JP2700348B2 - Ink jet recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus provided with a cleaning unit for wiping foreign substances such as ink and dust adhered to a discharge port surface of a recording head.

[Conventional technology]

A recording device such as a printer, a copying machine, and a facsimile is configured to record an image formed of a dot pattern on a recording material such as a sheet of paper or a plastic thin film based on the transferred image information.

The recording device can be classified into an ink jet type, a wire dot type, a thermal type, a laser beam type, and the like according to a recording method. Among them, the ink jet type (ink jet recording device) is configured such that a droplet (ink) is discharged from a discharge port of a recording head. The recording liquid is discharged and ejected and adhered to a recording material to perform recording.

This ink jet recording apparatus is a non-impact type recording apparatus, and has features such as low noise, easy high-speed recording, and easy color image recording by using multi-color ink. And it is rapidly spreading in recent years.

However, in the ink jet recording apparatus, since the recording is performed by directly discharging the ink from the fine discharge ports of the recording head, it is necessary to always keep the ink in a state in which the ink can be normally discharged. Different special considerations are needed.

For example, during printing operation, ink droplets or foreign matter such as paper dust or dust adhered to the discharge port surface due to ink mist or bouncing off from the recording material, resulting in defective discharge. For example, a cleaning means of a method of wiping off the adhered substance is used.

In particular, in a serial scan type ink jet recording apparatus in which a recording head is mounted on a carriage, a cleaning means is used which is provided with a fixed rubber blade and uses the movement of the recording head to wipe the discharge port surface.

[Technical problem to be solved by the invention]

However, in this type of conventional cleaning means, basically,
A line type ink jet that uses a fixed recording head, such as a full multi-type recording head, to set the wiper blade at a predetermined position by fixing or finely moving it, and to move the recording head to perform wiping. The recording apparatus has a problem that it is difficult to effectively clean the ejection port surface.

The present invention has been made in view of such a technical problem, and not only in the serial scan type ink jet recording apparatus but also in the line type ink jet recording apparatus, the discharge port surface of the recording head can be effectively reduced. It is an object of the present invention to provide an ink jet recording apparatus provided with a cleaning unit capable of wiping.

[Means for solving the problem]

According to the present invention, recording droplets are ejected and fly from a recording head,
In an ink jet recording apparatus for recording an image on a recording material conveyed at a position facing the recording head, a configuration in which cleaning means for cleaning a discharge port surface of the recording head is provided on the recording material conveying means, Not only the serial scan type ink jet recording apparatus but also the line type ink jet recording apparatus, an ink jet recording apparatus provided with a cleaning unit capable of effectively wiping the ejection port surface of the recording head while maintaining high-speed recording. To provide.

In the above configuration, it is preferable that the cleaning unit is configured by a wiper blade provided in the transport unit.

Further, in the above configuration, if the transporting unit is configured by an endless belt driven in the transporting direction of the recording material, an effective cleaning unit can be easily configured.

Further, in the recording apparatus having the endless belt-type conveying means, if the wiper blades are provided on the endless belt at predetermined intervals in consideration of the length of the recording material, high-speed recording is further facilitated. While maintaining
The discharge port surface can be effectively cleaned.

Further, in the recording apparatus provided with the endless belt type conveying means, the recording head is movably supported to a position where it contacts the endless belt,
By forming the cleaning means with the endless belt itself, it is possible to constitute an effective cleaning means,
In this case, the structure of the cleaning means can be simplified.

Further, each of the inventions having the above-described configuration is a cleaning unit that can effectively clean the ejection port surface of the recording head even in an ink jet recording apparatus using a full-multi type fixed line head as a recording head. Is provided.

[Action]

According to the present invention as described above, in a recording apparatus using a full multi-type fixed recording head, a wiper blade is provided on a belt for conveying a recording material, and a discharge port surface of the recording head is moved at a predetermined timing. By wiping, it is possible to remove foreign matters such as liquid droplets and paper dust adhering to the ejection port surface during printing, and to always maintain the ink ejection performance in a normal state.

〔Example〕

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

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

This embodiment is a case of a multi-color printing apparatus such as a color printing apparatus.

In FIG. 1, reference numeral 1 denotes a full-multi type fixed recording head having a length covering substantially the entire width of the recording material 11, and the recording head 1 includes a plurality of head units 1A, 1B,
It consists of 1C and 1D.

Each of the head units 1A, 1B, 1C, and 1D ejects a recording liquid (ink) of a different color.

In each of the head units 1A to 1D, a plurality of discharge ports are formed in a predetermined linear arrangement, and an electrothermal converter for generating discharge energy is disposed in a liquid path leading to each discharge port. .

