JP2003001836A - Hed ejection property retaining apparatus and recording apparatus equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head ejection property retaining apparatus having a wiping means capable of completely wiping ink, even in plural colors without mixing them, and a recording apparatus equipped with the retaining apparatus. SOLUTION: The apparatus is provided with a first wiper 111a for wiping the nozzle forming face of a recording head in a first direction, and a second wiper 111b for wiping the nozzle forming face of the recording head in a second direction different from the first direction. Thus, wiping can be performed in two directions to the recording apparatus having one recording head, so that ink can be completely wiped out to leave no residual ink. With regard to the recording apparatus in which two recording heads are arranged in parallel in the main scanning direction, one of the recording heads having plural colors of nozzles arranged in the sub-scanning direction, wiping can be performed by varying the wiping direction to each recording head. Thus, ink can be completely wiped out without mixing inks of each color.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head ejection characteristic maintaining device for maintaining a constant ink ejection characteristic of a recording head ejecting ink droplets onto a recording medium, and a recording apparatus provided with the head ejection characteristic maintaining device. Regarding

[0002]

2. Description of the Related Art Generally, an ink jet printer, which is one of recording devices, has a print head mounted on a carriage reciprocating in the main scanning direction and a recording medium such as printing paper intermittently in the sub scanning direction. Is provided with a recording medium feeding unit that feeds the recording medium in set amounts, and is configured to move the print head in the main scanning direction while feeding the recording medium in the sub-scanning direction to eject ink droplets from the print head to the recording medium. .

In general, a mono-color ink jet printer is equipped with one print head. A full-color ink jet printer is equipped with a black ink print head for ejecting black ink and a plurality of color ink print heads for ejecting inks of respective colors such as yellow, cyan, and magenta.

The print head in the ink jet printer having such a structure is provided with a pressure generating chamber and a nozzle opening connected to the pressure generating chamber. By storing ink in the pressure generating chamber and applying a predetermined pressure, the nozzle opening is opened. Ink droplets of a controlled size are ejected from the recording medium to the recording medium. Therefore, if the ink ejection characteristics at the nozzle openings of the print head fluctuate, the quality of the recorded image is greatly affected, and therefore the ink ejection characteristics must always be kept constant.

The ink ejection characteristics change due to increase in viscosity and solidification due to evaporation and drying of ink at the nozzle openings, clogging with solid matter, adhesion of dust, inclusion of bubbles, and the like. Therefore, the ink jet printer is provided with a head ejection characteristic maintaining device for eliminating the above-mentioned causes of variation and maintaining the ink ejection characteristic in a constant state.

This head discharge characteristic maintaining device is equipped with a capping device, a suction pump, and a wiping device.
The capping device is configured to seal the nozzle forming surface of the print head at the time of non-recording and isolate the nozzle opening from the outside, and has a function of suppressing evaporation and drying of ink and suppressing increase in viscosity and solidification. ing. Even if the nozzle forming surface is sealed with a capping device, it is not possible to completely prevent clogging due to solid matter in the nozzle opening and inclusion of air bubbles in the ink flow path. A suction pump is provided for this purpose.

The suction pump is constructed so that a negative pressure is applied to the nozzle opening in a state where the capping device seals the nozzle forming surface, and ink is forcibly sucked and discharged from the nozzle opening to remove solid matter. It also has the function of removing bubbles. This forcible suction / discharge process of ink by the suction pump is provided on the operation panel when the recording operation is restarted after the inkjet printer is stopped for a long time, or when the user recognizes that the quality of the recorded image has deteriorated. It is normally executed when the switch is operated.

When the ink is forcibly sucked and discharged by the suction pump, the ink may scatter and adhere to the nozzle forming surface of the printer head, and the meniscus of the ink in each nozzle opening is disturbed. Further, since foreign matter is likely to adhere to the nozzle forming surface of the print head over time, a wiping device for wiping the nozzle forming surface is provided as necessary.

