JPS62278071A - Method and apparatus for controlling carriage - Google Patents

Abstract

PURPOSE:To enable a satisfactory speed control irrespective of an initial position of a carriage, by a method wherein while a part for position detection is detected, the carriage is moved at an optimum speed, and when the carriage comes off the part for position detection, the carriage is decelerated for a predetermined period of time. CONSTITUTION:When a carriage 12 is stopped at a position A at which it faces a zone slit 44 of a slitted palte 38 constituting a linear encoder and a power source is switched ON at that position, the fact that the carriage 12 faces the zone slit 44 is detected through a signal from a light-receiving part 48, and the carriage 12 is moved for returning to a home position H at a maximum speed vm set as an optimum speed After the carriage 12 is moved past a position B, the carriage 12 is decelerated by braking. Then, the carriage 12 is moved to the home position H at a fixed speed vc in such a range that failure in ejeotion of an ink will not be caused by a shock even when the carriage 12 collides against a damper 24.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] This invention provides a method and apparatus for controlling the speed of a carriage used in, for example, an inkjet printer, which has a zone slit that indicates a printing range. Regarding.

[Prior Art] Conventionally, various proposals have been made regarding speed control methods for the carriage of a printer. For example, the number of slits arranged over the range of carriage movement is counted as the carriage moves, and the movement speed of the carriage is slowed down when it approaches a target point, for example, the home position of the carriage. , a speed control method for stopping a carriage at a target point has been proposed.

□ [Problems to be Solved by the Invention] Such a speed control method will work effectively if the current position of the carriage at the start of movement can be accurately recognized. However, if the current position of the carriage at the start of movement cannot be accurately recognized, such as when returning the carriage at an arbitrary position to the home position when the power is turned on, this speed @ control method For example, it is impossible to completely control the speed of the carriage and return the carriage to the home position at the fastest speed.

This invention has been made in view of the above-mentioned circumstances, and an object of the invention is to completely control the speed of the printer carriage no matter what position it is initially in. and the device f! It is to combine them.

[Means for Solving the Problems] In order to achieve the above object, a carriage speed control method according to the present invention detects a position detection part disposed up to a position a predetermined distance away from a target point. , while the position detected part is being detected, the carriage is moved at the optimum speed, and when the carriage leaves the position detected part, the carriage is decelerated for a predetermined period of time, and thereafter the target is moved at the decelerated speed. It is characterized by moving the carriage to a point.

Furthermore, the carriage speed control device according to the present invention includes:
a detection means for detecting whether the carriage is at a predetermined pressure am from the target point; and a detection means for directing the carriage toward the target point when the detection means detects that the carriage is separated from the target point by a predetermined distance or more. to move at optimal speed,
It is characterized by comprising a control means that decelerates when passing the target point and moves B to the target point at a predetermined speed.

[Function] According to the carriage speed control method and device related to the present invention, even if the current position of the carriage cannot be accurately recognized, by detecting the position detected part,
The carriage is moved toward the target point at the optimum speed, and when the carriage is removed from the position-detected part, it is recognized that it is a predetermined distance to the target point, and the carriage is decelerated for a predetermined time. It is designed to move to the target point at a constant low speed.

[Embodiment] Hereinafter, an embodiment of a carriage speed control method and apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

First, the head unit drive system of the printer will be explained with reference to FIG.

As shown, the head unit 10 is fixed on a movable carriage 12. A temperature sensor (not shown) is disposed inside the head unit 10.
It is configured to be able to detect the temperature near the head.

A guide shaft 1 that guides the carriage 12 in a reciprocating manner
4.16 are provided with their opposite ends supported by side plates 18.20, respectively. These guide shafts 14.1
One end (on the side plate 18 side) of 6 is fixed to the side plate 18 with a screw or the like, and the other end (on the side plate 20 side) is supported by the side plate 20 through a notched groove 20a.

A damper 22.24 is attached to the inner portion of each side plate 18.20 of the guide shaft 14.16. Are these dampers 22 and 24 strong against the carriage 12 even if the carriage 12 collides with them? E is provided to prevent grass from entering.

Note that the home position H of the carriage 12 as a target point is defined at the position where the carriage 12 abuts against the damper 24 on the side plate 20 side.

Corresponding to this home position H, a motor 26 for driving the carriage 12 is arranged. A pinion 28 is coaxially attached to the drive shaft of this motor 26.

This pinion 28 meshes with a gear portion 30a of a belt pulley 30 around which one portion of a timing belt 32 is wound. This belt pulley 30 is rotatably supported by a shaft portion fixed to the side plate 20.

