JPH02179757A - Image recorder - Google Patents

Abstract

PURPOSE:To prevent mixing of color inks from occurring by providing a cleaning blade for exclusive use for each recording head, and moving the blade in the longitudinal direction of the head to clean an ejecting surface of the head. CONSTITUTION:Each recording head is fixed to a head block 6, and cleaning blades 500C, 500M, 500Y and 500Bk for exclusive use for the heads, respectively, are disposed respectively at ejecting surfaces of the heads for each color. The blades are formed of an elastic material such as a silicone rubber, and are held by blade holders 501C, 501M, 501Y, 501Bk, respectively. An ink partition plate 8 is provided between each adjacent pair of the blades, and an ink seal is adhered between each of the partition plate 8 and the head block 6. Ink droplets containing refuse, bubbles or the like scraped off the ejecting surfaces by the blades flows along the partition plates 8 to drop into a recovering container 2, from which the recovered ink is discharged through an ink discharging port 13 into an ink discharging tank. The blade with the ink adhered thereto is cleaned by making contact with an ink absorber 502 disposed on the outside of the head. Thus, the refuse, bubbles and the like are securely removed from nozzle parts, and mixing of color inks can be prevented from occurring.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an image recording device having functions such as a facsimile machine, a copying machine, and a printer, and a multifunctional device having such functions;
The present invention relates to an image recording device used as an output device for a workstation or the like.

[Conventional technology]

The non-equivalent recording method has recently attracted attention because the noise generated during recording is so small that it can be ignored. Among them, there is a possibility of high-speed recording,
Moreover, the inkjet recording method is an extremely powerful recording method that can perform recording on so-called plain paper without requiring any specific fixing process.

A recording head applied to an inkjet recording device generally includes a fine liquid ejection opening (orifice), a liquid path, an energy acting part provided in a part of this liquid path, and a droplet forming device that acts on the liquid in the acting part. It is equipped with an energy generation means for generating energy.

Energy generating means for generating such energy include recording methods using electromechanical transducers such as piezo elements, irradiating electromagnetic waves such as lasers, absorbing them into the liquid and generating heat, and generating heat due to the heat generated. A recording method using an energy generating means that ejects and flies droplets by action, or a recording method using an energy generating means that ejects a liquid by heating the liquid with an electrothermal converter such as a heating element having a heating resistor. etc. Among these, the recording head used in the inkjet recording method, which discharges liquid using thermal energy, has a high density array of liquid discharge ports (orifices) for discharging recording droplets to form flying droplets. This makes it possible to record with high resolution. Among these, a recording head that uses an electrothermal converter as a thermal energy generating means is easy to make the overall size of the recording head compact, and is based on IC technology and microelectromechanical technology, which have recently made significant advances in technology and reliability in the semiconductor field. It is possible to fully utilize the advantages of processing technology, and it is easy to make it long and planar (two-dimensional), so it is easy to make multi-nozzles and high-density packaging, and it is also highly productive in large quantities. It is also possible to provide an inkjet recording head that is inexpensive to manufacture and an apparatus having the head.

In this way, using an electrothermal converter as an energy generation means,
An inkjet recording head manufactured through a semiconductor manufacturing process generally has a liquid path corresponding to each orifice, and applies thermal energy to the liquid filling the liquid path for each liquid path to draw the liquid from the corresponding orifice. An electrothermal transducer is provided as a means for ejecting liquid to form flying droplets. Moreover, the structure is such that liquid is supplied to these liquid passages from a common liquid chamber communicating with each liquid passage.

