JP2001293874A - Ink jet printer and its head cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head cartridge of a line type ink jet printer in which the ink ejecting section is protected at the time of nonuse while preventing dry up of ink and ink drops adhering to the ink ejecting section are removed. SOLUTION: The head cartridge 124 of an ink jet printer comprises a line head 120, and a cap 123 integrated with the head movably between a close position where the cap covers the ink ejecting section of the head and an open position for opening the ink ejecting section. The cap is moved along the head surface in parallel therewith at least in a region facing the ink ejecting section of the head and provided with ink ejection performance sustaining sections 123d, 123e facing the head surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an ink jet printer for recording characters, images, and the like by discharging ink droplets.

[0002]

2. Description of the Related Art An ink jet printer is a printer of the type that discharges ink droplets from thin nozzles provided side by side on a print head, lands on a recording medium, for example, paper, and records characters or images formed of dots. In addition, the recording speed is high, the recording cost is low, the color can be easily formed, the noise is small, and the size can be relatively easily reduced.

[0003] The ink-jet printer often outputs not only paper dedicated to ink-jet printing but also paper generally called plain paper such as PPC paper. For this reason, regarding the ink used, taking into account the color development, diffusion, durability and safety on paper,
Water is most often used as the main solvent. Then, the ink permeates on the paper after being discharged, and finally is fixed on the paper by evaporating water.

[0004] Actually, humectants, dispersants, preservatives and the like are added to ink used in an ink jet printer in addition to water as a solvent in accordance with the color material used. . These additives contribute to the stabilization of the ejection of the ink jet printer head, the control of ink diffusion and permeability on paper, the storage stability of the ink, and the like, but basically, the ink dries. is there. This is the same even when a solvent other than water or a solvent that hardly evaporates is used as the main solvent, and only the time until drying is increased.

[0005] The characteristics of such an ink are as follows. When ink is supplied to a head discharge portion of an ink jet printer head, and the ink discharge portion is in communication with the atmosphere, the solvent in the ink at the ink discharge portion has a problem. Will evaporate and dry. And such solvent evaporation,
As is well known, the process is continued until the solvent reaches a saturated vapor pressure in the atmosphere. Therefore, when the ink discharge unit communicates with the atmosphere, the drying speed of the ink changes greatly due to the influence of the environment. Further, as the density of the ink ejection section increases, the area where the ink comes into contact with the atmosphere increases, so that the solvent is easily evaporated. As a result, when the viscosity of the ink near the ink discharge portion increases, or particularly when the amount of evaporation of the solvent is large, the ink hardens and adverse effects such as deposition of the coloring material occur.

[0006] Ink jet printer heads have been increasingly miniaturized in recent years due to the demand for higher image quality, and the number of ink ejectors has become very large due to the demand for higher printing speed. ing. here,
The miniaturized ink ejection part is not only dust in the air,
Adhesion of fine dust and paper dust may cause clogging, and may cause serious damage due to contact. With the increase in the number of ink ejection parts, the possibility of clogging and damage is further increased. Has become.

Further, from the viewpoint of resource saving and ecology, it is necessary for the user to perform operations such as collecting the printer head, refilling the ink, and reattaching the printer head in order to eliminate the disposable of the ink jet type printer head. It is becoming. Therefore, there is a need for a printer head structure that prevents the user from directly touching the ink ejection unit and prevents the area around the ink ejection unit from being contaminated with ink during these operations.

[0008]

On the other hand, a protective means for protecting and cleaning the ink discharge portion of the printer head is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-256889.
Issue. As shown in FIG. 9, the protection means includes a protective cap 2 rotatably supported on both sides of the printer head 1 in a closed position covering a part of the head, and an open position separated from the head. It is configured to be able to swing between. Thereby, the protective cap 2
By oscillating about the rotation axis 1a with respect to the printer head 1, the wiping means 2b attached to the inner surface of the portion 2a of the printer head 1 that covers the ink ejection portion 1b
(See FIG. 10)
b, wipes off the ink adhering to the ink ejection portion 1b and, as shown in FIG. 10, covers and protects the ink ejection portion 1b and prevents drying of the ink near the ink ejection portion 1b. It is supposed to.

