JPH01308639A - Ink-jet printer - Google Patents

Abstract

PURPOSE:To cap an ink discharge head positively even when a power supply is interrupted carelessly by providing a carrier scanning mechanism with a spring means returning a carrier to the position of standby by resilient force and furnishing a cap mechanism with a means utilizing the restoring force of the carrier as the driving force of the carrier. CONSTITUTION:The scanning process of a carrier 3 is conducted against the force of a return spring 16, and resilient force for returning the carrier is accumulated gradually in the return spring 16. When setting is completed, a motor 8 is stopped, a plunger 5 is de-energized, the engagement of a plunger shaft 5a and a lead screw shaft 2 is released, and the carrier 3 is returned to constraint in the D direction by the force of the return spring 16. Capping operation and paper-feed operation are conducted by the force of the return spring 16, these operation is not interrupted even when a power switch is turned OFF during carrier return, and the clogging of a nozzle based on the careless opening of the nozzle is prevented completely.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ink jet printer, and particularly to a serial type ink jet printer in which an ink ejection head is moved along a recording medium.

(Prior Art and Problems to be Solved by the Invention) Conventionally, inkjet printers either have a cap mechanism to prevent the nozzles from clogging, or if the power is turned off in the middle of printing, the nozzles are left uncapped and the nozzles become clogged. There was a problem with it drying out and making it impossible to print.

Also, in order to solve the above problem, it is possible to consider a so-called power-off sequence mechanism in which the power supply is set to two stages and the safety switch is used as the power supply, or the cost increase due to additional circuits and switches cannot be avoided, and if the power supply is unplugged. was unable to respond.

(Means and effects for solving the problems) In view of the above problems, the present invention includes a carrier scanning mechanism equipped with a spring means for returning the carrier by a spring force, and a cap mechanism that applies the returning force of the carrier to the carrier scanning mechanism. The configuration is such that a means for use as driving force is provided. This ensures that the ink ejection head is capped even if the power is inadvertently turned off.

(Example) Embodiments of the present invention will be described above with reference to the drawings.

FIG. 1 is an overall perspective view showing one embodiment of the present invention, and FIG. 2 is a partially exploded perspective view. In FIGS. 1 and 2, l has a base, a left side plate 1a, and a right side plate 1b which are erected in parallel and integrated. A guide portion 1d for guiding a carrier, which will be described later, is formed on the front plate of the IC.

Le is a motor mounting base, If is a motor bearing plate, and 1g beam is a screw bearing plate, all of which are integrally provided at a predetermined position on the base l.

A lead screw shaft 2 is rotatably supported between the right side plate 1b and the lead screw bearing plate 1g.

Lead screw shaft 2 has lead grooves 2a spirally formed at a predetermined pitch, and a bevel gear 2b integrally formed at one end. A carrier 3 is slidably attached to the lead screw shaft 2, and the rear guide groove 3a or the kite portion 1d of the base 1 is inserted between the carrier and the lead screw shaft 2. 3
A cap lever pressing portion b is integrally formed with the carrier 3. 3C is a paper feed trigger pawl, which is also integrally formed on the underside of the carrier. 3d is a brake protrusion, which is integrally formed at the rear of the carrier. 4 is a stopper,
It is formed of a soft material such as rubber or urethane, and is attached to the left side of the carrier 3.

A plunger 5 is attached to the left side of the carrier 3, and when energized, the plunger shaft 5a is attracted and protrudes.
It is designed to engage with the sorting groove 2a of the lead screw shaft 2.

Reference numeral 6 denotes an ink sheet head, which is a so-called disposable type print head that is integrated with an ink tank 6a, and has a nozzle (not shown) formed in the center of the nozzle 6b. The print head 6 is detachably attached to the carrier 3 and comes into contact with a contact portion (not shown) provided on the bottom surface or a contact portion (not shown) provided on the top surface of the carrier 3.
It has continuity. A flexible cable 7 connects a contact portion (not shown) provided on the carrier 3 and a control board (not shown).

Next, the drive mechanism will be explained with reference to FIG.

Reference numeral 8 denotes a drive motor, which may be a DC motor that rotates only in one direction, and is attached to a motor mount le on the base l. Reference numeral 9 denotes a guide portion that is attached concentrically with the motor shaft, which will be described later.