FIG. 3 is a schematic configuration diagram of such an inkjet recording head, in which an electrothermal converter 1103, an electrode 1104, and a liquid are formed on a substrate 1102 through semiconductor manufacturing process steps such as etching, vapor deposition, and sputtering. Road wall 1
105 and a top plate 1106, an inkjet recording head is shown. A recording liquid 1112 is supplied from a liquid storage chamber (not shown) through a liquid supply pipe 1107 into a common liquid chamber 1108 of the recording pad 1101. In the figure, 1109 is a liquid supply pipe connector. The liquid 1112 supplied into the common liquid chamber 1108 is supplied into the liquid path 1110 by a so-called capillary phenomenon, and is stably held by forming a meniscus at the discharge port surface (orifice surface) at the tip of the liquid path. By supplying electricity to the electrothermal converter 1103, the liquid on the surface of the electrothermal converter is rapidly heated, bubbles are generated in the liquid path, and the expansion and contraction of the bubbles causes the liquid to be discharged from the discharge port 1111. A droplet is formed. With the above-described configuration, a high-density ejection port arrangement such as an ejection port density of 16 nozzles/mm, 128 ejection ports or 256 ejection ports, or even a multi-nozzle inkjet in which ejection ports are arranged over the entire recording width can be achieved. A recording head can be formed.

FIG. 4 is a schematic perspective view showing a configuration example of an inkjet printing apparatus in which the above-described inkjet printing head is actually arranged in the printing apparatus. In the figure, a print head 1101 similar to the above-described print head is driven by a motor 12.
The carriage 1214 is configured integrally with the carriage 1214 which is reciprocated on the rail 1213a by the drive of the carriage 1213a. Ink tank 1222Y, 1222M.

The ink contained in 1222C and 1222B is supplied into the recording head 1101 by pumps 1223Y, 1223M, 1223c, and 1223B. The recording member (recording paper) is conveyed along the platen roller 1212 and temporarily stopped. Then, the recording head 1101 is connected to the rail 121.
While moving forward along lines 3a and 1213b, ink is ejected to record an image. After recording an image for a predetermined paper width, the recording head 1101 moves to the rail 1213a again.

It moves back along 1213b and returns to the home position, but
During this time, the recording paper is conveyed by a desired amount by the platen roller 1212 and stopped again. Then, image recording is performed by repeating such operations.

A recording method in which printing is performed while reciprocating the recording head on the stopped recording paper is hereinafter referred to as a serial scan method.

The cleaning blade 500 is installed on the home position side or on the opposite side of the recording heads 15c, 15M, 15Y, and 158 outside the recording area. Each time the recording head moving forward in the width direction of the recording paper passes the cleaning blade, the blade comes into contact with the ejection surface of the recording head and cleans the ejection surface.

[Problem to be solved by the invention]

However, in the conventional apparatus, each print head ejection surface is 400 mm in the order of 100 → Y → M → C with one blade contact.
Because all color nozzles were cleaned, there were cases where color mixing occurred.

Furthermore, if the recording head is made multi-orifice and elongated to have the same width as the recording paper, the recording method will be completely different from the conventional serial scan method. In other words, the number of nozzles in a conventional serial scan recording head is 2 per head.
56 nozzles, whereas the long head used in the present invention has 4677 nozzles per 1 head, equivalent to the width of A4 size paper.
It's a nozzle. Therefore, the diameter of each orifice of the elongated head is extremely small, and the orifice portion is easily clogged by impurities and dryness of the ink, paper powder, dust in the air, and the like. Furthermore, since there are a large number of orifices, if the head becomes clogged, it is difficult to clean it or restore its function (and a cleaning means specific to the long head is required).

Therefore, the present invention solves various problems that occur when configuring an image recording apparatus using a multi-orifice recording head that is long enough to cover the width of recording paper, and provides an optimized image recording method and method. The purpose is to provide such equipment.

[Means to solve the problem]

According to the present invention, in an inkjet recording apparatus that performs recording with a long multi-nozzle head, a cleaning blade dedicated to each recording head is provided, and the head ejection surface is cleaned every second in the longitudinal direction of the head.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1(f) is a schematic explanatory diagram of an image recording apparatus for explaining one embodiment of the present invention. First, the outline of the image recording apparatus of this embodiment will be explained using FIG. 1(f). In the figure, 301 is a part of a scanner that reads a document and converts it into an electrical signal.

A signal based on the converted signal is sent to the printer section 30.
The signal is given to the recording head section 305 of No. 2 as a drive signal. Recording paper, which is one of the recording members stored in the paper feed section 303, is fed sheet by sheet toward the belt conveyance section 304 when necessary. When the recording paper passes through the belt conveyance section 304, an image is recorded by the recording head section 305, and the recording paper is sent out to the tray 420 via the fixing paper discharge section 307. Note that 306 is a recovery cap portion, which has a function to maintain the recording head portion 305 in a state where printing is possible at all times. Each of the above configurations will be explained in detail below.

First, the ink supply to the full-line elongated recording head used in this embodiment will be explained with reference to FIG. FIG. 2 is an explanatory diagram schematically showing the configuration of the long recording head and ink supply means, where 160 is the recording head, 1652 is a common liquid chamber in the recording head 1601, and 1653 is a recording liquid discharge This is a discharge port for discharging liquid arranged on the surface 1654. However, the discharge port 165 of this embodiment
Numerals 3 and 3 selectively drive heat-generating elements provided in liquid paths (not shown) leading to the individual ejection ports 1653, whose numbers are arranged all over the recordable width of the target recording material. This makes it possible to eject the recording liquid and perform recording without moving or scanning the head itself.

1655 is a recording liquid supply tank for supplying recording liquid to the recording head 160I; 1656 is a main tank for replenishing the supply tank 1655 with recording liquid;
55 to the recording head 16 through a supply pipe 1657.
01 common liquid chamber 1652, and when replenishing the recording liquid, it is possible to replenish the supply tank 1655 with recording liquid from the main tank 1656 via a one-way replenishment rectifier valve 1658 with a recovery pump 1659. Also, 16
60 is a one-way recovery rectifier valve used during a recovery operation to recover the ejection function of the recording head 1601;
1661 is a circulation pipe in which a recovery rectifier valve 1660 is interposed, and 1662 is the above-mentioned first supply pipe 16.
A solenoid valve 57 is installed, and 1663 is an air vent valve for the supply tank.

In the recording head 1601 and its recording supply system and recovery system configured in this way, when recording is performed, the solenoid valve 16
62 is kept open, and recording liquid is replenished from the supply tank 1655 into the common liquid chamber 1652 by its own weight, and is discharged from the liquid chamber 1652 via a liquid path (not shown).
I am guided by 3. In addition, during a recovery operation performed to remove air bubbles remaining in the common liquid chamber 1652 and the supply system and to cool the recording head 1601, the recovery pump 1659 is driven to supply the recording liquid to the common liquid chamber 16 through the circulation pipe 1661.
52 and from the common liquid chamber 1652 to the first supply pipe 16
57 allows the recording liquid to be returned to the supply tank 1655 for circulation. Furthermore, at the time of initial filling of the liquid path, etc., with the solenoid valve 1662 closed, the pump 1659 pumps the recording liquid through the circulation pipe 1661 to the common liquid chamber 1652, and as the bubbles are discharged, the recording liquid is discharged from the discharge port 1653. can be done.

Normally, such a recording head is left with ink remaining inside the ink ejection openings when not recording. A capping means having a cap that can be joined to the ejection port surface or the ejection port side of the print head is provided, and the cap and the print head are bonded during non-printing, so that the print head can be covered with a cap and the surroundings can be covered. The evaporation of the ink liquid in the liquid path and its attendant effects are avoided by sealing the air space at the joint part with ink vapor and bringing the space formed by the cap and the recording head to the saturated vapor pressure of the ink. Prevents increase in viscosity and drying of ink in the liquid path. However, in low-humidity environments or when recording is stopped for a long period of time, the viscosity of the ink may increase even if the above-mentioned capping is performed to prevent the ink liquid in the liquid path from evaporating. During printing after the printing pause period, it may not be possible to prevent ink from being ejected from the ejection ports or from being ejected unstablely. In the present invention, the problem of whether or not ink is ejected for the first time after a pause is solved as follows.
called "problem". To solve this problem, as described above, the recovery pump 1659 is driven to circulate and pressurize the ink, and an ink circulation and pressure means is also used to discharge the ink from all the ejection ports of the recording head. There is. Furthermore, if the above-mentioned non-ejection condition is slight, the entire energy generating means of the head is driven to perform an ink ejection operation similar to that used for recording on paper or the like. Since this is not ejection for recording an image, it is hereinafter referred to as "dry ejection" in the present invention.

As mentioned above, if the ink dries up due to being left in a non-recording state for a long time and its viscosity increases and it becomes stuck in the ejection port and/or the liquid path, pressurized circulation of the ink will cause the non-recording state to occur again. If the stuck state is slight in a relatively short period of time, the head is rotated to a state where printing can be performed by an idle ejection operation.

A recording member suitably used in this embodiment will be described.

In the inkjet recording method, small droplets of recording liquid called ink are ejected and recorded by adhering them to the surface of a recording paper such as paper. It is necessary that the image does not become blurry. In addition, the ink adhering to the recording member is quickly absorbed into the recording member, and there is no phenomenon of ink flowing out or seeping, especially when ink of different colors is repeatedly adhering to the same spot within a short period of time. It is preferable to have characteristics that can suppress the spread of printed dots to an extent that does not impair the clarity of the image quality. These characteristics may not be fully satisfied with copy paper called plain paper used in electrophotographic copying machines and other paper used as general recording paper. When printing with only one color or superimposing two colors on these papers, it is often possible to obtain a somewhat satisfactory image quality, but for example, when printing a full-color image by superimposing three or more colors of ink, When the amount of ink that adheres to the paper increases, it may not be possible to record a sufficiently satisfactory image quality.

In the inkjet recording apparatus of this embodiment, the paper that satisfies the above-mentioned characteristics is coated with a coating (such as fine powder silicone) on the base paper as disclosed in JP-A-56-148583. It is preferable to use a recording member coated with an acid. The ink is attached to the coating surface of the recording member. Therefore, in this embodiment, in order to record a higher quality image, coated paper is used when recording an image using ink of three or more colors, and coated paper is used when recording an image using ink of one or two colors. I try to select and use non-coated paper (Gi, which does not have the above coating). However, it is perfectly acceptable to record images using coated paper using one or two color inks.

In the scanner part 301, 401 is a document, and 402 is a document scanning unit that scans the document. The original scanning unit 402 includes a rod eye lens 403, a life-size color separation line sensor (color image sensor) 404, and an exposure means 405. At least when the document scanning unit 402 moves and scans in the direction of arrow A to read the image of the document 401 on the document table, the exposure lamp in the exposure means 405 in the document scanning unit 402 is turned on.
Reflected light from a document 401 is guided by a rod array lens 403 to a 1-magnification color separation line sensor (hereinafter referred to as a reading sensor) 40 which is a color information reading sensor.
4, reads the color image information of the document for each color, and converts it into electrical digital signals. This digital signal is sent to the printer section 302. Driving signals based on these signals are supplied to the recording heads for each color, and liquid is ejected.

Here, the recording head cleaning means used in the color inkjet recording apparatus will be further explained with reference to the schematic diagram shown in FIG. 1(a).

