JP2001293871A - Ink jet printer and its head cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head cartridge in which the ink ejecting section is protected at the time of nonuse in order to prevent dry up of ink and ink drops adhering to the ink ejecting section are removed completely. SOLUTION: The ink jet printer comprises means 121b, 123b for guiding a head cap 123 with respect to a head frame 121 wherein the head cap comprises a protective cap 123c and a wipe member 123e. The guide means guide the head cap from a state where the protective cap 123c thereof is touching the head (closed position) in the direction for separating the protective cap from the head. After being separated by a specified distance from the head, the head cap is guided with respect to the head frame along the head surface in parallel therewith while touching the wipe member 123e to the head surface. Subsequently, the head cap is brought close to the head frame and guided such that the entirety of the head cap rides over the head surface (open position).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[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.

SUMMARY OF THE INVENTION In view of the above, the present invention protects the ink discharge portion when it is not used, prevents drying of the ink, and completely removes ink droplets attached to the ink discharge portion. It is an object of the present invention to provide a head cartridge of a line type ink jet printer.

[0011]

According to the first aspect of the present invention, there is provided a head frame in which an ink jet type line type head is exposed on an outer surface, and a head cap disposed outside the head frame. Guide means for guiding the head cap to the head frame, wherein the head cap has a protective cap and a wipe member at a position facing the head, and the guide means is a head cap With respect to the head frame in a direction away from the head from a state in which the protective cap of the head cap is in contact with the head (closed position),
After a predetermined distance, the head cap is guided in parallel to the head frame while keeping the wipe member in contact with the head surface, and is guided in parallel along the head surface. Is achieved by a head cartridge of an ink jet printer, which is configured to guide over the head surface (open position).

According to the third aspect of the present invention, there is provided a head frame having a line type head of an ink jet system exposed on an outer surface, a head cap provided outside the head frame, and a head cap mounted on the head frame. The head cap has a protective cap and a wipe member at a position facing the head, and the guide means moves the head cap to the head frame. The head cap is guided in a direction away from the head from a state in which the protective cap is in contact with the head (closed position), and after a predetermined distance,
The head cap is guided parallel to the head surface while the wiping member is in contact with the head surface while being in contact with the head surface, and further, the head cap is moved closer to the head frame so that the entire head cap exceeds the head surface. This is achieved by an ink-jet printer having a head cartridge configured to guide (open position).

According to the first aspect of the present invention, when the protective cap of the head cap comes into contact with the head in the closed position, the ink discharge portion on the head surface is protected and the ink droplets on the ink discharge portion are dried. To prevent Further, when the head cap is guided in parallel along the head surface by being guided by the guide means with respect to the head frame, the wipe member of the head cap comes into contact with the head surface along the head surface, whereby The attached dust and ink droplets are wiped off, and the head surface is cleaned. When the head cap is guided by the guide means with respect to the head frame, the entire head cap is guided so as to exceed the head surface. So that printing by the head is performed normally.

Therefore, when not in use or not in use, the protective cap contacts the head in the closed position, thereby preventing drying of the ink and adhesion of dust and the like at the ink discharge portion of the head. In addition, when the head cap is guided in parallel with the head frame along the head surface, the dust and ink attached to the head surface are moved in parallel with the wipe member of the head cap being in contact with the head surface. Droplets and the like are reliably wiped off over the entire surface of the head, 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.

Further, in the ink jet printer, ink is ejected in order to maintain the ejection performance of the printer head, and an ink receiver for receiving the ejected 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.

For this reason, in claim 2, the protective cap is made of a material capable of absorbing ink as the discarded ink receiving means. For this reason, at the closed position of the head cap, the protective cap is opposed to the head, and in this state, if the ink is ejected from the ink ejection portion of the head, the ejected ink is discharged to the ink ejection receiving portion. Lands on the surface of the protective cap as a means and is absorbed.

[0017]

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 ink jet printer according to an embodiment of the present invention, and FIG. 2 is a sectional side view thereof. The ink jet printer 100 has a heating element (not shown) as a driving element for ejecting ink droplets, has a recording range of a substantially width dimension of the paper P, and has, for example, the number of ink droplets and the diameter of a dot. Modulating PNM (Pulse Number)
erModulation) system. The ink jet printer 100 has a configuration in which a line head 120, a paper feeding unit 130, a paper feeding unit 140, a paper tray 150, an electric circuit unit 160, and the like are disposed in a housing 110. The housing 110 is formed in a rectangular parallelepiped shape. A paper outlet 111 for the paper P is provided on one end side surface, and a tray entrance 112 of the paper tray 150 is provided on the other end side surface. The line head 120 is provided with four colors of CMYK (cyan, magenta, yellow, and black), and has a head chip constituting an ink discharge unit described later facing downward, and an upper end portion on the side of the paper discharge port 111. It is arranged in.

