JP2808362B2 - 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 that performs recording by discharging ink from a recording head onto a recording material on a transport belt.

[Conventional technology]

2. Description of the Related Art A recording device such as a printer, a copying machine, and a facsimile is configured to record an image composed of a dot pattern on a sheet-like recording material such as paper or a thin plastic plate based on 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) discharges ink onto a recording material to perform recording. Is performed.

The ink jet recording apparatus has advantages such as low noise since it is a non-impact method, and it is easy to record a color image using multicolor inks.

This ink jet recording apparatus uses a transport belt composed of an endless belt as a recording material transporting (paper feeding) means, and performs recording by discharging ink from a recording head onto the recording material on the belt. is there.

In addition, in this type of ink jet recording apparatus, an air flow is generated in the recording section in order to remove dust such as ink mist and paper dust which may be generated in the recording section between the recording head and the recording material. It has been proposed to use an air blowing means.

The conventional blower is configured to discharge air from the recording unit by an exhaust fan arranged on the paper discharge side (downstream in the transport direction) of the recording unit.

[Technical problem to be solved by the invention]

However, in the conventional blowing means using only such an exhaust fan, in the ink jet recording apparatus, in the first place, a duct connecting the exhaust fan and the recording head mounting portion completely surrounds the recording material passage portion. Because the operation of the exhaust fan and the conveyance of the recording material may occur at the same time, even if the exhaust fan is operated, the air inflow from gaps other than the recording head attachment part increases, and the recording unit to be exhausted There was a technical problem that it was not possible to quickly change the atmosphere.

Further, in the above-described conventional blowing means, when performing continuous recording, by providing a waiting time in the middle from the function, setting a small number of continuous recording, or setting a long recording time during continuous recording, It is necessary to adjust the recording operation to the exhaust performance, and there is a technical problem that the specifications of the recording apparatus are reduced.

The present invention has been made in view of such conventional technical problems, and can efficiently perform air exchange between a recording head and a recording material (recording portion), and can produce a high-density image. It is an object of the present invention to provide an ink jet recording apparatus which can output stably at high speed for a long time.

[Means for solving the problem]

The present invention provides an ink jet recording apparatus that performs recording by ejecting ink from a recording head to a recording material on a transport belt, wherein an air supply fan is provided on a sheet feeding side of the recording head,
By providing an exhaust fan on the discharge side of the recording head and changing the atmosphere of the recording unit by the air supply fan and the exhaust fan, the air exchange between the recording head and the recording material (recording unit) can be efficiently performed. An object of the present invention is to provide an ink jet recording apparatus which can perform well and can stably output a high-density image at high speed for a long time.

In the above configuration, it is preferable that an air supply / exhaust position for operating the air supply fan and the air exhaust fan is additionally set between the recording position of the recording head and the capping position.

〔Example〕

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

FIG. 1 shows a first embodiment of an ink jet recording apparatus according to the present invention.
FIG. 2 is a partial longitudinal sectional view showing a main part configuration when the recording head in the first position is at a recording position, and FIG. 3 is a longitudinal sectional view showing the recording head in the FIG. FIG. 3 is a partial vertical cross-sectional view showing a configuration of a main part at a capping position.

1 to 3, a recording head 1 is for full-color recording, and four recording heads 1C, 1M, 1Y, 1
B, that is, a recording head of cyan, magenta, yellow, and black ink colors.

The recording heads 1C, 1M, 1Y, and 1B are ink jet recording heads that discharge ink using thermal energy, and include an electrothermal converter for generating thermal energy.

Further, the ink jet recording heads 1C, 1M, 1Y, 1B
According to the method, recording is performed by ejecting ink from ejection ports by the growth of bubbles due to film boiling generated by the thermal energy applied by the electrothermal transducer.

These recording heads 1C, 1M, 1Y and 1B are positioned and held at equal intervals by a head holder 2, and by moving the position of the head holder 2 up and down, the recording position (FIGS. 1 and 2) is changed. Capping position (Fig. 3)
Can be set to.