The tip of the motor shaft lO is rotatably supported by the motor bearing plate If of the base l.

Reference numeral 11 denotes a rotary encoder, which is attached to the end face of the motor 8 and generates predetermined pulses by rotation of the motor shaft IO.

Note that the rotary encoder 11 may be a slit disk and a photosensor, or may be a method of detecting changes in magnetic flux using a magnet, and is not particularly limited.

Reference numeral 12 denotes a sprinkling kite for guiding a lead screw to be described later, and a groove 12a is formed on the outer periphery of the sprinkling kite for guiding a lead screw 16 to be described later. Also hole 12b
enters the guide portion 9 and is held rotatably.

A gear shaft 13 is formed at one end of the bevel gear 13a and meshes with the bevel gear 2b of the lead screw 2.

Further, a boss portion 13b around which a clutch spring 14 (described later) is wound is formed at one end of the gear shaft 13. The gear shaft 13 is fixed to the motor shaft IO.

A clutch spring 14 is wound around the boss portion 13b of the gear shaft 13, and functions as a so-called spring clutch.

14a is a trigger part, and 14b is a connecting part.

15 Ohm gear, connection part 14 of clutch spring 14
A hole 15a for engaging with b is formed at the end,
It is rotatably attached to the motor shaft 10.

Returning to FIG. 1, 16 is a return spring, one end of which is fixed to the left side of the carrier 3, the middle part of which is guided by the groove 12a of the sprink guide 12, and 180
'The direction is changed and the other terminal is fixed to the right side plate 1b.

A trigger arm 17 is rotatably attached to a shaft erected on the base 1, and is biased in one direction by a splinter (not shown), or a portion of the trigger arm 17 is in contact with a stop shaft 18 erected on the base 1. Rotation is restricted by contact and stopped at a predetermined position. A stop portion 17a is provided at one end of the trigger arm 17 at a position where it contacts the trigger portion 14a of the clutch spring 14, and a stop portion 17a is provided at the other end so as to engage with a paper feed trigger pawl 3c formed at the bottom of the carrier 3. arm claw 17
b is formed.

The arm claw 17b is made of a thin plate so that the rough portion 17c can be deformed.

Reference numeral 19 denotes a cap shaft, which is erected on the left side plate 1a and has a stepped shape. A cap arm 20 is attached to the cap shaft 19 so as to be rotatable and slidable in the axial direction. Reference numeral 20a represents a contact portion, which is formed at a position where it contacts the carrier lever pressing portion 3b of the carrier 3. Reference numeral 21 represents a cap, which is formed of a soft material such as rubber, and is positioned at a predetermined position of the cap arm 20. The cap spring 22 has a coil section inserted into the cap shaft 19 and is used as a compression torsion spring, and has the function of urging the cap arm 19 away from the cap 21 from the head by the terminal 22a, and the function of the coil section. It has a function of pressing the cap arm 20 against the stepped portion of the cap shaft 19. A stop washer 23 is attached to the end of the cap shaft 19 and receives the end 22b of the cap spring 22.

A cap cam 24 is installed upright on the left side plate 1a, and when the cap arm 20 slides on the cam portion 24a, the cap 21 is rotated in the direction 6 toward the printing spatula 1 to perform capping.

A flake rubber 25 is attached to the left side plate 1a, and is cleaned by scanning the nozzle surface 6b of the print head 6 with the carrier.

Reference numeral 26 denotes a paper feed roller shaft, which is rotatably attached to the left side plate 1a and the right side plate 1b, and has a worm wheel 26 at one end.
A is stuck.

A paper feed roller 27 has a cylindrical shape and is fixed to the paper feed roller shaft 26. 28 is a printing paper.

Reference numeral 29 is a paper press plate that holds the printing paper 28 and presses the paper feed roller 27.
It is in pressure contact with the

30 is paper bread.

A brake arm 31 is rotatably attached to the front plate lc of the base l. A brake arm spring 32 biases the brake arm 31 in one direction. The rotation of the brake arm 31 is restricted by a stopper (not shown), and the brake arm 31 is stopped at a predetermined position. 33 is a rotary tamper, which may be an oil tamper 1 or an air tamper, and has a flake protrusion 3d provided on the rear surface of the carrier 3, or a flake protrusion 3d which is fixed so as to maximize the flake effect when it suddenly comes into contact with the brake arm 31. has been done. 34 is a home position detection switch, which is attached to the 171 board 1c;
When you reach carrier 3 or the left end, make contact with the piece.

