JPH0829636B2 - Method for controlling writing implement up and down in automatic drawing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a method of driving and controlling a writing instrument of an automatic image drawing device (XY plotter) in a direction perpendicular to a screen.

[Conventional technology]

Japanese Patent Publication No. 53-34532 discloses an apparatus for driving and controlling a writing implement of a writing implement of an automatic image forming apparatus in a direction perpendicular to a sheet of paper or a drafting table, and a moving coil directly or indirectly connected to the writing implement. A high-speed writing implement vertical drive control system, comprising: a field component for driving a coil; and a drive circuit for accelerating and decelerating the writing implement and applying writing pressure to the writing implement after arriving at the drawing surface or a drafting table is disclosed. Have been. In the above method, when the writing implement is lowered, a positive current for rapidly lowering the writing implement is applied to the moving coil, and then a negative current is applied to the moving coil, so that the writing implement is decelerated and lands. The arrival of the writing instrument on the paper surface or the drawing table is detected by connecting the output end of the position detector that detects the moving amount of the moving coil to one of the input ends of the comparator and outputs a voltage signal. When a predetermined reference voltage is applied to the other input terminal of the position detector and the output voltage of the position detector matches this reference voltage, the comparator detects it and the writing instrument arrives on the paper or drawing board. I'm trying to do it. The reference voltage is
It is set to a value that exactly matches the output voltage of the position detector when the writing instrument arrives on the paper surface or drafting table.

When raising the writing implement, a negative current that rapidly raises the writing implement is applied to the moving coil, and then a reverse positive current is applied to decelerate the writing implement.
The writing instrument holding member is in contact with the upper limit stopper. The contact position of the writing implement holding member with the upper limit stopper is detected by the configuration of the position detector and the comparator, and after this detection, a negative current is applied to the moving coil to press the writing implement holding member against the upper limit stopper with a predetermined pressure. ing.

[Problems to be solved by the invention]

As described above, when the method of detecting that the writing instrument has arrived at the ascended position using the position detector and the comparator is adopted, the distance l between the tip of the writing instrument and the screen is increased when the writing instrument is raised. There is no problem if it is always constant over the entire area. However, if there is an error in the horizontality of the work screen and if the work screen has irregularities, the distance 1 will change depending on the position of the writing instrument on the work screen. This means that, when the reference voltage is constant, the position detector and the comparator cannot accurately detect the arrival of the writing instrument at the rising position.

However, when the writing instrument reaches the upper limit stopper position, the downward repulsive force Fa and the upward pressure Fb of the writing instrument are Fa> Fb.
The writing instrument bounces against the stopper surface when the relationship is true. Therefore, the writing implement does not bounce if a rising pressure larger than the repulsive force Fa is applied immediately after the writing implement arrives at the stopper surface, but the conventional writing implement control system can accurately detect the time when the writing implement arrives at the stopper face. Therefore, the writing instrument will bounce after reaching the stopper surface. When the writing instrument holding member is bound to the upper limit stopper when the writing instrument is raised and the writing instrument is bound as shown in FIG. 7, the descending stroke is changed when the writing instrument is lowered. For example, when the writing implement descending signal is input when the writing implement is at the position a and when the writing implement descending signal is received when the writing implement is at the position c, the length of the writing implement is l ₂ −l ₁ . When the writing tool is lowered at the point a and the writing tool is strongly lowered to the work screen, the writing tool strongly hits the work screen and the writing tool is damaged or the writing tool is moved to the work screen. There was a defect that caused a big bounce against.

Also, when the writing implement descending signal is input at point b, the writing implement begins to descend after a short delay because force is being applied upward. Therefore, the writing tool descent time varies depending on the magnitude of the force applied in the upward direction, and the writing tool lifting operation becomes unstable. The above problem can be solved by waiting until the writing tool bounces and then lowering the writing tool.
Since the waiting time becomes long, the drawing speed becomes slow. The present invention aims to eliminate the above defects.

