JPH0815837B2 - Writing instrument control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a drawing device such as an XY plotter or a drawing machine, or a control device for a writing instrument (pen or the like) in a recording device.

[Prior Art] In order to bring a pen such as an XY plotter into contact with a writing surface in a state with less impact, an air damper may be used to mechanically brake. However, if this method is adopted, high-speed response cannot be obtained. In order to solve this type of problem, the applicant of the present application has proposed a method of electrically controlling the current of the pen drive coil in Japanese Patent Laid-Open No. 63-13799. According to this method, pen up and / or near ideal
Alternatively, down control becomes possible.

Further, Japanese Patent Laid-Open No. 61-228997 discloses that the type of pen is determined and the pen up / down control and the writing control are performed according to the type of pen.

[Problems to be Solved by the Invention] However, the up / down response characteristic and the drawing quality cannot be sufficiently improved only by switching the pen up / down and the writing control according to the type of the pen. That is,
The ink in the pen decreased with the use of the pen, and the up / down response characteristics and the drawing quality could not be kept constant from the start of use to the end of use because the weight of the pen changed.

Therefore, an object of the present invention is to provide a writing instrument control device that can always obtain the optimal down state and / or the optimal writing state of the writing instrument.

[Means for Solving the Problems] The present invention for achieving the above object includes a writing instrument which is formed so as to cause a change in the weight thereof by writing.
A writing instrument driving device that drives the writing instrument to selectively contact the recording surface by electromagnetic action based on a drive coil, and writing instrument information that reads the weight of the writing instrument and generates a writing instrument information signal indicating the weight of the writing instrument. A signal generator,
The optimum writing instrument having a memory in which optimum writing instrument down pressure information and / or writing pressure information corresponding to the weight of the writing instrument is written in advance and corresponding to the writing instrument information signal given from the writing instrument information signal generator. A writing instrument control device having a control circuit for reading down pressure information and / or writing pressure information from the memory so as to obtain an optimum down state and / or an optimum writing state of the writing instrument. It is a thing.

As described in claim 2, it is desirable to read the weight of the writing instrument and the type of the writing instrument at the same time, and use this for control.

[Operation] In the invention of claim 1, the weight of the writing instrument that changes in accordance with the use of the writing instrument is detected every moment, and the writing instrument down pressure information and / or the writing pressure information optimal for this weight is read from the memory. Based on this, the down state and the writing state of the writing instrument are controlled. Therefore, the optimum down state and /
Alternatively, the optimum writing state can be obtained.

According to the invention of claim 2, optimum control can be performed when a plurality of types of writing instruments are used.

[Embodiment] Next, a pen control device according to an embodiment of the present invention will be described with reference to the drawings.

X- of the embodiment of the present invention shown in FIGS.
A pen control device for a Y plotter includes first, second, third and fourth plate-like permanent magnets 1 for forming a magnetic circuit.
Includes 1, 12, 13, and 14. These four magnets 11, 12, 13, 14
Are respectively flat rare-earth cobalt magnets, each formed in a quadrangle. The first and third permanent magnets 11,
One of the main surfaces of 13 has a north pole, and the other main surface, that is, the right surface, has a south pole. The second and fourth permanent magnets 12 and 14 are magnetized substantially uniformly so that one main surface, that is, the left surface, becomes the S pole, and the other main surface, that is, the right surface becomes the N pole. There is. As is apparent from FIGS. 2 to 5, the first permanent magnet 11 is fixed to one support member 15 so as to extend in the vertical direction, that is, the Y-axis direction. The second permanent magnet 12 is the first
The permanent magnets 11 are arranged adjacent to each other and fixed to one supporting member 15. The third permanent magnet 13 has the other support member 16
Is fixed to the first permanent magnet 11 and is opposed to the first permanent magnet 11. The fourth permanent magnet 14 is fixed to the support member 16 below the third permanent magnet 13 and is arranged so as to face the second permanent magnet 12. As a result, a first space 17 is created between the first permanent magnet 11 and the third permanent magnet 13, and a second space 18 is created between the second permanent magnet 12 and the fourth permanent magnet 14. Is born.