Except during recording, the recording head 1 (recording heads 1C, 1M,
Any one or all of 1Y and 1B are set at the capping position, and are capped by the head cap 3 (a state in which the discharge port surface on which the discharge ports are formed is sealed).

The head cap 3 includes an ink absorber 32 such as a sponge for cleaning the ejection port surface during the ejection recovery operation, a sealing member 33 for sealing a contact portion between the cap 3 and the head holder 2, and waste in the cap 3. A drain 34 for discharging ink is provided.

The head holder 2 is provided with a sealing member 21 for sealing the gap between the holder and the recording head 1.

A recording material 5 such as a sheet or a thin plastic sheet stored in a paper cassette is supplied onto a transport belt 4 through a paper feed roller, a guide roller, a guide plate, and the like, and is transported by the transport belt 4 through a recording unit. .

The transport belt 4 is constituted by an endless belt that is stretched by rotating a driving roller 42 and a driven roller 43. In the area of the recording section, the recording material 5 and the recording head 1
Is supported by a flat platen 41 for making the gap between them constant (for example, about 0.5 mm).

In order to bring the recording material 5 into close contact with the transport belt 4, a charge is applied to the transport belt 4 by the charging roller 6.

The charging roller 6 is held by a mounting case 61 and is pressed against the conveyor belt 4 by an urging spring 62.

Reference numeral 63 denotes a sheet pressing blade for ensuring that the recording material 5 sent into the transport belt 4 is in close contact with the belt.

A fan attachment member 73 is fixed to the head holder 2, and an exhaust fan 71 and an air supply fan 72 are attached to the attachment member 73.

The position of the exhaust fan 71 is set on the sheet discharge side of the recording head 1, and the position of the air supply fan 72 is set on the sheet supply side of the recording head 1.

The exhaust fan 71 is for exhausting air between the recording head 1 and the recording material 5, and is provided with the air supply fan 72.
Is for supplying air between the recording head 1 and the recording material 5.

Reference numeral 74 denotes a fan filter for capturing ink mist, water vapor, dust, and the like in the air discharged from the exhaust fan 71 and preventing them from diffusing into the recording apparatus.

Reference numeral 22 denotes a head side plate for fixing the head holder 2 from both sides.

A rack gear 81 for moving the head unit (head holder 2) up and down is fixed to the head side plate 22.

FIG. 1 shows a state where the head unit is lowered to the recording position.

Reference numeral 85 denotes a motor for moving the head unit (recording head 1) up and down. The recording head 1 rises when rotating clockwise.

The driving force of the motor 85 is transmitted to the pulley 83 via the timing belt 86, and the rotational force is transmitted to the driving gear 82 meshing with the rack gear 81 via a gear (not shown).

Reference numeral 84 denotes a tension pulley for maintaining the tension of the timing belt 86 at a predetermined value.

Reference numerals 91, 92 and 93 denote position detecting sensors for detecting the position of the head unit (recording head 1), respectively.
Reference numeral 91 denotes a position at which recording can be performed on the recording material 5, reference numeral 92 denotes a position at which the head cap 3 can cap the ejection opening surface, and reference numeral 93 denotes a position at which the head cap 3 is a head unit. This is for detecting the evacuation position when moving down.

Reference numeral 101 denotes a pre-registration roller, which is configured to detect that the leading end of the fed recording material 5 has reached the pre-registration roller 101 by a pre-registration sensor (not shown).

Reference numeral 201 denotes a paper discharge sensor for detecting the passage of the recording material 5 when the recording material 5 after passing through the recording unit is discharged to a paper discharge stacker or the like.