[Means for solving problems]

In order to solve the above problems, the present invention relates to a device for energizing a moving coil to control an elevation of a writing instrument. When the writing instrument is raised, the writing instrument is accelerated and decelerated in a rising direction by a strong force, and the maximum stroke of the writing instrument is approximately 1 At / 2, the rising speed becomes zero, then the writing tool is given an arbitrary rising force to accelerate it, and then the moving coil is energized so as to gradually apply an appropriate upward pressure to the writing tool. It is a thing.

[Action]

The lifting stroke of the writing instrument is the flatness of the drawing board, the thickness of the paper,
If the writing instrument holding member reaches the upper limit stopper too early when the writing instrument rises when the writing instrument changes due to an error in the manufacturing accuracy, etc., the writing instrument holding member will not be able to reach the upper limit stopper when an arbitrary raising force is applied to the writing instrument. Arrive at. In this state, the holding member of the writing instrument does not bounce with respect to the upper limit stopper immediately after the descending speed of the writing instrument reaches zero. If the writing tool holding member arrives at the upper limit stopper too late, the writing tool arrives at the work screen when the writing tool holding member is gradually subjected to upward pressure, but immediately after that, a larger upward pressure is applied. Bounds at the time of collision with the upper limit stopper of the writing instrument are suppressed to a minimum. The writing instrument holding member arrives at the upper limit stopper,
The range is set when an arbitrary upward force is applied to the writing tool holding member or when upward pressure is gradually applied. As a result, the rising time of the writing instrument can be shortened.

[Embodiment] The configuration of the present invention will be described below with reference to an embodiment shown in the accompanying drawings.

In FIG. 4 to FIG. 6, 2,2a is X on the table 4.
It is a Y rail movably supported in the coordinate direction, and a Y cursor 6 is movably attached to the Y rail. A drawing head 8 is connected to the Y cursor 6, and a writing tool holding member 10 is movably supported by a guide 12 on a substrate 8a of the head 8. The writing tool holding member 10 has a writing tool.
14 is detachably fixed. The writing instrument holding member 10
A moving coil 16 is fixedly mounted on the holder attached to the holder, and the moving coil 16 faces the field constituting portion 18 arranged on the substrate 8a. The moving coil
When a positive current is applied to 16, the writing instrument holding member 10
The writing instrument 14 descends against 20 and the writing instrument 14 descends in cooperation with the holding member 10, and the tip of the writing instrument 14 contacts the sheet on the table 4. When a negative polarity current is applied to the moving coil 16, the writing instrument holding member 10 is configured to rise until it is locked by the upper limit stopper 22 fixed to the substrate 8a. When the X motor is driven, the Y rails 2 and 2a move in parallel in the X coordinate direction along the table 4, and the Y cursor 6 moves along the Y rails 2 and 2a when the Y motor is driven. Is configured. In the automatic drawing device, the stroke of raising and lowering the writing instrument is not constant due to the flatness of the table surface, the thickness of the paper, the manufacturing accuracy of the writing instrument, and the like. The range in which the stroke changes is 1 mm, the minimum stroke is 1 mm, and the maximum stroke is 2 mm. In FIG. 1, a pen type designation device 46 including an optical reader provided on the drawing head 8 side with a code signal indicating the type of pen formed on the writing instrument 14, that is, the type of a ballpoint pen, hollow pen, or the like.
And the pen type code signal is input to the CPU 48. The CPU 48 sets the proper writing pressure when pen down based on the pen type code signal, and the digital information is D / A.
Input to converters 50 and 52. The D / A converters 50 and 52 convert the writing pressure digital information into −v1 and + v1 analog voltage signals, respectively. When the writing instrument 14 is in the raised position, a −I current is supplied to the moving coil 16 and the writing instrument holding member 10 is in elastic contact with the upper limit stopper 22, as shown in FIG. In this state, the digital signal corresponding to the acceleration current D1 is transmitted from the CPU 48 at the timing of T1 in FIG.
It is supplied to the converter 54, and the falling acceleration analog voltage signal is supplied from the D / A converter 54 to the constant current driver 56, and the moving coil 16 is supplied with the current D1. As a result, the writing instrument 14 rapidly descends toward the surface of the table 4. next,
A digital signal corresponding to the deceleration current U1 is supplied from the CPU 48 to the D / A converter 54 at the timing of T2, and the D / A converter 54 is supplied with the digital signal.
The falling deceleration analog voltage is supplied from 54 to the constant current driver 56, and the current U1 is supplied to the moving coil 16 at the timing of T2. As a result, the writing instrument 14 is rapidly decelerated, and the writing instrument 1 is moved to a position approximately 1/2 of the maximum descending stroke of the writing instrument 14, that is, in the present embodiment, when the writing instrument 1 is lowered by 1 mm.
The descending speed of 4 becomes zero. Next, at the timing of T3 from the CPU 48, a digital signal corresponding to the acceleration current D2 is supplied to the D / A converter 54, and a falling acceleration analog voltage signal is supplied from the D / A converter 54 to the constant current driver 56. Then, the moving coil 16 is supplied with the acceleration current D2. Next, the timing signal b (see FIG. 2) is input from the CPU 48 to the control end of the waveform shaping circuit 58, and the waveform shaping circuit 58 has a fixed portion having a changing portion VS that gradually changes toward the proper writing pressure voltage level. The voltage signal VST is output and the moving coil 16
The fixed current signal PT having F is energized at the timing of T4 '. The landing range of the writing instrument 14 is set within the range of T3 and T4. Therefore, when the descending stroke of the writing instrument is the minimum stroke, the writing instrument 14 will land on the paper surface at T3. At this time, the accelerating speed of the writing instrument 14 is zero, and a force is applied immediately after that, so the writing instrument 14 does not bounce. When the writing implement 14 lands during T4, the writing implement is accelerated by the acceleration current D2, and the time of the writing pressure drop section is shortened. If the writing implement 14 lands during T4, after it lands, a writing pressure that is even larger than the repulsive force is gradually applied, which works to hold down the writing implement 14 and the bounce cycle of the writing implement 14 It gets shorter. The level of the current signal D2 is set to a value corresponding to a force obtained by adding about 20 to 30 grams to the proper writing pressure, in accordance with the writing instrument with the weakest writing pressure when using several types of writing instruments 14.