Since the one and the other support members 15 and 16 shown in FIG. 2 are magnetic plates that do not magnetically saturate, four permanent magnets 11 are provided.
˜14 form a magnetic closed circuit as shown by the dotted line in FIG. A plurality of arrows drawn from the center line of the first space 17 and the second space 18 below the chain line in FIG. 3 indicate the direction and strength of the magnetic field on this center line. That is, the length of the arrow indicates the strength of the magnetic field, and the direction of the arrow indicates the direction of the magnetic field. As is apparent from FIG. 3, a magnetic field in the first direction from the right to the left is generated in the first space 17, and the second magnetic field is generated in the space 18 in the second direction opposite to the first direction. Directional magnetic field is generated. The first permanent magnet 11 and the second permanent magnet 12 are vertically adjacent to each other with different polarities, and the third permanent magnet 13 and the fourth permanent magnet 14 are vertical with different polarities. Since they are arranged adjacent to each other in the direction, the distribution of the magnetic field, that is, the lines of magnetic force in the first and second spaces 17, 18 is determined by the interaction of the four permanent magnets 11-14. As a result, the strength of the magnetic field at the boundary P ₀ between the first space 17 and the second space 18 shown in FIG. 3 depends on the action of the upper two permanent magnets 11 and 13 and the lower two permanent magnets. It is substantially zero due to the cancellation of the action of the magnets 12, 14. Also the boundary
In the region near P ₀ , the magnetic field strength gradually increases almost linearly. The strength of the magnetic field in the first and second spaces 17 and 18 will be described in more detail. In the first space 17, the strength of the magnetic field gradually increases from the boundary P ₀ to the position P ₁ , and then gradually decreases. On the other hand, in the second space 18, the strength of the magnetic field in the second direction gradually increases from the boundary P ₀ to the position P 2, and then gradually decreases. Therefore, the magnetic flux distribution, that is, the strength of the magnetic field is substantially S-shaped as a whole.

The drive coil 19 wound in a quadrangle shown in FIGS. 1 and 2 is movably arranged in the first and second spaces 17 and 18, and is substantially the first space 17. Has a first portion 19a displaced therein and a second portion 19b displaced substantially within the second space 18. When a direct current for moving the pen down is passed through the drive coil 19, a current flows through the first portion 19a with a direction from right to left as shown by the arrow as shown in FIG. , The current flows in the second portion 19b with a directionality from the left to the right as shown by the arrow. However, since the direction of the magnetic field acting on the first portion 19a is opposite to the direction of the magnetic field acting on the second portion 19b, eventually both the first portion 19a and the second portion 19b move downward. To do. The drive coil 19 moves from the position shown in FIG. 4 to the fifth position.
When moving to the position shown in the figure, the strength of the magnetic field acting on the coil 19 changes according to the change in the position of the coil 19. if,
When the torque for lowering the coil 19 from the position shown in FIG. 4 to the position shown in FIG. 5 is applied while keeping the current of the coil 19 constant, the coil 19 moves in the range from the position P1 to the position P2 in FIG. At times, the strength of the magnetic field acting on the first portion 19a decreases, while the strength of the magnetic field acting on the second portion 19b increases. Therefore, the torque of the drive coil 19 varies little.

The moving member 21 shown in FIGS. 1 and 2 is fixed to the drive coil 19 and is a pen 22 as a writing tool for an XY plotter.
Has an arm 21a supporting the. In order to move the moving member 21 along the Y axis, a slide bearing 23
Is mounted on the moving member 21, and a shaft or pin 24 extending in the vertical direction is engaged with the bearing 23. Further, the right end of the moving member 21 is linearly guided in the vertical direction by the guide member 25. The pin 24 and the guide member 25 are arranged on the fixing member 27. Reference numeral 26 denotes a coil spring for returning the moving member 21, which is wound around the pin 24 and arranged between the moving member 21 and the fixed member 27. A stopper 28 is provided on the guide member 25 to determine the upper limit of the moving member 21.

The Hall element 29 as a position detector is arranged in the center of the hollow portion 30 of the drive coil 19, and is fixed to the moving member 21 in a fixed positional relationship with the coil 19. The Hall element 29 moves in the first and second spaces 17 and 18 having the magnetic field shown in FIG. 3 and generates a voltage corresponding to the magnetic field.
That is, the Hall element 29 generates an output voltage corresponding to the positions of the drive coil 19 and the pen 22. Since the hall element 29 for position detection is arranged in the center of the coil 19, the magnetic field strength changes linearly and gradually P1 in FIG.
It moves in the range of ~ P2 and generates a voltage that corresponds to that position relatively accurately. Therefore, the current of the drive coil 19 can be controlled according to the change in the position of the drive coil 19. Further, the holing element 29 for position detection is the drive coil 19
Since it is arranged in the hollow portion 30, the special space for providing the position detecting means can be small.

