JPH03274164A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To improve durability of a discharge opening surface by preventing the discharge opening surface of a recording head from deteriorating due to stains by a method wherein driving of a cleaning means is controlled according to a degree of recording operation of the recording head for a quantity of recorded image data or a size of the recorded image and others. CONSTITUTION:After having executed recording operation by a specific number of scanned lines, when a blade contacting operation signal is generated with a control circuit 16, the control circuit 16 drives a blade driving means 48, and a driving motor 5 is driven via a pulse motor driver 23 advancing a blade 47 to a position of hitting on a discharge opening surface recording heads 2a, 2b. By moving a carriage 1 by a pulse content in the arrow A direction from a record starting position, the discharge opening surfaces of the recording heads 2a, 2b are cleaned with the blade 47. Thereafter, the carriage 1 is moved. After cleaning the discharge opening surfaces of the recording heads 2a, 2b again, the blade 47 goes back to be in a blade released state. Besides, the carriage 1 is returned to the record starting position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording apparatus that records an image on a recording material by ejecting and flying recording droplets.

[Prior art] Recording devices such as printers, copiers, and facsimile machines print paper or plastic sheets based on transferred image information.
An image consisting of a door pattern is recorded on a recording material such as H.

The recording device may be an inkjet type,
It can be divided into wire dot type, thermal type, laser beam type, etc. Among these, inkjet type (inkjet recording device) ejects small droplets of recording liquid (ink) from the ejection opening of the recording head, and prints them onto paper or paper. The bottom of the groove is so that it can be attached to a recording material such as a plastic thin plate for recording.

This Inkciend recording device has lower operating noise than other recording methods, and its basic mechanical f1v construction is simple and inexpensive, and is used in various fields as a recording output device for computers, word processors, etc. .

However, this type of printing apparatus performs printing by ejecting recording liquid (hereinafter referred to as ink) directly from the ejection ports of the print head, and other printing methods are used to keep the ink in a state where it can be ejected at all times. requires special consideration.

For example, if paper grains, dust, additional ink, ink droplets, etc. adhere to the ejection orifice surface (the surface where the ejection orifices are provided) of the recording head, the ink droplets ejected from the ejection orifices may be affected by these foreign substances. As a result, recording defects such as non-ejection and distortion of recorded images may occur.

Conventionally, in order to clean the ejection orifice surface of the print head, a flexible blade is provided opposite to the recording heel E' to wipe off the ejection orifice surface of the print head. has been adopted.

As such leaning means, there have been proposed ones in which a flexible blade is slid back and forth against the ejection orifice surface of the recording head, and ones in which the wiping direction of the blade is set in one direction.

[Technical problem to be solved by the invention] However, if the cleaning operation of the ejection port surface using the flexible blade is continued for a long period of time, the blade itself will wear out and deteriorate due to repeated sliding with the recording head. However, there have been problems in that the cleaning effect of the discharge port surface is reduced, or conversely, the discharge port surface is damaged by the blade.

FIG. 9(A) is a schematic diagram showing a stable discharge state of the recording head, and FIG. 9(B) is a schematic diagram showing a state in which recording dots are disturbed due to foreign matter adhering to the discharge port surface. FIG. 10 is a schematic diagram showing a state in which foreign matter is attached to the discharge port surface by the blade.

As shown in FIG. 9(A), in the initial stage of use of the flexible blade, the recording dots produced by the recording head '2 are normal;
As the blade 47 (Fig. 1O) is used for a long time, as shown in Fig. 9(B)8 and Fig.
The plate material may adhere to the ejection port surface 22 due to friction with the ink.
As a result, the amount of ink droplets ejected from each ejection port of the recording head 2, as well as the ejection characteristics such as the ejection direction and ejection speed, are disturbed, and density unevenness and streaks due to the disturbance of the recording dots on the recording material occur. There was a technical issue that occurred.

The present invention has been made in view of the above-mentioned conventional technical problems, and provides an ink side printing apparatus that prevents contamination and deterioration of the ejection port surface of the print head and allows the print head to always maintain stable printing. The purpose is to provide

[Means for solving problems]

The present invention detects an amount related to the degree of recording operation, such as the movement of a carriage, and controls the abutment and release of the flexible blade against the ejection port surface based on the detection result. The number of times of contact with the discharge port surface is reduced, thereby achieving the above object.

