JP2000263767A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording apparatus which prevents an ink mist generated at the time of recording from adhering to members in the apparatus. SOLUTION: The ink jet recording apparatus which records by discharging ink from a recording means has a transfer means 2 for transferring a recording medium 1 and a carriage 4a movable while loading a recording head. A cover member 5 for covering a recording face is set via a predetermined distance to the recording face of the recording medium at the rear side in a recording movement direction of the carriage 4a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus which performs recording by discharging ink from recording means mounted on a moving carriage.

[0002]

2. Description of the Related Art A recording device having a function such as a printer, a copying machine, a facsimile or the like, or a recording device used as an output device of a composite electronic device or a workstation including a computer or a word processor, etc. It is configured to record an image on a recording medium such as a thin plastic plate. These recording devices
Depending on the recording method, inkjet, wire dot,
It can be divided into thermal type, laser beam type, etc.

In a serial type printing apparatus employing a serial scan system in which main scanning is performed in a direction intersecting with a conveying direction (sub-scanning direction) of a recording medium, an image is formed by a recording means mounted on a carriage which moves along the recording medium. Is printed (main scanning), a predetermined amount of paper is fed (pitch transport) after printing of one line is completed, and then the image of the next line is printed (main scanning) on the stopped recording medium. ) Is repeated to record the entire recording medium.

[0006] Of the above recording apparatuses, an ink jet recording apparatus is, as shown in FIG.
Recording is performed by ejecting ink to the 51, and the recording means can be easily made compact, high-definition images can be recorded at high speed, and recording is performed on plain paper without special processing. In addition, the non-impact method has low running costs and has low noise, and has the advantage that it is easy to record a color image using multicolor inks.

[0005]

However, the ink jet recording apparatus performs recording by spraying liquid ink onto a recording medium 51, and fine ink generated around ink droplets 52 when the recording head 50 discharges ink. Fog-like ink (self-mist) 53a, when ink droplets land on the paper surface, especially when ink droplets are already struck on the paper surface and ink droplets are overshot, the ink is splashed in the form of mist due to the impact of the landing. Ink mist such as mist 53b may be generated.

[0006] The amount of the ink mist generated increases due to an increase in the ink ejection speed, an increase in the amount of ink ejection and the number of ink ejections due to the use of low-density ink and small-drop-diameter ink droplets for high-quality recording.

[0007] The ink mist generated by this recording is:
As shown in FIG. 6, the negative pressure generated behind the carriage by the scanning of the carriage 54 causes the ink to be taken up in the printing apparatus, and the wound ink mist 53c adheres to the inside of the printing apparatus.

When the ink mist adheres to the inside of the apparatus, not only does the hand become dirty when the user needs to open the cover to operate, but also the operation of the regular apparatus due to the influence of the mist adhered to various mechanisms. May be damaged.

For example, if it adheres to the sliding portion of the carriage, the load at the time of scanning changes, and there is a possibility that the carriage cannot be scanned with high accuracy. In addition, when using an encoder, if an optical system is used, a reading error will occur due to mist adhering to the encoder film, and if a magnetic system is used, the sliding resistance in the sensor unit will increase and the encoder will be pulled, resulting in poor recording. Or

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide an ink jet recording apparatus in which ink mist generated during recording does not adhere to members in the apparatus. is there.

[0011]

A typical configuration according to the present invention for achieving the above object is to transport a recording medium in an ink jet recording apparatus which performs recording by discharging ink from a recording head. Means, and a carriage capable of mounting and moving a recording head, wherein a cover member for covering the recording surface at a predetermined distance from a recording surface of a recording medium is provided at a rear side of the carriage in the recording movement direction. It is characterized by.

In the above configuration, the presence of the cover member prevents the ink mist generated by the recording from being affected by the negative pressure generated by the carriage scanning, thereby preventing the problem that the ink mist adheres to the inside of the apparatus. can do.

Further, if the cover member is formed in a box shape with a cover surface substantially parallel to the recording surface of the recording medium and a rib portion substantially perpendicular to the cover surface, the ink mist can be formed in the cover member. Gather inside and naturally return to the recording surface.

If the ribs are not provided on the downstream side in the transport direction of the recording medium, the ink mist collected in the cover section will come out of the apparatus by transporting the recording medium.

