JP4929756B2 - Inkjet printer - Google Patents

Description

  The present invention relates to an ink jet printer provided with means for preventing ink leakage from nozzles when an ink cartridge is mounted.

  An ink jet printer records characters and figures by ejecting ink particles onto a recording medium such as plain paper. The ink particles are ejected from a recording head in which a plurality of nozzles are arranged toward the recording medium. The recording head is moved in the left and right main scanning directions, and the recording medium is sub-scanned perpendicular to the main scanning direction. Recording is performed while transporting in the direction.

  The ink ejected from the recording head is appropriately supplied from the ink cartridge every time it is ejected from the nozzle, and the ink cartridge storing this ink is replaced with a new ink cartridge when the ink runs out. It is possible.

  To remove an empty ink cartridge and install a new ink cartridge in the printer, first unlock the pressure lever that secures the ink cartridge to the holder, and connect the ink supply port of the ink cartridge and the joint of the holder. Remove the empty ink cartridge from the holder.

  Next, a new ink cartridge is inserted into the holder. When the ink cartridge is inserted into the holder, the ink supply port of the ink cartridge engages with the joint part of the holder, and the released pressure lever is returned to the locked position, so that the ink supply port of the ink cartridge and the joint part of the holder are connected. This completes the setting of the ink cartridge.

  In this way, after replacing the ink cartridge, the ink in the nozzles of the recording head may leak and hang down on the nozzle surface. If the recording head is moved in this state, the contact of the dripping ink will occur. May contaminate internal components such as recording media and paper pressers.

  This is because when the ink cartridge is replaced, the air trapped between the ink supply port of the ink cartridge and the joint portion of the holder is compressed by the movement of the ink cartridge to the set position, and the pressure rises. This is because a pressure is generated to push out the nozzle from the nozzle.

  That is, for example, in the case where a rubber seal member for securing a sealing property is attached to the tip of the joint portion of the holder, if the ink cartridge is inserted into the holder and the pressing lever is locked, the ink cartridge The ink supply port is fixed to the set position while being pressed against the seal member. When the ink cartridge is set in this way, an ink supply path is formed which communicates the ink cartridge and the recording head and ensures airtightness.

  When the ink supply port and the seal member are in close contact with each other until the ink cartridge is fixed at the set position, the air trapped between the ink supply port and the seal member escapes to the outside. I can't do that. As the ink cartridge is moved to the set position, the gap between the ink supply port and the seal member becomes narrower, and the biting sky is compressed.

  As a result, the pressure in the ink supply path rises, and the ink remaining in the nozzles is pushed outward while the pressure is about to be released toward the recording head with less resistance. If a fine filter is provided at the ink supply port of the ink cartridge to filter the ink, the surface tension of the meniscus of the ink stretched on the filter resists the above pressure rise, and the pressure rise Is directed toward the recording head having the lower resistance as described above.

As an apparatus provided with a means for preventing such ink leakage, an apparatus provided with an air vent for discharging air to be caught in at least one of the ink supply port of the ink cartridge and the seal member of the joint part of the holder is provided. It has been proposed (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 9-277554 (pages 3 to 6, 8, 9 and FIGS. 2 and 9)

  However, in the above-described conventional configuration, the air to be trapped can be discharged to the outside until the ink supply port of the ink cartridge and the seal member of the holder are sealed, but the seal between the ink supply port and the seal member can be discharged. Once the air-tightness in the ink supply path is secured, the trapped air cannot be discharged.

  Accordingly, an object of the present invention is to provide an ink jet printer that does not cause ink leakage due to air entrapment when an ink cartridge is mounted.

