JPH0493260A - Ink jet printer - Google Patents

Abstract

PURPOSE:To prevent a nozzle from clogging to improve a printing quality by a method wherein a recording head is moved to a position opposed to a suction device by a controller based on an earlier time between a time elapsing a predetermined time from an initial time and a time upon completion of printing of a predetermined amount of data, and a nozzle clog is removed by the suction device. CONSTITUTION:A clog removing action is performed based on an earlier time between a time T2 elapsing a predetermined time (t) from an initial time and a time T1 at the end of a time (a) required for printing a predetermined amount of data. In this case, the action is based on the time T1. Namely, after a recording head 4 is moved to a position opposed to a suction device 11, a nozzle clog is removed by the suction device 11. A time required for this movement and clog removal is ignorably short in comparison with the times (t), (a). Therefore, the start and end times of the movement and clog removal action are assumed to be the same. The movement and clog removal action is repeated based on the end time T1 as a new initial time.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an inkjet printer that rationally controls a suction device for removing clogged nozzles so that printing functions can be performed smoothly.

[Conventional technology]

A conventional example will be described below with reference to the drawings. FIG. 4 is a perspective view of a conventional example. Note that this figure is also common to the perspective view of the embodiment. In the figure, LA and IB are side plates made of steel plates, which are erected on the base 10 parallel to each other,
It constitutes a frame in which each mechanism described later is installed. A guide rail 2 is installed between the side plates IA and IB at right angles thereto, and guides the carriage 3 in its travel. A recording head 4 is mounted on this carriage 3. 5 is a belt, and a predetermined portion thereof is fixed to the carriage 3; 6 is a motor that drives the belt 5; That is, the motor 6 is attached to the outer surface of the side plate 1B, and the recording pad 4 is driven to travel via the belt 5 by the motor 6. Reference numeral 7 denotes a cylindrical platen, around which the recording paper 9 is wound less than once, and is fed out, facing the recording head 4 at a predetermined location on the outer circumference, thereby recording on the surface of the recording paper 9. Have them do it. 8 is platen 70
This is a motor for rotation, that is, for feeding out the recording paper 9. The motor 8 is attached to the outer surface of the side plate IB. Reference numeral 11 denotes a suction device, which is installed between the side plate 1^ and the left side surface of the platen 7. When the recording head 4 is not used for a long period of time or when printing becomes blurred during use, the recording head 4 is moved to a position facing the suction device 11 so that nozzle clogging can be removed in a timely manner. FIG. 5 is a perspective view of a conventional suction head. Note that this figure is also a perspective view of the suction head of the embodiment. In the figure, a suction device head 12 is a bowl-shaped member whose end edge has an oval shape capable of containing all of the nozzle openings of the recording head 4, and is made of an elastic material. FIG. 6 is a plan view of a conventional recording head, and FIG. 7 is a side sectional view thereof. Note that FIGS. 6 and 7 are common to the recording head of the embodiment. In Figures 6 and 7,
The recording head 4 is made of glass. A plurality of ink nozzles 22. are formed by etching or machining a metal plate or the like. lJt injection flow path 23. Ink pressurization chamber 25
After the cavity plate 21 forming the ink supply path 26 and the ink reservoir 27 and the vibration plate 29 are laminated and integrated, a piezoelectric element 30 as an electromechanical transducer is bonded to a position facing the ink pressurizing chamber 25. It has a certain configuration. In such a configuration, when a voltage as an electric signal is applied to the piezoelectric element 30, the diaphragm 29 moves into the ink pressurizing chamber 25.
2) Displaces inward and drastically reduces its volume, and ink equivalent to that volume is ejected from the ink nozzle 22, which becomes ink droplets that are spotted on the recording paper and printed. Become.