Furthermore, if the cover member is configured to overlap between or overlap the transport members provided with the recording area interposed therebetween, the ink mist is more effectively prevented from scattering into the apparatus. It is possible to do.

Further, if the cover member is made of a water-repellent member, the adhesion of ink mist to the cover member itself can be prevented.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an ink jet recording apparatus according to one embodiment of the present invention will be described with reference to the drawings.

[First Embodiment] FIGS. 1 and 2 show an ink jet recording apparatus according to a first embodiment.
FIG. 1 is a schematic side view of the recording unit, and FIG. 2 is a schematic front view of the recording unit.

This recording apparatus sandwiches and conveys a fed recording medium 1 such as paper or a plastic sheet in the direction of arrow a by a conveying means 2, and records the recording medium 1 on the back side supported by a platen 3. 4 is reciprocated for recording.

The conveying means 2 is provided with a conveying member comprising a conveying roller 2a and a pressing roller 2b for pressing the recording medium on the upstream side in the conveying direction of the recording medium 1 with the recording area interposed therebetween. Is nip-conveyed to the recording area. A discharge member including a discharge roller 2c and a spur roller 2d pressing the recording medium against the discharge roller 2c is provided downstream of the recording area, and discharges the recording medium 1 recorded by the recording means to a discharge tray (not shown). I do.

The recording means 4 is arranged in a direction in which the carriage 4a intersects the recording medium conveyance direction along the guide shaft 4b (FIG. 1).
The ink cartridge 4c in which the recording head 4c1 and the ink tank 4c2 are integrated is mounted on the carriage 4a, and the carriage 4a is moved in the direction indicated by an arrow in FIG. The recording is performed by discharging the ink from the recording head to the recording medium 1 while moving in the direction b, that is, by a so-called serial type ink jet recording method.

That is, the recording head 4c1 is provided with a fine liquid discharge port (orifice), a liquid path, an energy action section provided in a part of the liquid path, and a droplet forming energy acting on the liquid in the action section. It has energy generating means for generating energy.

As an energy generating means for generating such energy, a recording method using an electromechanical transducer such as a piezo element, an electromagnetic wave such as a laser is irradiated to generate heat, and droplets are discharged by the action of the heat. There are a recording method using an energy generating means, and a recording method using an energy generating means for discharging a liquid by heating a liquid by an electrothermal converter such as a heating element having a heating resistor.

Among them, a recording head used in an ink jet recording method for discharging a liquid by thermal energy has a high density of liquid discharge ports (orifices) for discharging a recording droplet to form a discharge droplet. Since they can be arranged, high-resolution recording can be performed. Among them, a recording head using an electrothermal transducer as an energy generating means is advantageous because it can be easily made compact, easily mounted at a high density, and inexpensively manufactured.

In the present embodiment, the ink is ejected by energizing the electrothermal transducer in response to a recording signal and utilizing the film boiling caused by the thermal energy to grow and shrink bubbles generated in the ink. The recording is performed by discharging the ink from the discharge port.

The rear side of the carriage 4a in the recording movement direction (the direction of the arrow b in FIG. 2) is a predetermined distance from the recording surface of the recording medium 1 conveyed on the platen 3 in this embodiment. A plate-like cover member 5 parallel to the recording surface is provided integrally with the carriage 4a at a distance of about 1 mm to 2 mm. Further, in the recording medium transport direction, the cover member 5 covers the recording area from just before the pressing roller 2b on the upstream side of the recording area to just before the spur roller 2d on the downstream side of the recording area, or in the recording medium transport direction. , And overlaps the rollers 2b and 2d to cover the recording area.

During recording, when the carriage 4a moves in the direction of arrow b in FIG. 2, a negative pressure is generated on the rear side in the moving direction. Therefore, if the cover member 5 is not provided,
As described above, the ink mist generated at the time of printing due to the negative pressure tends to fly up. However, in this embodiment, since the cover member 5 is provided,
The ink mist 6 cannot be sucked up rearward, and as a result, the ink mist hardly scatters in the apparatus. Further, since the distance between the recording medium 1 and the cover member 5 is small and covers the entire recording area in the transport direction of the recording medium, the generated ink mist 6 is mostly generated on the recording surface of the recording medium 1 before spreading in the apparatus. Adheres to the surface and does not scatter in the apparatus.

Thus, it is possible to prevent a recording failure or the like caused by the ink mist adhering to the components in the apparatus.