As apparent from FIGS. 1 and 2, a speed detection coil 32 as a speed detector is coaxially wound around the outer circumference of the drive coil 19. Therefore, the velocity detecting coil 32 moves together with the driving coil 19 in the magnetic fields of the first and second spaces 17 and 18. As a result, a voltage corresponding to the speed of the speed detection coil 32, that is, a speed detection signal is obtained from this coil 32. That is, the speed of the pen 22 can be detected by the coil 32. This speed detection coil 32, like the drive coil 19,
Since the upper portion 32a substantially located in the first space 17 and the lower portion 32b substantially located in the second space 18 are provided, the speed detecting coil 32 has a range from the position P1 to the position P2 in FIG. When moving, if the strength of the magnetic field acting on the upper portion 32a decreases, the strength of the magnetic field acting on the lower portion 32b increases. Therefore, the induced voltage of the entire coil 32 does not change much due to the change of the position of the coil 32, and an output voltage corresponding to the moving speed of the coil 32 is generated.

The pen controller further includes various circuits shown in FIG. The pen drive current control supply circuit 33 of FIG. 6 comprises a diode 34, a differential amplifier 35, a resistor 36, and first and second phase compensation circuits 37 and 38. The output of the differential amplifier 35 is connected so that a drive current Ia flows through the drive coil 19.
One input terminal (inverting input terminal) of the differential amplifier 35 is connected to the up / down signal line 39 and also has a resistance.
It is connected to the speed detection coil 32 via 36 and the first phase compensation circuit 37, and is further connected to the current detector 40 via the second phase compensation circuit 38. The current detector 40 is connected in series to the drive coil 19, and the current detection signal corresponding to the current flowing therethrough is a low-pass filter or a phase compensation circuit composed of a resistor.
It is negatively fed back to the differential amplifier 35 via 38. The speed detection voltage Vc obtained from the speed detection coil 32 is also negatively fed back to the differential amplifier 35 via the phase compensation circuit 37 composed of a low pass filter or a resistor. The other input terminal (non-inverting input terminal) of the differential amplifier 35 is connected to the control voltage line 41. The pen drive current control supply circuit 33 is substantially the same as that disclosed in Japanese Patent Laid-Open No. 63-13799.

A pen information signal generator 42 generates a pen information signal indicating the weight of the pen 22.

Reference numeral 43 denotes a CPU for forming a control circuit, which forms and outputs an optimum control signal Vs according to a predetermined program. The CPU 43 is connected to the input / output device 44 by a bus 45, and is also connected to a RAM (random access memory) 46 and a ROM (read only memory) 47. The ROM 47 includes a table in which optimum pen down pressure information and / or writing pressure information corresponding to the weight of the pen is written in advance.

Since the position detection Hall element 29 is connected to the input / output device 44 via the A / D converter 48, it can give a position detection signal to the CPU 43. Since the pen information signal generator 42 is connected to the input / output device 44, the pen information signal can be given to the CPU 43 via this.

The pen position reference level signal generator 49 (hereinafter referred to as the pen down busy level signal generator) is a pen position reference level signal (hereinafter referred to as the pen down busy level signal) indicating that the pen is in a position close to the recording surface. It is connected to the input / output device 44.

The up / down signal line 39 derived from the input / output device 44 is connected to the inverting input terminal of the differential amplifier 35. Control signal line 50 derived from the input / output device 44
Is connected to the non-inverting input terminal of the differential amplifier 35 via the D / A converter 51.

Next, the operation of the pen control device of FIGS. 1 to 6 will be described with reference to the flow chart of FIG. 7 at the time of pen down and FIG. 8 showing the change of the pen height. When the pen down control is started as shown in block 61 of FIG. 7, the pen information signal generator 42 first receives the pen 22 as shown in block 62.
The pen information signal is transmitted by optically or mechanically reading the weight of the ink (or the remaining amount of ink). The pen information is sent to the CPU 43, and the CPU 43 reads the optimum control signal from the ROM 47 from the address corresponding to the pen information (pen weight), as shown in block 63, and obtains the weight-corrected down pressure signal. The pen information signal generator 42 has a function to read the weight of the pen 22 and the type of the pen at the same time, and sends the pen information indicating the weight and the type, and the ROM 47 corresponds to the weight and the type of the pen 22. Stores down pressure information and / or writing pressure information,
It is also possible to read this based on the pen information and control the writing instrument drive device.

Since the pen is at a high position at the start of pen down shown in block 64, a high level position detection signal is obtained from the position detection Hall element 29. The CPU 43 compares the position detection signal with the corrected down pressure signal and outputs the larger signal. Therefore, in the early stage of pen-down, the high-level position detection signal is converted into an analog signal by the D / A converter 51 and input to the differential amplifier 35, and a current corresponding to this flows in the drive coil 19. Note that the up / down signal on the line 39 is at a low level (zero volt) during pen down. When the pen is lowered, the position detection signal becomes smaller, and at a certain set point, the corrected down pressure signal becomes larger than the down pressure signal based on the position detection signal. As a result, the corrected down pressure signal is output from the input / output device 44, converted into an analog signal by the D / A converter, and given to the differential amplifier 35.