That is, in the inkjet recording apparatus of the present invention, there is a cleaning means for cleaning the ejection orifice surface of the print head, and a drive for operating the cleaning means. and a control means for controlling the cleaning means, and is configured to control the driving of the cleaning means according to the degree of recording operation such as the amount of recorded image data or the size of the recorded image. Check the contamination and deterioration of the head ejection port surface,
An object of the present invention is to provide an inkjet recording device that can improve the durability of the ejection port surface and maintain stable recording at all times.

〔Example] Hereinafter, the present invention will be specifically described with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of an ink side recording apparatus according to the present invention.

In FIG. 1, 52, 1 is a carry carrying 7F2a and 2b to multiple records (two in the illustrated example).

Reference numeral 64 is an endless belt, a part of which guides and supports the carriage 1 in a movable manner.
It is connected to the.

Reference numeral 5 denotes a drive motor (pulse motor), and the carriage I is driven by the drive motor 5 to move along the recording surface of the recording material 6 on the guide shaft 3 via the belt 4 .

7 is a conveyance roller that conveys the recording material 6, 8A and 8
A guide roller 9 that guides the recording material 6 is a recording material conveyance motor.

On the other hand, the recording heads 2a and 2b are provided with a liquid path 10 for discharging ink droplets toward the recording material 6, and the liquid path 10 is connected to supply tubes 12a and 12b from ink tanks 11a and llb. Ink is supplied via flexible cables 12A, 12 to ejection energy generating means (not shown) provided in each liquid path 10.
An ink ejection signal is selectively supplied via B.

Further, a head heater 14 is provided in the recording heads 2a and 2b.
a, 14b and temperature detection means 15a15b are provided, and detection signals from the temperature detection means 15a, 15b:;
Based on this signal, the control circuit I6 controls the driver 17 and the power supply 1.
The power U heat in the head heater 14a or 14b is controlled via B.

Reference numeral 20 denotes a camping means that comes into contact with the ejection opening surfaces of the recording heads 2a, 2b during non-recording, and moves the recording heads 2a, 2b to a position facing the capping means 20 during non-recording.

After that, the capping means 20 is connected to the camp driving means 2.
5, the elastic member 44 is brought into pressure contact with the discharge port surface, and camping is performed.

The capping means 20 accommodates the volatile component solution 46 in the ink in its closed space 2OA, and also stores the volatile component solution 46 in the ink.
A liquid retaining member 45 impregnated with liquid 6 is housed inside.

Due to this, 1 volume'tj, 46 volatile grasses are added to space 2.
The ink is filled in the liquid path IO to prevent the volatile components of the ink from evaporating from the ejection opening of the liquid path IO, so that the component ratio of the ink in the liquid path IO does not change.

In addition, as a volatile component, the ink itself or i8 liquid, which is a component obtained by removing the dye from the ink, is effective.
Furthermore, in the case of water-based ink, Aoi distilled water and the like are effective.

Furthermore, as the liquid holding member 45, a sponge-like porous member, a plastic sintered body, or the like is effective.

In FIG. 1, numeral 31 denotes a clogging prevention means that receives ejected ink when the recording head performs an idle ejection operation.

This clogging prevention means 3■ is equipped with a liquid receiver member 32 as a liquid receiving part that faces the recording heads 2a and 2b and absorbs the ink that has been jetted, and is located between the capping means 20 and the recording start position. It is located in

18, the liquid receiver is the capping means 20 as the member 32
As in the case of , a sponge-like porous member or a plastic sintered body is effective.

Reference numeral 47 in FIG. 1 indicates a flexible blade as a cleaning means for cleaning the ejection opening surfaces of the recording rads 2a and 2b. By controlling the control circuit 16, contact and release of the recording heads 2a and 2b from the ejection port surface are controlled.

Additionally, the flexible blade 47 used here is as follows:
Urethane rubber with a hardness of 50' (JISA) or higher is effective.

FIG. 2 is a schematic plan view for explaining the operation of the recording head of the printing apparatus shown in FIG. 1, and the same elements as shown in FIG. Their explanation will be omitted.

In FIG. 2, 34 is a recording start position detection sensor;
is a capping means position 146 sensor which detects that the recording heads 2a, 2b are at a predetermined recording start position and eight key knob positions (positions facing the capping means 20).

Reference numeral 35 denotes a position detection sensor which detects the reference position of the idle ejection operation performed when the recording heads 2a, 2b move in the scanning direction.

The operation of the recording apparatus described in FIG. 1111121 and FIG. 2 will be described below.

