JPH10202907A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent bubbles from entering into ink and nozzles from getting clogged while a head unit is put out of use for a long time by providing a nozzle sealing mean that seals airtightly the ink nozzles of a print head in a manner of facing the print head in a printing waiting position of a head unit. SOLUTION: A head unit 2 in a tape printer has a print head 6 in which many ink nozzles 5 are arranged orderly, an ink cartridge 8 is mounted above it in a detachable manner, and the print head 6 and the ink cartridge 8 are mounted on a carriage 9. In such case, the nozzle sealing means 10 that seals the ink nozzles 5 is arranged in a manner of facing the print head 6 of the head unit 2 that has moved to the 'power off' position F. The nozzle sealing means 10 is comprised of a sealing rubber 61 that seals three groups 11 of ink nozzles simultaneously and is held in a holder 62 and a rotary arm 64 that contacts and separates the sealing rubber 61 to and from the print head 5.

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 in which a head unit having a print head reciprocates with a series of printing operations.

[0002]

2. Description of the Related Art In an ink-jet printer, even a slight impact (for example, a drop of about 1 to 2 cm) destroys a meniscus on a nozzle surface of a print head, or bubbles are mixed in ink, resulting in a defective ink ejection. ”Or“ bending ”in which the ink ejection angle bends, which may result in poor printing. Therefore, in a commercially available ink jet printer, the meniscus may be destroyed even when the ink jet printer is simply moved. Cleaning is performed. On the other hand, a cap faces the print head at the home position,
The nozzle surface is covered to protect the nozzle from drying of ink and dust.

[0003]

Therefore, assuming the emergence of an ink jet printer that is portable or frequently moved, cleaning is performed very frequently, automatically or manually. In such a case, the consumption of the ink becomes severe and the commercial value of the printer is lost. Further, since the suction tube connected to the cap is open to the atmosphere on the waste ink tank side, if the printer is left for a long time (several months), the ink may dry and the nozzles may be clogged. .

SUMMARY OF THE INVENTION The present invention can prevent bubbles from being mixed into ink upon impact, make it difficult for the meniscus on the nozzle surface to be destroyed, and reliably prevent nozzle clogging during long-term storage. It is an object of the present invention to provide an ink jet printer capable of performing the following.

[0005]

According to an ink jet printer of the present invention, a head unit having a print head reciprocates with a series of printing operations in an ink jet printer facing a print head at a print standby position of the head unit. And a nozzle sealing means for hermetically sealing the ink nozzles of the print head.

According to this configuration, when the head unit moves to the print standby position, the nozzle sealing means hermetically seals the ink nozzles of the print head. When the ink nozzle is sealed, in the ink flow path from the ink cartridge to the ink nozzle, the end on the ink nozzle side is sealed by the nozzle sealing means, and the end on the ink cartridge side is substantially sealed by the ink holding material. State. For this reason, even if the ink in the ink flow path receives an impact via the printer, the ink does not easily pulsate, and the meniscus on the nozzle surface is not destroyed. In addition, since the ink nozzle is hermetically sealed, no bubbles are mixed into the ink even if an impact is received. Further, since the ink nozzle is completely sealed, the ink does not dry, and the ink nozzle does not become clogged even if the printing operation is not performed for a long time.

In this case, the nozzle sealing means has a sealing member for sealing the ink nozzles, and a moving mechanism for moving the sealing member to the sealing position. It is preferable to move the sealing member to the sealing position in conjunction with the movement to the standby position.

According to this configuration, when the head unit moves to the print standby position, the moving mechanism moves the sealing member to the sealing position in conjunction with the movement of the head unit to seal the ink nozzle. Therefore, the ink nozzle at the print standby position can be reliably sealed.

In this case, the print head is provided with a plurality of color-specific ink nozzle groups composed of a plurality of ink nozzles, and the sealing member is provided with a plurality of sealing nozzles corresponding to each ink nozzle group. It is preferable to have a convex part.

According to this structure, each sealing projection of the sealing member is pressed against the corresponding ink nozzle group to seal it, so that all the ink nozzle groups are sealed on a single surface. As compared with the case of sealing, a pressing force for sealing can be uniformly and appropriately applied to each ink nozzle group. Therefore, even when the ink nozzles of the plurality of ink nozzle groups are sealed, defective sealing can be effectively prevented. In addition, since the ink attached to each sealing projection does not flow to other sealing projections, color mixing does not occur at the tip of the ink nozzle.

In these cases, it is preferable that the moving mechanism is a cam mechanism that operates using the moving head unit as an input unit, or a link mechanism that operates using the moving head unit as an input unit.