The wiping device has a wiping member made of an elastic plate such as rubber whose base end side is held by a holder, and the edge portion of the wiping member on the tip end side is elastically pressed against the nozzle forming surface and relatively. It is configured to move the nozzle back and forth to clean the nozzle formation surface, and in addition to wiping ink and foreign matter adhering to the nozzle formation surface, uniformize the ink meniscus at each nozzle opening, that is, stabilize it. It has the function of

As the wiping method by this wiping device, so-called side wiping is performed in which the wiper is set and the print head is moved in the printing direction, that is, the main scanning direction to wipe it, and the wiper is fixed in the paper feeding direction. That is, there is so-called vertical wiping in which the wiping is performed by moving in the sub-scanning direction. These wiping methods are selectively used according to the type of ink, that is, the dye, pigment, and reactive ink, and the arrangement of the nozzles of the print head, that is, the nozzles in which a plurality of colors are distributed in the main scanning direction or the sub scanning direction. There is.

[0011]

However, when one of the wiping methods is applied to one print head, the ink may remain on both sides of the print head to contaminate the printing paper. In recent years, for example, one print head that ejects only black ink and one print head in which nozzles that eject cyan, magenta, and yellow inks are arranged in the sub-scanning direction, respectively, are provided in the main scanning direction. Inkjet printers arranged in parallel have been proposed.

However, when an ink that coagulates when the respective colors are mixed is used in such an ink jet printer, two print heads are arranged side by side in the main scanning direction and therefore can be wiped sideways. I can't
On the other hand, since cyan, magenta, and yellow nozzles are arranged in the sub-scanning direction, vertical wiping cannot be performed.

The present invention has been made in view of the above-mentioned various problems, and an object thereof is to provide a head having a wiping means capable of wiping ink completely and even if there are plural colors, without wiping. An object of the present invention is to provide an ejection characteristic maintaining device and a recording device including the same.

[0014]

To achieve the above object, in a head ejection characteristic maintaining device according to a first aspect of the present invention, the ink ejection characteristic of at least one recording head that ejects ink droplets onto a recording medium is maintained. In the apparatus, a first wiper that wipes the nozzle forming surface of the recording head in a first direction, and a second wiper that wipes the nozzle forming surface of the recording head in a second direction different from the first direction. And a wiping means having a.

As a result, since the recording apparatus having only one recording head can be wiped in two directions, the ink can be completely wiped without leaving the ink. In addition, when two or more recording heads are arranged side by side in the main scanning direction, and one recording head has nozzles of a plurality of colors arranged in the sub scanning direction, coagulation occurs when the respective colors are mixed. Even when using different inks,
Since it is possible to deal with each recording head by changing the wiping direction, it is possible to completely wipe the ink without mixing the inks of the respective colors.

According to a second aspect of the present invention, in the head ejection characteristic maintaining device according to the first aspect, the first wiper and the second wiper are driven by the same drive source. . As a result, the number of parts can be reduced.

According to a third aspect of the present invention, in the head ejection characteristic maintaining device according to the first aspect, the first wiper and the second wiper are arranged on the same member. As a result, the number of parts can be further reduced.

According to a fourth aspect of the present invention, in the head ejection characteristic maintaining device according to any one of the first to third aspects,
The first wiper and the second wiper are arranged at an opening angle of about 90 degrees. Accordingly, the two wipers can alternately perform the wiping operation with respect to the recording apparatus having only one recording head without interfering with each other. Further, with respect to a recording apparatus in which two recording heads are arranged side by side in the main scanning direction and nozzles of a plurality of colors are arranged in one recording head in the sub scanning direction, one recording head is wiped by the first wiper. After that, since the first wiper can be positioned in the middle of the two recording heads and the other recording head can be wiped by the second wiper, the wiping work efficiency can be improved.

According to a fifth aspect of the present invention, in the head ejection characteristic maintaining device according to any one of the first to fourth aspects,
The recording head includes a plurality of heads, and one of the first and second wipers is selected to wipe the nozzle forming surface of each head. This allows each wiper to correspond to each recording head even when using ink that coagulates when each color is mixed, so that ink of each color can be completely mixed without being mixed. Can be wiped off.