First, during recording, the carriage l is driven and the sensor 34
Each liquid path 10 of the recording heads 2a and 2b is selectively driven while traveling in the direction of the arrow from the recording start position detected at .

As a result, ink droplets are ejected, and an image or the like is recorded on the recording width portion P (FIG. 1) of the recording material 6 in a cross pattern.

Thus, as shown in FIG. 2, when the recording heads 2a and 2b are advanced by P1 pulses from the recording start position by the pulse motor 5 and recording for one scan is completed, the carriage 1 is driven in the direction of arrow B to start recording. When returning to the starting position, the recording material 6 is moved by the width of the recording width portion P by the arrow C in FIG.
The paper is fed in this direction, and the above operation is repeated again.

FIG. 3 is a schematic plan view showing how the recording heads 2a and 2b are cleaned by advancing and retracting the blade 47 as a cleaning means.

1 to 3, after the recording operation as described above has been performed for a predetermined number of scans, when a blade contact operation signal is generated in the control circuit 16, as shown in FIG. As shown in FIG. 2, the control circuit 16 drives the blade drive means 48 to advance the blade 47 to a position where it contacts the ejection opening surfaces of the recording heads 2a and 2b, while driving the drive motor 5 via the pulse motor driver 23. Carriage 1
By sending P2 pulses from the recording start position in the direction of arrow A, the ejection port surfaces of the recording heads 2a and 2b are cleaned (wiped) by the blade 47.

Thereafter, as shown in FIG. 3(B), the carriage 1 is moved in the direction of arrow B, and after the ejection opening surfaces of the recording heads 2a and 2b are cleaned again, as shown in FIG. 3(C). ,
The blade 47 is retracted by the blade driving means 48, and the plate is released.

On the other hand, the carriage l returns to the recording start position, and the above-described operation is repeated.

FIG. 4 is a timing chart of an operation in which a blade 47 serving as a cleaning means contacts the ejection port surfaces 22 of the recording heads 2a and 2b to clean the ejection port surfaces.

In FIG. 4, a case is shown in which the blade 47 is moved forward and backward every time two scans of recording operations by the recording heads 2a and 2b are completed to clean the ejection port surface 22 of the recording head.

FIG. 5 shows a second inkjet recording device according to the present invention.
FIG. 4 is a schematic plan view showing the cleaning operation by the blade 47 in the implementation stage.

In the embodiment described above, the blade 47 is connected to the recording head 2.
The cleaning operation of bringing the blades 47 into contact with the ejection port surfaces 22 of a and 2b was performed during the reciprocation of the carry and ji 1, but in this embodiment, the blade 47 is moved to record only when the carrynor X1 moves forward. It is controlled so that it comes into contact with the discharge port surfaces of the doors 2a and 2b.

That is, after the recording operation has been performed for a predetermined number of scans, when the blade contact operation signal is generated from the control circuit 16,
As shown in FIG. 5(A), the blade 47 is advanced by the blade driving means 48 to the position where it comes into contact with the dors 2a and 2b4, and then the carriage 1 is moved from the recording start position in the direction of the arrow P. The ejection port surfaces 22 of the recording heads 2a and 2b are cleaned by being sent by the pulse amount.

Thereafter, as shown in FIG. 5(B), the blade 47
Before the carriage 1 moves in the direction of arrow B, it is moved backward by the blade drive means 48.

Therefore, carriage 1:! , to the record, G2a, 2b
The ejection opening surface returns to the recording start position without contacting the blade 47, and the operations described in ff and f are repeated.

By bringing the blade 47 into contact with the ejection opening surfaces of the recording heads 2a and 2b only when the carriage 1 moves forward, stains and scratches on the ejection opening surfaces 22 of the recording heads 2a and 2b are further reduced. can be done.

FIG. 6 shows the third inkjet recording device according to the present invention.
FIG. 2 is a schematic perspective view showing an example.

In this embodiment, a flexible plate 47 as a cleaning means for the recording head is provided between the upright position of the recording start 1 and the clogging prevention means 31 for idle ejection, and the flexible plate 47 is used as a cleaning means for the recording head. It is configured to control the operation according to the amount of recorded image data.

In other words, contamination (ink adhesion) caused by ink droplets on the ejection port surfaces 22 of the recording heads 2a and 2b is caused by
, 2b. Therefore, if the total number of ink droplets ejected from the recording heads 2a and 2b is small, cleaning #4 (cleaning) of the ejection port cylinder 22 by the flade 47 ) frequency can be reduced.

Therefore, in the present invention, the recording heads 2a, 2b
The frequency and timing of bringing the blade 47 into contact with the ejection port surface 22 is controlled based on the total number of ink droplets ejected from the ink droplets, that is, the recorded image data or the recorded image size.

In this way, when the total number of ink droplets ejected is small,
By freezing the frequency of the cleaning operation of the ejection port surface 22 by the blade 47, and conversely, when the total number of ejected ink droplets is large, the frequency of the cleaning operation is increased accordingly. In addition to eliminating unnecessary contamination and abrasion deterioration of the discharge port surface 22, the discharge port surface 22 can be cleaned efficiently.

FIG. 7 shows a control algorithm for driving the blade 47 using the image data D1, D given to the recording heads 2a, 2b.

This is a diagram.

In FIG. 7, the recorded image data D1 and Db are shown as
The comparator 50 compares the value of D. The circuit 16 is configured to control contact and release of the blade 47 by the blade drive means 48 by inputting the signal to the circuit 16 .

As mentioned above, FIG. 8 is a timing chart when controlling the drive of the blade 47 according to the recorded image data. In the figure, the drive timing (and frequency) of the blade 47 is According to the image data D, (1
), ([1), and (III).

In each of the above embodiments, a flexible blade 47 is used as a means for cleaning the ejection port surfaces 22 of the recording heads 2a and 2b, and the cleaning is performed by bringing the blade 47 into contact with the ejection port surfaces 22. Although described above, the present invention is also applicable to cases where other types of cleaning means are used.

For example, as another means of cleaning the recording heads 2a and 2b, an air knife (air stream) may be used to clean the recording heads 2a and 2b.
, 2b may be cleaned in a non-contact manner.

Even when cleaning the ejection port surface 22 using such an air flow, foreign matter mixed in with the air may adhere to the ejection port surface 22, or the air may become trapped inside the liquid path lO of the recording heads 2a, 2b. In addition, the viscosity of the ink in the liquid path 10 of the recording heads 2a, 2b increases due to the air flow, and as a result, the recording heads 2a, 2b cannot maintain stable recording. It may disappear.

The present invention can also be applied to a non-contact type cleaning means using such an air knife.
, 2b as in the present invention, it becomes possible to maintain stable recording operations of the recording heads 2a, 2b.

According to the embodiment described above, ink droplets are ejected from the ejection ports of the recording heads 2a and 2b, and the ink droplets are ejected onto the recording material 6.
In an inkjet recording apparatus that performs recording by adhering to the ejection port surface 22 of the recording heads 2a and 2b, a flexible plate '47, which is a means for cleaning the ejection port surface 22 of the recording heads 2a and 2b, is brought into contact with and released from the ejection port surface 22. The ejection opening surface 2 of the blade 47 is controlled according to the degree of recording operation, such as the amount of recorded image data or the recorded image size.
To prevent contamination and deterioration of the ejection port surface 22 while maintaining sufficient cleaning effect by minimizing the number of times of contact with the recording hem F'2a, 2bc'. As a result, an inkjet recording apparatus was obtained which is capable of recording image defects such as density unevenness and streaks due to changes in the ejection characteristics from each of the ejection ports 2a and 2b.

The present invention provides excellent effects particularly in bubble jet recording heads and recording apparatuses among ink jet recording systems.

As for typical configurations and principles thereof, it is preferable to use the basic principles disclosed in US Pat. No. 4,723,129 and US Pat. No. 4,740,796, for example.

This method can be applied to both the so-called on-demand type and the continuous type, but especially in the case of the on-demand type, it is necessary to place the liquid (ink) on the sheet or liquid path where it is held. The electrothermal transducer S generates thermal energy by applying at least one drive signal that corresponds to recorded information and causes a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer S. This method is effective because it causes film boiling on the heat-active surface of the recording head, resulting in the formation of bubbles in the liquid (ink) in one-to-one correspondence with this drive signal.

Due to the growth and contraction of these bubbles, liquid (
ink) to form at least one droplet.

It is more preferable to set the drive number 73 in a pulse form, because the growth and contraction of the bubbles is carried out immediately and appropriately, so that liquid (ink) can be ejected with particularly excellent responsiveness. As this pulse-shaped drive signal, US Pat. No. 4,463,359
No. 4,345,262.

Further, if the conditions described in US Pat. No. 4,313,124 concerning the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be achieved.

