JP3124668B2 - Ink jet recording device - Google Patents

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 for adsorbing a recording medium by an electrostatic attraction device and heating and fixing an image after recording.

[0002]

2. Description of the Related Art An electrostatic attraction device is a device which applies a voltage between a plurality of electrodes to generate an electrostatic force to attract an object to be attracted. Is used to hold a recording medium.

[0003] In particular, in the case of an ink jet recording apparatus, if the fixing accuracy and smoothness of the recording medium are not maintained, the recorded image is displaced and the image quality is remarkably deteriorated. is necessary. As a configuration for holding the recording medium in this manner, in addition to the electrostatic suction configuration, for example, there is a configuration in which the recording medium is suctioned by using a negative pressure generated by a fan, and the like. (1)
In recent years, it is often used for fixing and holding recording media in inkjet recording devices because of its simple configuration, (2) no moving parts, (3) easy downsizing of the device, and (4) no noise generation. Have been.

In the ink jet recording apparatus,
In order to improve the image quality, in addition to ensuring the fixed holding of the recording medium, the recording medium after recording is also heated. This is because heating promotes fixing of the ink and reduces bleeding of the ink.

Therefore, in order to realize an ink jet recording apparatus having high recording quality, it is desirable to use both electrostatic adsorption and heat fixing on a recording medium.

[0006]

However, in a conventional ink jet recording apparatus using both electrostatic adsorption and heat fixing, adsorption of a recording medium is performed by an electrostatic adsorption apparatus.
For the heat fixing, a heating wire heater formed separately from the electrostatic suction device or a heat roller incorporating a heater has been used.
For this reason, there is a problem that the size of the device is increased and the cost of the device is increased.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a small-sized, low-cost ink jet recording apparatus having a heating action.

[0008]

In order to achieve the above object, a typical configuration according to the present invention is a conveyance belt that conveys a recording medium that receives ejection of ink from a recording unit, and a conveyance belt that opposes the recording unit. And an electrostatic suction device for holding the recording medium on the conveyance belt in a fixed manner so as to face the recording means, wherein The electrostatic attraction device has a pair of electrodes arranged at intervals, a circuit for applying a voltage between the electrodes, and a circuit for applying ink to the recording medium. And a circuit for flowing a current for causing at least one electrode to generate heat, wherein the recording medium can be fixedly held and the ink can be dried and fixed.

[0009]

[0010]

In the above construction, when a voltage is applied between the pair of electrodes, an electrostatic attraction force is generated between the electrodes, and the recording medium is attracted to the transport belt. When a current is applied to at least one of the electrodes, the electrodes generate heat. For this reason, it is possible to simultaneously perform the suction holding of the recording medium and the heating and fixing of the ink in the ink jet recording.

[0011]

【Example】

[First Embodiment] Next, an embodiment according to the present invention will be specifically described with reference to FIGS. FIG. 1 is a schematic explanatory view of an ink jet recording apparatus, and FIG. 2 is a structural explanatory view of an electrostatic attraction apparatus for fixing and holding a recording medium to be recorded by the recording apparatus.

In this ink jet recording apparatus, as shown in FIG. 1, a recording medium 1 is conveyed by conveying means 2 and recorded by recording means 3. Further, at the time of recording, the recording medium 1 is configured to be fixedly held by an electrostatic attraction device 4 disposed at a position facing the recording means 3 with the conveyance belt 2d interposed therebetween.

(Conveying Means) In the structure of the conveying means 2, a conveying belt 2d is stretched over rollers 2a, 2b, 2c. The transport belt 2d is located at a position upstream and downstream in the transport direction of the recording medium 1 with the recording means 3 interposed therebetween.
The pinch rollers 2e and 2f that follow the rotation of d are in contact. Therefore, when a motor (not shown) is connected to one of the rollers 2a, 2b, and 2c and driven to rotate, the transport belt 2d rotates, and the recording medium 1 is transported by the transport belt 2d.
Is transported in the direction of the arrow in FIG.

(Recording means) The recording means 3 has a structure in which a belt 3c is stretched between pulleys 3a and 3b, and a carriage 3d is connected to the belt 3c.
A recording head 3e is mounted on d. Accordingly, when the motor 3f connected to the pulley 3a is driven forward and backward, the carriage 3d reciprocates, and the recording head 3e is driven in synchronization with this movement to perform recording on the recording medium 1. A guide member (not shown) for guiding the reciprocating movement of the carriage 3d is provided.

In this embodiment, an ink jet recording head for discharging and recording ink is used as the recording head 3e. That is, the recording head 3e includes a fine liquid ejection port (orifice), a liquid path, an energy operation section provided in a part of the liquid path, and an energy for generating a droplet forming energy to act on the liquid in the operation section. Generating means.

As an energy generating means for generating such energy, a recording method using an electromechanical transducer such as a piezo element or the like, 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 liquid discharge port (orifice) for discharging a recording droplet to form a discharge droplet at a high density. 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 can easily be made compact, and has the advantages of IC technology and microfabrication technology, which have recently made remarkable progress in technology in the field of semiconductors and markedly improved reliability. It is advantageous because it can be used for two reasons, high-density mounting is easy, and the manufacturing cost is low.

(Electrostatic attraction device) Next, the structure of the electrostatic attraction device 4 will be described. As shown in FIG.
a and the ground electrode 4b are arranged at a small interval, and a high-voltage power supply 4c is connected between the electrodes 4a and 4b. The ground electrode 4b has a long current path in order to increase the electric resistance, and one end is grounded.

A low-voltage power supply 4d is connected to both ends of the ground electrode 4b so that a current flows through the ground electrode 4b.

In the above configuration, since a high voltage is applied between the high voltage electrode 4a and the ground electrode 4b by the high voltage power supply 4c, an electrostatic attraction force is generated by Coulomb force. The recording medium 1 is suction-fixed to the transport belt 2d by this suction force.

On the other hand, when a low voltage is applied to the ground electrode 4c by the low-voltage power supply 4d, a current flows in the closed circuit, and the electrode 4b having a large electric resistance generates Joule heat and generates heat. Due to this heat generation, the recording medium 1 from which the ink droplets have been ejected from the recording head 3e is heated, and the ink is dried and fixed. That is, the electrostatic suction device 4 simultaneously performs fixed holding of the recording medium 1 facing the recording unit 3 and drying and fixing of the ink.

As described above, the fixing and holding of the recording medium 1 and the heat fixing are simultaneously performed by the electrostatic attraction device 4, so that the device can be quickly and high-quality without increasing the size of the device or increasing the cost of the device. Ink jet recording can be performed.

[Second Embodiment] Next, a second embodiment of an electrostatic suction device and a recording apparatus using the same will be described with reference to FIGS. The same members as those in the first embodiment described above are denoted by the same reference numerals, and description thereof will be omitted.

The recording apparatus shown in FIG. 3 is an ink-jet recording apparatus for full-color recording. The difference from the first embodiment is that the recording head 3e can discharge yellow, magenta, cyan and black inks, respectively. That is, the number of recording heads is provided. By discharging the four color inks from the recording heads 3e according to image signals, full-color recording is performed.

In the above-described full-color printing, the amount of ink ejected is larger than in the case of single-color printing. Therefore, in this embodiment, the amount of heat generated by the electrostatic suction device 4 is increased. That is, the configuration of the electrostatic suction device 4 in this embodiment is the same as that shown in FIG.
As shown in FIG. 7, the high voltage electrode 4e and the ground electrode 4b are arranged at a minute interval, and a high voltage is applied between the electrodes 4e and 4b to generate an electrostatic attraction force, which is the same as the first embodiment. However, in this embodiment, the high-voltage electrode 4e is
The difference from the first embodiment is that the current path is configured to be long so that the electric resistance increases as in b, and the low voltage power supply 4f is connected to both ends of the high voltage electrode 4e.

As a result, the high voltage electrode 4e is connected to the ground electrode 4b.
In the same manner as described above, current flows through the closed circuit, and Joule heat is generated. That is, as described in the first embodiment, not only the heat generated by the ground electrode 4b but also the high-voltage electrode 4e generates heat, and the amount of heat generated is large, and the amount of ink discharged to the recording medium 1 during full color printing is large. Even in this case, the ink is dried and fixed quickly as in the case of the monochromatic recording.

[Other Embodiments] In the above-described first and second embodiments, the ink jet recording system is used as a recording means. It is more preferable to perform recording by discharging the ink from the discharge port by the growth and shrinkage of the bubble generated in the ink using the film boiling generated in the ink by the thermal energy applied by the ink.

With respect to 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, the system 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 to
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 the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or 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 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.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record.

Such a recording head may have a configuration satisfying its length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even with the above-mentioned serial type, the recording head fixed to the carriage or mounted on the carriage enables electrical connection with the apparatus main body and supply of ink from the apparatus main body. 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 30 ink itself
It is common to control the temperature so that the viscosity of the ink is in the stable ejection range by adjusting the temperature within the range of not less than 70 ° C and not more than 70 ° C if the ink is in a liquid state when the use recording signal is applied. good. In addition, positively prevent the temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or use an ink that solidifies in a standing state to prevent evaporation of the ink. In any case, the ink is liquefied by the application of the heat energy according to the recording signal, and the ink is liquefied, and the liquid ink is discharged. The present invention is also applicable to a case where an ink that liquefies for the first time by energy is used.

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-described 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 copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function May be used.

In the above-described embodiment, the serial recording method has been exemplified. However, the present invention is not limited to this, and a so-called line recording method may be used.

[0042]

According to the present invention, as described above, by applying a voltage between a pair of electrodes, a recording medium can be fixedly held on a transport belt by electrostatic attraction generated between the electrodes. By passing a current through at least one of the electrodes, the electrodes generate heat and dry and fix the ink ejected on the recording medium. Therefore, since it is not necessary to configure the holding and heating of the recording medium by separate members as in the related art, it is possible to reduce the size of the recording apparatus and to reduce the cost.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a recording apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a configuration of an electrostatic suction device according to the first embodiment.

FIG. 3 is a schematic diagram illustrating a recording apparatus according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of a configuration of an electrostatic suction device according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Recording medium 2 ... Conveying means 3 ... Recording means 3e ... Recording head 4 ... Electrostatic adsorption device 4a ... High voltage electrode 4b ... Ground electrode 4c ... High voltage power supply 4d ... Low voltage power supply

Claims (4)

(57) [Claims] A transport belt that transports a recording medium that receives ink ejected from a recording unit; and a transport belt that is disposed at a position facing the recording unit with the transport belt interposed therebetween, and the recording medium is placed on the transport belt. An electrostatic attraction device for fixedly holding the recording means facing the recording means,
An ink jet recording apparatus comprising: a pair of electrodes arranged at intervals; a circuit for applying a voltage between the electrodes; and an ink ejected to the recording medium. And a circuit for flowing a current for causing at least one of the pair of electrodes to generate heat in order to dry the recording medium, wherein the recording medium can be fixedly held and the ink can be dried and fixed. Ink jet recording device. 2. The ink jet recording apparatus according to claim 1, further comprising a circuit for flowing a current to each of the pair of electrodes. 3. An ink jet recording apparatus according to claim 1, wherein said recording means performs full color recording. 4. An ink jet recording apparatus according to claim 1, wherein said recording means records an image using ink droplets formed by thermal energy.