However, according to the protection means having such a configuration, when the ink ejection section 1b wipes off the ink,
Since the wiping means 2b moves along the surface of the ink discharge portion 1b while the protection cap 2 swings around the rotation axis 1a, the trajectory is circular. Therefore, in the case where the head ejection portions 1b are formed for each color as in a color printer, the leading ends thereof are aligned at the same position, and the head ejection portions 1b are arranged in a plurality of rows in the sheet feeding direction corresponding to the left-right direction in FIG. There is a problem that the wiping means 2b cannot completely wipe off the ink from the surface of the ink ejection section 1b which is arranged flat in each row, and there is a problem that the wiping remains.

In view of the above, the present invention has been made in consideration of the above-described problems, and has been made in consideration of the above circumstances. It is an object of the present invention to provide a type ink jet printer and its head cartridge.

[0011]

According to the first aspect of the present invention, there is provided an ink jet type line head, a closed position for covering the ink discharge portion of the head, and an open position for opening the ink discharge portion. And a cap integrated with the head so as to be moved between positions, wherein the cap is moved in parallel along the surface of the head at least in a region opposed to the ink ejection portion of the head. In addition, the present invention is achieved by a head cartridge of an ink jet printer, wherein the cap includes an ink discharge performance maintaining portion facing the head surface.

[0012] Further, according to the present invention, there is provided an ink jet type line type head,
A cap integrated with the head so as to be moved between a closed position for covering the ink ejection portion of the head and an open position for opening the ink ejection portion, wherein the cap is at least the head of the head. The cap is achieved by an ink jet printer including a head cartridge having an ink ejection performance maintaining section facing the head surface while being moved in parallel along the head surface in a region facing the ink ejection section.

According to the first aspect of the present invention, when the cap is in contact with the head in the closed position, the ink ejection portion on the head surface is protected and the ink droplets on the ink ejection portion are prevented from drying. When the cap is moved from the closed position to the open position, the ink discharge performance maintaining portion of the cap, particularly the wipe member, moves along the head surface, thereby wiping dust and ink droplets adhered to the head surface. Then, the head surface is cleaned.

In this case, since the cap is integrated with the head to form a head cartridge, the cap is closed when the head cartridge is not used or not used, such as when the head cartridge is replaced or newly installed. By being in contact with the head surface at the position, drying of the ink and adhesion of dust and the like at the ink discharge portion of the head are prevented, and the discharge performance maintaining portion, particularly the wipe member, moves in parallel along the head surface for cleaning. By doing so, dust, ink droplets and the like adhering to the head surface are reliably wiped off over the entire head surface, and the head surface is completely cleaned. This prevents the user from erroneously soiling a finger or the like with ink due to ink droplets attached to the head surface, for example, when replacing the head cartridge.

According to a second aspect of the present invention, the head includes:
In the case where the ink ejecting units are arranged in a plurality of rows in the sheet feeding direction, and the caps open and close the ink ejecting units in each row, one cap covers all the ink ejecting sections in each row. The structure is simplified and the cost is reduced.

According to the third aspect of the invention, the cap is moved to the open position so as not to interfere with the printing operation of the printer during printing, and when the cap is retracted from the surface of the head, the cap is moved relative to the head frame. The entire head cap is guided over the head surface by being guided by the guide means, so that the entire head cap is retracted at the open position so as not to interfere with the printing operation of the head at the time of printing. Is normally performed.

Here, in the ink jet printer, the ink is discarded in order to maintain the ejection performance of the printer head, and an ink receiver for receiving the discarded ink droplets is required. In this case, in the case of a serial type inkjet printer in which the head moves, an ink receiver is provided on the side of the paper transport path,
The head moves to that position and can be thrown away. However, in the case of a line type ink jet printer in which the head does not move, it is necessary to provide an ink receiver below the paper transport path, and it is not possible to perform ink disposal during printing.