According to this configuration, the ink nozzle can be reliably and automatically sealed without requiring a power source for the moving mechanism.

In these cases, it is preferable that the printing object is a tape-shaped member.

According to this structure, since the impact resistance can be improved, the printer itself can be made compact and portable.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A case where an ink jet printer according to an embodiment of the present invention is applied to a tape printing apparatus will be described below with reference to the accompanying drawings. This tape printing apparatus performs color printing of desired characters or the like input by keys on a tape by an ink jet method, and cuts a printed portion of the tape to create a label. FIG.
As shown in FIG. 2 and FIG.
Unit 2 for performing printing on the head, and a head drive unit 3 for reciprocating the head unit 2 in the left-right direction for printing.
And a waste ink processing unit 4 to which the head unit 2 faces when printing is stopped or when printing is stopped.

The head unit 2 is, as shown in FIG.
A print head 6 having a large number of ink nozzles 5 arranged at the end thereof; a cartridge holder 7 provided above the print head 6; an ink cartridge 8 removably mounted on the print head 6 via the cartridge holder 7; Carriage 9 on which head 6 and ink cartridge 8 are mounted
The carriage 9 is connected to the head driving unit 3. The ink cartridge 8 has three ink tanks 21, 21 and 21 and is integrally formed. The three ink tanks 21, 21 and 21 store inks of three colors of cyan, magenta and yellow, respectively. (See FIG. 3). Correspondingly, the print head 6 is provided with a total of six nozzle rows composed of a plurality of ink nozzles 5, two for one color (see FIG. 5). Then, three color inks of cyan, magenta and yellow are appropriately ejected to the same point on the tape T so as to obtain dots of a desired color.

As shown in FIG. 3, the ink cartridge 8 has a cartridge case 22 composed of a main body case 22a and a lid case 22b provided so as to close the upper end of the main body case 22a. As described above, the inside of the cartridge case 22 includes the three ink tanks 21, 21, 21.
Each ink tank 21 is filled with an ink holding material 23 that absorbs and stores ink. An ink supply port 24 for supplying ink is formed at the end of the main body case 22a corresponding to each ink tank 21, and the ink cartridge 8 is connected to the print head 6 at the ink supply port 24.

Each ink supply port 24 is provided in the lid case 22b.
Three ink injection ports 25 and 2 corresponding to
5, 25 are formed through. Also, the lid case 22b
Are formed on the upper surface thereof, three ventilation grooves 26, 26, 26 whose downstream ends are respectively connected to the respective ink inlets 25.
Each ventilation groove 26 is provided with a cover case 2 so that a long path can be taken.
The upper end of the upper case 2b is formed in a meandering shape, and each upstream end extends to the central side edge 27 of the lid case 22a so as to align the three ventilation grooves 26, 26, 26.

On the upper surface of the lid case 22a, a film 28 is thermocompression-bonded so as to cover the ventilation groove 26 from above without leaving the ink inlet 25 and the open end. The inlet 25 and the ventilation groove 26 form a ventilation hole 29 of each ink tank 21. In other words, the three meandering vent holes 2
9 is opened to the atmosphere at the central side edge portion 27 of the lid case 22b, so that air is supplied to each of the ink tanks 21 along with the supply of ink, and evaporation of water in each of the ink tanks 21 is suppressed. I have.

As shown in FIGS. 1 and 2, the head drive unit 3 includes a carriage motor 31 and a pair of pulleys 32.
a, 32b, an endless timing belt 33 stretched between a pair of pulleys 32a, 32b, and a carriage guide shaft 34 for guiding the movement of the carriage 9 described above. The carriage guide shaft 34 has both ends supported on the upper part of the main frame 35, and the carriage 9
The upper part is slidably attached to the carriage guide shaft 34.

The carriage motor 31 is attached to the left front plate 35a of the main frame 35 from behind.
A pulley 32a on the driving side is attached to an output shaft 31a of the carriage motor 31 that protrudes forward through the left front plate 35a. The driven pulley 32b is attached to the right front plate 35b of the main frame 35 with respect to the driven pulley 32a. And both pulleys 3
A fixed piece 36 extending from the carriage 9 is connected to the timing belt 33 extending between 2a and 32b, and the head unit 2 moves as the timing belt 33 runs. That is, with the forward / reverse rotation of the carriage motor 31, the timing belt 33 travels forward / reverse,
The print head 6 and the ink cartridge 8 mounted on the carriage 9 are guided by the carriage guide shaft 34 and reciprocate in the left-right direction.

