JPH06328701A - Ink jet printer - Google Patents

Abstract

PURPOSE:To provide an ink jet printer not damaging the durability of the water repelling agent of an ink jet recording head, not requiring the separation of a cap part from the recording head at the time of the squeezing operation of an ink absorbing member and reduced in the dimension of the cap part. CONSTITUTION:A roller-shaped ink absorbing member 6 is provided in a cap 5 in a rotationally drivable manner and, when the cap 5 comes into contact with a recording head 120 at the home position of the recording head 120, the ink absorbing member 6 does not come into contact with the recording head 120 to hold a fine interval (g). A squeeze roller 7 is so provided as to be pressed to the surface of the ink absorbing member 6 and rotated following the rotation of the ink absorbing member 6 to squeeze out the ink absorbed into the ink absorbing member 6 to remove the same. The removed ink is discharged from a waste ink tube 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet printer, and more particularly to a recovery means for an inkjet recording head.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, an inkjet printer of this type has an inkjet recording head 12.
0 and a head recovery device 126. The inkjet recording head 120 is detachably mounted on a carriage 116 that slides on two parallel guide shafts 119A and 119B by a drive belt 118 driven by a drive motor 117 and moves left and right, and a platen 124.
Printing is performed on a recording medium (not shown) above, and the head recovery device 126 includes a cap portion 126A which is a capping mechanism for receiving ink discharged during the recovery operation of the recording head. .

As shown in FIG. 3A, the cap portion 126A removes the ink absorbed by the ink absorber 36 in the cap 35 which is open at one side to accommodate the ink absorber 36. For this purpose, a partition plate 37 for pressing the ink absorber and a cam 38 driven by a drive shaft 38a for moving the partition plate 37 in the horizontal direction are provided, and the bottom of the cap 35 is removed from the ink absorber 36. A waste ink tube 39 for guiding the ink to the outside is provided.

To perform the head recovery operation, at the home position of the ink jet recording head 120, the recording head 120 and the cap portion 126A are brought into contact with each other so that the nozzles 121 and the ink absorber 36 are in contact with each other. When the ink is circulated in the recording head 120, the ink thickened in the nozzle 121 is discharged to the ink absorber 36 together with other inks (FIG. 3).
(See (A)). After a predetermined time, the circulation of the ink is stopped, the cap portion 126A is separated from the recording head 120, and then the drive shaft 38a is driven by a drive device (not shown) to rotate the cam 38, as shown in FIG. 3B. Thus, the partition plate 37 is moved in the horizontal direction to move the ink absorber 3
6 is pressed to squeeze and remove the ink absorbed by the ink absorber 36, and the squeezed ink is discharged from the waste ink tube 39 to an external waste ink absorber (not shown).

[0005]

In the conventional ink jet printer described above, since the ink jet recording head and the ink absorber of the cap portion are in direct contact with each other during the recovery operation of the recording head, the surface of the recording head is It has the drawback of reducing the durability of the water repellent agent, and further keeps the head away from the cap part during the squeezing operation even at the home position so that the ink absorbed by the ink absorber does not flow back into the nozzle due to the squeezing operation. Since the sequence is complicated because the operation is required, the size of the cap is increased by providing the cam mechanism on the cap, which leads to the size increase of the device.

The object of the present invention is not to reduce the durability of the water repellent agent of the ink jet recording head, and it is not necessary to separate the cap portion from the recording head during the squeezing operation of the ink absorber. Is to provide a small inkjet printer.

[0007]

In an ink jet printer of the present invention, a head recovery means for discharging ink from nozzles after jetting is provided in a cap contacting the ink jet recording head during a recovery operation, and between the ink jet recording head and the head. A roller-type ink absorber that is rotatably drivable and arranged at a minute interval, and an ink absorber that is installed inside the cap by pressing the ink absorber to remove ink from the ink absorber. The recording head of the ink jet printer has an electrothermal converter for generating thermal energy for ink ejection, or the recording head has an electrothermal converter. A method of ejecting ink from an ejection port by utilizing film boiling generated in ink by thermal energy applied by a converter There it is desirable.

