JPS63115755A - Inkjet recovery device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to an ink recovery device for an inkjet recording apparatus, and specifically to a means for controlling the amount of ink suction when sucking ink from a nozzle of an inkjet recording head. The present invention relates to an ink recovery device comprising:

[Prior Art] Generally, in an inkjet recording apparatus, in order to prevent ink discharge failure caused by clogging of the ink discharge ports provided in the recording head or air intrusion from the ink discharge ports, An ink recovery device may be provided to normalize ink ejection by sucking ink from the ink ejection ports.

However, with conventional ink recovery devices of this type, recovery operations were performed using a preset constant amount of ink suction regardless of the degree of clogging or air entrainment, so in some cases, the amount of ink suction was more than necessary. There was a problem that the ink was sucked and the ink was wasted.

[Problems to be Solved by the Invention] Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide an ink recovery device that can adjust the amount of ink suction according to the degree of ink ejection failure. be.

[Means for Solving the Problems] In order to achieve such an object, the present invention provides a suction means for suctioning ink from a nozzle portion of an inkjet recording head, and a variable setting time for sucking ink by the suction means. The invention is characterized by comprising a control means for.

[Function] The present invention uses a pulse motor to operate a cap mechanism that seals the orifice of a nozzle of a recording head, a negative pressure generation source as a suction means connected to a suction tube connected to this sealing cap, and an atmosphere release mechanism. Since the pulse motor is stopped when a negative pressure is generated and the timing of operation of the atmospheric release mechanism is controlled, the amount of ink suction can be adjusted.

[Examples] Examples of the present invention will be specifically described below with reference to the drawings.

FIG. 2 shows an example of a schematic configuration of a liquid jet recording apparatus adapted to the present invention.

In FIG. 2, 1 is a recording head, and the recording head 1
has an ink reservoir supplied from an ink supply source, a channel for ejecting the stored ink, and an orifice formed at the tip thereof, and a means for generating energy for ejecting the ink, such as electricity. It is equipped with an energy converter consisting of a voltage element, which is one of the mechanical converters, and a heating resistor, which is one of the electrothermal converters.

This recording head 1 is one in the case of monochrome recording, but
In the case of color recording, for example, four inks are provided depending on the color of the ink.

These recording heads 1 are mounted on a carriage 2, and the carriage 2 has two wooden guides! T! 1II18, so as to be freely slidable.

The recording head 1 is connected to the carriage 2 by a flexible cable 6, and control signals for the recording head 1 are sent thereto.

Further, although not shown in the drawings, the carriage 2 is connected to wiring for carrying out signal input from the main body of the apparatus.

The carriage 2 is fixed in the middle of an endless belt 14, and the carriage 2 is reciprocated by running the belt 14 with a motor 16.

One set of upper and lower rollers 10°lO parallel to the guide shaft 18
and 12 and 12 are provided facing the carriage 2, and the recording paper P is guided while being sandwiched between the respective rollers.

A paper feed motor 8 is fixed to one end of the roller lO, and feeds the recording paper P.

On the other hand, the home position H is provided with a suction recovery device 20 according to the present invention.

Examples of embodiments of this suction device are shown in FIGS. 1 and 3.

The suction recovery device 20 is assembled based on a substrate 20a, and a pulse motor 25 for driving a pump 26 is fixed to a part thereof.

The first cam plate 24, which is provided integrally with the gear 24b, is rotated by the pulse motor 25 via a pinion gear 25a, gears 25b, 25d, and 24b fixed to the output shaft of the pulse motor 25. A second cam plate 19 is fixed coaxially with the gear 24b between the first cam plate 24 and the gear 24b, and the second cam plate 19 is also rotated by the pulse motor 25.

Two trapezoidal cams 24a are provided on the upper surface of the first cam plate 24, spaced apart by a predetermined angle in the circumferential direction. A cam portion 2nd constituting a ventilation opening/closing portion is protruded in a symmetrical manner from the circumferential surface of the first cam plate 24.

Furthermore, a cam portion 24c is also provided on the circumferential surface of the second cam plate 19.
A detection switch 30 consisting of a microswitch or the like detects the operation of the cam portion 24c.

Reference numeral 29 denotes a pump lever that moves the piston 26a of the pump 26 up and down, and the pump lever 29 is rotatably mounted via a tld 29b provided on a support frame 29a protruding from the base plate. There is.