Each of the head units (recording heads) 1A to 1D is an ink jet recording head that discharges ink by using thermal energy, and includes an electrothermal converter for generating thermal energy.

In addition, the ink jet recording heads 1A to 1D perform recording by discharging ink from discharge ports by growth of bubbles due to film boiling generated by thermal energy applied by the electrothermal transducer.

In FIG. 1, reference numeral 2 denotes a head mounting frame for fixing the full multi-recording head 1, and reference numeral 3 denotes a recording medium 11 supplied in the direction of arrow F and fed by a feed roller 6 to electrostatically attract the recording material 11 onto a conveying means. Reference numerals 4 and 4 denote transport belts (transporting means composed of endless belts) for attracting and transporting the recording material 11 attracted by the attracting charger 3 in the direction of arrow H.

While the recording head 1 is transported by the transport belt 4,
The recording material 11 recorded on the recording medium 11 is separated from the transport belt 4 and sent out in the direction of arrow S, and is discharged by the discharge roller 5.

On the transport belt (endless belt) 4, a wiper blade 7 for wiping the ejection opening surfaces of the head units 1A to 1D is provided.

In the illustrated example, the wiper blade 7 is provided at one position on the conveyor belt 4, and a blade detection sensor for detecting the passage of the wiper blade 7 is provided at a predetermined position on the path of the conveyor belt 4. 8 are provided.

Further, a cleaner 9 is provided at a predetermined position in the path of the conveyor belt 4 for wiping off the deposits on the wiper blade 7 and cleaning the wiper blade 7.

The wiper blade 7 can be formed of, for example, a silicon or urethane rubber blade.

In FIG. 1, each of the head units 1A to 1D
, Replaceable ink cartridge for each color
From 10, the corresponding color ink is supplied.

FIG. 2 is a block diagram of a control system for controlling the timing of the operation of cleaning the recording head 1 of the ink jet recording apparatus of FIG. 1 by the wiper blade 7 and the timing of the operation of feeding the recording material 11.

Therefore, the wiping operation of the ejection port of the recording head 1 will be described below.

When the wiper blade 7 attached to the conveyor belt 4 passes just before the blade detection sensor 8 with the movement of the conveyor belt 4, the detection signal is transmitted to the control circuit 12, and the feed roller 6 The control circuit 12 controls the recording material 11 to be fed onto the conveyor belt 4 at a predetermined timing after the wiper blade 7.

The recording material 11 sent onto the transport belt 4 is transported toward the recording head 1 while being attracted to the transport belt 4 by the attraction charger 3.

In this case, since the wiper blade 7 is located in front of the recording material 11, the wiper blade 7 wipes the ejection opening surface of the recording head 1 with the movement of the transport belt 4, and Recording is performed on the recording material 11.

After the recording material 11 is recorded, it is separated from the conveyor belt 4 and sent in the direction of arrow S, and is discharged by the paper discharge roller 5.

The wiper blade 7 comes into contact with the cleaner 9 by the movement of the conveyor belt 4 in the direction of the arrow H, and after being cleaned by the cleaner 9, is returned to the initial position again.

As described above, according to the ink jet recording apparatus shown in FIG. 1, even in the case of the full multi-type fixed recording head 1 covering the entire width of the recording material 11, the transporting belt (endless belt) 4 that moves. By utilizing the transport interval of the recording material 11 above, the recording head 1
Can be effectively wiped by the wiper blade 7.

The cleaning of the wiper blade 7 is also performed by the cleaner 9 disposed in the path of the transport belt 4.
Can be performed simultaneously using the movement of

Therefore, by always wiping the ejection port surface with the wiper blade 7 that is always cleaned, the ejection port surface of the recording head is always maintained in a cleaned state in which foreign matters such as ink mist and paper dust are not attached. As a result, a recording head cleaning means capable of effectively preventing defective discharge was obtained.

The ejection port cleaning means described with reference to FIGS. 1 and 2 is similarly applied to the case where the recording head 1 is a serial scanning recording head which reciprocates in the width direction of the recording material 11. be able to.

FIG. 3 is a schematic side view showing another embodiment of the ink jet recording apparatus according to the present invention.

In this embodiment, a plurality of wiper blades 7 are provided on the transport belt (endless belt) 4 at predetermined intervals in consideration of the length of the recording material 11 in the structure of FIGS. 1 and 2 described above. Things.

The structure of the present embodiment differs from that of FIG. 1 in that a plurality of wiper blades 7 are used, and the other parts have substantially the same structure.

Therefore, in FIG. 3, the portions corresponding to the respective portions in FIG. 1 are denoted by the same reference numerals, and the detailed description thereof will be omitted.