According to a sixth aspect of the invention, in the head ejection characteristic maintaining device according to any one of the first to fifth aspects,
It has two planetary gears for transmitting a driving force to the wiping means and one rotating means for rotating each planetary gear. By switching the meshing of each planetary gear, the normal rotation / reverse rotation of the rotation means can be performed. It is characterized in that a driving means capable of driving the wiping means is provided for both of them.

According to a seventh aspect of the invention, in the head ejection characteristic maintaining device according to the sixth aspect, the drive means is
The sun gear connected to the rotating means and meshed with each planet gear; and the toothless gear connected to the wiping means and meshable with each planet gear. After driving, the driving is cut off.

Since the wiper of the wiping means can be moved by both forward and reverse rotations of the rotating means, the position of the wiper can be easily initialized. Therefore, it is not necessary to provide a flag for detecting the initialized position of the wiper on the cam for driving the wiper and sensing as in the conventional case, thereby facilitating the assembly and adjustment of the apparatus and reducing the cost of the apparatus. be able to. Furthermore, the wiper can be reliably positioned at a predetermined position only by rotating the partly tooth-missing gear to the partly tooth-missing part by the planetary gear.

According to an eighth aspect of the present invention, in the head ejection characteristic maintaining device according to the seventh aspect, the toothless gear is
It is characterized in that it is constituted by a wiper gear that drives the wiping means and a four-series gear that meshes with each of the planetary gears. As a result, the rotation of each planetary gear can be reliably transmitted to the wiper gear, so that the positioning accuracy of the wiper can be improved.

According to a ninth aspect of the present invention, in the head ejection characteristic maintaining device according to the eighth aspect, the wiper gear is provided with a lever and a cam mechanism for moving the wiping means horizontally with respect to the recording head. It is characterized by As a result, the present invention can be applied to the conventional wiping means having a lever or a cam mechanism, so that the time and effort such as design changes can be simplified.

According to a tenth aspect of the invention, in a recording apparatus having a recording head for ejecting ink droplets onto a recording medium, the head ejection characteristic maintaining device according to any one of the first to ninth aspects is provided. It has a feature. This allows
It is possible to provide a recording device that achieves each of the above operations.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing an example of the construction of an ink jet printer which is one of the recording apparatuses according to the embodiment of the present invention, and FIG. 2 is a head according to the embodiment of the present invention. FIG. 4 is a plan view showing a configuration example of a wiping unit and a driving unit of the ejection characteristic maintaining device, and FIG. 3 is a side view of the wiping unit and the driving unit. The ink jet printer shown in FIG. 1 has, for example, a paper width of 594 mm (JIS
It is a large printer that can print on relatively large size printing paper such as standard A1 size and 728 mm (JIS standard B1 size).

This ink jet printer is provided with a paper feed unit 11, a recording unit 12 and a paper discharge unit 13 from the upper side to the lower side. The print sheet is subjected to predetermined printing in the process of being sent from the paper feed unit 11 to the recording unit 12 and then the paper discharge unit 13, and is discharged to the outside. The sheet conveyance path 14 at the time of printing is formed with an inclination of, for example, 65 degrees with respect to the horizontal plane. Guide shaft 16 by drive belt 15
The nozzle forming surface of the print head 18 mounted on the carriage 17 that reciprocates along the main scanning direction is also inclined, for example, at 65 degrees so as to be parallel to the paper transport path 14.

At the home position of the carriage 17, a head ejection characteristic maintaining device 100 for maintaining the ink ejection characteristic of the print head 18 in a constant state.
Is provided. Then, when the carriage 17 is located at the home position, the head ejection characteristic maintaining device 100 performs processing for maintaining the ink ejection characteristic of the print head 18.