It is more preferable that the cover member 5 is made of a water-repellent member to which ink does not easily adhere, because it is difficult for ink mist to adhere to the cover member 5 itself.

[Second Embodiment] In the above-described embodiment, an example was shown in which the cover member 5 was formed of a flat plate member. However, as shown in FIGS. 3 and 4, the cover member 5 may be formed in a box shape. Good. FIG. 3 is an explanatory perspective view of a cover member according to the second embodiment. FIG. 4 is an explanatory plan view of a recording unit according to the second embodiment.
This is the same as the embodiment.

The cover member 5 according to this embodiment has a rib 5b substantially perpendicular to the cover surface 5a formed on the edge of the cover surface 5a substantially parallel to the recording surface of the recording medium 1, and has a box-like shape as a whole. Is formed. The cover surface 5a is slightly away from the recording medium 1 and the end of the rib 5b has a small interval of about 1 mm to 2 mm from the recording medium 1 so that the box is lying down.

By configuring the cover member 5 as described above, the same effects as those of the first embodiment can be obtained. In addition, the generated ink mist is collected in a box-shaped space. Is spontaneously dropped onto the recording surface of the recording medium 1 and spills out of the apparatus without scattering into the apparatus.

[Third Embodiment] In the above-described second embodiment, an example is shown in which the cover member is formed in a box shape lying down, but the cover member may be configured as shown in FIG.

FIG. 5 (a) shows the ribs of the cover member 5 of the second embodiment, in which no ribs are provided on the downstream side in the recording medium conveyance direction, and the ribs 5b are on the upstream side in the recording medium conveyance direction. Only the portion parallel to the transport direction is provided, and the downstream side in the transport direction of the recording medium is opened.

In this way, the ink mist collected in the cover member 5 falls on the surface of the recording medium, and easily goes out of the apparatus together with the conveyance of the recording medium. For this reason, the scattering of the ink mist in the apparatus can be more effectively prevented.

When the shape of the rib portion 5b is inclined or curved with respect to the recording medium conveyance direction as shown in FIGS. 5B and 5C, the ribs 5b are collected in the cover member 5. The ink mist can be naturally pushed downstream by the movement of the carriage in the recording medium transport direction, and the generated ink mist can be more actively sent out of the apparatus.

[Other Embodiments] In the above embodiment, the cover member 5 is provided integrally with the carriage 4a. However, the cover member 5 may be provided on an ink cartridge mounted on the carriage 4a. Good.

Further, in the above-described embodiment, the ink jet recording system is used as the recording means. However, an electric current is supplied to the electrothermal converter according to the recording signal, and the ink is generated in the ink by the thermal energy applied by the electrothermal converter. It is more preferable that the recording is performed by discharging the ink from the discharge port by the growth and shrinkage of the bubble generated in the ink using the film boiling.

Regarding the typical configuration and principle, it is preferable to use the basic principle disclosed in, for example, US Pat. Nos. 4,723,129 and 4,740,796. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to a sheet or a liquid path holding a liquid (ink). By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise above nucleate boiling,
This is effective because heat energy is generated in the electrothermal transducer, thereby causing film boiling on the heat-acting surface of the recording head. As a result, bubbles in the liquid corresponding to this drive signal one-to-one can be formed. The liquid is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are immediately and appropriately performed, so that particularly excellent liquid ejection can be achieved, which is more preferable.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable.

Further, if the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of a discharge port, a liquid path, and an electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, The present invention also includes a configuration using U.S. Pat. Nos. 4,558,333 and 4,459,600 which disclose a configuration in which a heat acting portion is arranged in a bending region.

Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal transducer for a plurality of electrothermal transducers, or an aperture for absorbing pressure waves of thermal energy. Unexamined Japanese Patent Application Publication No.
The effect of the present invention is effective even in a configuration based on JP-A-59-138461. That is, according to the present invention, the recording can be performed reliably and efficiently regardless of the form of the recording head.

In addition, even in the case of the serial type described above, when the recording head is fixed to the carriage or mounted on the carriage, electrical connection with the apparatus main body and supply of ink from the apparatus main body become possible. A replaceable chip type recording head or a cartridge type recording head in which an ink tank is provided integrally with the recording head itself may be used.