As the transport belt 4 moves, the wiper blades 7 on the transport belt 4 pass one after another immediately before the sensor 8 for detecting the blade. In this embodiment, the detection signal is generated. Each time, the feed roller 6 is driven by the control circuit 12, and the next recording material 11 is fed onto the transport belt 4 one by one.

In this case, the recording material 11 is controlled so as to be quickly fed at a timing that does not interfere with the next wiper blade 7.

The moving position of the wiper blade 7 and the recording material
The timing control of the eleventh feeding operation can be executed by the same control system as in FIG.

According to the embodiment shown in FIG. 3, by arranging the recording material 11 on the transport belt 4 composed of an endless belt at intervals in consideration of the length of the recording material 11, every time recording is performed on each recording material 11, The wiper blade 7 can wipe the discharge port surface of the recording head 1, so that the discharge port surface can be always maintained in a clean state while maintaining higher-speed printing.

The print head cleaning means in FIG. 3 is similarly applied to a serial scan type ink jet printing apparatus in which a print head is mounted on a carriage and reciprocates along a recording material 11 as in the case of FIG. And a similar effect can be achieved.

FIG. 4 is a schematic side view showing still another embodiment of the ink jet recording apparatus according to the present embodiment.

This embodiment also shows a case of a multi-color recording device such as a color recording device.

In FIG. 4, reference numeral 1 denotes a full-multi type fixed recording head having a length substantially covering the entire width of the recording material 11, and the recording head 1 includes a plurality of head units 1A, 1B,
It consists of 1C and 1D.

Each of the head units 1A, 1B, 1C, and 1D ejects a recording liquid (ink) of a different color.

To each of the head units 1A to 1D, ink of a corresponding color is supplied from an ink cartridge 10 that can be replaced for each color.

In each of the head units 1A to 1D, a plurality of discharge ports are formed in a predetermined linear arrangement, and an electrothermal converter for generating discharge energy is disposed in a liquid path leading to each discharge port. .

In FIG. 4, the full multi-recording head 1 is held by a head mounting frame 2, and a recording material 11 supplied in the direction of arrow F is fed onto a transport belt 4 by feed rollers 6.

At a position on the upstream side of the recording head 1 in the path of the transport belt (endless belt) 4, the fed recording material
An adsorption charger 3 for electrostatically adsorbing 11 to the transport belt 4 is provided.

The transport belt 4 as a transport unit is driven in the direction of arrow H, and sucks and transports the sucked recording material 11 in the direction of arrow H.

The recording material 11 is conveyed by the conveyance belt 4 immediately before the discharge port surface of the recording head 1, and the recording material 11 recorded by the recording head 1 during the conveyance is separated from the conveyance belt 4. The sheet is then sent in the direction of arrow S, and is further discharged by the discharge roller 5.

Therefore, in the present embodiment, the recording head 1
The discharge port surface is supported so as to be movable in a direction (directions of arrows U and D) separating from and abutting on the conveyor belt 4, and is driven and controlled so as to abut and separate from the conveyor belt 4 at a predetermined timing. can do.

That is, in the present embodiment, the transport belt 4 itself is used as a wiping member (cleaning means) at a predetermined timing, and a fixed number of the recording materials 11 are used.
After recording, the feeding of the recording material 11 is stopped halfway and the recording head 1 is brought down to bring the discharge port surface of the recording head 1 into contact with the moving conveyor belt 4,
The discharge port surface is wiped by the transport belt 4 for a predetermined time.

After this wiping operation, the recording head 1 is lifted in the direction of the arrow U and returned to the original recording position.

Further, a cleaner 9 for wiping foreign substances such as ink and paper powder adhered to the conveyor belt 4 by the wiping operation is provided at a predetermined position in the path of the conveyor belt 4. After the transport belt 4 is cleaned by bringing it into contact with the belt 4,
And the recording on the recording material 11 is restarted.

FIG. 5 is a flowchart showing a control procedure of the above wiping operation.

In FIG. 5, when the recording operation is started, the driving of the transport belt 4 is started in step S1, and in step S2, only one recording material 11 is fed onto the transport belt 4 by the feed roller 6, and the next recording is performed. Feeding of the material 1 stops.

After recording on the recording material 11 in step S3, it is detected in step S4 whether or not the recording material 11 has passed downstream of the recording head 1. If the recording material 11 has passed, the process proceeds to step S5 to perform recording. The head 1 is moved down to contact the moving conveyor belt 4, and the discharge port surface of the recording head 1 is wiped by the conveyor belt 4 for a predetermined time in step S 6.

