JPH0316917B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION -Field of Industrial Application- The present invention relates to a pen control device for drawing devices such as X-Y plotters and drafting machines, and particularly to drawing devices that use a lead pen with a tip (sharp pencil). The present invention relates to a pen control device.

-Prior Art- A plotting device such as an X-Y plotter, for example a multi-pen type X-Y plotter as shown in FIG.
A pen cartridge 2 is supported movably in the Y direction on this guide shaft 1, picks up a selected one of the recording pens P located in the pen storage section 3a of the main body 3 into the pen cartridge 2, and starts recording with the pen cartridge 2. The pen cartridge 2 is driven in the X-Y direction to the desired position and brought into contact with the pen writing surface (pen down) by the pen up-down control device provided in the pen cartridge 2, and the pen cartridge 2 is moved in the X-Y direction according to the drawing shape and as required. Accordingly, by moving the pen away from the writing surface (pen-up), recording is performed on the writing surface.

By the way, the present invention proposes a pen up-down control device that electrically controls the current of the pen up-down drive coil in order to improve responsiveness and reduce the impact between the pen and the recording surface, instead of the conventional plunger solenoid system. The applicant has already proposed this (for example, Japanese Patent Application No. 191837-1982 and Japanese Patent Application No. 65636-1982).
These pen up/down control devices have the mechanism shown in FIGS. 6 and 7. The paint cartridge main body 11 has a sliding portion 11A for sliding in the Y-axis direction along a guide shaft 12, and a sliding portion 11A for sliding in the Y-axis direction along a guide shaft 12, and a sliding portion 11A for sliding in the Z-axis direction
A pen holder 11B that is movably held in the axial direction (pen up and down directions) and holds the pen 14.
Equipped with. A drive coil 1 is installed in the pen holding portion 11B.
5, a speed detection coil 16, and a position detector (for example, a Hall element) 17 are provided. In addition, the paint cartridge main body 11 includes a pair of plate-shaped permanent magnets 18A,
18B are arranged facing each other as illustrated in the cross section taken along line A-A' in FIG. Therefore, the pen holder 11B is driven in the pen up and pen down directions, and the driving force is adjusted by the magnitude of the current. During this driving, the coil 16 detects a voltage proportional to the speed, and the Z-axis direction of the permanent magnets 18A and 18B is adjusted. The position detector 17 detects a position signal corresponding to the position by changing the strength of the magnetic field due to the difference in position. 19 is a return spring when the pen is lifted up, and 11C is a stopper that determines the pen-up position. Further, 20 is a recording paper.

As shown in FIG. 8, the pen control circuit includes a current control circuit 21 that controls the polarity and magnitude of the current supplied to the drive coil 15, and includes a detection signal from a current detector 22 and a speed detection coil 16 as a feedback system.
The adder 23 adds the detection signals and the phase compensation circuit 24 performs phase compensation, and the position detection signal from the position detector 17 and the setting value from the pen pressure setting device 25 are selected as the drive current setting value. When the control signal from the pen-up-down control signal generation circuit 27 commands pen-down, the circuit 26 selects and takes in the drive current, and when the control signal from the pen-up-down control signal generating circuit 27 commands pen-down, the drive current is set according to the drive current setting value from the selection circuit 26. Feedback control is performed based on the value.

In _such a control circuit, for pen down control, as shown in _{FIG .} is selected by the selection circuit 26 as the drive current set value, and the position
When P _B is exceeded, the selection circuit 26 selects the pen pressure setting signal V _B from the pen pressure setting device 15 and sets it as the drive current setting value. In addition, the phase compensation circuit 24
acts as a delay element. This allows the position
At the beginning of driving with P _A , the signal V _A is high and the amount of feedback is zero (phase lag), so a relatively large drive current is obtained, increasing the pen-down response and positioning.
As the pen approaches P _B , the signal V _A decreases and a braking action is generated by the speed detection signal to reduce the impact when the tip of the pen contacts the recording surface.

During pen-up, the current control circuit 2 receives a pen-up command from the up-down control signal generation circuit 27.
1 is given a constant drive current set value with a polarity opposite to that when the pen is down, and the pen is brought up in cooperation with the return spring 19.