The ink jet printer according to claim 1, wherein the ink supply path of the ink cartridge is connected to a recording head provided with a nozzle for ejecting ink by a joint portion that is communicated with the ink introduction path. An ink supply path configured to communicate an ink chamber in the ink cartridge and the recording head, wherein the ink supply path is connected between the ink supply port of the ink cartridge and the joint portion. Corresponding to the pressure increase caused by the intrusion of air into the inside, a pressure increase absorbing means that is deformed toward the outside of the ink supply path and suppresses the pressure increase is provided in the ink supply path, and the pressure increase absorption means A tube member constituting a part of the ink supply path, and the tube member is Is characterized by connecting the pressure the recording head so as to expand in the radial direction corresponding to the increase in the supply passage and with said joint portion.

According to the ink jet printer of this aspect, the pressure increase absorption means is provided in the ink supply path, and the pressure increase absorption means corresponds to the pressure increase of the air that has entered the ink supply path, and the ink supply path Even if the air trapped at the time of connection between the ink supply port of the ink cartridge and the joint portion is compressed by deforming outward and absorbing the pressure increase, the ink supply Since the pressure in the passage does not increase and the ink in the nozzle is not pushed outward, ink leakage from the nozzle can be prevented.
Further, the pressure increase absorbing means constitutes a part of the ink supply path, and connects the recording head and the joint portion so as to expand in a radial direction in response to the pressure increase in the ink supply path. Therefore, when the pressure in the ink supply path is increased by the air trapped at the time of connection between the ink supply port of the ink cartridge and the joint portion, the film-like member rises by expanding in the radial direction. Absorb the pressure to do. Therefore, the ink in the nozzle is not pushed out, and leakage of the ink from the nozzle can be prevented.

According to a second aspect of the present invention , in the ink jet printer according to the first aspect, the tube member has elasticity .

According to the inkjet printer described in claim 2, in the boosting-absorbing means, permanent set is less likely to occur due to the deformation.

According to a third aspect of the present invention , in the ink jet printer according to the first or second aspect, the pressure-absorbing absorbing means is restored after the ink is ejected from the nozzle or after the suction. According to the ink jet printer of the third aspect , when the ink cartridge is replaced next time, the boosting absorption unit can be in a reset state.

An ink jet printer according to a fourth aspect of the present invention is the ink jet printer according to any one of the first to third aspects, wherein the ink introduction path extends from the joint portion and the cylindrical member having one end fixed to the ink introduction port of the recording head. A tubular connecting member that connects the other end of the tubular member and the tubular portion, and the pressure-absorbing means is the tubular member of the ink introduction path, the tubular portion, It is provided in at least one of the connecting part and the joint part.

According to the ink jet printer according to claim 4 , by providing the pressure-absorbing absorbing means in at least one of the cylindrical member, the tubular portion, the connecting member, and the joint portion constituting the ink introduction path, There is no need to provide the pressure-absorbing absorption means for each ink cartridge.

An ink jet printer according to a fifth aspect is characterized in that in the ink jet printer according to any one of the first to fourth aspects, the ink supply port of the ink cartridge is connected to the joint portion via an elastic seal member.

According to the ink jet printer according to claim 5 , since the airtightness between the ink supply port and the joint portion is increased, the ink supply path with high airtightness that does not cause an increase in pressure due to entry of air is provided. To be composed.

In the ink jet printer according to the first aspect of the present invention, ink does not leak from the nozzle even if air is caught when the ink supply port of the ink cartridge is connected to the joint portion. Parts are not soiled. In addition, since the tube member swells in the radial direction, the pressure increase in the ink supply path can be absorbed, so even if air is caught when the ink supply port of the ink cartridge is connected to the joint portion, the ink leaks from the nozzle. The recording medium and internal parts are not soiled by replacing the ink cartridge.

The ink jet printer according to claim 2 is provided with a highly durable pressure absorbing means.

In the ink jet printer according to the third aspect, it is not necessary to restore the pressure-absorbing absorption means, and the ink cartridge can be easily replaced as usual.

In the ink jet printer according to the fourth aspect , since it is not necessary to provide the pressure-absorbing means for each ink cartridge, the cost and labor for providing the pressure-absorbing means can be reduced.

The ink jet printer according to the fifth aspect of the present invention combines the advantages of both the absence of ink leakage from the nozzles when the ink cartridge is replaced and the smooth supply of ink during recording.

  An embodiment of an ink jet printer according to the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view perpendicular to the main scanning direction of the carriage of the ink jet printer according to the present invention. The carriage 1 reciprocates in the main scanning direction along a carriage shaft 2 provided so as to penetrate the carriage 1 in the main scanning direction and a guide plate (not shown) provided in parallel with the carriage shaft 2. It is like that. A head holder 4 that supports the recording head 3 is mounted on the carriage 1, and a pressing lever 6 for fixing the ink cartridge 5 mounted on the head holder 4 is provided on the top.

  The head holder 4 is formed in a box shape with a wall provided at the end of each side of the bottom wall 4a formed in a quadrangle shape, and the ink cartridge 5 can be mounted inside. ing. And one of the four walls is formed sufficiently lower than the other three walls. Hereinafter, the lower wall will be referred to as the front wall 4b, the wall facing the front wall 4b will be referred to as the rear wall 4c, and a set of facing walls that do not appear in the drawings will be referred to as side walls.

  The recording head 3 is supported on the lower surface of the bottom wall 4 a of the head holder 4. The recording head 3 is formed by laminating a nozzle plate 3a in which nozzles for ejecting ink are formed, a cavity plate 3b for containing ink, and an actuator 3c for generating energy for ejecting ink, and a drive signal is transmitted to the actuator. An input wiring member 3d is attached to the upper surface.

  The recording head 3 is fixed to the bottom wall 4a of the head holder 4 with the nozzle plate facing downward. Further, the recording head 3 is exposed to the bottom wall 4a of the head holder 4 with the nozzles of the nozzle plate exposed. A covering cover plate 7 is attached.

  Further, as shown in the enlarged view of FIG. 2A, the bottom wall 4a is provided with an ink introduction path 11 to be described later for introducing the ink of the ink cartridge 5 attached to the head holder 4 into the recording head 3. The opening 4d is formed.

  The lower portion of the joint portion 8 that connects the ink supply port 51a of the ink cartridge 5 is fitted into the opening portion 4d from above.

  In the joint portion 8, a communication hole serving as an ink flow path is formed penetrating in the vertical direction, and a tubular portion 8 a is formed projecting from the lower portion.

  A cylindrical member 9 having one end fixed to an ink inlet (not shown) of the recording head 3 is disposed in the opening 4d. The other end of the cylindrical member 9 and the tubular portion of the joint portion 8 are disposed. A portion 8 a is connected by a rubber tube-like connecting member 10 fitted to the outer periphery thereof, and an ink introduction path 11 that guides ink to the recording head 3 extends from the joint portion 8 to the recording head 3. Has been.

  Further, a support plate 12 having a through hole 12a at a position corresponding to the joint portion 8 is attached to the bottom wall 4a in a state where the upper portion of the joint portion 8 is exposed from the through hole 12a and the upper surface of the bottom wall 4a is covered. It has been. The through hole 12a of the support plate 12 is formed larger than the diameter of the joint portion 8, and the ink supply port 51a of the ink cartridge 5 is fitted to the tip of the joint portion 8 exposed from the through hole 12a. An elastic rubber seal member 13 having a recess 13a is attached.

  When the ink cartridge 5 is mounted on the head holder 4 configured as described above, and the ink supply port 51a of the ink cartridge 5 is connected to the joint portion 8 via the seal member 13, an ink chamber 51b described later of the ink cartridge 5 is provided. And the recording head 3 communicate with each other, and an ink supply path 14 is formed.