On the other hand, the other portion of the timing belt 32 is wound around an idle pulley 34 rotatably supported at a position opposite to the home position H. In this manner, the timing belt 32 is driven to travel by driving the motor 26.

Note that this idle pulley 34 is rotatably supported by a shaft portion fixed to a slide plate 36 that is slidably attached to the side plate 18. The slide plate 36 is slid as appropriate and is fixed to the base plate 18a of the side plate 18 while applying an appropriate tension to the timing belt 32.

This timing belt 32 is partially attached to the carriage 1.
It is fixed to the bottom of 2. In this way, as the timing belt 320 runs, the carriage 12 and the head unit 10 mounted thereon are driven back and forth along the guide shaft 14.16, as shown by arrows X and Y in the figure. I'll do it one day.

A ribbon-shaped slit plate 38 constituting a linear encoder is disposed on the back side of the travel range of the carriage 12. This slit plate 38 is maintained parallel to the guide shaft 16 and tensioned via slit plate receiving portions 18b and 20b provided on each side plate 18.20, respectively.

Further, holes 38a are provided at both ends of the slit plate 38.

38b are formed respectively, and one hole 38a is formed in the side plate 1.
8 and engages with the protrusion 18c formed in the other hole 38b.
The hook of the tension member 40 provided on the side plate 2o is engaged with the portion 40a. This tension member 40 is. The tension member 4o is slidably attached to the end of the guide shaft 16, and is urged outward by a spring (not shown) to apply appropriate tension to the slit plate 3B.

As shown in FIG. 2, this slit plate 38 has equal pitch slits 42 arranged at equal pitches for giving ink ejection timing on the upper side, and a position cover for indicating the print position on the lower side. A zone slit 44 as a detection section is provided along the extending direction of the slit plate 38. One end of the zone slit 44 on the home position H side is set to be spaced apart from the home position H by a predetermined distance.

Furthermore, a light emitting section 46 and a light receiving section 48 that constitute a linear encoder are attached to the carriage 12 so as to face each other with a slit plate 38 interposed therebetween. The light emitting section 46 includes a substrate 46a and a pair of light emitting elements 46b and 46c arranged vertically on the substrate 46a. On the other hand, the light receiving section 48 includes a substrate 48a and a pair of light emitting elements 46b arranged vertically on the substrate 48a.
, a pair of light receiving elements 48b facing each other, 46c,
48c, and a light receiving slit plate 48d disposed between the slit plate 38 and the light receiving elements 48b and 48c.

In this light receiving slit plate 48d, pitch slits 48e having the same pitch are formed at positions corresponding to the equal pitch slits 38a on the upper side of the slit plate 38.
One slit 48f is formed at a position corresponding to the lower zone slit 38b.

Also, corresponding to the home position H, the carriage 12
A home position sensor 50 is attached to the side plate 20 for detecting that one end of the vehicle is at the home position H.

In the configuration described above, the characteristic operation of this embodiment will be explained below.

Usually, the carriage 12 is returned to the home position H at the end of the operation. Therefore, even if the power is turned off and then turned on again,
Since the position of the carriage 12 is regulated by the home position H, the movement start position of the carriage 12 can be accurately recognized.

However, if the power is cut off while the carriage 120 is traveling, the carriage 12 will not return to the home position H but will stop at an arbitrary position. Therefore, when the power is turned on next time, the current position of the carriage 12 will be uncertain.

In such a case, this embodiment operates as follows.

For example, as shown in FIG.
It is assumed that the linear encoder stops at a position shown in , that is, a position facing the zone slit 38b of the slit plate 38 constituting the linear encoder, and that the power is turned on at this position. In this state, the carriage 1 is
2 is opposed to the zone slit 38b, and the carriage 12 is at the maximum speed v as the optimum speed.

The return operation toward the home position H is performed.

Like this, the carriage! No matter which position 2 is, the carriage 12 is at the home position H at the maximum speed ■1.
Since the system returns toward the target position, efficient operation is realized.

This return operation at the maximum speed V is continued until the carriage 12 leaves the zone slit 38b, in other words, until the end of the zone slit 38b is detected as indicated by the symbol B in the figure.

After passing the position indicated by the symbol B, the brake is applied and the carriage 12 is decelerated. Even if the carriage 12 collides with the damper 24, the carriage 12 is moved to the home position H at a constant speed vc within a range in which ink failure does not occur due to the impact.

Here, the time t1 from when the carriage 12 is started until it passes the end of the zone slit 38b is measured,
Depending on the length of this time t1, the time t for applying the brake
2 is determined.