This reciprocating motion has a total of four stop positions across a printing area S where actual printing is performed in a series of printing operations. The print area S is set between a forward movement start position A and a backward movement start position (return position) B. On the right side of the printing area S, a flushing position C,
The main suction position D, the idle suction position E, and the power OFF position F are set on the right side of the print area S. Head unit (print head 6) 2 at flushing position C
The main cap (details will be described later) 41 of the waste ink processing unit 4 that receives the waste ink faces each other with a gap. When printing is paused, immediately after printing, and when the power is turned on
At times, the print head 6 faces the flushing position C, and an ink ejection operation (flushing) from all the ink nozzles 5 is performed.

The head cap (print head 6) 2 at the main suction position D is provided with the main cap 41 described above.
Will adhere. When a predetermined time elapses from the end of printing to the next power-on, or when cleaning is selected by key input, the print head 6 faces the main suction position D and the main cap 41 comes into close contact with the main suction position D. The cleaning is performed by suction. Further, when it is necessary to suck the waste ink in the main cap 41, such as after cleaning, the print head 6 faces the empty suction position E while keeping the main cap 41 in close contact. Of the waste ink is performed.

On the other hand, the power-off position F is a so-called home position, and the head unit (print head 6) 2 at the power-off position F is provided with nozzle sealing means for sealing the ink nozzles 5 of the print head 6 (for details, 10 (to be described later).

When the power is turned on, the head unit 2 once performs flushing while facing the flushing position C, and enters a standby state for printing. Although not shown, the left front plate 35a of the main frame 35 includes
A position detection sensor composed of a photo interrupter or the like is attached, and a light shielding plate protruding from the carriage 9 faces the position detection sensor, whereby the position of the head unit 2 (reference position).
Is detected. That is, this detection position is a reference position for step feed with respect to each of the positions A to E in addition to the power-off position F which is the print standby position of the print head 6.

The waste ink processing section 4 has a main cap 41 facing the print head 6, a main cap moving mechanism 42 for moving the main cap 41 forward and backward, and suctioning waste ink in the main cap 41 and ink of the print head 6 ( And a waste ink pump 43 that leads to a waste ink tank (not shown) after performing idle suction and main suction. Main cap 41
Is connected to a suction tube 44 connected to the waste ink pump 43, and is connected to an atmosphere release tube 46 having a distal end connected to an atmosphere release valve 45. When suction is performed with the air release valve 45 in the “open” state, idle suction is performed, and when suction is performed in the “closed” state, actual suction is performed. Further, the inside of the main cap 41 is filled with an ink absorbing material 47 that stores the waste ink so as to absorb the waste ink. The waste ink absorbed by the ink absorbing material 47 is sucked by the waste ink pump 43 at a corn where a certain amount is accumulated (empty suction).

The main cap moving mechanism 42 is composed of a fixed-side mechanism frame 48 and a movable-side cap holder 49. The cap holder 49 slides left and right with respect to the mechanism frame 48 while holding the main cap 41. Mounted freely. The cap holder 49 is provided with a pair of cam projections 50, 50,
A mechanism frame 48 corresponding to the pair of cam projections 50, 50 is provided.
Is provided with a pair of cam members 51 and 51 having inclined surfaces. The cam projection 50 and the cam member 51 constitute a linear motion cam 52 for moving the main cap 41 toward and away from the print head 6.

That is, when the head unit 2 is separated from the waste ink processing section 4, the cap holder 49 holding the main cap 41 is urged by the first coil spring 53 to be at the left moving end position, and Main cap 4
1 is in the retracted position by the operation of the translation cam 52. In this state, when the head unit 2 moves rightward and stops at the flushing position C, the print head 6 faces the main cap 41 with a gap.

Further, as the head unit 2 moves rightward beyond the flushing position C, the print head 6
The right end of the head unit 2 abuts the cap holder 49, and the head unit 2 moves rightward with the cap holder 49. When the cap holder 49 moves rightward, the main cap 41 gradually advances due to the action of the translation cam 52. When the head unit 2 stops at the main suction position D, the main cap 41 reaches the forward position and comes into close contact with the print head 6. In this state, the atmosphere release valve 45 is closed, and the print head 6 is cleaned by driving the waste ink pump 43.

Further, when the head unit 2 slightly moves rightward beyond the main suction position D, the idle suction position E
Reach In this movement, the main cap 41 moves while being in close contact with the print head 6 by the action of the linear motion cam 52, but the plug of the atmosphere release valve 45 is pushed, and the atmosphere release valve 45 is opened. Here, by driving the waste ink pump 43, idle suction for sucking waste ink in the main cap 41 is performed. On the other hand, when the head unit 2 moves leftward from this state, the cap holder 49 also moves leftward by the first coil spring 53, and returns to the original position. Incidentally, reference numerals 54 and 5 in the figure
4 is a main cap 41 closely attached to the print head 6,
The second coil spring urges the print head 6 lightly.

On the other hand, at the power-off position F, a nozzle sealing means 10 for sealing the ink nozzle 5 is provided facing the print head 6 of the head unit 2 moved to this position. As described above, the print head 6 is provided with a total of six nozzle rows composed of a plurality of ink nozzles 5, two rows for one color, and two rows for one color.
The rows are ink nozzle groups 11, and three (three colors) ink nozzle groups 11, 11, 11 are arranged (see FIG. 5).

Therefore, the nozzle sealing means 10 includes a sealing rubber (sealing member) 61 for simultaneously sealing the three ink nozzle groups 11, 11, and 11, and a rubber holder 62 for holding the sealing rubber 61. The movable side of the nozzle sealing means 10 is constituted by the sealing rubber 61 and the rubber holder 62. On the other hand, the fixed side of the nozzle sealing means 10 has a fixed frame 63 facing the lower surface of the rubber holder 62, and a rotating arm 64 bridged between the fixed frame 63 and the rubber holder 62.

The sealing rubber 61 is formed of butyl rubber, silicon rubber or the like, and as shown in FIG.
And three sealing projections 61b projecting on the base 61a,
61b, 61b. Three sealing projections 6
1b, 61b, and 61b are arranged at equal intervals so as to cross the base portion 61a, and correspond to the three ink nozzle groups 11, 11, and 11 described above. In such a configuration, the ink nozzles 5 of each of the ink nozzle groups 11 are sealed with the upper surface of each sealing projection 61b, and sealing failure due to bending of the base 61a during pressing is prevented. Can be.

A cam projection 65 is formed at the right end of the lower surface of the rubber holder 62.
A cam surface 66 with which the cam projection 65 slides is formed on the upper surface of the. That is, the cam projection 65 and the cam surface 66 constitute a linear motion cam 67 for moving the sealing rubber 61 up and down. On the other hand, a rotation arm 64 extending from the fixed frame 63 is rotatably attached to the left end of the rubber holder 62. Further, a compression spring 68 is disposed along the rotating arm 64, and the compression spring 68 lightly urges the sealing rubber 61 in close contact with the print head 6 toward the print head 6.

When the rubber holder 62 moves leftward from the position at the right movement end position, the left end of the rubber holder 62 moves upward by the rotating arm 64, and at the same time, the left end of the rubber holder 62 moves linearly. It moves upward by the cam action of the cam 67. As a result, the rubber holder 62 approaches the print head 6 while moving substantially in parallel, and when the rotating arm 64 is almost vertical, the sealing rubber 61 is moved to the print head 6.
Adhere to That is, the translation mechanism 67 and the rotating arm 64 constitute a moving mechanism for moving the sealing rubber 61 up and down.

When the head unit 2 moves to the left toward the power-off position F, a projection (not shown) provided on the head unit 2 abuts against the rubber holder 62 and moves the rubber holder 62 to the left. . Rubber holder 62
Is moved to the left, the rubber holder 62 is moved upward by the action of the rotating arm 64 and the translation cam 67. When the head unit 2 reaches the power-off position F, the sealing rubber 61 comes into close contact with the print head 6 and hermetically seals the ink nozzle 5. The compression spring 68 has a lower end fixed to the fixed frame 63, and becomes curved when the rubber holder 62 moves to the left (although not shown in the figure). Therefore, when the head unit 2 moves rightward from the power-off position F, the sealing rubber 61 and the rubber holder 62
8 to return to the original position while moving downward. In this case, however, the rubber holder 62 may be returned to the right movement end position by another spring.

Next, referring to FIG.
A second embodiment of the present invention will be described. In this embodiment, a rubber holder 72 that holds a sealing rubber 71 is provided so as to be vertically movable, and is urged upward by a first spring 74 having one end fixed to a fixed frame 73. Further, a pin 75 instead of a cam projection is attached to the rubber holder 72. On the other hand, a slider 76 is provided movably in the left-right direction along the rubber holder 72, and the slider 76 is urged rightward by a second spring 77. The lower surface of the left side of the slider 76 is a cam surface 78, and a pin 75 of the rubber holder 72 is in sliding contact with the cam surface 78 from below. That is, the linear motion cam 7 for vertically moving the sealing rubber 71 by the cam surface 78 and the pin 75.
9 are configured.

When the slider 76 moves leftward from the right end position, the rubber holder 72 is urged by the first spring 74 by the action of the translation cam 79 and moves upward. Thereby, the rubber holder 72 approaches the print head 6 while moving substantially in parallel, and the sealing rubber 71 comes into close contact with the print head 6.