In the pen control device as described above, there has been a problem that writing fails when the ink or sharp lead runs out during a writing operation. If writing fails, writing must be resumed after replacing the pen or replenishing ink and lead, resulting in the inconvenience of writing and reducing drawing efficiency. In particular, sharp pencil pens can store a large number of leads in the lead storage section, but when changing the lead, the next lead does not always follow, and even if it does, it often causes scratches, and one lead cannot be used. When it wears out, it is necessary to bring out the next lead to the tip of the pen or replace the pen, and the writing length that can be written with one lead is relatively small (for example, writing length 2 m / lead length 1 mm).
As a result, writing errors are more likely to occur.

-Object of the Invention- In view of the above-mentioned conventional problems, the present invention provides a pen control device that determines in advance whether or not a reed tip pen has a lead, thereby eliminating writing failures. The purpose is to

-Structure of the Invention- The present invention provides a control device for exchanging pens and controlling pen up-down and writing according to drawing data. a position detector that detects the height position of the pen relative to the recording surface when the tip of the pen contacts the recording surface; and a position detector that detects the pen height position of the position detector when the determination signal of the pen discriminator indicates a tip-knock type lead pen; and control means for replacing the pen when the signal is lower than the normal pen-down height position by more than a predetermined amount.

-Embodiment- FIG. 1 is a block diagram of an apparatus showing an embodiment of the present invention, and parts having the same functions or the same configuration as those shown in FIG. 8 are designated by the same reference numerals. CPU30, ROM3
1. A microcomputer equipped with a RAM 32 and an input/output circuit 33 takes in drawing data DATA via the input/output circuit 33, and provides position control data in the X and Y directions to the motor control circuit 34 according to this data DATA. According to this data, the motor control circuit 34 drives the motors (pulse motor or servo motor, etc.) 35 and 36 to move the pen cartridge according to the drawing data and to change the pen according to the specification of the pen type used for drawing. . Further, the microcomputer supplies the pen up/down control signals UP/DOWN and the drive current set value V _S via the D/A converter 37 to the current control circuit 21 in accordance with the plotting data. In addition, the microcomputer receives the position detection signal from the position detector 17.
V _A is taken in through the A/D converter 38 .

In such a microcomputer-based pen movement, exchange, and up/down control device, a pen discriminator 39 is connected to the input/output circuit 33.
The pen discriminator 39 is for discriminating the pen on the replaced pen cartridge. For example, as shown in FIG. Coded colored tapes 14A, 14B, 14C for specifying the ink color and grade (for example, the difference in the thickness of the lead of the reed tip pen) and the ink color and grade (for example, the difference in the thickness of the lead of the reed tip pen)
The pen discriminator 39 optically detects the colored tapes 14A, 14B, and 14C of the pen 14 picked up by the pen holder 11B, thereby obtaining pen discrimination code data associated with the pen 14. .

The pen type discrimination signal from the pen discriminator 39 and the position detection signal from the position detector 17 are used to determine whether or not pen replacement is necessary during drawing control by the CPU 30 using a reed pen with a retractable tip. The determination control by the CPU 30 will be explained in detail below.

FIG. 3 shows the main part of a flowchart (subroutine) of determination control by the CPU 30. When entering pen down to start drawing, the CPU 30 first sends a pen down command to the current control circuit 21 and D/D.
Pen down control is performed by applying a pen pressure set value to the A converter 37 (step S1). Here, the pen pressure setting value is a value corresponding to a pen discrimination signal from the pen discriminator 39 or a pre-stored setting value.

Next, after completing the pen down control, the CPU 30 uses the pen discrimination signal from the pen discriminator 39 to determine whether or not the pen type is a latch type lead pen (step S2). takes in the position detection signal P _H from the position detector 17 in the pen down state through the A/D converter 38 and the input/output circuit 33 (step S3). The detection signal P _H is the reference pen down position signal.
Determine whether or not the _P
S4), if it is low, it is assumed that the tip of the reed pen has no lead, and the pen replacement control is performed. CPU30
When it is determined in step S2 that it is not a reed pen with a reed tip, and when it is determined in step S4 that there is a lead (P _H ≧P _S −α), normal writing control is started.