After a predetermined time from the start of the wiping, the cleaner 9 is brought into contact with the conveyor belt 4 in step S7, and the conveyor belt 4 is cleaned in step S8.

Next, in step S9, the recording head 1 is raised to return to the recording position, and the cleaner 9 is separated from the transport belt 4 in step S10. Thereafter, the process returns to step S2, where the recording material 11 is transferred onto the transport belt 4. Feeding is resumed, and recording on the next recording material 11 is performed.

According to the ink jet recording apparatus described above with reference to FIGS. 4 and 5, even in the case of the fixed recording head 1 of the full multi type which covers the entire width of the recording material 11, the transfer belt (endless belt) 4 By utilizing the movement and using the transport belt 4 itself as a wiping member, the ejection opening surface of the recording head 1 can be effectively wiped.

In addition, the cleaner 9 disposed on the path of the conveyor belt 4 can simultaneously clean the conveyor belt 4 as a wiping member by using the movement thereof, so that the wiping member (conveyor belt) 4 that is always cleaned surely. The discharge port surface can be wiped.

In this way, the ejection port surface of the recording head can always be maintained in a cleaned state in which foreign matters such as ink mist and paper dust are not adhered, and thus the recording head cleaning means capable of effectively preventing ejection failure. was gotten.

The cleaning means for the recording head described with reference to FIGS. 4 and 5 is also an ink jet recording apparatus in which the recording head 1 is mounted on a carriage or the like and is configured to reciprocate along the recording material 11, ie, The same effect can be achieved in a serial scan type ink jet recording apparatus, and the same effect can be achieved.

The present invention provides an excellent effect particularly in an ink jet recording apparatus using a valve jet type ink jet recording head among the ink jet recording methods.

The representative configuration and principle are preferably performed using the basic principle disclosed in, for example, US Pat. Nos. 4,723,129 and 4,740,796.

This method can be applied to any of the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, it is arranged on a sheet or a liquid path holding a liquid (ink). By applying at least one drive signal to the electrothermal transducer, which corresponds to the recorded information and provides a rapid temperature rise exceeding nucleate boiling,
This is effective because thermal energy is generated in the electrothermal transducer, and the film is boiled on the heat-acting surface of the recording head. As a result, bubbles in the liquid (ink) can be formed in one-to-one correspondence with the drive signal.

By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed.

When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,434,262 are suitable.

Further, if the conditions described in US Pat. No. 4,431,324 of the invention relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As a configuration of the recording head, in addition to the combination configuration (a linear liquid flow path or a right-angled liquid flow path) of a discharge port, a liquid path, and an electrothermal converter as disclosed in each of the above-mentioned specifications, a heat acting section A configuration using U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration in which the is bent, is also included in the present invention.

In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing pressure waves of thermal energy. The present invention is also effective as a configuration based on JP-A-59-138461, which discloses a configuration in which is adapted to a discharge unit.

Further, 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 reduced by a combination of a plurality of recording heads as disclosed in the above specification. Either a configuration that satisfies the above or a configuration as a single recording head that is integrally formed may be used, but the present invention can more effectively exert the above-described effects.

In addition, a replaceable chip-type recording head that can be electrically connected to the apparatus main body and supplied with ink from the apparatus main body by being attached to the apparatus main body, or provided integrally with the recording head itself The present invention is also effective when a cartridge type recording head is used.

It is preferable to add recovery means for the printhead, preliminary auxiliary means, and the like, which are provided as components of the printing apparatus of the present invention, since the effects of the present invention can be further stabilized.

If these are specifically mentioned, for the recording head,
Capping means, cleaning means, pressurizing or suction means, preheating means using an electrothermal transducer or another heating element or a combination thereof, and performing a predischarge mode in which discharge is performed separately from recording. Is also effective for performing stable recording.

Further, the printing mode of the printing apparatus is not limited to the printing mode of only the mainstream color such as black, but may be a printing head integrally formed or a combination of a plurality of printing heads. The present invention is extremely effective for an apparatus having at least one of the full colors.

In the embodiments of the present invention described above, the ink is described as a liquid, but the ink is solidified at room temperature or below, and is softened or liquid at room temperature, or the ink itself is 30 ° C. In general, the temperature is adjusted within a range of not more than ° C. and the temperature is controlled so that the viscosity of the ink is in a stable ejection range. Therefore, it is sufficient that the ink is in a liquid state when the use recording signal is applied.