Next, the operation of the above embodiment will be explained mainly with reference to the timing chart shown in FIG.

First, the motor 8 is energized to rotate the lead screw shaft 2 in eight directions. In this state, carrier 3
is pushed to the left end by the force of the return splinter 16. Therefore, the cap arm 20 is also pressed to the left end, and the cap 21 is pressed against the nozzle surface 6b of the print head 6 by one movement of the cap cam 24a, thereby maintaining the cap state.

Next, when the sorting screw shaft 2 reaches a predetermined speed or reaches a predetermined speed, the plunger 5 is energized. As a result, the plunger shaft 5a protrudes and fits into the lead groove 2a of the rotating lead screw shaft 2 while the screw shaft 2 rotates at least once. This state is shown in FIG. 5(a).

Sorting groove 2a of lead screw shaft and plunger shaft 5a
When the carriers 3 and 3 are fitted together, the carrier 3 starts moving in the direction C in FIG. After this, when the carrier 3 enters the printing range, printing (recording) is performed on the printing paper 28 by the printing head 6.

This scanning process of the carrier 3 is performed by the return spring 16
Therefore, during this time the return spring 1
6 is accumulating spring power for career return. Note that the return splinter 16 has a length sufficient for the range of movement of the carrier 3, and is curved and guided by a rotatable spring guide in the middle, so that the spring constant is It is possible to make the motor 8 smaller.
Load fluctuations are set to an almost negligible level.

Also, since printing is performed while receiving a printing timing signal from the rotary encoder 11, the carrier 3
Even if there are speed fluctuations, the position of the printed item will not drop.

In addition, if you want to further improve the position of printed items.

It has two systems of motor drive voltage and one rotary encoder.
All you have to do is check the timing signal in step 1 and apply the electronic servo.

When printing is completed, the motor 8 is stopped, and then the plunger 5 is de-energized. As a result, as shown in FIG. 5(b), the engagement between the plunger shaft 5a and the word screw shaft 2 is released, and the carrier 3 is returned to the restraint in the direction in FIG. 1 by the force of the return spring 16.

When the carrier 3 moves out of the printing range and comes in front of the home position r, it comes into contact with the flake protrusion 3d of the carrier 3 or the flake arm 31, and the carrier is greatly decelerated. After this, while the carrier 3 is further moved to the Baume position, the cat bink operation and paper feeding operation are started.

First, when the carrier 3 moves toward the home position from the state shown in FIG. 3(a), the trigger claw 3c of the carrier and the arm claw 17b of the trigger arm 17 engage, and
Rotate the trigger arm 17 in the E direction as shown in b).

When the trigger arm 17 rotates, the trigger portion 14a of the clutch spring 14 escapes from the stop portion 17a and is released. As a result, the clutch spring 14 is wound around the boss portion 13b of the gear shaft 13, and the clutch is turned on, resulting in a power transmission state. At this time, the trigger part 14 of the clutch spring 14
When the stop part 17a escapes, the stop part 17a enters the distance #S corresponding to the color of the clutch breaking, and even if the motor 8 is stopped, the trigger arm 17 will not return and lock again. .

Almost parallel to the clutch ON operation described above, the pressing portion 3b of the carrier 3 presses the abutting portion 20a of the cap lever 20 toward the home position as the carrier moves, and moves the cap lever 20 in the center direction in FIG. move it to The moved cap lever 20 is pressed on its back side by the cam portion 24a of the cap cam 24, and performs a capping operation of pressing the cap 21 against the printing pad 6.

This capping operation is completed before the carrier 3 reaches the home position at the left end in FIG. On the other hand, the paper feeding operation is not completed even when the carrier 3 reaches the home position.The paper feeding operation will be explained next.

First, the carrier 3 returns, the trigger arm 17 rotates in the E direction in FIG. 3(b), and the clutch consisting of the clutch spring 14, the boss portion 13b of the gear shaft 13, etc. is turned on as described above. Ta. Thereafter, before the carrier 3 reaches the home position, the motor 8 is energized and rotated in the direction C in FIG. This causes the worm gear 15 to rotate,
The paper feed roller 27 is conveyed in the paper feed direction (F direction).