As shown in FIG. 1(a), Ic, IM, IY, and IBk are inkjet recording heads each carrying 1 Itl of cyan, magenta, yellow, and black ink, and are at the recovery positions described above. Each recording head is fixed to a head block 6, and cleaning blades 500C, 500M dedicated to each head are installed on the head ejection surface of each color.
500Y and 5008k are respectively arranged. These blades are made of an elastic material such as silicone rubber, and are equipped with blade holders 501C, 501M, 501Y,
501Bk. As shown in the schematic perspective view of FIG. 1(b), each blade is initially waiting outside the recording area in the longitudinal direction of the recording head (in the width direction of the recording paper), and the head is in the non-ejecting state (dust is not ejected). , slimy taste,
It is activated when the ink becomes viscous, has an unpleasant taste, etc., and the ejection surface needs to be cleaned. As shown in the schematic perspective view of FIG. 1(c), the blades 500 of each color held in the blade holder 501 are driven by screws 503 in the longitudinal direction of the head. Since the state of the head ejection surface for each color is different, the blades can be driven independently. Additionally, the end of the head is chamfered so that the blade can easily come into contact with the head ejection surface.

The state of sliding contact between the recording head and the blade is preferably such that the corner of the blade contacts the head ejection surface, as shown in FIG. 1(c).

As shown in FIG. 1(a), an ink partition plate 8 is provided between the blades of each color, and an ink seal is glued between each partition plate 8 and the head block 6. Make a seal. Ink droplets containing dust, air bubbles, etc. scraped off from the head ejection surface by the blade fall into the recovery system container 2 along the partition plate 8, and are discharged to a discharge ink tank (not shown) by the discharge ink tank 13 provided at the bottom. is configured to be Further, the ink adhering to the blade is cleaned by the blade coming into contact with an ink absorber 502 (shown in FIGS. 1(b) and 1(C)) disposed outside the head.

As described above, by providing a dedicated blade for each color, color mixing can be prevented, and dust, air bubbles, etc. attached to the head ejection surface can be removed for each nozzle.

Another embodiment of the color inkjet recording apparatus described above will be described using the schematic cross-sectional view of FIG. 1(d).

Each recording head IC as shown in FIG. 1(d).

IM, IY, and IBk are held by a head block 6, and a blade 500 is provided as a cleaning member on the head ejection surface.
is installed. This blade is made of an elastic material such as silicone rubber as described above, and is fixed to the blade holder 501. As shown in the schematic perspective view of FIG. 1(e), the blade holder 501 includes a screw 503 and a shaft 50.
4, the head is disposed so as to be movable in the longitudinal direction. As the blade holder moves, the blade comes into contact with the head ejection surface and cleans each color nozzle one by one.

Since the blade 501 is integrally molded for each head, it can be moved with a single screw, and the drive mechanism is easy.
Cost can be reduced by reducing the number of parts. Further, although the blade is integrally molded, the cleaning portions on the head ejection surface are of different colors, so color mixing can be prevented.

〔Effect of the invention〕

As described above, according to the image recording apparatus of the present invention, a dedicated cleaning blade is provided on the long head of each color and is brought into sliding contact with the long head in the longitudinal direction of the head, thereby removing dust, air bubbles, etc. Each piece is securely removed,
Furthermore, color mixing can be prevented and a leaning means suitable for long heads can be obtained.

[Brief explanation of the drawing]

FIG. 1(a) and FIG. 1(d) are schematic explanatory diagrams for explaining a portion of a head cleaning means in an inkjet recording apparatus according to an embodiment of the present invention. FIGS. 1(b), 1(c), and 1(e) are schematic perspective views for explaining the cleaning means, respectively. FIG. 1(f) is a schematic explanatory diagram of an inkjet recording apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating the configuration of a head and an ink supply means in a full-tooth inkjet recording apparatus. Figure 3 is a schematic diagram of the inkjet recording head;
The figure shows a schematic configuration diagram of an inkjet recording apparatus in which the recording heads shown in FIG. 3 are arranged. FIG. 5 shows a block diagram of the head cleaning means in FIG. 4.

Claims (2)

[Claims] (1) An inkjet recording apparatus that records images using a plurality of recording heads, characterized in that a cleaning means dedicated to each head is provided. (2) Claim (1) characterized in that the recording head is a long head having a width comparable to the width of the recording paper, and is provided with a cleaning means that moves in the same direction as the arrangement direction of the ink ejection ports (nozzles). ).