Note that if the starting position of the carriage 12 is above the home position from the position indicated by the symbol B, the carriage 12
is at a constant speed VC from the beginning, moving towards the home position H at 6
be moved.

A circuit for realizing such an operation will be explained with reference to figure 's4.

As shown in the figure, an output signal ZS from a light receiving element 48c outputting information from the zone slit 38b of the encoder.
is applied to one input terminal of the first AND gate 52 and the differentiating circuit 54.

Note that this output signal ZS is set to be "H" when the carriage 12 is facing the zone slit 38b. A reference clock signal from a reference clock 58 is applied to the other input terminal of the first AND gate 52 and one input terminal of the second AND gate 56 .

On the other hand, the output from the first AND gate 52 is given to the first timer 60, and the output of this first timer 60 is
It is applied to a third AND gate 64 via a multiplier 62. Here, the output signal ZS from the zone slit 38b is inverted via the inverter 66, and then sent to the other input terminal of each of the second and third AND gates 56 and 64 and the output signal ZS to the other input terminal of the second and third AND gates 56 and 64, respectively, and the output signal ZS from the zone slit 38b. is given to.

Further, a differentiating circuit 54 and a second and third AND gate 5
The output from 6.64 is given to a second timer 70 as a down counter.

The motor control circuit 68 is connected to the motor 26 and controls the driving of the motor 26.

This motor control circuit 68 includes a CPU, a ROM for storing control programs, and an R used as a work area.
The CPU drives the motor 26 according to a control program written in the ROM. The control program stored in this ROM is as shown in FIG.

That is, when the control is started, in step S1, it is determined whether the output signal ZS from the zone slit 38b is "H", that is, whether the signal from the inverter 66 is "L". . When the output signal ZS is "H", the first timer is started and it is determined in step S2 whether the output signal ZS changes from "H" to "L", and unless it changes, the first timer is started in step S3. The counting operation of the timer is stopped, and the motor 26 is driven so that the carriage 12 moves at the maximum speed vI11, and if it is determined in step S2 that the state has changed from "H" to "H", in step S4 , stops the counting operation of the first timer, applies a brake to the motor 26, and decelerates the carriage 12.

Here, as will be described later, after the initial value of the second timer determined from the count value of the first timer is set at the time when the output signal ZS changes, the second timer 70 starts and the step At s5, it is checked whether the count of this second timer 7o becomes "0", and the deceleration operation continues unless it becomes "0". Further, in step s5, when it is detected that the count value of the second timer 70 has become "0", the deceleration operation is canceled in step s6, and in step S7, the carriage 12 is moved to a speed v
The motor 26 is driven so that the vehicle travels at a constant speed at c.

Note that if the output signal Zs is not "H" in step S1, step S7 is immediately executed.

After this step S7 is executed, in step S8, it is determined whether the carriage 12 reaches the home position H based on the detection signal TS from the home position sensor 50, and unless the carriage 12 reaches the home position H, step S7 is continued. On the other hand, if it is determined in step S8 that the carriage 12 has reached the home position H, step S9
At this point, the driving of the motor 26 is stopped, and the operation of returning the carriage 12 to the home position H is completed.

Next, referring again to FIG. 4, the operation of the illustrated circuit will be described.

That is, when the carriage 12 is stopped at the position indicated by A in FIG. 3, the output signal ZS is "H" and the first
AND gate 52 is opened, and motor control circuit 68 moves carriage 12 toward home position H at maximum speed vII+ without using second timer O. Furthermore, by opening the first AND gate 52, the first timer 60 starts counting time using the reference clock 58.

When the carriage 12 reaches the position indicated by B, the output signal zS is inverted and becomes "H", and the motor control circuit 68 starts decelerating the motor 26. In response to the inversion of this signal, the pulse signal generated in the differentiating circuit 54 is input to the second timer 70, so that the first timer 60
The time tl counted by is multiplied by a predetermined number via the multiplier 62, and the second timer 70
sent to.

Then, by inverting the output signal zS, the second A
The ND gate 56 is opened, the reference clock signal from the reference clock 58 is inputted to the second timer 70, and in response, the second timer 70 receives the reference clock signal corresponding to the time t1 counted by the first timer 60. The current down operation starts from the time t2 set.

In this way, the second timer 70 changes its output to "0".
The motor control circuit 68 performs a deceleration operation until the time is reached. Then, when the output of the second timer 70 becomes "O", the motor control circuit 68 moves the carriage 12 at the speed VC.
Change to move at a constant speed of H
The operation will stop when it reaches .

As described in detail above, according to this embodiment, the operation of moving the carriage to the home position can be executed at high speed when the control system is initialized when the power is turned on, or after the printing operation is completed. In addition, even if a home position sensor is not provided, it is possible to prevent ink from being ejected due to the impact of the carriage colliding with the damper.