As shown in FIGS. 2 and 3, the head ejection characteristic maintaining device 100 includes a wiping means 110 and a wiping means 11 for wiping the nozzle forming surface as necessary.
The driving means 170 for driving 0 is provided. As shown in FIGS. 2 and 3, the wiping unit 110 includes two wipers 111a and 111b and a wiper holder 112. The first wiper 111 a is a wiper for lateral wiping that moves the print head 18 in the printing direction, that is, the main scanning direction to wipe the print head 18, and the second wiper 11 a.
1b is for fixing the print head 18, fixing the print direction,
That is, it is a wiper for vertical wiping that moves in the sub-scanning direction and wipes it.

With this arrangement, an ink jet printer having only one print head 18 can be wiped in two directions.
It is possible to wipe completely without leaving ink. Also, as shown in FIG. 4, two print heads 18a,
18b are arranged side by side in the main scanning direction, nozzles 19a for each color of cyan C, magenta M, and yellow Y are arranged in the sub scanning direction on one print head 18a, and black K only for the other print head 18b. Nozzle 19b
Even when the ink that coagulates when the respective colors are mixed is used for the ink jet type printer in which the print heads are arranged, the wiping direction can be changed for the respective print heads 18a and 18b. Therefore, it is possible to wipe completely without mixing the inks of the respective colors. It is also possible to deal with three or more print heads by changing the wiping direction depending on the nozzle arrangement.

Each of the wipers 111a and 111b is formed of rubber into a substantially rectangular flat plate shape, and is arranged so that its tip end rubs against the nozzle forming surface of the print head 18 at an opening angle of about 90 degrees. There is. By arranging the wipers 111a and 111b at an opening angle of about 90 degrees in this way, two wipers 111 are provided for an ink jet printer having only one print head 18.
The a and 111b can alternately perform the wiping operation without interfering with each other. The reason for setting the angle to about 90 degrees is that it may be angled instead of parallel to the print head in order to reduce the load fluctuation of the carriage during wiping.

Also, two print heads 18a, 18a
b are arranged side by side in the main scanning direction, and one print head 18
For example, the nozzle 19a for each color of cyan C, magenta M, and yellow Y is arranged in a in the sub-scanning direction in a, and the nozzle 19b for only black K is arranged in the other print head 18b. After wiping one print head 18a with one wiper 111a, the first wiper 111a may be positioned between the two print heads 18a and 18b, and the other print head 18b may be wiped with the second wiper 111b. Therefore, the wiping work efficiency can be improved. Depending on the type of ink, wiper 11
1a and 111b may be formed of felt or plastic.

The wiper holder 112 is formed of plastic into a substantially rectangular flat plate shape. Then, while holding the wipers 111a and 111b such that the tip portions of the wipers 111a and 111b protrude from the upper end portions, the wiper moving means 18 that constitutes a driving means 170 described later is formed.
0, it moves in the vertical direction indicated by the arrow a in FIGS. 2 and 3.

The driving means 170, as shown in FIGS. 2 and 3, is a forward / reverse switching means 171 and a wiper moving means 18.
It has 0. The forward / reverse switching means 171 is a sun gear 174 disposed coaxially with the shaft of a driving force transmission gear (not shown).
And a forward rotation planet gear 176 and a reverse rotation planet gear 177 arranged on a substantially L-shaped planet lever 175 so as to mesh with the sun gear 174, and a toothless gear capable of meshing with each planet gear 176, 177. 178 is provided.

The toothless gear 178 is a planetary gear 17 for normal rotation.
6, four reverse first to fourth toothless gears 178a, 178b, 17 meshing with the reverse rotation planetary gear 177 and the wiper gear 181 constituting the wiper moving means 180 described later.
8c and 178d. Depending on the rotation direction of the driving force transmission gear that transmits the rotation of the motor, which is a rotation means (not shown), that is, depending on the rotation direction of the motor, either the forward rotation planet gear 176 or the reverse rotation planet gear 177 is set via the planet lever 175. The sun gear 174 meshes with the first tooth-missing gear 178a or the second tooth-missing gear 178b.
The rotation is transmitted via.