[Problem B that the invention attempts to solve]

Conventionally, although a suction device is provided, it is not always properly and rationally operated, resulting in problems such as deterioration of printing quality and reduction in operating rate. The second object of the invention is to provide an inkjet printer that solves the problems of the conventional technology and rationally controls a suction device for removing clogged nozzles so that the printing function can be performed smoothly. There is a particular thing.

[Means to solve the problem]

In order to solve this problem, an inkjet printer according to a first invention includes a suction device for removing nozzle clogging of a recording head, and has two methods: a time point when a predetermined time has elapsed from an initial point in time, and a point in time when a predetermined time has elapsed from an initial point in time; After moving the recording head to a position facing the suction device based on the earlier of the time point and the time point when a predetermined amount of printing is completed, the recording head is caused to remove the nozzle clogging. The apparatus includes a control section that causes the recording head and the suction device to repeat the movement and clogging removal, respectively, with the end of removal as a new initial point. In the inkjet printer according to the second invention, in the first invention, the control section removes the nozzle clogging;
The suction device maintains a predetermined suction pressure state for a set time.

[Effect]

In the inkjet printer according to the first invention, the control unit determines when a predetermined time has elapsed from an initial point;
After the recording head moves to a position facing the suction device based on the earlier of the time when a predetermined amount of printing is completed,
A suction device removes the nozzle blockage, and this movement
Move, using the end point of the blockage removal as the new initial point.
The unclog is repeated. In the inkjet printer according to the second aspect of the invention, the control unit causes the suction device to maintain a predetermined suction pressure state for a set time in order to remove nozzle clogging.

【Example】

Embodiments of an inkjet printer according to the present invention will be described below with reference to the drawings. This embodiment is completely the same as the conventional example in terms of configuration.
The difference lies in the software. FIG. 1 is a time chart showing the operating points of the embodiment. Time T is plotted on the horizontal axis, and each operation time point is shown with the initial time point being 0 point. Note that the initial stage refers to inkjet
This is when the printer is powered on. First, a time T2 when a predetermined time t has elapsed from the initial time,
Time T1 when the time a required to print a predetermined amount of characters ends
Based on the earlier of , in this case time T1,
A unclog operation is performed. That is, after the recording head moves to a position facing the suction device, the nozzle clogging is removed by the suction device. Here, the predetermined time t is a value that has nothing to do with whether the recording head prints or not, and it is important that ink and dust dry in the nozzle area and cause clogging, or that air bubbles get mixed into the ink. It is determined from the perspective that it is related to the passage of time. Further, the time a is determined from another viewpoint that clogging is likely to occur depending on the amount of printing. From a safe perspective, the clog removal process is performed based on the earlier of T1 and T2 at each time point T1. Now, the time required for this movement and clogging removal is each time t,
Since it is negligibly short compared to a, it is assumed that the start and end points of movement and blockage removal are simultaneous, and the movement and blockage removal are repeated with this end point TI as a new initial point. In other words, for the second time, the time t is
Since the time required to reach the predetermined print amount is shorter than time T3 and time T3 is earlier than time T4, the clogging removal process is performed at time T3. Therefore, the third initial time point is time T3. This time, the time t is shorter than the time C for reaching the predetermined print amount, so the initial point in time for the fourth time is time T5. Next, since the time t is longer than the time d for reaching the predetermined print amount, the initial point of the fifth time is time T7. The same process will be repeated thereafter. The operating points of the suction device in the above embodiment will be further explained with reference to the flowchart of FIG. In step S1, it is determined whether the activation signal is turned on. Here, "the activation signal is on" means that the power switch of the embodiment is turned on, the print signal becomes inputtable, and the printer becomes activated. When the activation signal is turned on, in the next step S2, counting of the elapsed time T and the print amount (number of characters) N is started, that is, counting is started. In step S3, whether T is longer than a predetermined time or not,
In step S4, it is determined whether N is equal to or greater than the predetermined print amount n, and the process proceeds to step S5 based on which one reaches the predetermined print amount n or less. In step S5, it is determined whether printing is in progress, and Y
ES, that is, if a printing operation is in progress, it waits until the printing operation comes to a break and ends. When the suction operation is completed, a suction operation is performed as a subroutine in step S6. That is,
After moving the printer to a position facing the suction device and aligning the suction head with the nozzle of the recording head, suction is applied to remove the clog (see FIGS. 4 and 5). When this suction operation is completed, T and N are reset in step S7. After step S7 and step 33. If in S4, both T and N are less than the predetermined values t and n, respectively, the process returns to step S3 and the above procedure is repeated until the stop signal is turned on in step S8, that is, the IIT source switch of the printer is turned off. . When the stop signal is turned on in step S8, the series of processes ends. The above is an explanation of how to determine a reasonable timing for removing clogs. Next, we will discuss reasonable working conditions for removing clogs. FIG. 3 is a characteristic diagram of the clog removal rate versus suction pressure in the example, which was obtained experimentally. This figure is a characteristic diagram with suction duration Z as a parameter, where the horizontal axis represents suction pressure (negative pressure) P and the vertical axis represents clog removal rate R. Note that the clogging removal rate R is expressed as the frequency of good printing. In FIG. 3, Zl, Zm, Z2. The time is longer in the order of Z3. - As a general rule, the larger the suction pressure and the longer the suction duration, the better the clog removal rate. In particular, when the suction pressure was Pg+ or more, a clog removal rate of 100% could be obtained with a suction duration of 21 or more. The shorter the suction duration, the better.
It can be said that the optimal conditions for the clog removal work are the suction pressure Pm and the suction duration Zm.

【Effect of the invention】

In the first invention, the control unit moves the recording head to a position facing the suction device based on the earlier of the time when a predetermined time has elapsed from the initial time and the time when printing of a predetermined amount has been completed. After this movement, the nozzle blockage is removed by a suction device. Move, using the end point of the blockage removal as the new initial point.
The removal of the clog is repeated; in the second invention, the control section further causes the suction device to remove the nozzle blockage.
A predetermined suction pressure state is maintained for a set time. Therefore, the present invention has the following superior effects compared to the conventional technology. (1) First. According to each of the second inventions, since nozzle clogging is prevented, the printing function of the printer can be smoothly performed, and printing quality and printer operation rate can be improved. (2) In particular, according to the second invention, nozzle clogging can be removed under optimal conditions in the shortest time and at the lowest cost, and at the same time, the printer operating rate can be improved.

[Brief explanation of drawings]

FIG. 1 is a time chart showing the operating points of the embodiment according to the present invention, FIG. 2 is a flowchart showing the operating points of the suction device in the embodiment, and FIG. 3 is a characteristic diagram of the clog removal rate versus suction pressure in the embodiment. Fig. 4 is a common perspective view of the embodiment and the conventional example, Fig. 5 is a perspective view of the suction head common to the embodiment and the conventional example, and Fig. 6 is a plan view of the recording head common to the embodiment and the conventional example. , FIG. 7 is a side sectional view of the same. Code explanation 4: Recording head, 9: Recording paper, 11: Suction device, Taku 3
Figure 40: Go to 1st draw -/de

Claims (1)

[Scope of Claims] 1) In a printer equipped with a suction device for removing nozzle clogging of a recording head, a point in time when a predetermined amount of time has elapsed from an initial point in time, and a point in time when a predetermined amount of printing has been completed from the initial point in time. After moving the recording head to a position facing the suction device based on the earlier of the two, the recording head is caused to remove the nozzle clogging, and the end point of this movement and removal of the clogging is set as a new initial point, An inkjet printer characterized by comprising a control unit that causes the recording head and the suction device to repeat the movement and clogging removal, respectively. 2) The inkjet printer according to claim 1, wherein the control unit causes the suction device to maintain a predetermined suction pressure state for a set time in order to remove nozzle clogging.