Therefore, when the ink discharge performance maintaining section is an ink receiving section that receives and absorbs discarded ink, the cap is closed at the closed position. When the ink is ejected from the ink ejection portion of the head in this state, the ejected ink lands on the surface of the ink receiving portion and is absorbed.

According to the sixth aspect of the present invention, when the ink receiving portion is made of a porous material, the ink that has landed on the ink receiving portion is well absorbed by the porous material.

According to the seventh aspect of the present invention, when the cap is constituted by a plurality of strip-shaped rigid shutters connected to each other, the shutter is opened and closed by a driving gear rotationally driven by an external force. As a result, the cap is moved between the closed position and the open position, and the shutter is wound or rolled on one side of the head, so that the cap is efficiently used in a small space in the head cartridge. And the entire head cartridge is made compact.

[0021]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention, and therefore, various technically preferable limitations are added. However, the scope of the present invention is not limited to the following description in the following description. It is not limited to these forms unless otherwise stated.

(Overall Configuration of Printer) FIG. 1 is a partially sectional perspective view showing the overall configuration of an embodiment of an ink jet printer of the present invention, and FIG. 2 is a sectional side view thereof. This ink jet printer 100 has a heating element (not shown) as a driving element for ejecting ink droplets, has a recording range of approximately the width of the paper P, and modulates the diameter of a dot with the number of ink droplets. PNM (Pulse Number M
and a line head 120 having a modulation function.

The ink jet printer 100 has a housing 1
10, a line head 120, a paper feed unit 130, a paper feed unit 140, a paper tray 150, an electric circuit unit 160, and the like are arranged. The housing 110 is formed in a rectangular parallelepiped shape, and has a discharge port 111 for the paper P on one side surface.
The tray entrance 112 of the paper tray 150 is provided on the other side surface. Line head 120
Are provided for four colors of CMYK (cyan, magenta, yellow, and black), and are disposed above an end portion on the side of the paper discharge port 111 so that an ink discharge section described later faces downward.

The paper feed unit 130 includes a paper feed guide 131,
Paper feed rollers 132 and 133, a paper feed motor 134, pulleys 135 and 136, and belts 137 and 138 are provided. The paper feed guide 131 is formed in a flat plate shape, and is disposed below the line head 120 at a predetermined interval. Each of the paper feed rollers 132 and 133 is a pair of rollers in contact with each other, and is disposed on both sides of the paper feed guide 131, that is, on the tray entrance 112 side and the paper discharge port 111 side. The paper feed motor 134 is disposed below the paper feed guide 131, and is connected to the pulleys 135 and 136 and the belt 13.
7, 138 are connected to the respective paper feed rollers 132, 133.

The paper feed unit 140 includes a paper feed roller 141, a paper feed motor 142, and a gear 143.
0 is disposed on the tray entrance 112 side. The paper feed roller 141 is formed in a substantially semi-cylindrical shape, and is disposed near the paper feed roller 132 on the tray entrance 112 side. The paper feed motor 142 is disposed above the paper feed roller 141 and is connected to the paper feed roller 141 via a gear 143.

The paper tray 150 is formed in a box shape capable of storing a plurality of sheets of A4 size paper P, for example, and a paper support 152 locked by a spring 151 is provided at one end of the bottom surface.
Are provided from the lower side of the paper feeding unit 140 to the tray entrance 112. Electric circuit section 160
Is a part for controlling the driving of each part.
It is arranged above 50.

An operation example of such a configuration will be described. After turning on the power of the inkjet printer 100, the user places the paper tray 150 in the tray entrance 11
2, a predetermined number of sheets P are stored and pushed into the paper tray 150. Then, the paper support 152 lifts one end of the paper P by the action of the spring 151 and presses the paper P against the paper feed roller 141. Then, the feed motor 142
The paper feed roller 141 is rotated by the driving of the
From the paper tray 150 to the paper feed roller 132.

Subsequently, the paper feed rollers 132 and 133 are rotated by the driving of the paper feed motor 134, and the paper feed rollers 132 feed the paper P fed out by the paper feed guide 131.
Send to Then, the line head 120 operates at a predetermined timing to discharge ink droplets from the nozzles and land them on the paper P, thereby recording dots of characters and images. Then, the paper feed roller 133 discharges the fed paper P from the paper discharge port 111. The above operation is repeated until the recording is completed.

FIGS. 3 and 4 are perspective views showing the specific structure of the line head 120 in the ink jet printer 100 shown in FIG. 1 as viewed from above and below. FIG. 5 is another perspective view showing the line head 120 as viewed from below. Angle perspective view, FIG.
FIG. 3 is a perspective view showing a cap housed in the line head 120. The line head 120 is, as shown in FIG.
The head frame 121 includes a head frame 1
Reference numeral 21 has a function of an ink tank, and a slit-shaped ink supply hole (not shown) is formed on the surface 121a for each color as an ink discharge portion.
The head chips 122 are bonded to both sides of each ink supply hole in a staggered manner. These head chips 122 communicate with the ink tanks of the corresponding colors, and are formed so as to be continuous so as to form a line along the width direction of the paper as shown in the drawing. A plurality of rows of such head chips 122 are formed on the surface of the head frame 121 as shown.

As shown in FIG. 5, the head frame 121 is formed of, for example, a resin, and has cam grooves 121b formed at both ends thereof as guide means for opening and closing the cap, which will be described later. A step portion 121c provided along the other end for storing the rubber blade, a step portion 121d for escaping the cap provided along the other end edge, and bearing holes 121e provided at both ends.

Further, the line head 120 has a cap 123 which is connected to the head frame 121 so as to be openable and closable. The head frame 121 and the cap 123 constitute a head cartridge 124. This cap 123 is connected to the line head 120 of FIG.
Are accommodated in the head frame 121. As shown in FIG. 6, the cap 123 includes a shutter 123a composed of a plurality of strip-shaped members inserted between both side surfaces of the head frame 121, and guide means protruding from both sides of each strip-shaped member of the shutter 123a. Cam pin 1
23b. The cap 123 includes a rubber lip 123 c for sealing the surface of the head chip 122 of the head frame 121, an ink absorber 123 d for absorbing and holding discarded ink, and an ink discharge portion of the head chip 122. Rubber blade 123 as wipe member for cleaning nozzle surface
e is attached by bonding or the like. As shown in FIG. 6, the rubber lip 123c is a part of a quadrangular frame body, and accommodates an ink absorber 123d that spreads in a planar shape inside the rubber lip 123c. This ink absorber 123d
Is formed of, for example, a polyurethane foam material having a function of absorbing liquid. The rubber lip 123c has an inclined shape such that the thickness gradually increases from the closed position side to the opposite side, as shown in FIG.

Here, the cap 123 has its cam pins 123b engaged with cam grooves 121b provided at both ends of the head frame 121, and a spring (not shown), as shown by an arrow A in FIG. To a closed position. Further, the cap 123 is connected to a feed gear 123g, and the feed gear 123g is
The drive gears 123h provided at both ends are connected to a drive mechanism (not shown). Here, the feed gear 123g
The drive gear 123h is inserted into the bearing hole 121e and is rotatably supported. Thereby, the cap 123 is opened by being moved in the direction opposite to the arrow A in FIG. 4 by this drive mechanism, or is closed in the direction of the arrow A by the tension of the spring.

At this time, the cam groove 121b moves the cap 123 near the closed position in parallel with the head frame 121, and changes the direction of the cap 123 by 180 degrees in the intermediate region. And has a function of moving the cap 123 in the opposite direction and parallel to the head frame 121 again near the open position. For this reason, the cam groove 121b is formed in a semicircular or substantially horizontal U-shape. Thereby, the cap 123 approaches the head frame 121 near the closed position, and the rubber lip 123c as a protective cap abuts on the head frame surface 121a,
The head chip 122 is hermetically closed, and at the open position, the entire cap 123 is configured to retreat above the head frame surface 121a.

The head cartridge 12 according to the present embodiment
The inkjet printer 100 provided with the printer 4 is configured as described above, and operates as follows according to the flowchart shown in FIG. 7 when performing printing. First, when the ink jet printer 100 is not used, the cap 123 is in the closed position shown in FIG.
The rubber lip 123c abuts on the head frame surface 121a to cover and seal all the head chips 122. In this closed position, the ink absorber 123d does not contact the head chip 122. Thereby, the head chip 1
22 is protected, and drying of the ink in the nozzles of the head chip 122 is prevented.

When printing is started, in the flowchart of FIG. 7, first, in step ST1, the motor of the drive mechanism (not shown) is started, and the cap 123 is moved from the closed position against the tension of the spring. Moved and released. At this time, the cam pin 123b of the cap 123 moves in parallel along the head surface according to the shape of the cam groove 121b. As a result, as shown in FIG.
The rubber lip 123c separates from the head frame surface 121a based on the inclined surface shape, and the head chip 122 is opened to the atmosphere, and at the same time, the rubber blade 123e lightly contacts the head frame surface 121a.

Subsequently, in step ST2, the cap 1
23 is temporarily stopped, and the drive of the line head 120 is controlled in step ST3, so that the head chip 122 ejects discarded ink. At this time,
The discarded ink lands on the surface of the ink absorber 123d provided on the surface of the cap 123 and is absorbed.

Subsequently, in step ST4, the cap 1
When the 23 is further moved, the cam pin 123b of the cap 123 moves along the horizontal portion of the cam groove 121b, so that the cap 123 moves parallel to the head frame 121 in the horizontal direction. At that time, FIG.
As shown in (B), the ink droplets, dust, and the like adhering to the nozzle surface of each head chip 122 are wiped off by the rubber blade 123e moving while contacting along the head frame surface 121a. Here, cap 1
The horizontal translation of the nozzles 23 ensures that the surfaces of the flatly arranged head chips 122 in each row are cleaned.

Next, at step ST5, the cap 12
When the third cam pin 123b moves along the turning portion of the cam groove 121b, the entire cap 123 moves above the head frame surface 121a as shown in FIG. Come. As a result, the cap 123 is retracted upward from the paper conveyance path in the inkjet printer 100, and does not interfere with the printing operation of the inkjet printer 100.

Thereafter, in step ST6, the printing operation of the ink jet printer 100 is performed, and
When the printing operation ends at T7, the cap 123 starts moving in the direction of arrow A according to the tension of the spring at step ST8. Thus, when the cap 123 moves from the state shown in FIG. 8B to the state shown in FIG. 8A, the head chip 1 is again moved by the rubber blade 123e.
After the cleaning of the surface of No. 22 is performed, FIG.
The rubber lip 123c covers and seals all the head chips 122, prevents the ink of the head chips 122 from drying, and protects the head chips 122.

According to the ink jet printer 100 having such a configuration, the nozzles as the ink discharge portions of the head chips 122 of the line head 120 are covered with the rubber lip 123c of the cap 123 when not in use and when not in use. As a result, the evaporation of the solvent of the ink is prevented, the drying of the ink is prevented, and the dust and the like are protected from adhering. Further, even during the printing operation, the cap 123 moves from the open position to the closed position (or the position shown in FIG. 8B) so that the nozzles of the head chip 122 can be cleaned and the ink can be discarded. it can.

Further, since the rubber lip 123c covers and seals the head chip 122, it functions as a protective cap, the ink absorber 123d functions as a discarded ink receiver, and the rubber blade 123e functions as a wipe member. become. Therefore, since all of them are housed in the head cartridge 124, the overall configuration is simplified, the cost is reduced, and when the head cartridge 124 is replaced, the rubber blade 123e and the ink absorber 123
Since the replacement of d can be performed at the same time, the maintainability is improved. Also, the cap 123
Since all the head chips 122 of each color of the line head 120 can be covered, the overall configuration is simplified and the cost is reduced.

Further, when the head cartridge 124 is replaced, the nozzle of the head chip 122, which is the ink ejection portion of the line head 120, is covered with the cap 123. Will not get dirty. Further, there is no need for the user to perform an operation of moving the cap 123 to the closed position when replacing the head cartridge 124 or before and after the printing operation, so that the burden on the user is reduced.

[0043]

As described above, according to the present invention, when not in use, the ink ejection portion is protected, the ink is prevented from drying, and the ink droplets attached to the ink ejection portion are removed. Thus, an extremely excellent ink jet printer and its head cartridge can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view, partly in section, showing the entire configuration of an ink jet printer having one embodiment of a head cartridge according to the present invention.

FIG. 2 is a sectional side view of the inkjet printer of FIG.

FIG. 3 is a perspective view of the head cartridge in the inkjet printer of FIG. 1 as viewed from above.

FIG. 4 is a perspective view of the head cartridge of FIG. 3 as viewed from below.

FIG. 5 is a perspective view of a head frame of the head cartridge of FIG. 3 as viewed from below.

FIG. 6 is a perspective view of the cap of the head cartridge of FIG. 3 as viewed from above.

FIG. 7 is a flowchart illustrating a printing operation of the inkjet printer of FIG. 1;

FIG. 8 is a side view sequentially showing the movement of the cap during the printing operation of the inkjet printer of FIG. 1;

FIG. 9 is an enlarged perspective view of a main part showing an example of head protection means in a conventional ink jet printer.

FIG. 10 is a sectional view of a protection means of the head of FIG. 9;

[Explanation of symbols]

100 ... inkjet printer, 110 ...
..Housing, 111 ... Paper discharge port, 112 ... Tray entrance, 120 ... Line head, 121 ... Head frame, 122 ... Head chip, 123 ... Cap, 124 ... .Head cartridge, 130
・ Paper feed unit, 131 ・ ・ ・ Paper feed guide, 132, 13
3: paper feed roller, 134: paper feed motor, 1
35, 136: pulley, 137, 138: belt, 140: paper feed unit, 141: paper feed roller, 1
42 ... feed motor, 143 ... gear, 150 ...
・ Paper tray, 151 ・ ・ ・ Spring, 152 ・ ・ ・ Paper support, 160 ・ ・ ・ Electrical circuit

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shigeyoshi Hirashima 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 2C056 EA16 EA17 EA27 FA13 HA23 JA03 JA05 JA10 JA17 JA29 JB04 JC10 JC23

Claims (10)

[Claims] An ink-jet type line head; a cap integrated with the head so as to be moved between a closed position for covering the ink ejection portion of the head and an open position for opening the ink ejection portion. Wherein the cap is moved in parallel along the head surface at least in a region opposed to the ink ejection portion of the head, and the cap is provided with an ink ejection performance maintaining portion opposed to the head surface. A head cartridge for an ink jet printer, comprising: 2. The ink jet printer according to claim 1, wherein the head includes ink ejection units arranged in a plurality of rows in a paper feeding direction, and the cap opens and closes the ink ejection units in each row. Inkjet printer head cartridge. 3. The head cartridge according to claim 1, wherein the cap is moved to an open position and retracted from the head surface so as not to interfere with the printing operation of the printer at the time of printing. . 4. The head cartridge for an ink jet printer according to claim 1, wherein said ink discharge performance maintaining section is a wipe member for wiping a head surface. 5. The head cartridge according to claim 4, wherein the ink discharge performance maintaining unit also serves as an ink receiving unit that receives and absorbs the discarded ink. 6. The head cartridge according to claim 5, wherein the ink receiving portion is made of a porous material. 7. The head cartridge according to claim 1, wherein the cap comprises a plurality of rectangular rigid shutters connected to each other. 8. The head cartridge according to claim 8, wherein the cap is stored in the head cartridge. 9. The head cartridge according to claim 8, wherein the movement of the shutter is performed by a driving gear that is driven to rotate by an external force. 10. A head integrated with the head so as to be moved between an ink-jet type line type head, a closed position covering the ink discharge portion of the head, and an open position opening the ink discharge portion. Wherein the cap is moved in parallel along the head surface at least in a region facing the ink discharge portion of the head, and the cap has an ink discharge performance maintaining portion facing the head surface. An ink jet printer comprising a head cartridge.