JPH0284398A - Plotter - Google Patents

Abstract

PURPOSE:To ensure that an analog waveform line to be drawn is drawn as s uniform line by a method wherein at the time of moving a printing head from one plotting point to the next, the head is once moved in the opposite direction to provide an approaching section, and then the head is moved at a fixed velocity between the plotting points. CONSTITUTION:First, input signals are taken into a controlling circuit 13, and a target position Xa for a head 8 and a feed quantity for a recording paper (p) are calculated. A motor 11 is rotated reversely, whereby the head 8 is moved reversely by an approaching section DELTAx. Immediately upon the reverse movement, the head 8 is started moving toward the target position Xa. The approaching section DELTAx is so set that the head 8 started moving toward the target position Xa can be moved at a fixed velocity after the time t* when the head 8 is passed again through its initial position X0. After the head 8 is passed through the initial position X0, the head 8 jets ink droplets toward the paper (p) at predetermined intervals, thereby plotting an analog waveform line. Because the head 8 is being moved at the fixed velocity at the time of plotting, the plotting density of the line is uniform over the entire length thereof, without any breakage or partial dot gaining.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a plotter, and more specifically, to a plotter that can draw analog waveforms in uniform lines.

(B) Conventional Technology A plotter is used to record analog waveforms such as chromatograms. For example, an inkjet plotter includes a platen that supports recording paper, a platen drive means that rotates the platen, and moves the recording paper.
An inkjet print head (located opposite to this platen) that ejects ink droplets onto the recording paper on the platen.
There are known devices that include a head (hereinafter sometimes simply referred to as a head) and a head moving mechanism that moves the head along the platen.

The plotter plots an analog waveform based on an input signal. In this case, while the head moves from one plot point to another, the head jets ink at regular intervals, the plot points are connected by lines, and an analog waveform is drawn.

(c) Problems to be Solved by the Invention In the conventional plotter described above, it is inevitable that a delay in power transmission occurs in the drive system of the head. Therefore, when moving from one plot point to the next plot point, the head speed V
As shown in FIG. 5(b), the speed rises from 0 and reaches a constant velocity after a certain period of time.

Therefore, as shown in FIG. 5(a), the head position 'lfx increases gradually at first, and then increases at a constant rate.

At this time, ink is ejected at regular intervals as shown by the small black circles in Figure 5(a), but since the head position X does not increase linearly at first, at the beginning of drawing the line connecting the plot points, , the density of the plot becomes high, and conversely the density becomes low at the end of the line. For this reason, when the distance between the plots increases and the henodo is required to move at a high speed, as shown in Figure 5 (C), the line becomes thicker at the beginning of the line, and conversely, the line becomes thicker at the end of the line. is interrupted, making the plotted analog waveform difficult to see.

The present invention has been made in view of the above, and an object of the present invention is to provide a plotter in which analog waveform lines do not become thick or are interrupted.

(d) Means and operation for solving the problems In order to solve the above problems, the plotter of the present invention includes a platen that supports recording paper, a platen drive mechanism that rotationally drives this platen, and a platen that faces the platen. When moving the head from one plot point to another, the print head is moved in the opposite direction. The head moving mechanism is characterized by comprising a head speed control means for controlling the head moving mechanism so that the head moves at a constant speed between the plot points by providing a run-up section.

In the plotter of this invention, the head runs backwards to provide a run-up section, the head is accelerated within this run-up section, and when the head returns to the previous pron point, it is at a constant speed. This controls the movement to the next plot point while maintaining a constant speed. Therefore, the plot density between plot points is constant from beginning to end, and the analog waveform line can be recorded without becoming thick or interrupted.

(E) Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 2 is a perspective view showing the plotting mechanism of the plotter 1 according to the embodiment. 2 is a platen, to which the power of a stepping motor (platen drive mechanism) 4 is transmitted via a gear transmission mechanism 3 . A recording paper p is supported on this platen 2 and fed in the Y direction.