However, this rotation of the worm gear 15 rotates once and then stops 1x. The reason for this is that while the worm gear 15 rotates once, the carrier 3 moves and the arm claw 17b of the trigger arm 17 and the trigger claw 3C of the carrier 3 engage or disengage. This is because, as shown in ), the trigger arm 17 has returned to the same state as in FIG. 3(a) due to the spring force. Therefore, when the worm gear 15 rotates once and returns, the trigger part 1 of the clutch spring 14
4a is again engaged with the stop portion 17b of the trigger lever 17, the clutch is turned off, and the transmission of the rotational force of the motor 8 to the worm gear 15 is cut off.

The paper feed amount by one rotation of the worm gear 15 is equivalent to one scanning vertical width of the print head 6.

By performing the above actions, I reached 3rd place in career or home position.
After confirming that the home position detector 34 or ONI has returned to the carrier 3, the printing process ends. When printing next time, the above operation will be repeated, or when the carrier 3 moves in direction C, as shown in FIG. 4(b),
Arm claw 17b escapes downward, trigger arm 1
7, it will not rotate in the opposite direction.

As described above, according to this embodiment, the motor 8 performs the scanning of the recarrier 3, the operation of the cap 21, and the paper feed roller 27.
The number of parts decreases and the number of parts decreases, causing the parts to perform the following actions.
It becomes possible to create a new model and lower costs. Furthermore, since the character pinking operation and paper feeding operation are performed by the force of the return spring 16, even if the power switch is turned off while the carrier is being restored, these operations will not be interrupted. This is particularly important in character pink operations, as it completely prevents nozzle clogging due to inadvertent opening of the nozzle.

FIG. 7 shows another embodiment, in which the same reference numerals as those in the above-mentioned embodiment are given to rotating parts, or illustrations thereof are omitted. 3
5 is a guide shaft, 36 is a wire winding pulley 37
The wire is wound around the wire several times, and tension is applied by a tension pulley 38 provided at the other end. wire 36
A part of the carrier 3 is fixed to the carrier 3.

A tension arm 39 rotatably supports the tension pulley 38, and generates tension force using the spring force of the arm portion 39a.

The take-up pulley 38 is rotatably attached to the motor shaft lo. 4o is an electromagnetic clutch that is energized to engage the clutch and connect the motor shaft 10 and the take-up pulley 38.

In the above configuration, the carrier 3 is scanned by controlling the energization of the electromagnetic clutch 40, and by turning off the energization, the driving force is cut off and the carrier 3 is returned to the home position by the return spring 16. The N-yap mechanism, paper feed mechanism, and rake mechanism are the same as those in the previous embodiment.

(Effects) As described above, according to the present invention, even if the power is accidentally turned off and stored, the carrier is always capped by the spring means of the carrier scanning mechanism and the carrier restoring force utilizing means of the capping mechanism. In addition, it is possible to provide a highly reliable inkjet printer that does not cause clogging of the inkjet head.

[Brief explanation of the drawing]

Figure i1 is an overall perspective view of an embodiment of the present invention. Figure 2 is a detailed explanation of the drive mechanism. Figures 3 (a) to (c) are illustrations of the operation of the trigger arm. Figures 4 (a) to (c) are illustrations of the trigger arm. 5(a) and 5(b) are diagrams explaining the relationship between the lead screw shaft and the plunger. Figure 6 is a timing chart. Figure 7 is a perspective view of another embodiment. 1...Base, 2...・Lead screw, 3
...Carrier, 5...Plunger 6...Print head, 8...Motor 11...Rotary encoder, 13...Gear shaft 14
...Clutch spring, 15...Worm I6...
・Return spring, 17...Trigger arm, 21...Cap 26a
...Two ohm wheels, 27...Paper feed roller, 2nd...Printing paper/7
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Claims (1)

[Claims] In an inkjet printer, the carrier scanning mechanism includes a carrier scanning mechanism that reciprocates a carrier carrying an inkjet head along a recording medium, and a cap mechanism that covers the ejection part of the inkjet head when it returns to a standby position. An inkjet printer comprising a spring means for returning the carrier to a standby position by a spring force, and wherein the cap mechanism has means for using the returning force of the carrier as its driving force.