That is, the power of the head unit 2 is turned off.
When the head unit 2 moves leftward toward the position F, a protrusion (not shown) provided on the head unit 2 hits the slider 76 and moves the slider 76 leftward. When the slider 76 moves to the left, the rubber holder 72 moves upward by the action of the translation cam 79. When the head unit 2 reaches the power-off position F, the sealing rubber 71
And the ink nozzle 5 is hermetically sealed. On the other hand, when the head unit 2 moves rightward from the power OFF position F, the slider 76 moves rightward in the reverse procedure, and the sealing rubber 71 moves away from the print head 6.

As described above, according to the present embodiment, when the power is turned off without using the tape printer 1, the print head 6
Since the ink nozzle 5 is sealed, the evaporation of water from the ink nozzle 5 is prevented, and no trouble such as clogging of the ink nozzle 5 occurs even if the ink nozzle 5 is left for a long time. Further, by sealing the ink nozzle 5, even if the tape printing apparatus 1 receives an impact, pulsation of the ink is suppressed, so that the meniscus on the nozzle surface is broken or bubbles are prevented from being mixed into the ink. be able to. Therefore, even if the tape printing apparatus 1 is portable and is placed in an environment that is easily affected by impact, it is possible to effectively prevent printing defects due to the incorporation of air bubbles and the destruction of the meniscus.

Further, the sealing rubber 61 in the first embodiment is used.
Moves toward and away from the print head 6 while moving as the head unit 2 moves, so that the sealing rubber 61 and the print head 6 do not rub each other, and the sealing operation is performed smoothly. In addition, the linear motion cam 67 in the first embodiment
Instead of this, a second rotating arm may be provided in this portion. In such a case, a parallel link mechanism is formed between the rubber holder 62 and the fixed frame 63, and the sealing operation of the ink nozzles 5 is performed by the parallel link mechanism.

In this embodiment, the case where the ink jet printer is applied to a tape printing apparatus has been described. However, it goes without saying that the present invention can be applied to a general ink jet printer. Further, the nozzle sealing means may include a unique driving means for moving the sealing rubber.

[0043]

As described above, according to the ink jet printer of the present invention, the ink nozzles can be sealed in the printing standby state, so that the clogging of the ink nozzles can be effectively prevented even when the printer is left for a long time. In addition to this, it is possible to prevent air bubbles from being mixed into the ink in response to an impact, or to have a structure in which the meniscus on the nozzle surface is not easily broken. Therefore, even if the printer is portable or moves frequently and is placed in an environment that is susceptible to impact, or even if it is left for a long period of time, printing defects can be effectively prevented. can do. Conversely, a printer suitable for carrying can be configured.

[Brief description of the drawings]

FIG. 1 is a structural diagram around a head unit of an ink jet printer according to an embodiment of the present invention.

FIG. 2 is a front view around a head drive unit of the inkjet printer according to the embodiment.

FIG. 3 is a structural diagram of an ink cartridge of the inkjet printer according to the embodiment.

FIG. 4 is a front view around a head unit according to a second embodiment.

FIG. 5 is a perspective view illustrating a relationship between a sealing rubber and an ink nozzle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tape printing device 2 Head unit 3 Head drive part 5 Ink nozzle 6 Print head 10 Nozzle sealing device 11 Ink nozzle group 61 Seal rubber 64 Rotating arm 67 Linear cam

Claims (6)

[Claims] 1. A head unit having a print head,
An ink jet printer that reciprocates with a series of printing operations, comprising a nozzle sealing unit that faces the print head at a print standby position of the head unit and hermetically seals ink nozzles of the print head. Characteristic inkjet printer. 2. The nozzle sealing unit includes a sealing member for sealing the ink nozzle, and a moving mechanism for moving the sealing member to a sealing position. The inkjet printer according to claim 1, wherein the sealing member is moved to a sealing position in conjunction with movement of the head unit to a print standby position. 3. The print head is provided with a plurality of color-specific ink nozzle groups each including a plurality of the ink nozzles, and the sealing member includes a plurality of ink nozzle groups corresponding to the respective ink nozzle groups. 3. The ink jet printer according to claim 2, further comprising a sealing projection. 4. The ink jet printer according to claim 2, wherein the moving mechanism is a cam mechanism that operates using the moving head unit as an input unit. 5. The inkjet printer according to claim 2, wherein the moving mechanism is a link mechanism that operates using the moving head unit as an input unit. 6. The ink jet printer according to claim 1, wherein the printing object is a tape-shaped member.