A comparison of the pen down busy level provided by the pen down busy level signal generator 49 with the pen position detection signal is made while the pen continues to descend under control of the corrected down pressure signal and is shown in block 65. A pen down busy check signal is obtained. When the pen position detection signal becomes lower than the pen down busy level, the CPU 43 sends the correction soft landing pressure signal to the D / A converter 51 as shown in block 66.
To the differential amplifier 35 via. This corrected soft landing pressure signal is supplied for the time determined by timer 1 as indicated by block 67. After the timer 1 time has elapsed, the CPU 44 outputs a corrected writing pressure signal, as shown in block 68, which is provided to the differential amplifier 35. After the corrected writing pressure is set, after the time of the timer 2 shown in block 69 has elapsed, drawing is started as shown in block 70, and drawing is ended in block 71. The time of the timer 2 is set to stabilize the writing pressure and wait for the ink to be discharged.

Since the speed detection voltage Vc obtained by the speed detection coil 32 is connected to the inverting input terminal of the differential amplifier 35, the pen down speed is braked when the pen descending speed becomes higher than a certain level.

[Modification] The present invention is not limited to the above-described embodiments, and the following modifications are possible, for example.

(1) The remaining amount of ink in the pen 22 may be detected by the pen information signal generator 42, and a signal indicating the weight of the pen 22 may be output.

(2) Pen 22 is not limited to one that uses ink,
It may be a writing instrument such as a mechanical pencil or a pencil.

(3) In the embodiment, the position detection signal is supplied to the differential amplifier 35 during pen down, but the down pressure signal created by the CPU 43 from the beginning may be supplied.

(4) All control signals (correction down pressure signal, correction soft landing signal,
The corrected writing pressure signal) may be sequentially generated in a predetermined sequence regardless of the position detection signal.

[Effects of the Invention] As described above, according to the invention of each claim, since the writing instrument drive device is controlled in consideration of the change in the weight of the writing instrument, the optimum down pressure and / or the optimum writing pressure can be easily achieved. Therefore, the pen-down response characteristic and / or the drawing quality can be improved.

[Brief description of drawings]

1 is a partially cutaway front view of a pen control device according to an embodiment of the present invention, FIG. 2 is a sectional view showing a portion corresponding to line II-II of the device of FIG. 1, and FIG. FIG. 4 is a sectional view showing directions and strengths of magnetic fields based on the first to fourth permanent magnets in the apparatus shown in FIG. 1, and FIG. 4 is a sectional view showing a state where the drive coil is moved upward in the apparatus shown in FIG. 5 and 5 are cross-sectional views showing a state in which the drive coil is moved downward in the device of FIG. 1, and FIG. 6 is a drive coil, a position detector, a speed detection coil and the like of the device of FIG. FIG. 7 is a circuit diagram showing an electric circuit to be coupled, FIG. 7 is a flow chart showing an operation at the time of pen down, and FIG. 19 ... Drive coil, 22 ... Pen, 29 ... Position detection Hall element,
32 ... Speed detection coil, 33 ... Pen drive current control supply circuit,
42 ... Pen information signal generator, 43 ... CPU, 47 ... ROM.

Claims (2)

[Claims] 1. A writing instrument which is formed so that its weight is changed by writing, and a writing instrument drive device which drives the writing instrument to selectively contact the recording surface by an electromagnetic action based on a driving coil. A writing tool information signal generator that reads the weight of the writing tool and generates a writing tool information signal that indicates the weight of the writing tool, and optimal writing tool down pressure information and / or writing pressure information corresponding to the weight of the writing tool is written in advance. An optimum down state of the writing instrument by reading the optimum writing instrument down pressure information and / or writing pressure information corresponding to the writing instrument information signal given from the writing instrument information signal generator from the memory. And / or a control circuit for controlling the writing instrument driving device so as to obtain an optimum writing state. 2. One of a plurality of types of writing instruments formed so that the weight thereof is changed by writing is driven so as to be selectively brought into contact with a recording surface by an electromagnetic action based on a drive coil. A writing instrument drive device, a writing instrument information signal generator that reads the type and weight of the writing instrument and generates a writing instrument information signal indicating the type and weight of the writing instrument, and an optimal writing instrument down corresponding to the type and weight of the writing instrument Pressure information and / or writing pressure information is previously written in the memory, and the optimum writing instrument down pressure information and / or writing pressure information corresponding to the writing instrument information signal given from the writing instrument information signal generator is stored in the memory. A control circuit for controlling the writing instrument driving device so as to obtain an optimum down state and / or an optimum writing state of the writing instrument by reading from a memory. Writing instrument controller.