The wiper moving means 180 comprises a wiper gear 181, a lever 182 and a cam mechanism 183. The wiper gear 181 is arranged so as to mesh with the third toothless gear 178c. The cam mechanism 183 is a pin 183a integrally provided on one end side surface of the lever 182.
And a groove 183b provided in the wiper holder 112. Then, one end of the lever 182 is locked by inserting the pin 183a into the groove 183b, and the other end is arranged coaxially with the wiper gear 181.

In such a structure, the driving force of the motor is transmitted from the driving force transmission gear to the sun gear 174 and then to the planetary gear 176 for forward rotation, which meshes with the rotation of the planetary lever 175.
Alternatively, the reverse planetary gear 177 to the first toothless gear 178a
Alternatively, it is transmitted to the second tooth-chipped gear 178b, and further transmitted to the wiper gear 181 via the third tooth-chipped gear 178c and the fourth tooth-chipped gear 178d. Thereby, the wiping means 110 can be moved in the vertical direction.

The wiping means 110 having the above configuration.
And head ejection characteristic maintaining device 1 including drive means 170
The operation of 00 will be described with reference to FIGS. In the initial state, as shown in FIG.
The carriage 17 on which 8b is mounted is the wiping means 11
The wiping means 110 is located off the movement path of 0, and is located on the leftmost side in the drawing.

From this state, when the motor is driven in the normal direction to rotate the planet lever 175, the planet gear 1 for normal rotation is
76 meshes with the first partly tooth-missing gear 178a. Then, the rotational force of the sun gear 174 is transmitted from the forward rotation planet gear 176 to the first toothless gear 178a, and further from the third toothless gear 178c to the wiper gear 181, and the lever 182 pivots to cause the cam mechanism 183 to rotate the wiper holder 112. Starts moving to the right in the figure.

When the wiper gear 181 reaches the tooth-missing portion of the third tooth-missing gear 178c and is disengaged, the wiper gear 181 idles, so that the movement of the wiper holder 112 is stopped as shown in FIG. At this time, the wiping unit 110 is located on the rightmost side in the drawing, and the wiper 111a is in a "set" state, that is, a state in which the print head 18a can be wiped.

From this state, as shown in FIG. 6, the wiper 111a wipes the nozzle forming surface of only the print head 18a by moving the carriage 17 on which the print heads 18a and 18b are mounted downward in the drawing.
Then, as shown in FIG. 7, the movement of the carriage 17 is stopped. At this time, the wiper 111a is located between the print heads 18a and 18b, and
a is in the “reset” state, that is, the print head 18
In the wiping completed state of a, the wiper 111b is in the "set" state, that is, the print head 18b can be wiped.

From this state, when the motor is driven in the reverse direction to rotate the planet lever 175, the reverse planet gear 177 meshes with the second toothless gear 178b as shown in FIG. Then, the rotational force of the sun gear 174 is transmitted from the reverse planetary gear 177 to the second partly toothless gear 178b and further from the third partly toothless gear 178c to the wiper gear 181, and the lever 182 rotates to cause the cam mechanism 183 to rotate the wiper holder 112. Starts moving to the left in the figure. Then, as shown in FIG. 9, the wiper 111b is connected to the print head 18b.
The nozzle forming surface of is wiped.

When the wiper gear 181 reaches the tooth-missing portion of the third tooth-missing gear 178c and is disengaged, the wiper gear 181 idles, so that the wiper holder 112 stops moving, as shown in FIG. At this time, the wiping means 110 is located on the leftmost side in the drawing, and the wiper 111b is in the "reset" state, that is, the wiping completion of the print head 18b.

In the above-described embodiment, the head ejection characteristic maintaining device 100 having the wiping means 110 has been described, but the head ejection characteristic maintaining device also having the capping means and the suction means may be similarly configured. The same effect can be obtained. Further, in the above-described embodiment, the printer has been described as an example, but the present invention is not limited to this, and can be applied to, for example, a facsimile apparatus, a copying apparatus, or the like.