 Next, the writing instrument lifting operation will be described.

Acceleration current U1 from CPU48 at the timing of T5 in Fig. 3
A digital signal corresponding to is supplied to the D / A converter 54,
The rising acceleration analog voltage signal is supplied from the D / A converter 54 to the constant current driver 56, and a current is supplied to the moving coil 16.
U1 is energized. As a result, the writing instrument 14 rapidly rises from the drawing screen. Next, from the CPU48, at the timing of T6,
The digital signal corresponding to the deceleration current D1 is supplied to the D / A converter 54, the rising deceleration analog voltage is supplied from the D / A converter 54 to the constant current driver 56, and the current D1 is supplied to the moving coil 16. It As a result, the writing tool 14 is decelerated rapidly, and the rising speed of the writing tool 14 becomes zero at a position approximately half the maximum lifting stroke of the writing tool 14, that is, 1 mm above the working screen in this embodiment. Next, at the timing of T7 from CPU48, the digital signal corresponding to the acceleration current U2
It is supplied to the D / A converter 54, the rising acceleration analog voltage signal is supplied from the D / A converter 54 to the constant current driver 56, and the moving current 16 is supplied with the acceleration current U2. Next, CPU4
The timing signal b'is input from 8 to the control end of the waveform shaping circuit 60, and the waveform shaping circuit 60 outputs a fixed voltage signal having a changing portion that gradually changes toward the proper stopper pressure contact voltage level, and the moving coil 16 The changed part PF ′
A fixed current signal PT ′ having a voltage of  is energized. The rising locking range of the writing instrument 14 is set within the range of T7 and T8. Therefore,
When the rising stroke of the writing instrument is the minimum stroke,
At T7, the writing instrument holding member 10 comes into contact with the upper limit stopper 22. At this time, since the rising speed of the writing tool holding member 10 is zero and a force is applied immediately after that, the writing tool holding member 10 does not bounce. When the writing implement 14 is locked during T8, the acceleration of the writing implement is accelerated by the acceleration current U2, and the duration of the writing implement raising section is shortened. During the period between T8, when the writing instrument 14 is locked by the upper limit stopper 22, after being locked, a pressure larger than the repulsive force is gradually applied to the upper limit stopper 22, and this causes the writing instrument holding member 10 to move. It works to press down on the upper limit stopper 22, and the bouncing cycle of the writing instrument 14 is also shortened.

In this embodiment, the reverse current signal is used to set the lifting speed of the writing instrument to zero at a position approximately 1/2 of the maximum lifting stroke, but it is particularly limited to the method of decelerating by the reverse current. Not a thing. In addition, the current signals PF, PF ′
May change linearly, or may change in a quadratic curve as shown in FIG. 8 (b). Further, the acceleration current signals D2 and U2 when the writing instrument is moved up and down may not be set, but may be set so that the writing instrument is landed or locked by the upper limit stopper at T4 and T8.

〔effect〕

As described above, according to the present invention, even when the lifting stroke of the writing instrument changes, the writing instrument is locked upward with the pressing force applied immediately after the rising speed becomes zero, or the writing instrument contacts the upper limit stopper. Since it is locked upward in a region where the contact pressure gradually increases, it is possible to suppress the occurrence of bouncing when the writing instrument is lifted and locked, and it is possible to improve the drawing speed.

[Brief description of drawings]

1 is a block circuit diagram, FIG. 2 is an explanatory diagram, FIG. 3 is an explanatory diagram, FIG. 4 is a sectional view, FIG. 5 is a plan view, FIG. 6 is a side view, and FIG. 7 is an explanatory view. FIG. 8 is an explanatory diagram. 2, 2a …… Y rail, 4 …… Table, 6 …… Y cursor, 8…
… Drawing head, 8a …… Substrate, 10 …… Writing tool holding member, 12…
… Guides, 14 …… Writing instruments, 16… Moving coils, 18…
… Field component, 20 …… Spring, 22 …… Upper limit stopper,

Claims (2)

[Claims] 1. A device for controlling a current to a moving coil to drive and control a writing instrument connected to the moving coil in a direction perpendicular to a screen, a holding member of the writing instrument being engaged with an upper limit stopper from a lowered state. When raising the writing tool until it is stopped, first, a current for raising the writing instrument is applied to the moving coil so that the writing instrument suddenly rises, and then, a current for reducing the rising speed of the writing instrument is applied to the moving coil to cause the writing instrument to move. About the maximum stroke 1 /
When it reaches 2, the rising speed becomes almost zero, and then a changing current that gradually increases from a small absolute value toward a predetermined stopper contact pressure setting current value is applied to the moving coil. A method for controlling a writing instrument up and down in an automatic drawing device, characterized in that it is energized. 2. A device for controlling a current to a moving coil to drive a writing instrument connected to the moving coil in a direction perpendicular to a screen, a holding member of the writing instrument being engaged with an upper limit stopper from a lowered state. When raising the writing tool until it is stopped, first, a current for raising the writing instrument is applied to the moving coil so that the writing instrument suddenly rises, and then, a current for reducing the rising speed of the writing instrument is applied to the moving coil to cause the writing instrument to move. About the maximum stroke 1 /
When the speed reaches 2, the rising speed is set to be substantially zero, and then the moving coil is momentarily supplied with a writing implement rising acceleration current that is larger than the stopper contact pressure setting current value.
A method of controlling writing implement up-and-down in an automatic drawing device, wherein a changing current gradually increasing from a small absolute value toward a predetermined stopper contact pressure setting current value is applied to the moving coil.