It is preferable to add recording head recovery means, preliminary auxiliary means, and the like provided as components of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. To be more specific, capping means for the recording head, cleaning means, pressurizing or suctioning means, preheating means using an electrothermal conversion type or another heating element or a combination thereof, and printing Performing a preliminary ejection mode for performing another ejection is also effective for performing stable printing.

The type and number of recording heads mounted on the carriage are, for example, not only those provided for one color ink but also a plurality of inks having different recording colors and densities. May be provided in plurality. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, and may be a combination of a plurality of print heads integrally formed. To at least one of the full-color devices.

In addition, in the above-described embodiment, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature, or an ink jet recording system The ink itself
Generally, the temperature is controlled within the range of 30 ° C or more and 70 ° C or less to control the temperature so that the viscosity of the ink is in the stable ejection range. Good. In addition, actively prevent the temperature rise due to thermal energy by using the energy of the state change from the solid state of the ink to the liquid state,
Alternatively, an ink that solidifies in a standing state for the purpose of preventing evaporation of the ink is used, and in any case, the ink is liquefied by application of heat energy according to a recording signal, and a liquid ink is discharged, or a recording sheet is used. It is also applicable to a case where an ink having a property of being liquefied for the first time by thermal energy, such as an ink which starts to solidify at the time when the temperature reaches.

The ink in such a case is disclosed in JP-A-54-5
No. 6847 or Japanese Patent Application Laid-Open No. Sho 60-71260, in which the porous sheet is opposed to the electrothermal converter in a state of being held as a liquid or solid substance in the concave portion or through hole of the porous sheet. It is good. The most effective one for each of the above-mentioned inks is to execute the above-described film boiling method.

Further, as the form of the above-mentioned ink jet recording apparatus, in addition to the one used as an image output terminal of an information processing apparatus such as a computer, a copy apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function May be used.

[0050]

The present invention is constructed as described above.
By the presence of the cover member, the ink mist generated by the recording is not affected by the negative pressure generated by the carriage scanning, and the problem that the ink mist adheres to the inside of the apparatus can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a recording unit.

FIG. 2 is a schematic front view illustrating a recording unit.

FIG. 3 is an explanatory perspective view of a cover member according to a second embodiment.

FIG. 4 is an explanatory plan view of a recording unit according to a second embodiment.

FIG. 5 is an explanatory perspective view of a cover member according to a third embodiment.

FIG. 6 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Recording medium 2 ... Conveying means 2a ... Conveying roller 2b ... Pressing roller 2c ... Discharge roller 2d ... Spur roller 3 ... Platen 4 ... Recording means 4a ... Carriage 4b ... Guide shaft 4c ... Ink cartridge 4c1 ... Recording head 4c2 ... Ink tank Reference numeral 5: Cover member 5a: Cover surface 5b: Rib portion 6: Ink mist

Claims (7)

[Claims] 1. An ink jet recording apparatus which performs recording by discharging ink from a recording head, comprising: transport means for transporting a recording medium; and a carriage movable on which a recording head is mounted. An ink jet recording apparatus, further comprising a cover member that covers the recording surface at a predetermined distance from a recording surface of a recording medium at a rear side in the recording movement direction. 2. The recording apparatus according to claim 1, wherein the cover member has a cover surface substantially parallel to a recording surface of the recording medium, and a rib portion substantially perpendicular to the cover surface, and a gap between the cover surface and the recording surface. 2. The ink jet recording apparatus according to claim 1, wherein a distance between the end of the rib portion and the recording surface is narrower than that. 3. The ink jet recording apparatus according to claim 2, wherein the cover member covers the recording surface of the recording medium in a box shape with the cover surface and the rib portion. 4. The ink-jet recording apparatus according to claim 2, wherein the cover member has a shape in which only the downstream side in the transport direction of the recording medium is opened by the cover surface and the rib portion. Recording device. 5. The transport means has a transport member and a discharge member across a recording area in a transport direction of the recording medium, and the cover member has an end close to the transport member and the discharge member, or The ink jet recording apparatus according to any one of claims 1 to 4, wherein the ink jet recording apparatus is provided so as to overlap between members. 6. The ink jet recording apparatus according to claim 1, wherein the cover member is made of a water repellent material. 7. The apparatus according to claim 1, wherein the recording means supplies a current to the electrothermal transducer in response to a signal, and discharges the ink using thermal energy generated by the electrothermal transducer. Ink jet recording device.