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 fed paper P to 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 of the specific configuration of the line head 120 in the ink jet printer 100 of FIG. 1 as viewed from above and below. As shown in FIG. 5, the line head 120 includes a head frame 121.
The head frame 121 has the function of an ink tank, and has a slit-shaped ink supply hole (not shown) formed for each color on its surface 121a. On both sides of each of the ink supply holes, a head chip 122 as a discharge unit is stuck in a staggered manner, and is arranged in a line (row). The head chips 122 communicate with the ink tanks of the corresponding colors, and a plurality of rows of the head chips 122 are formed on the head frame surface 121a.

Here, the head frame 121 is formed of, for example, a resin, and has cam grooves 1 formed at both ends thereof as guide means for opening and closing a head cap to be described later.
21b, a step 121c for storing a rubber blade provided along one edge, and a step 121d for escaping a cap provided along the other edge, and further fixed in the housing 110 protruding from both ends. And a mounting hole 121e.

Further, the line head 120 includes a head cap 1 connected to the head frame 121 so as to be openable and closable.
23, and a head cartridge 124 is provided by the head frame 121 and the head cap 123.
Is composed. The head cap 123 includes side portions 123a opposed to both sides of the head frame 121 from outside, and cam pins 123b as guides protruding inward from these side portions 123a. Further, the head cap 123 includes a rubber lip 123c as a protective cap for sealing the surface of the head chip 122 of the head frame 121, and an ink absorber 123d for absorbing and holding the discarded ink.
In addition, a rubber blade 123e as a wipe member for cleaning the nozzle surface of the ink ejection unit of the head chip 122 is attached by bonding or the like. The rubber blade 123e is made of a resilient and deformable rubber material or the like, and is formed in a wall shape extending to a higher position at the most front side in FIG. The rubber lip 123c is disposed at a position one step lower than the rubber blade 123e in the figure, and is formed of an elastic, deformable material. Further, the ink absorber 123d is a plate-shaped member having a predetermined area, which is formed of, for example, a polyurethane foaming agent or the like as a material capable of absorbing and holding the liquid, integrally with the rubber lip 123c. In this embodiment, the front corner of the plate-shaped ink absorber 123d is formed as a rubber lip 123c.

The head cap 123 has a cam pin 123b which engages with cam grooves 121b provided at both ends of the head frame 121 and a spring 123f.
As shown by an arrow A in FIG. Further, the head cap 12
3 is connected to a drive mechanism (not shown) by drive grooves 123g provided at both ends, and is opened by being moved in the direction opposite to the arrow A in FIG. It is closed in the direction of arrow A by tension.

At this time, the cam groove 121b is moved between the closed position where the cam pin 123b of the head cap 123 is located at the end of the cam groove 121b in the direction of arrow A and the open position where the cam pin 123b is located at the opposite end. The cap 123 is formed so as to approach the head frame 121 and to move the head cap 123 in parallel with the head frame 121 in the intermediate region. That is, the cam groove 1
In FIG. 8, 21b is formed so as to extend obliquely upward near both ends, and has an intermediate region formed horizontally. Further, the cam groove 121b is formed such that the oblique portion on the far side (left side) extends upward with a steeper slope. As a result, the head cap 123 approaches the head frame 121 at the closed position, the rubber lip 123c as a protective cap abuts on the head frame surface 121a to seal the head chip 122, and at the open position, The entire head cap 123 is configured to retract above the surface 121a of the head frame 121.

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 head cap 123 in FIG. 6 is in the closed position shown in FIG.
23e is stored in the step portion 121c of FIG.
The rubber lip 123c abuts on the head frame surface 121a to cover and seal the head chip 122. In this closed position, the ink absorber 1
23d does not contact the head chip 122. This protects the head chip 122 and prevents drying of the ink in the nozzles of the head chip 122.

When printing is started, in the flowchart of FIG. 7, first, in step ST1, the motor 140 of the driving mechanism is started, and the head cap 123 is moved from the closed position against the tension of the spring 123f. Moved and released. At this time, the cam pin 123b of the head cap 123 moves along the slope according to the shape of the cam groove 121b, thereby separating from the head frame 121. As a result, as shown in FIG. 8B, the rubber lip 123c separates from the head frame surface 121a, the head chip 122 is opened to the atmosphere, and at the same time, the rubber blade 123e is moved to the head frame surface 121a.
Lightly touch a.

From this state, in step ST2, the cam pin 123b of the head cap 123 is
When the end of the diagonal portion b is reached, the head cap 123
Is temporarily stopped, and the drive of the line head 120 is controlled in step ST3, so that the head chip 1
The discarded ink is ejected from 22. At this time, the discarded ink lands on the surface of the ink absorber 123d provided on the surface of the head cap 123 and is absorbed.

Subsequently, at step ST4, when the head cap 123 is further moved, the head cap 12
Since the third cam pin 123b moves along the horizontal portion of the cam groove 121b, the head cap 123 moves parallel to the head frame 121 in the horizontal direction. At this time, as shown in FIG.
The ink droplets, dust, and the like adhering to the nozzle surface of each head chip 122 are wiped off by the 23e moving while contacting along the head frame surface 121a. Here, the horizontal movement of the head cap 123 ensures that the flat surface of each head chip 122 is cleaned.

Next, in step ST5, when the cam pin 123b of the head cap 123 moves along the oblique portion of the cam groove 121b, the head cap 123
As shown in FIG. 8D, the entire head frame surface 1
It moves above 21a and is brought to the open position. As a result, the head cap 123 is retracted upward from the paper transport 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 is completed in T7, in step ST8, the head cap 123 starts to move in the direction of arrow A according to the tension of the spring 123f. Thus, when the head cap 123 moves from the state shown in FIG. 8C to the state shown in FIG. 8B, the surface of the head chip 122 is cleaned again, and then the state shown in FIG. In this state, the rubber lip 123c covers and seals the head chip 122, prevents the ink in the head chip 122 from drying, and protects the head chip 122.

According to the ink jet printer 100 having such a configuration, when the nozzles serving as the ink ejection portions of the head chips 122 of the line head 120 are not used and are not used, the rubber lip 12 of the head cap 123 is used.
Since the ink is covered and sealed, the evaporation of the solvent of the ink is prevented, and the drying of the ink is prevented.
It is protected without dust and the like adhering. Further, even during the printing operation, the head cap 123 is moved from the open position to the closed position (or the position shown in FIG. 8B), thereby cleaning the nozzles of the head chip 122 and discharging ink. Can be.

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 these are all attached to the head cap 123, 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 123d are replaced.
Can be exchanged at the same time, so that maintainability is improved. Also, the head cap 123
Can entirely cover the head chips 122 of each color of the line head 120, so that the overall configuration is simplified,
Costs will be reduced.

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

[0038]

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 completely removed. Thus, a head cartridge of a line type ink jet printer 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.

6 is a perspective view of a head cap in 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;

8 is a side view sequentially showing the movement of the head cap during the printing operation of the ink jet printer of FIG.

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: head cap, 130 ..Paper feed section, 131 ... Paper feed guide, 132, 133 ... Paper feed roller, 13
4 Paper feed motor, 135, 136 Pulley
137, 138: belt, 140: paper feed unit, 1
41: paper feed roller, 142: paper feed motor, 14
3 ... gear, 150 ... paper tray, 151 ...
.Spring, 152: paper support, 160: electric circuit section

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shigeyoshi Hirashima 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F term (reference) 2C056 EA16 EA17 FA13 HA06 JA03 JA05 JA10 JA17 JB04

Claims (3)

[Claims] 1. A head frame having an inkjet type line-type head exposed on the outer surface, a head cap disposed outside the head frame, and a guide unit for guiding the head cap to the head frame. Wherein the head cap has a protective cap and a wipe member at a position facing the head, and the guide means contacts the head cap with the head frame and the protective cap of the head cap contacts the head. The head cap is guided in a direction away from the head from the state, and after a predetermined distance, the head cap is guided parallel to the head frame along the head surface while the wiping member is in contact with the head surface. Move closer to the head frame and the entire head cap exceeds the head surface Characterized by being configured to urchin guide, the ink jet printer head cartridge. 2. The head cartridge for an ink jet printer according to claim 1, wherein said protection cap is made of a material capable of absorbing ink, as a discarded ink receiving means. 3. A head frame having a line type head of an ink jet type exposed on an outer surface, a head cap disposed outside the head frame, and guide means for guiding the head cap to the head frame. Wherein the head cap has a protective cap and a wipe member at a position facing the head, and the guide means contacts the head cap with the head frame and the protective cap of the head cap contacts the head. The head cap is guided in a direction away from the head from the state, and after a predetermined distance, the head cap is guided parallel to the head frame along the head surface while the wiping member is in contact with the head surface. Move closer to the head frame and the entire head cap exceeds the head surface Characterized in that it comprises a structure and the head cartridge for sea urchin guiding ink jet printer.