The configuration of the recording head includes, in addition to the combination configuration of an ejection port, a liquid path, and an electrothermal converter (straight liquid flow path or right-angled liquid flow path) as disclosed in each of the above-mentioned specifications. U.S. Pat. No. 4,558,333 and U.S. Pat.
A configuration using No. 0 MeiW book is also included in the present invention.

In addition, Japanese Patent Application Laid-Open No. 123670 of 1982 discloses a till rule in which a common slit is used as a discharge part of a plurality of electrothermal transducers, and a method for absorbing pressure waves of thermal energy is disclosed. The present invention is also effective with a configuration based on Japanese Patent Application Laid-open No. 13846I of 1982, which discloses a configuration in which holes correspond to discharge portions.

Furthermore, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length can be increased by combining multiple recording heads as disclosed in the above-mentioned specification. Either a configuration that satisfies the above conditions or a configuration as a single recording head formed integrally may be used, but the present invention can more effectively exhibit the above-mentioned effects.

In addition, a replaceable chip-type recording head that is attached to the main body of the device and enables spiritual connection with the main body of the device and supply of ink from the main body of the device, or a printhead that is integrated into the recording head itself. The present invention is also effective when a cartridge-type recording device is used.

Further, it is preferable to add recovery means, preliminary auxiliary means, etc. for the recording head, which are provided as a configuration of the recording apparatus of the present invention, because the effects of the present invention can be further stabilized.

Please list these specifically.Li, for the recording head,
Capping means, cleaning means, pressurizing or suction means, preheating means using an electrothermal transducer or a separate heating element, or a combination thereof, and a preliminary ejection mode that performs ejection other than recording. It is also effective to perform stable recording.

Furthermore, the recording mode of the recording device is not limited to recording only mainstream colors such as black.

The present invention is also extremely effective for devices equipped with at least one of multiple colors of different colors or full colors of mixed colors. be.

[Effects of the Invention] As is clear from the above description, the inkjet recording apparatus of the present invention includes a recording head that performs recording by ejecting and flying recording droplets from an ejection port, and a cleaning device that cleans the ejection port surface of the print head. and a control means for controlling a driving means for operating the cleaning means, and controlling the driving of the cleaning means according to the extent of the recording operation of the recording head, such as the amount of recorded image data or the size of the recorded image. Since the I precept has been adopted, an inkjet recording apparatus that can prevent contamination and deterioration of the ejection orifice surface of the print head, improve the durability of the ejection orifice surface, and maintain stable printing at all times. provided.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of an inkjet recording apparatus according to the present invention, and FIG. 2 is a schematic plan view for explaining the operation of the recording head of the recording apparatus of FIG. 1.
3 is a schematic plan view showing the state of the cleaning operation of the recording head by the cleaning means of the inkjet recording apparatus of FIG. 1, FIG. 4 is a timing chart of plate' drive in the cleaning operation of the recording head of FIG. 3, FIG. 5 is a schematic plan view showing the state of the cleaning operation of the recording head by the cleaning means of the second embodiment of the inkjet recording apparatus according to the present invention, and FIG. 6 is the third embodiment of the inkjet recording apparatus according to the present invention. FIG. 7 is a schematic perspective view showing an ink tube according to the present invention. FIG. 8 is a diagram showing a control system for driving a blade in accordance with recorded image data in a recording device; FIG. Chart, FIG. 9 is a schematic diagram showing stable ejection and ejection failure states of the recording head,
FIG. 10 is a schematic diagram showing a state in which foreign matter has adhered to the recording head from the blade. Below, the reference symbols for the main components in the drawings are listed. l-carriage, 2a, 2b-recording head, 5-
Carriage, drive motor, 6-recording material, 10--liquid path, 16--control circuit, 20 capping means, 2
2.---Discharge port surface, 25- Cap driving means, 31
-----Clogging prevention means, 32 liquid receiver is a member, 47---
---Cleaning means (flexible blade), 4B-
- Blade drive means, arrows A, B - Carriage movement direction. Figure 3 Figure 5 Figure 9 (B) Do-no-do Figure 10 Brush-do

Claims (1)

[Claims] (1) A recording head that performs recording by ejecting and flying recording droplets from an ejection port, a cleaning device that cleans the ejection port surface of the print head, and a control device that controls a drive device that operates the cleaning device; An inkjet recording apparatus characterized in that driving of the cleaning means is controlled according to the degree of recording operation of the recording head, such as the amount of image data recorded or the size of a recorded image.