In addition, the above operation can be performed by using software.
It becomes possible to significantly reduce the circuit scale.

Furthermore, by using a servo mechanism in the speed control circuit,
By using a current limiter that can stabilize the speed and can be variably controlled, it is possible to prevent the motor from seizing in the event of a collision or the like.

[Effects of the Invention] As described in detail above, the carriage speed control method according to the present invention detects a position detected part disposed up to a predetermined distance from a target point, and While detecting the position, the carriage is moved at the optimum speed, and when the carriage is removed from the position detected part, the carriage is decelerated for a predetermined period of time, and thereafter the carriage is moved to the target point at the reduced speed. It is characterized by things. Further, the carriage speed control device according to the present invention includes a detection means for detecting whether or not the carriage is separated from a target point by a predetermined distance; When the carriage is detected, the carriage is moved toward the target point at an optimum speed, and when the carriage passes the target point, the carriage is decelerated, and the carriage is moved to the target point at a predetermined speed. Therefore, according to the present invention, it is possible to provide a carriage speed control method and apparatus that can completely control the speed of a printer carriage, no matter what position it is initially in.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of a carriage speed control device according to the present invention, Fig. 2 is an exploded perspective view showing a linear encoder used in the speed control device shown in Fig. 1, and Fig. 3 4 is a diagram showing an embodiment of the carriage speed control method according to the present invention, FIG. 4 is a circuit diagram showing a circuit for executing the speed control method shown in FIG. 3, and FIG. 3 is a flowchart showing a ROM control program. In the figure, 10... Head unit, 12... Carriage, 14. 16... Guide shaft, 18.
20... Side plate, 22; 24... Damper, 2
6...Motor, 28...Pinion, 30...
・ Belt brake, 32... Timing belt, 34... Slide plate, 36... Slit plate, 40... Tension member, 42... Equally spaced slits, 44... Zone slit , 46
... Light emitting section, 48... Light receiving section, 50... Home position sensor, 52... First AND gate, 54... Differential circuit, 56... Second AND
Gate, 58... Reference clock, 6°...
First timer, 62... Multiplier, 64...
Third AND gate, 66... Inverter, 68
...Motor control circuit, 70...Second timer.

Claims (11)

[Claims] (1) Detect the position detected part placed a predetermined distance away from the target point, and while detecting this position detected part, move the carriage at the optimum speed so that the carriage does not move at the position detected position. A method for controlling the speed of a carriage, which is characterized in that the carriage is decelerated for a predetermined period of time when the carriage comes out of the detection section, and thereafter the carriage is moved to a target point at the reduced speed. (2) Carriage speed control according to claim 1, wherein the predetermined time for decelerating the carriage is set corresponding to the time during which the position detected portion is being detected. Method. (3) The reduced speed is set to a speed within a range that does not give an excessive impact to the carriage when the carriage collides with the target point. Carriage speed control method described in . (4) The carriage speed control method according to claim 1, wherein the target point is a home position of the carriage. (5) The carriage speed control method according to any one of the preceding claims, wherein the position-detected portion includes a zone slit. (6) Carriage speed control according to any one of the preceding claims, characterized in that when the position detected part is not detected in the initial stage, the carriage is moved to the target point at a constant predetermined speed. Method. (7) The predetermined speed is set to a speed within a range that does not give an excessive impact to the carriage when the carriage collides with the target point. The described carriage speed control method. (8) detection means for detecting whether or not the carriage is separated from the target point by a predetermined distance; and when the detection means detects that the carriage is separated from the target point by a predetermined distance or more, the carriage is moved to the target point; 1. A speed control device for a carriage, comprising control means for moving the carriage at an optimum speed towards the target point, decelerating the carriage when the carriage passes the target point, and moving the carriage at a predetermined speed to the target point. (9) The detection means includes a zone slit extending along the traveling direction of the carriage, and the zone slit has an end portion spaced a predetermined distance from the target point. A carriage speed control device according to scope 8. (10) The detection means detects that the carriage is separated from the target point by a predetermined distance or more when the carriage is facing the zone slit, and when the carriage is out of the zone slit, the carriage is located at the target point. 10. The carriage speed control device according to claim 9, wherein the carriage speed control device detects that the carriage is located within a predetermined distance from the carriage. (11) The control means includes a first timer that measures the time during which the carriage is moving while facing the zone slit, and sets a deceleration time of the carriage based on the time measured by the first timer. 11. The carriage speed control device according to claim 10, further comprising a second timer for controlling the speed of the carriage.