Here, the reason why the leadless determination process can be performed using the position detection signal V _A will be explained with reference to the sectional views of the reed pen with a tip end shown in FIGS. 4A and 4B. In FIG. 4A, a tip cap 41 is connected to the cylindrical body 40 by screwing into an internal coupling fitting 42, and the lead 43 in the cylindrical body 40 is passed from the tip of the lead storage part 44 through the chuck 45 to the pen tip tube 46. sent to. The chuck 45 is urged by a compression spring 48 against the outer circumferential cylinder 47 in a direction to return it to the storage part 44 side, and grips the core 43 by the pressing force via the small sphere 49 between the chuck 45 and the cylinder 47. This provides a gripping force that resists the return of the core 43. The pen tip tube 46 has a spring 50
It is urged in the protruding direction by the spring 50, and is pushed into the tip cap 41 by the pressing force (writing pressure or tip notch) against the spring 50. A rubber 51 for gripping the lead 43 is provided at the rear end of the pen tip tube 46, and when the pen is up, the pen tip tube 46 is configured to grip the lead 43 with the gripping force of the rubber 51 and feed it out. .

As shown in FIG. 4A, in such a tip-knot type reed pen, in the normal pen-down state, the pen tip tube 46 has a size smaller than the tip cap 41.
Writing begins with only H _S protruding, and the lead wears out depending on the amount of writing, but the next time the pen is raised, the rubber 51 grips the lead 43 and is sent out by the return force of the spring 50, and the next time the pen is brought down, the H _S
Returns to a prominent state. That is, when the pen is down, it is always in the state shown in FIG. 4A, and the dimension H _S does not change. The position detection signal V _A in this state is stored as a reference pen-down position signal P _S , and a predetermined amount α is also set. On the other hand, when the lead inside the pen tip tube 46 is worn out and its rear end becomes below the tip of the chuck 45, the pen tip tube 46 moves closer to the tip cap 41 according to the amount of lead consumption, as shown in FIG. 4B. It gets pushed inside. Therefore, the pen position detection signal P _H corresponding to the protrusion dimension H _S is read when the pen is down, and
Reference pen down position signal to memorize this signal P _H
By comparing P _S with the difference between the predetermined amount α (P _S −α), it is possible to determine whether the lead is missing before the lead is completely consumed.

In the embodiment, a case is shown in which the presence or absence of a lead is determined when the pen is down, but in a device where the amount of writing in one pen down is likely to be more than one lead, steps S2 to S4 may be periodically executed during writing. or S3 and S4
By performing this process, writing failures can be prevented in advance.

-Effects of the Invention- As described above, according to the present invention, when writing with a reed tip reed pen, the pen is replaced by a predetermined amount lower than the normal pen-down height position, which causes the pen to run out of lead. This has the effect of being able to reliably prevent writing errors by identifying the information in advance.

[Brief explanation of the drawing]

FIG. 1 is a device configuration diagram showing an embodiment of the present invention;
FIG. 2 is a schematic configuration diagram illustrating the pen discriminator 39 in FIG. 1, FIG. 3 is a flowchart for controlling the lead-free determination by the microcomputer in FIG. 1, and FIGS. 4A and 4B are 5 is a plan view of a multi-pen type X-Y plotter, and 6 is a partially cutaway side view of a pen cartridge.
Fig. 7 is a sectional view of the main part along line A-A' in Fig. 6, Fig. 8 is a pen up-down control circuit diagram, and Fig. 9 is a characteristic diagram for explaining the pen down control in Fig. 8. It is. 2... Pen cartridge, 3a... Pen storage section,
11B...Pen holding part, 14...Pen, 14A,
14B, 14C... Colored tape, 15... Drive coil, 16... Speed detection coil, 17... Position detector, 21... Current control circuit, 30... CPU,
31...ROM, 32...RAM, 33...input/output circuit, 34...motor control circuit, 35...pulse motor, 39...pen discriminator.

Claims (1)

[Claims] 1. In a control device that changes pens and controls pen up-down and writing according to drawing data, there is a pen discriminator that determines the type of pen picked up on the pen cartridge, and a pen-down control that determines whether the tip of the pen touches the recording surface. a position detector for detecting the pen height position with respect to the recording surface when the discrimination signal of the pen discriminator indicates a tip-knock type reed pen, and the pen height position signal of the position detector is higher than the normal pen-down height position. and control means for replacing the pen when the amount of the pen is lower than a predetermined amount.