[0008]

In order to recover the recording head of the printer, the roller-type ink absorber that can be driven to rotate is provided at a minute interval so as not to contact the recording head in the cap that contacts the recording head. It is possible to squeeze the ink by rotating the ink absorber while keeping the cap in contact with the recording head without damaging the water repellent.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. 1 is a schematic vertical cross-sectional view of a cap portion of a head recovery device for an inkjet printer according to the present invention.
FIG. 1A is a diagram showing a state in which a cap is in contact with a printer head during a recovery operation, and FIG. 1B is a diagram showing a state in which ink absorbed by an ink absorber is removed by a squeeze roller.

The cap 5 has a box shape with an opening on the upper surface,
The edge of the opening is an edge 5a with which the lower surface of the inkjet recording head 120 can come into flat contact. Inside the cap 5, a roller-shaped ink absorber 6 is rotatably provided by a driving device (not shown), and the recording head 120 is provided.
Is contacted with the edge 5a of the cap 5 at the home position, a minute gap g is maintained between the ink absorber 6 and the lower surface of the recording head 120 having the nozzle 121. A squeeze roller 7 is provided in contact with the surface of the ink absorber 6 so as to press it, and its central axis is parallel to the central axis of the ink absorber 6 and is rotated by the rotation of the ink absorber 6, The ink absorbed by the absorber 6 can be squeezed and removed. A waste ink tube 9 is provided at the bottom of the cap 5 so that the ink removed from the ink absorber 6 is discharged to an external waste ink absorber (not shown).

FIG. 2 is a schematic vertical sectional view of a cap portion according to a second embodiment of the present invention. The cap 5 ′ is provided with an ink level sensor 14 for detecting the ink level so that the level of the ink squeezed out from the ink absorber 6 by the squeeze roller 7 rises and the ink absorber 6 is not soaked with ink. The waste ink pump 13 is operated to discharge the waste ink to a waste ink absorber (not shown).

Next, the operation of this embodiment will be described. In the first embodiment, the head recovery device provided at the position facing the home position of the recording head 120 increases the viscosity discharged from the nozzle 121 when the nozzle recovery operation of the recording head 120 is performed. Ink containing ink is absorbed by the roller-type ink absorber 6, and the absorbed ink is removed from the ink absorber because it is squeezed by the squeezing roller 7 that is driven and rotated as the ink absorber 6 rotates. It is discharged from the waste ink tube 9 to the outside. In the second embodiment,
The sensor 14 detects the level of the ink removed from the ink absorber 6, and the waste ink pump 13 is driven to discharge the ink so that the ink level does not rise.

The present invention is particularly effective in an ink jet recording head and a recording apparatus for recording by forming flying droplets by utilizing thermal energy among the ink jet recording methods.

Regarding the typical constitution and principle of the ink jet recording system to which the present invention is applied, for example, the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 is used. What is done is preferred. This method can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal which corresponds to the recorded information and which causes a rapid temperature rise exceeding nucleate boiling, to the electrothermal converter being generated, thermal energy is generated in the electrothermal converter,
This is effective because film boiling is caused on the heat-acting surface of the recording head, and as a result bubbles can be formed in the liquid (ink) that correspond one-to-one to this drive signal. The liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. It is more preferable to make this drive signal into a pulse shape because bubbles can be immediately and appropriately grown and contracted, so that liquid (ink) ejection with excellent responsiveness can be achieved.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, further excellent recording can be performed.

In addition to the combination of the ejection port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) disclosed in the above-mentioned specifications, the construction of the recording head is not limited. A configuration using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which a heat acting portion is arranged in a bending region, is also included.

In addition, JP-A-59-123670 discloses a structure in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and a pressure wave of thermal energy is absorbed. A configuration based on Japanese Patent Application Laid-Open No. 59-138461, which discloses a configuration in which the opening corresponds to the ejection portion, is also effective.

Further, as a full line type recording head having a length corresponding to the maximum recording medium width that can be recorded by the recording apparatus, the length can be increased by combining a plurality of recording heads as disclosed in the above-mentioned specification. The present invention can exert the above-mentioned effects more effectively, although it may have a configuration that satisfies the above requirement or a configuration as one recording head integrally formed.