[0046]

As described above, according to the head ejection characteristic maintaining apparatus and the recording apparatus having the same according to the present invention, the recording apparatus having only one recording head is wiped in two directions. Therefore, the ink can be completely wiped without leaving the ink. In addition, an ink that coagulates when the colors are mixed in a recording apparatus in which two recording heads are arranged side by side in the main scanning direction and nozzles of a plurality of colors are arranged in one recording head in the sub scanning direction. Even when using, since it is possible to deal with each recording head by changing the wiping direction, it is possible to completely wipe the recording heads without mixing the inks of the respective colors.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration example of an inkjet printer which is one of recording apparatuses according to an embodiment of the present invention.

FIG. 2 is a plan view showing a configuration example of a wiping unit and a driving unit of the head ejection characteristic maintaining device according to the exemplary embodiment of the present invention.

FIG. 3 is a side view of the wiping means and the driving means of FIG.

FIG. 4 is a first diagram showing an operation of the head ejection characteristic maintaining device of FIG.

FIG. 5 is a second diagram showing the operation of the head ejection characteristic maintaining device of FIG.

FIG. 6 is a third diagram showing the operation of the head ejection characteristic maintaining device of FIG.

FIG. 7 is a fourth diagram illustrating the operation of the head ejection characteristic maintaining device in FIG.

FIG. 8 is a fifth diagram showing the operation of the head ejection characteristic maintaining device of FIG.

9 is a sixth diagram showing the operation of the head ejection characteristic maintaining device of FIG. 2. FIG.

FIG. 10 is a seventh diagram showing the operation of the head ejection characteristic maintenance device of FIG.

[Explanation of symbols]

18a, 18b print head 100 Head discharge characteristic maintenance device 110 Wiping means 111a, 111b wiper 112 wiper holder 170 Drive means 171 forward / reverse switching means 174 sun gear 175 Planetary lever 176 Forward rotation planetary gear 177 Reversed planetary gear 178 missing tooth gear 178a First missing tooth gear 178b Second missing tooth gear 178c Third missing tooth gear 178d Fourth missing tooth gear 180 Wiper moving means 181 wiper gear 182 lever 183 cam mechanism

Claims (10)

[Claims] 1. A device for maintaining ink ejection characteristics of at least one recording head for ejecting ink droplets onto a recording medium, comprising: a first wiper for wiping a nozzle forming surface of the recording head in a first direction; 2. A head ejection characteristic maintaining device comprising: a wiping unit having a second wiper for wiping a nozzle forming surface of a recording head in a second direction different from the first direction. 2. The head ejection characteristic maintaining device according to claim 1, wherein the first wiper and the second wiper are driven by the same drive source. 3. The head ejection characteristic maintaining device according to claim 1, wherein the first wiper and the second wiper are arranged on the same member. 4. The head ejection characteristic according to claim 1, wherein the first wiper and the second wiper are arranged at an opening angle of about 90 degrees. Maintenance device. 5. The recording head comprises a plurality of heads,
The head ejection characteristic maintaining device according to any one of claims 1 to 4, wherein one of the first and second wipers is selected to wipe the nozzle forming surface of each head. . 6. The two planetary gears for transmitting a driving force to the wiping means and one rotating means for rotating each planetary gear are provided, and by switching the meshing of each planetary gear, The head ejection characteristic maintaining device according to any one of claims 1 to 5, further comprising a driving unit that can drive the wiping unit for both forward rotation and reverse rotation. 7. The drive means is connected to the rotating means and is meshed with the planet gears, and the sun gear is connected to the wiping means, and the drive means is meshable with the planet gears. 7. The head ejection characteristic maintaining device according to claim 6, further comprising a tooth gear, wherein the drive is cut off after the wiping means is driven. 8. The head ejection characteristic maintenance according to claim 7, wherein the tooth-missing gear is composed of a wiper gear that drives the wiping means and a four-series gear that meshes with each of the planetary gears. apparatus. 9. The wiper gear is provided with a lever and a cam mechanism for moving the wiping means horizontally with respect to the recording head.
The device for maintaining head ejection characteristics according to item 4. 10. A recording apparatus having a recording head for ejecting ink droplets onto a recording medium, comprising the head ejection characteristic maintaining device according to claim 1. Description: