 10
The stroke correction amount is sent to the correction drive control means 12,
Printing of the second stroke is performed.

When it is determined by the previous re-stroke printing determination means 9 that the difference between the distance detection data for the first stroke and the second stroke is large and the first stroke printing was not performed with an appropriate correction amount. In this case, the distance detection data for the first stroke and the second stroke are sent to the restroke printing correction amount determining means.

The correction amount for restroke printing determined based on the distance detection data sent by the restroke correction amount determining means 11 is sent to the correction drive control means 12, and reprinting of the first stroke is performed. .

The above-described printing operation is sequentially performed for printing after the third stroke, and the printing of the - character is completed.

FIG. 2 is a diagram showing a specific configuration of an embodiment of the present invention,
Reference numeral 15 denotes a control device that performs various controls on the drive device 1 as shown in FIG.

To explain the configuration of the control device 15, the program ROM 2
A program for controlling the CPtJlB is written in the CPtJlB, and the CPU 18 takes in the key input signal 16 from the input boat 17 and the distance detection data signal from the length measuring device 6, and stores the storage means data RO in accordance with this program.
Read the control data of M14 or use RA again.
It performs arithmetic processing while exchanging data with M21, and outputs the processed data to the output boat 19 as necessary.

The drive device l has a portion that is moved in the left-right direction by an X-pulse motor drive circuit 22, an X-pulse motor 23, and an X-drive mechanism 24, and a portion that is moved in the left-right direction by an It consists of an X-Y drive device 2 consisting of a part that moves in the height direction, and a Z drive device 3 that includes a Z pulse motor drive circuit 28, an X pulse motor 29, and an X drive mechanism 30 and moves in the height direction, The brush 5 held by the brush holding means 4 is moved to X and Y.

Drive in 3 directions of Z.

The sensor holding means 31 of the non-contact distance detection means 6 is attached to the X-Y drive device 2, and the sensor holding means 31 of the non-contact distance detection means 6 is attached to the X-Y drive device 2.
That is, it moves in the X-Y direction.A sensor 32 is attached to this sensor holding means 31, and the height to the surface of the printing paper 34 is measured by length measurement @33.

The operation of the brush plotter configured as described above will be explained.

In this embodiment, the characters to be printed are determined manually by the key 16. The CPU 18 reads the signal from the key input 16 via the input board 17 and determines the corresponding character from this signal.

Also, the signal to end character input is manually input from the key. In this way, the character string input using the keys is printed.

The character size and printing position of each character are also determined by the key input 16.

Next, details of the printing process will be explained according to the flowchart shown in FIG.

Thereafter, steps 5TEP1 to 5TEP17 are repeated for all characters printed.

In 5TEPI, the distance between the centers of the character frames of printed characters is measured in order to calculate the initial stroke correction amount.

Let this distance be La.

In 5TEP2, the reference distance Lo is subtracted from the distance La measured in 5TEP1 to obtain the correction amount dL.

The reference distance Lo is a distance such that when the brush is moved to the height position O, the tip of the brush comes to the paper surface, assuming that the height to the printing paper surface is this reference distance Lo. In other words, the reference distance Lo is a distance that does not require correction.

Thereafter, steps 5TEP3 to 5TEP17 are repeated until all strokes have been printed and one character has been printed.

5TEP3 reads out the control data of the stroke to be printed, that is, the coordinate point sequence Pi, P2, . . . Pk.

Let the number of data points be k.

The control data read here consists of a coordinate string of X, Y, and Z moving position points as shown in FIG.

X, Y are coordinate systems with the origin (0,0) at the bottom left, and Z
is expressed with the paper surface as O and the upward direction as positive.

The data X and Y in FIG. 4 are illustrated in FIG.

This data shows the print data of "mountain", the first stroke is Pi-P7, and the second stroke is P8-P14.
, the third stroke is P15 to P19, and the fourth stroke is P21 to P26.

For the read data, k-1 times, 5TEP4~5T
Repeat EP5.

5TEP6 determines whether this is finished.

i at 5TEP4;! Movement amount dX i, dY i, dZ
i is determined from the difference in position coordinates Pi+1-Pi.

5TEP5 is the step pulse output interval Txi required to move the calculated distance by a line segment at the speed ■.

Tyi and Tzi are calculated using the following equations.

Txi= S/l dX L Tyi= S/l dY L Tzi=S/1dZi S=5qr((dX i)' + (dY i)"
+ (dZ i)')/V where 1 l is the absolute value and sqr is the square root.

In 5TEP6, it is determined whether the data for l strokes is finished, and if it is not finished, the process returns to 5TEP4.

If the data is finished, it is assumed that the data pre-processing stage is finished, and the actual printing and driving are then performed.

In 5TEP7, the brush is moved to the stroke printing start position.

Here, the brush is still raised.

Correction is performed by moving in the height direction by the correction amount dL at this position.

In 5TEP8, the output time interval T calculated in 5TEP5
xi, T yi, T zi and dX i, dY i
, dZ i-step pulse motor is driven.

In 5TEP9, the distance at each data position is measured and this measured value is set as Li.

At 5TEP 10, it is determined whether the data is finished, that is, the printing of one stroke is finished, and if the data is not finished, the process returns to 5TEP8.

In 5TEPII, the arithmetic mean of the height data Li at each data position measured while performing stroke printing is calculated and set as the height Ls during stroke printing.

5TEP 12 compares the corrected height La of the printed stroke, that is, the predicted height La, with the height Ls measured during actual printing. The difference between La and Ls is thought to be due to a change in the paper surface due to the lowering of the tip.

If this paper surface variation exceeds a certain value E, it is assumed that the stroke was not written correctly, and printing is performed again.

The value of this constant value E is determined based on the allowable range of variations in print thickness.

If reprinting is to be performed, the process branches to 5TEP13, and if reprinting is not to be performed, the process branches to 5TEP15.

5TEP13 is the La update process when reprinting,
The original L is calculated by multiplying the paper surface fluctuation amount (Ls-La) by a constant.
Add to s.

Here, K is a constant with a value of about 1.0-1.5, and when it is set as LO, La=Ls, and the value of the variation is updated with the same value.

FIG. 7 shows the state of this update.

In this figure, the updated new La is shown as La'.

5TEP14 subtracts the reference height LO from the updated La to calculate a new correction amount dL.

After this, in order to reprint with this new correction amount, 5TEP7
Return to

On the other hand, if you do not perform stroke reprinting, 5TEP
In step 15, La is updated by setting La=Ls.

When printing the next stroke, correction is performed based on the height of the paper surface during printing of the previous stroke.

In 5TEP 1 B, a new correction amount dL is calculated by subtracting the reference height Lo from the updated La.

At 5TEP17, it is determined whether or not all strokes have been printed, that is, one character has been printed.If not, the process returns to 5TEP3 to print the next stroke.

In 5TEP1B, it is determined whether printing of all characters has been completed, and if not, the process returns to the first 5TEPI.

If the processing has been completed, the character printing processing is ended.

While making corrections for each stroke in this way, the X pulse motor drive circuit 22 and the Y pulse motor are driven in accordance with the positions in the longitudinal and lateral directions via the output boat 19 in FIG. 2 according to the read control data. Give instructions to the circuit 25 and to the X pulse motor drive circuit 28 corresponding to the position in the height direction, and drive the X pulse motor 23, Y pulse motor 26, and Z pulse motor 29 according to the instructions,
By moving the brush 5 held in the brush holding means 4 by the X drive mechanism 24, Y drive mechanism 27, and Z drive mechanism 30, high quality printing can be achieved even when the height of the printing paper surface changes due to lowering of the brush. Can draw calligraphy characters.

In this example, the amount of correction for the initial stroke of a character is calculated from the height measurement value at one point at the center of the character frame. It is also possible to calculate the correction amount by taking more than three measurement points and setting the printing surface as a polyhedral surface or a curved surface.

In this embodiment, height measurement during stroke printing is performed at each line segment break, but it is also possible to perform this measurement at regular time intervals.

Further, in this embodiment, the arithmetic mean of the measured values for each line segment is used as the representative value during stroke printing, but the maximum variation point (minimum value), median value, etc. can also be used as the representative value.

In this embodiment, when updating the height La after correction when reprinting the stroke, a factor of 2 is added to the constant of the amount of variation (Ls-La), but this can be updated using an appropriate function relationship. You can also do things.

At this time, it is also possible to change the update amount depending on the size of the character, the amount of movement of the stroke print in the height direction, etc.

In addition, when measuring strokes, the measurement must be made at a position slightly away from the tip of the brush, so if the printing paper surface is tilted and the measurement cannot be made correctly, it is necessary to measure the position slightly away from the brush tip. The height of the area to be measured is measured before printing, and from this height data and the data of the height measurement of the printing area before printing, such as correction for each character,
It is also possible to correct the height measurement value during stroke printing due to the deviation of the measurement position, and to determine whether to reprint the stroke or update La based on this value.

In this example, the distance measured by the length measuring device is directly Z.
Although we have explained this as a linear value with the unit of movement distance of 1 step of It can be used by converting it into a

(Effects) With conventional line segment unit correction control, it is not possible to move smoothly, and with character unit correction based on measured values before printing, if the brush lowers the paper surface, the correction cannot be performed. It doesn't work well and that part becomes thin.

There is no problem with the character-by-character correction method if the paper surface fluctuation caused by this brush can be eliminated by using a presser foot, but if you try to write addresses on envelopes without a presser foot, the line thickness may vary depending on the location due to the paper surface fluctuation caused by this brush. will change.

FIG. 7 shows an example of printing an address on an envelope using character-by-character correction.

This was printed without using a presser foot at all, just by placing it on the paper.

In the case of this note envelope, the upper left and lower right sides are raised, and when you lower your brush to write on these areas, the surface of the paper goes down. For example, the first ``mountain'' or the last The word "sama" in "Sama" becomes thinner, and the bottom part of the address and company name column becomes thinner.

FIG. 8 shows an example of printing after performing height correction for each stroke.

Similar to the example in FIG. 7, printing was performed without a presser foot.

If there was a paper surface variation of about 0.2111v* or more, the stroke was reprinted, and in this case, 1.4 times the variation amount was taken as the correction amount.

FIG. 9 shows how the paper surface changes at this time.

In FIG. 9, the height of the paper surface for each stroke of each character is connected to form a graph.

If you reprint the stroke here, mark it as a white circle
The horizontal bar "OJ" indicates the height after correction when reprinting.
−” indicates.

Looking at Figure 8, in Figure 7 the letters have become thinner due to changes in the paper surface due to brush strokes, but the thickness has been maintained even for the lower part of the name "F", "Mr.", address, and company name. There is.

If you look at Figure 9, you can see that the ``mountain'' part of the name goes down by nearly two degrees when the brush is lowered.

In this case, redrawing is performed twice.

In addition, in the part of the company name "...Technical Research Institute Co., Ltd.", the height of the paper surface after the brush is lowered is almost constant, and printing is performed at this height by reprinting the initial stroke, and the characters are printed at this height. The thickness is kept constant.

As shown above in the printing example, high-quality calligraphy characters can be printed even when the height of the paper changes due to stroke-by-stroke height correction and reprinting when the brush is lowered.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic configuration of the present invention, FIG. 2 is a block diagram showing the specific configuration, FIG. 3 is a flowchart showing the control method, FIG. 4 is a diagram showing print data, Figure 5 shows an example of printing using this print data.
The figure is a diagram explaining a method of correcting print data, Figure 7 is a diagram showing a print sample in the conventional example, Figure 8 is a diagram showing a print sample according to the present invention, and Figure 9 is a diagram showing a specific correction state of print data. FIG. l... Drive device, 2... X-Y drive device, 3...
Z drive device, 4. Brush holding means, 5. Brush, 6.
. . . Non-contact distance detection means, . . . Initial stroke correction amount determination means, 9 . . . Re-stroke printing determination means, 10
...Next stroke correction amount determining means, 11... Re-stroke correction amount determining means, 12... Correction drive control means,
E3...Character arrangement determining means, 14...Control data storage means.

Claims (1)

[Claims] A Z drive device, which is a drive means perpendicular to the printing paper of the brush holding means that holds the brush, is attached to an X-Y drive device, which is a horizontal drive means, based on control data stored in the storage means. By driving the X-Y and Z drive devices, the writing brush is continuously driven and controlled in the three directions of X, Y, and Z with respect to the printing paper, and is placed at a predetermined printing position based on the determination by the character arrangement determining means. In a brush plotter that draws calligraphy characters of different sizes, the print stroke unit is calculated based on distance detection data, which is the distance from the print paper surface detected by a non-contact distance detection means attached to the X-Y drive device. The first stroke at the start of printing is based on the correction amount determined by the initial stroke correction amount determining means from the distance detection data before printing at the printing point. After the second stroke, the distance detection data for the printing stroke is compared with the distance detection data for the next stroke based on the correction amount determined by the next stroke correction amount determining means from the distance detection data detected during printing of the previous stroke. When the re-stroke printing determining means determines that re-printing is necessary, the re-stroke printing is performed based on the correction amount determined by the re-stroke printing correction amount determining means from the distance detection data for the printing stroke and the next stroke. A brush drive control method for a brush plotter.