A roller 29 is provided at the tip of the pump lever 29 to ride on a cam 24a protruding from the first cam plate 24.
c is provided. Further, the other end of the pump lever 29 is in contact with the piston 26a of the pump 26 via a projection 29d. Therefore, the cam 24 rotated by the roller 29c
Each time the pump lever 29 touches the piston 26
Move a up and down.

Ink is sucked from the recording head 1 by this vertical movement of the piston 26a. The piston 26a is always given a force in the protruding direction by a spring provided in the pump, and the roller 24c side is always set on the first cam plate 24.

21 is a cap holder, and the cap holder 21 holds caps 22a to 22d that are in close contact with the nozzle portion of the recording head 1 and suck ink. This cap holder 2
A plurality of caps 22a to 22d made of an elastic member such as rubber are fixed to the cap 1.

Each of the caps 22a to 22d is provided with an ink absorber 37 on the lower inside thereof, and each cap is separately connected to the pump 26 via tubes 27a to 27d.

This cap holder 21 is slidably provided on the substrate 2Qa, and a spring (not shown) is attached to the pump 26.
It is constantly pressed in the direction away from. Further, a gear 23 is rotatably supported on the lower side of the cap holder 21.

An inner cam 23a is formed on the upper surface of the gear 23, and a shaft 21a protruding from the lower end of the cap holder 21 is in contact with the inner cam 23a via a roller.

Therefore, as the gear 23 rotates, the cap holder 21 repeatedly returns to the pump 26 side by the protrusion of the cam 23a. Note that the cap holder 21 is located at the switch 31.
detected by.

On the other hand, each cap 22a-22d has, in addition to tubes 27a-27d for ink suction, ventilation cubes 28a-28d for ventilating the suction system when each cap 22a-22d is in close contact with the nozzle portion of the recording head 1. The ventilation cubes 28a to 28d reduce the pressure increase in the suction system that occurs when the caps 22a to 22d are brought into close contact with the nozzle' portions by ventilation.

The other ends of the ventilation tubes 28a to 28d are fixed to a support frame 21b integral with the cap holder 21 and located between the first cam plate 24 via a rubber stopper 32, as shown in FIG. Further, the upper end of the support frame 21b is rotatably supported on the upper end of a rotary lever 35 via a shaft 36.

The lower end of the rotating lever 35 is located at a position facing the first cam plate 24, and a plug 33 is located at a position facing the rubber plug 32.
has. The rotating lever 35 is pressed toward the first male plate 24 by the return plate 35a. Further, the stopper 33 is pressed toward the rubber stopper 32 by a spring 33a, and its working limit is regulated by a stopper 33b.

Therefore, according to the rotation of the first cam plate 24, the cam plate 2
When the flat parts P and Q of 4 come into contact with the rotating lever 35, the ventilation in the tubes 28a to 28d can be opened and closed.

FIG. 5 shows the operation timing of each component in the suction recovery device 20 when the recording head 1 is located at the home position H.

In FIG. 5, when the recording head 1 finishes printing one line and is positioned in front of the suction recovery device 20, the pulse motor 25
starts operating, and the first cam 24. The inner cam 23a and the second cam 19 are rotated.

Then, the cap holder 21 is pressed toward the recording head 1 side at timing A by the inner cam 23a, and the cap 22a
The caps 22a to 22d are in close contact with the nozzles of the recording head 1, and at timing B, the caps 22a to 22d are "closed".

Further, the second cam 19 turns the microswitch 31 OFF at timing C to detect that the cap is closed.Furthermore, the first cam 24 causes the ventilation tube 28 to
The plugs 33 from a to 28d are at timing D and timing E.
When the rotation of the ventilation system and the first suction cam 24 progresses, the roller 29c of the pump lever 29 rides on the cam 24c at timing F, so the pump lever 2
9 actuates the piston 26a.

The pump 26 is in a suction operation state, and the negative pressure of the pump 26 is applied to the cap 22a22 via the suction tubes 27a to 27d.
d, and the ink is sucked from the nozzle orifice of the recording head 1. When this state of attraction actually begins,
This is the point in time when a predetermined period of time has passed since the pump 26 starts operating, and is the timing F-1 shown in FIG. 5, that is, the point in time when the pulse is applied n after the pulse motor 25 starts operating.

From this point on, motor control for temporarily stopping the pulse motor is started. This motor control time is managed by a timer described later. This motor control makes it possible to delay the timing of venting the suction system, which is under negative pressure.In other words, by controlling the negative pressure suction holding time of the suction system, the amount of ink suction can be variably controlled. Become.

In addition, the pulse motor 25 can be temporarily stopped by the pulse motor 25.
All you have to do is turn off the power to the terminal or stop the 8th shift of the phase.

By controlling the amount of ink suction, it is possible to maintain an appropriate suction time, especially when suctioning ink from a single color multi-nozzle, when suctioning ink from multiple multicolor recording heads, or when the orifice diameters of the nozzles are different. is possible.

As explained above, by performing a series of operations in which the pulse motor is rotated in one direction, the pulse motor is rotated to a specified pulse rate, the pulse motor is stopped for a certain period of time, and then restarted. Recovery by pressure suction becomes possible.

FIG. 6 shows an example of a circuit configuration in an embodiment of the present invention.

In FIG. 6, 101 is a control unit that drives and controls the pulse motor 25, and the control unit 101 includes an arithmetic processing unit (CPU) 101-1 that executes the control procedure shown in FIG. 7, and stores this control procedure. Read-only memory (ROM)
) 101-2, random access memory (RAM) that stores counters and variables used in this control procedure
101-3.

Reference numeral 102 is a timer that measures the time for which the pulse motor 25 is temporarily stopped.

FIG. 7 shows an example of the control procedure of the control 101 in the embodiment of the present invention.

In FIG. 7, when a microswitch (not shown) detects that the recording head has finished printing and is located at the home position H shown in the second drawing, the control section 101 starts the pulse motor 25 in step S1. motor 2
5 begins to rotate, the recovery system 20 brings the caps 22a to 22d into close contact with the recording head 1, and the tube 2
Since ventilation and pump driving of 8a and 28d are performed, ink is sucked from the recording head 1.

Next, the control unit 101 counts the drive pulses of the pulse motor 25 (Step S2), and when the number of pulses reaches a predetermined number n1, stops the pulse motor 25 (Steps 53 to 5).
4).

Next, the control unit 101 sets the timer 104 to temporarily stop the pulse motor 25 for a predetermined period of time (steps 54 to S5).
). At this time, even if the pulse motor 25 is stopped, ink suction continues as long as the suction system is under negative pressure, so the longer the pulse motor is temporarily stopped, the greater the amount of suction ink will be.

Note that although the timer 102 is provided in this embodiment, the CPU
Time may be counted by counting reference clock pulses within l0I-1. ' When the timer 102 measures the starting time of the motor 25,
Based on the detection signal, the control unit 101 starts the motor 25, and performs empty suction inside the cap in a ventilation state using the pump 26, which maintains negative pressure. Next, in steps 57 to S8, when the number of pulses of the pulse motor 25 reaches the number of pulses that rotates the cam 24 once, the control section 101 stops the pulse motor 25 and ends this control procedure.

In the embodiment of the present invention, the ink suction amount is controlled by variably setting the pause time of the pulse motor 25.
The inflow suction amount may be controlled by driving at a low frequency during this period.

[Effects of the Invention] As is clear from the above description, according to the present invention, the difference in negative pressure suction time caused by the number of nozzles in the recording head, the number of installed orifice holes, etc. can be compensated for by the drive source of the recovery device. By controlling only the pulse motor, it is possible to secure the amount of ink suction for proper ejection recovery and prevent unnecessary consumption of ink, which has the effect of downsizing the ink supply device. It will be done.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a configuration in an embodiment of the present invention, FIG. 2 is a perspective view showing an example of a main part of a recording device to which the present invention is applied, and FIG. 3 is a suction recovery in an embodiment of the present invention. A plan view of the device, FIG. 4 is a side view of the ventilation opening/closing mechanism in the embodiment of the present invention, FIG. 5 is a timing chart explaining an example of the operation in the embodiment of the present invention, and FIG. 6 is the circuit configuration in the embodiment of the present invention. Block diagram showing an example. FIG. 7 is a flowchart showing an example of a control procedure in an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Recording head, 2... Carriage, 19... Second cam plate, 20... Suction recovery device, 21... Cap holder, 22a 22d... Cap, 23.24b... - Gear, 24... First cam plate, 25... Pulse motor, 26... Pump, 27a 27d... Tube, 28a 28d -... Ventilation tube, 29... Pump lever, 33. ... Plug, 35 ... Rotating lever, 37 ... Absorber, 101 ... Control unit, 101-1 ... CPU, 101-2 ... ROM. 101-3...RAM. 102...Timer. FIG. 3 is a plan view of the suction recovery device 20 in the embodiment of the present invention.

Claims (1)

Claims: An inkjet recovery device comprising: suction means for sucking ink from a nozzle portion of an inkjet recording head; and control means for variably setting a time period during which the suction means sucks the ink.