The platen 2 is provided with 16 head moving mechanisms 5. The head moving mechanism 5 includes a guide rod 6, a carriage 7, an inkjet print head (hereinafter simply referred to as head) 8, pulleys 9a and 9b, a wire 10, and a stepping motor 11. The guide rod 6 is provided parallel to the platen 2, and a head carriage 7 is mounted on the guide rod 6 so as to be slidable in the X direction, and a head 8 is fixed onto the head carriage 7. The pulley 9a is attached to the rotating shaft of the motor 11, and a wire 10 is stretched between this pulley 9a and another pulley 9b.

The head carriage 7 is driven in the X direction by this wire 10.

FIG. 3 is a plotter diagram schematically showing the circuit configuration of the example plotter. Reference numeral 12 denotes an input circuit that processes input signals, and its output is taken into the control circuit 13. The control circuit 13 connects the motors 4 and 1 via a motor drive circuit 14.
1 and also controls the head 8 via a head drive circuit 15.

This control circuit 13 controls the X of the head 8 based on the input signal.
It has a function of determining the position in the direction and the feed m of the recording paper p in the Y direction, and a function of temporarily moving the head 8 in the reverse direction.

Next, the operation of the plotter according to the embodiment will be explained with reference to FIGS. 1 and 4.

First, an input signal is taken into the control circuit 13 [step (hereinafter referred to as ST) l, see FIG. 1], and the control circuit 13 determines the target position (next plot point) Calculate the amount (Sr1).

Next, the motor 11 rotates in reverse, and the head 8 moves in the run-up section ΔX.
(See also Sr1, Figure 4 (a) CO>). Immediately after completing the reverse movement, the head 8 returns to the target position
Start moving towards 1 (forward running) (Sr4
). The run-up section ΔX is a distance over which the head 8 can move at a constant speed after the time t* when the head 8, which has started moving toward the target position X1, passes through the original position (original plot point) Xo again. It is said that

When the head 8 passes the original position x0, the determination at Sr5 becomes YES, and the process branches to Sr1. In Sr1, the head 8 jets ink droplets onto the recording paper p at predetermined time intervals, and a line representing an analog waveform is drawn. At this time, since the head 8 is moving at a constant velocity vc, the plot density of this line is uniform from the beginning to the end of the line, and the line is not interrupted or partially thickened.

At Sr7, it is determined whether the head 8 has reached the target position WX1. While this determination is NO, movement of the head 8 and ink ejection continue. On the other hand, the judgment of Sr7 is YES
In this case, the flow branches to Sr1, and the head 8 is stopped, and the ink jetting of the head 8 is also stopped. When the process of Sr1 is completed, the process returns to STI again. In this way, S
By repeating the processing from TI to ST8, an analog waveform is drawn on the recording paper p.

(v) As described in detail, when the plotter of this invention moves the print head from one plot point to the next, the print head is once moved in the opposite direction to provide a run-up section. , further comprising print head speed control means for controlling the print head moving mechanism so that the print head moves at a constant speed between the plot points, so that the line of the analog waveform drawn is It has the advantage of being uniform.

[Brief explanation of drawings]

FIG. 1 is a flow diagram illustrating the operation of a plotter according to an embodiment of the present invention, FIG. 2 is a perspective view illustrating the plotting mechanism of the plotter, and FIG. 3 is a circuit configuration of the plotter. Plotter diagrams for explanation, Fig. 4(a) and Fig. 4(b)
5(a) and 5(b) are diagrams respectively explaining the head position and head speed of the conventional plotter, and FIG. (C) is a diagram showing lines drawn by the conventional plotter. 2 Ni platen, p: Recording paper, 4/11 Ni tipping motor, 5: Head moving mechanism, 8: Inkjet print head, 13: Control circuit. Figure 1 Patent applicant Shimadzu Corporation Representative Patent attorney Shigeru Nakamura Figure Figure (a) Figure (b)

Claims (1)

[Claims] (1) A platen that supports recording paper, a platen drive mechanism that rotationally drives this platen, a print head provided opposite to this platen, and a print head moving mechanism that moves this print head along the platen. When moving the print head from one plot point to the next, the print head is moved in the opposite direction to provide a run-up section, and the print head moves between the plot points. A plotter comprising print head speed control means for controlling the print head moving mechanism so that the print head moves at a constant speed.