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

Also provided as a configuration of the recording device,
It is preferable to add recovery means, preliminary auxiliary means, etc. to the recording head because the effects of the present invention can be further stabilized. Specific examples thereof include capping means, cleaning means, pressurizing or suctioning means for the recording head, preheating means using an electrothermal converter or another heating element or a combination thereof, and recording. It is also effective to perform a stable recording by performing a preliminary discharge mode in which another discharge is performed.

Further, as the recording mode of the recording apparatus, not only the mainstream color such as black is recorded but also the recording head may be integrally formed or a plurality of them may be combined. The present invention is also extremely effective for a device provided with at least one of full colors by color mixing.

In the embodiments of the present invention described above, the ink is described as a liquid, but it is an ink that solidifies at room temperature or lower and that softens at room temperature, or is a liquid, or the above-mentioned liquid. In the inkjet method, the temperature of the ink itself is generally adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that the viscosity of the ink is within a stable ejection range. It may be in a liquid form.

In addition, the temperature rise due to the thermal energy is positively prevented by using it as the energy for changing the state of the ink from the solid state to the liquid state, or the ink is solidified in a standing state for the purpose of preventing evaporation of the ink. In some cases, such as ink that is liquefied by applying heat energy according to a recording signal and ejected as a liquid ink, or one that has already started to solidify when it reaches a recording medium. The use of an ink having a property of being liquefied only by heat energy is also applicable to the present invention. In such a case, the ink is disclosed in JP-A-54-5684.
No. 7 or JP-A-60-71260, a mode in which the porous sheet is opposed to the electrothermal converter in the state of being held as a liquid or solid in the recess or through hole of the porous sheet. May be In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as a form of the recording apparatus according to the present invention, in addition to the one provided integrally or separately as an image output terminal of information processing equipment such as a word processor or a computer, a copying apparatus combined with a reader or the like, May take the form of a facsimile machine having a transmission / reception function.

[0025]

As described above, according to the present invention, when the nozzle of the ink jet recording head is recovered, the roller type ink absorber which can be driven to rotate is not brought into contact with the head in the cap that comes into contact with the recording head. By providing the ink absorber, it is possible to remove the ink from the ink absorber with the cap kept in contact with the recording head without impairing the water repellency of the head. Therefore, it is difficult to separate the ink absorber from the head at the home position. Since there is no need for such an operation, the sequence is simple, and since it is not necessary to provide a cam mechanism inside the cap, the size of the cap can be reduced, and the device can be downsized.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional view of a cap portion of an inkjet printer of the present invention, FIG. 1 (A) is a diagram showing a state during a recovery operation, and FIG. 1 (B) is a diagram showing an action of a diaphragm roller.

FIG. 2 is a schematic vertical sectional view of a second embodiment of the present invention.

3A and 3B are schematic vertical cross-sectional views of a cap portion of an ink jet printer according to a conventional technique, FIG. 3A is a diagram showing a state during a recovery operation, and FIG. 3B is a diagram showing a diaphragm operation of an ink absorber. is there.

FIG. 4 is a perspective view showing a configuration of an inkjet printer.

[Explanation of symbols]

 5, 5 ', 35 Cap 5a Edge 6 Roller type ink absorber 7 Squeeze roller 9,39 Waste ink tube 13 Waste ink pump 14 Ink level sensor 36 Ink absorber 37 Partition plate 38 Cam 38a Drive shaft 116 Carriage 117 Drive motor 118 Drive Belt 119A, 119B Guide Shaft 120 Inkjet Recording Head 121 Nozzle 124 Platen 126 Head Recovery Device 126A Cap Part g Minute Interval

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B41J 2/185 B41J 3/04 102 R

Claims (3)

[Claims] 1. An inkjet printer having a head recovery means for discharging ink from nozzles of an inkjet recording head after jetting, wherein the head recovery means has the cap for contacting the inkjet recording head during a recovery operation. It was provided with a minute gap between it and the head.
A roller-type ink absorber that can be driven in rotation, and a squeezing roller that is installed in the cap by pressing the ink absorber to remove ink from the ink absorber and that is driven by the rotation of the ink absorber. An inkjet printer having: 2. The ink jet printer according to claim 1, wherein the recording head includes an electrothermal converter for generating thermal energy for ejecting ink. 3. The recording head according to claim 1, wherein the ink is ejected from an ejection port by utilizing film boiling generated in the ink by thermal energy applied by the electrothermal converter. Inkjet printer.