In addition, the temperature rise due to thermal energy is positively prevented by using it as energy for changing the state of the ink from the solid state to the liquid state, or the ink that solidifies in a standing state to prevent evaporation of the ink is used. Or use
In any case, heat is first applied by heat energy, such as one in which the ink is liquefied and ejected as an ink liquid by application in accordance with the recording signal of the heat energy, or one which starts to solidify when it reaches the recording material. The present invention is also applicable to the use of an ink having a liquefying property.

In such a case, as in JP-A-54-56847, the ink is opposed to the electrothermal converter while being held as a liquid or a solid in the concave portions or through holes of the porous sheet. It is good also as a form.

In the present invention, the most effective one for the above-described ink is to execute the above-described film boiling method.

〔The invention's effect〕

As is clear from the above description, according to the present invention, in the ink jet recording apparatus for ejecting recording droplets from a recording head and recording an image on a recording material conveyed at a position facing the recording head, the recording target is provided. Since the transporting means for the recording material is provided with a cleaning means for cleaning the ejection opening face of the recording head, not only in the serial scan type inkjet recording apparatus but also in the line type inkjet recording apparatus, high-speed recording is similarly performed. Is provided, there is provided an ink jet recording apparatus provided with a cleaning means capable of effectively wiping the ejection port surface of the recording head while maintaining the above condition.

According to the second aspect of the present invention, in the above configuration, since the cleaning unit is configured by the wiper blade provided in the transport unit, an ink jet recording apparatus that can achieve the same effect is provided.

According to the third aspect of the present invention, in the above configuration, the transporting means is constituted by an endless belt driven in the transport direction of the recording material, so that the same effect can be achieved easily and reliably. An inkjet recording device is provided.

According to the fourth aspect of the present invention, in the above configuration, the wiper blades are provided on the endless belt at predetermined intervals in consideration of the length of the recording material. In addition, there is provided an ink jet recording apparatus capable of effectively cleaning the ejection port surface while maintaining high-speed recording.

According to the fifth aspect of the invention, the recording head is movably supported at a position where the recording head comes into contact with the endless belt, and the cleaning means is formed by the endless belt itself. With a simple configuration,
An ink jet recording apparatus capable of cleaning the ejection port surface more effectively is provided.

According to the sixth aspect of the present invention, in addition to the above configuration, the cleaning unit having the above configuration is implemented in the ink jet recording apparatus using the full multi-type fixed type line head. There is provided an ink jet recording apparatus capable of reliably cleaning a discharge port surface of a fixed recording head.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing one embodiment of an ink jet recording apparatus according to the present invention, and FIG. 2 is a control for controlling the timing of a cleaning operation of a discharge port surface and a recording material conveying operation of the recording apparatus of FIG. System block diagram, FIG. 3 is a schematic side view showing another embodiment of the ink jet recording apparatus according to the present invention, FIG. 4 is a schematic side view showing another embodiment of the ink jet recording apparatus according to the present invention, FIG. 5 is a flowchart showing a control procedure of a printing operation and a discharge port surface cleaning operation of the printing apparatus of FIG. In the following, reference numerals indicating the main parts in each drawing are listed. DESCRIPTION OF SYMBOLS 1 ... Recording head, 1A, 1B, 1C, 1D ... Head unit, 4 ... Conveying belt, 6 ... Feed roller, 7 ... Wiper blade, 8 ... Sensor for blade detection, 9 ... Cleaner, 11 ...... Recording material, 12 ... Control circuit.

Claims (8)

(57) [Claims] A recording head for ejecting and flying recording liquid droplets;
In an ink jet recording apparatus for recording an image on a recording material conveyed at a position facing the recording head, a cleaning means for cleaning a discharge port surface of the recording head is provided in the recording material conveying means. Inkjet recording apparatus. 2. An ink jet recording apparatus according to claim 1, wherein said cleaning means is a wiper blade provided on said transport means. 3. An ink jet recording apparatus according to claim 1, wherein said conveying means is an endless belt driven in a conveying direction of said recording material. 4. The ink jet recording apparatus according to claim 3, wherein said wiper blades are provided at predetermined intervals on said endless belt. 5. An ink jet recording apparatus according to claim 3, wherein said recording head is movably supported at a position where said recording head comes into contact with said endless belt, and said cleaning means is formed by said endless belt itself. 6. An ink jet recording apparatus according to claim 1, wherein said recording head is a full-multi type fixed line head. 7. The recording head according to claim 1, wherein the recording head is a recording head that discharges ink by using thermal energy, and is an ink jet recording head that includes an electrothermal transducer for generating thermal energy. The ink-jet recording apparatus according to claim 1. 8. An ink jet recording apparatus according to claim 7, wherein ink is ejected from an ejection port by growth of bubbles due to film boiling generated by thermal energy applied by said electrothermal transducer.