1 to 3, the ink jet recording apparatus according to the present invention, that is, recording is performed by discharging ink from the recording heads 1C, 1M, 1Y, and 1B onto the recording material 5 on the transport belt 4. In the ink jet recording apparatus to be performed, an air supply fan 72 is provided on the paper supply side of the recording heads 1C, 1M, 1Y, and 1B, and an exhaust fan 71 is provided on the paper ejection side of the recording head, and the air supply fan 72 and the exhaust fan 71 are provided. The present invention provides an ink jet recording apparatus characterized in that the atmosphere of the recording section is exchanged.

The operation of this ink jet recording apparatus is as follows.

When the recording material 5 passes through a pre-registration roller 101 and a pre-registration sensor (not shown) located in front of the platen 41 (paper feed side),
The air supply fan 72 and the exhaust fan 71 are turned on based on a signal that detects the passage, and the air blowing of the recording unit is started.

The air supply fan 72 and the exhaust fan 71 are turned off by a detection signal when the recording material 5 has passed the paper discharge sensor 201.

The air supply / exhaust performance of the recording unit by the air supply fan 72 and the exhaust fan 71 depends on the gap between the recording head 1 and the recording material 5 (or the platen 41). The larger the gap, the higher the air supply / exhaust efficiency. Become.

On the other hand, the distance between the recording head 1 and the recording material 5 is about 0.5 mm.
When multiple recording heads (four in the illustrated example) are used as in color recording, the flow resistance tends to increase and the supply / exhaust efficiency tends to decrease.

Therefore, except during recording, the recording head 1 is raised to a predetermined height to increase the distance between the recording head 1 and the platen 41 to an appropriate value.
In this state, it is desirable to perform the air supply / exhaust operation by turning on the air supply fan 72 and the exhaust fan 71.

Therefore, in the embodiment shown in FIGS. 1 to 3, the supply / exhaust operation by the supply fan 72 and the exhaust fan 71 is performed by the recording head 1 including the capping position in addition to the above-described recording position. It is configured so that it can be performed even when it is at a predetermined height position between the capping position and the recording position (head down).

When the air supply / exhaust fans 72 and 71 are operated at the predetermined height position, the recording head 1 is raised to a position for air supply / exhaust after the recording is completed, and air supply / exhaust is performed for a predetermined time. Turn off fans 72 and 71.

In this manner, by performing the air supply / exhaust operation even at the position where the recording head 1 is raised, the ink mist and the like adhering to the transport belt 4 and the periphery thereof can be further reduced.

Further, the time of the air supply / exhaust operation at the recording position can be shortened, so that the air supply / exhaust operation can be incorporated in the middle of the continuous recording, and the throughput of the recording apparatus can be further improved. .

According to the embodiment described above, the recording heads 1C, 1M, 1
An air flow is generated between the recording head and the recording material 5 by both the exhaust fan 71 and the air supply fan 72 provided on the paper discharge side and the paper supply side of Y and 1B (head unit). Atmosphere can be replaced efficiently,
The following effects were achieved.

i) Since the amount of ink mist in the atmosphere and the amount of ink adhered to the ejection port side are reduced, the number of non-ejection recovery operations can be reduced, and an ink jet recording apparatus capable of recording a stable high-quality image in a high throughput state. was gotten.

ii) Since the dew condensation on the discharge port surface due to water vapor is reduced, an ink jet recording apparatus capable of freely performing continuous recording is obtained.

iii) The contamination of each part due to the scattering of the ink mist was significantly reduced. In particular, since the amount of scattering on the conveyor belt 4 was reduced, the recording material 5 was not stained.

iv) Since the heat radiation effect at the ink ejection portion of the recording head 1 is increased, the allowable heat generation during recording can be increased, and high-density recording can be continued for a long time.

v) In general, it has become easy to output a high-density image at high speed.

Second Embodiment FIG. 4 shows a second embodiment of the ink jet recording apparatus according to the present invention.
FIG. 5 is a partial longitudinal sectional view showing a main part configuration when the recording head in FIG. 4 is at a recording position, and FIG. 6 is a longitudinal sectional view in FIG. FIG. 3 is a partial vertical cross-sectional view illustrating a configuration of a main part when a recording head is at a capping position.

In the present embodiment, the air supply fan 72 is fixed to the cap 3, and the exhaust fan 71 is fixed to the head holder 2 as in the first embodiment.

Also in the present embodiment, the positional relationship between the fans 72 and 71 and the recording head 1 when the recording head 1 is at the recording position is selected so as to be substantially the same as that in the first embodiment.

This embodiment is different from the first embodiment in that the mounting position of the air supply fan 72 is changed, and the other parts have substantially the same configuration as that of the first embodiment. Are indicated by the same reference numerals, and their detailed description is omitted.

Also in the present embodiment, the air supply / exhaust operation is performed by operating the exhaust fan 72 and the exhaust fan 71 even when the recording head 1 is at the recording position and when the recording head is raised to a desired height. Thus, substantially the same operation as in the first embodiment can be performed.

Therefore, according to the present embodiment, the same operation and effect as those obtained by the first embodiment can be achieved.

Third Embodiment: FIG. 7 shows a third embodiment of the ink jet recording apparatus according to the present invention.
FIG. 8 is a partial longitudinal sectional view showing a main part configuration when the recording head in FIG. 7 is at the recording position, and FIG. 9 is a longitudinal sectional view showing the embodiment of FIG. FIG. 3 is a partial vertical cross-sectional view illustrating a configuration of a main part when a recording head is at a capping position.

In this embodiment, the air supply fan 72 is fixed to the head holder 2 as in the case of the first embodiment, but the exhaust fan 71 is fixed to the recording apparatus main body side (a frame or the like). I have.

Also in the present embodiment, the positional relationship between the fans 72 and 71 and the recording head 1 when the recording head 1 is at the recording position is selected so as to be substantially the same as that in the first embodiment.

This embodiment is different from the first embodiment in that the mounting position of the exhaust fan 71 is changed, and the other parts have substantially the same configuration as that of the first embodiment. Portions are indicated by the same reference numerals, and detailed description thereof is omitted.

Also in this embodiment, the air supply fan 72 and the exhaust fan 71 are operated to perform the air supply / exhaust operation when the print head 1 is at the print position and also when the print head is raised to a desired height. For example, substantially the same operation as that of the first embodiment can be performed.

Therefore, according to the present embodiment, the same operation and effect as those obtained by the first embodiment can be achieved.

In the above-described embodiment, the case where the present invention is applied to a line-type inkjet recording apparatus using a line-type recording head 1 that covers a recording area in the paper width direction of the recording material 5 has been described as an example. The present invention can be similarly applied to an ink jet recording apparatus of another recording method, such as a serial scan type ink jet recording apparatus in which a recording head is mounted on a carriage and moves in a direction traversing a recording material. The effect can be achieved.

In the above embodiment, the four recording heads 1C, 1M,
Although the case of the color ink jet recording apparatus using 1Y and 1B has been described, the present invention is directed to monochromatic recording using one recording head, or gradation recording using a plurality of recording heads having the same color but different densities. The present invention can be applied similarly regardless of the number of recording heads or ink colors, such as an inkjet recording apparatus, and can achieve the same effect.

The present invention, in particular, among the inkjet recording system,
The present invention provides an excellent effect in an ink jet recording apparatus using a bubble jet type ink jet recording head proposed by Canon Inc.

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. 4,313,124 relating to 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 electric heat exchanger 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 a printing mode of only a 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, positively prevent temperature rise due to thermal energy as energy for changing the state of the ink from a solid state to a liquid state, or prevent ink that solidifies in a standing state to prevent evaporation of the ink. Or use
In any case, heat is first applied by heat energy, such as one in which ink is liquefied and ejected as an ink liquid by application in accordance with a recording signal of heat energy, and one which already starts to solidify when reaching a recording material. Use of an ink having a liquefying property is also applicable to the present invention.

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 apparent from the above description, according to the present invention, in an ink jet recording apparatus that performs recording by discharging ink from a recording head onto a recording material on a conveyance belt, an air supply fan is provided on a sheet feeding side of the recording head. Since the exhaust fan is provided on the paper discharge side of the recording head and the atmosphere of the recording section is exchanged by the air supply fan and the exhaust fan, the air exchange between the recording head and the recording material (recording section) can be efficiently performed. The present invention provides an ink jet recording apparatus which can perform the printing well and can further improve the heat radiation effect in the ink discharge section, and can stably output a high-density image at high speed for a long time.

According to the second aspect of the present invention, in addition to the above configuration, a configuration is provided in which a supply / exhaust position for operating the air supply fan and the exhaust fan is additionally set between the recording position and the capping position of the recording head. An ink jet recording apparatus capable of further enhancing the above effects is provided.

In the present invention, the air supply fan and the ventilation fan may be operated by the same drive motor, or may be controlled by separate motors, and may be simultaneously or sequentially or separately driven at a predetermined timing.

It goes without saying that the present invention is not limited to the fan of the present invention, but includes a well-known or known blower.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of an ink jet recording apparatus according to the present invention, FIG. 2 is a partial longitudinal sectional view showing a main part configuration when a recording head in FIG. 1 is at a recording position, FIG. 3 is a partial longitudinal sectional view showing a main part configuration when the recording head in FIG. 1 is at a capping position, FIG. 4 is a longitudinal sectional view showing a second embodiment of the ink jet recording apparatus according to the present invention, FIG. 5 is a partial longitudinal sectional view showing a main part configuration when the recording head in FIG. 4 is at the recording position, and FIG. 6 is a main part configuration when the recording head in FIG. 4 is at the capping position. FIG. 7 is a longitudinal sectional view showing a third embodiment of the ink jet recording apparatus according to the present invention, and FIG. 8 is a view showing a main part configuration when the recording head in FIG. 7 is at a recording position. 9 is a partial longitudinal sectional view, and FIG. 9 is a state where the recording head in FIG. 7 is at the capping position. It is a partial longitudinal sectional view showing the main structure. In the following, reference numerals indicating major components in the drawings are listed. 1, 1C, 1M, 1Y, 1B Recording head 2, Head holder 3, Cap 4, Conveying belt 5, Recording material 6, Charging roller 41 Platen 42 …… Drive roller, 43 …… Follower roller, 71 …… Exhaust fan, 72 ……
Air supply fan, 81 ... Rack gear, 82 ... Drive gear, 85 ...
... Motor for raising and lowering the print head, 86 ... Timing belt, 91 ... Sensor for position detection (recording position), 92 ... Sensor for position detection (capping position), 93 ... Sensor for position detection (upper limit retreat position) , 101 ... Roller in front of cash register, 201 ...
... Sheet discharge sensor.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasushi Murayama 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Setsu Uchida 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Tatsuo Mitomi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masaharu Nemura 3-30-2, Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yasuyuki Takanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 2 / 01,29 / 00

Claims (4)

(57) [Claims] An ink jet recording apparatus for ejecting ink from a recording head onto a recording material on a transport belt to perform recording is provided with an air supply fan on a paper feed side of the recording head.
An ink jet recording apparatus, comprising: an exhaust fan provided on a paper discharge side of a recording head, wherein the atmosphere of a recording unit is exchanged by the air supply fan and the exhaust fan. 2. An air supply / exhaust position for operating said air supply fan and said exhaust fan is additionally set between a recording position of said recording head and a capping position.
3. The ink jet recording apparatus according to claim 1. 3. The recording head according to claim 1, wherein said recording head is a recording head that discharges ink using thermal energy, and is an ink jet recording head including an electrothermal converter for generating thermal energy. The ink-jet recording apparatus according to claim 1. 4. The ink-jet recording apparatus according to claim 3, wherein said recording head discharges ink from a discharge port by growth of bubbles due to film boiling generated by thermal energy applied by said electrothermal transducer. Recording device.