  The ink supply path 14 is provided with a pressure increase absorbing means 15 that is deformed corresponding to an internal pressure increase and absorbs the rising pressure. As shown in FIG. 2B, the pressure-absorbing absorption means 15 is formed with a through hole 8b communicating with the outside and the ink supply path 14 at a position where it does not interfere with the seal member 13 in the upper part of the joint portion 8, and rubber. A thin film-like member 16 made of metal is attached to the outer peripheral surface of the joint portion 8 so as to close the through hole 8b.

  By providing the pressure increase absorbing means 15 in the ink supply path 14 in this way, ink leakage from the nozzles when the ink cartridge 5 is attached to the head holder 4 can be prevented. Before this will be described next, the ink cartridge 5 will be briefly described.

  The ink cartridge 5 is formed in a box shape having a narrow lateral width, and includes a box-shaped case member 51 having an open upper surface and a lid member 52 attached to the upper portion of the case member 51. The interior is partitioned into an absorber housing chamber 51d that houses a porous material 51c that is an ink absorber, an ink chamber 51b that stores ink, and an air introduction chamber 51f that takes in air and leads it to the absorber housing chamber 51d. ing.

  The case member 51 is formed by integrally forming both side walls not shown in the drawing, the bottom wall 51g, and the front wall 51h and the rear wall 51k arranged in the front and rear in the depth direction, and between the side walls. The partition wall 51m which comprises the absorber housing | casing chamber 51d with both side walls is formed in the U shape seeing from the side. Appropriate spaces are provided between the partition wall 51m and the front wall 51h, the rear wall 51k, and the bottom wall 51g, and a U-shaped space is formed between the inner surface of the case member 51 and the outer surface of the partition wall 5m. ing. By partitioning this space with a partition wall 51n provided between the bottom wall 51g of the case member 51 and the bottom of the partition wall 51m, an ink chamber 51b on the front wall 51h side and an air introduction chamber 51f on the rear wall 51k side Is configured. A communication hole 51p that connects the absorber housing chamber 51d and the ink chamber 51b is formed at the bottom of the partition wall 51m.

  The bottom wall 51g of the case member 51 is provided with an air communication hole 51q that communicates the outside with the air introduction chamber 51f and an ink supply port 51a that communicates with the ink chamber 51b. The ink supply port 51a is formed by providing a through hole in the bottom wall 51g and recessing the periphery of the through hole in a circular shape on the lower surface of the bottom wall 51g. A filter 51r is attached to the upper surface of the bottom wall 51g so as to cover the ink supply port 51a.

  On the other hand, the lid member 52 is formed with projecting portions 51s and 51t that engage with the absorber housing chamber 51d and the ink chamber 51b, respectively, so that the front wall 51h, the rear wall 51k, and both side walls of the case member 51 are formed. The upper end surface and the upper end surface of the partition wall 51m are fused. The lid member 52 is formed with a communication passage 51u that communicates the air introduction chamber 51f and the absorber housing chamber 51d, and the air in the air introduction chamber 51f can flow into the absorber housing chamber 51d. . The open upper surface of the communication path 51u is sealed with a sealing material 51v.

  Ink chamber 51b stores ink supplied from porous material 51c in absorber housing chamber 51d. When the ink stored in the ink chamber 51b is supplied from the ink supply port 51a through the filter 51r, outside air is taken in from the air communication hole 51q of the bottom wall 51g of the case member 51 and is stored in the absorber housing chamber 51d. While being supplied, the ink of the porous material 51c is supplied into the ink chamber 51b from the communication hole 51p at the bottom of the partition wall 51m.

  In an unused ink cartridge, the amount of ink absorbed by the porous material 51c is smaller than the amount of ink that can be absorbed, so that negative pressure is generated in the ink cartridge 5 and the filter 51r The ink in the ink chamber 51b that is in contact with the filter 51r has a meniscus in the eye so that it does not leak outside through the ink supply port 51a.

  In order to replace such an ink cartridge 5, the pressure lever 6 of the carriage 1 is raised to release the lock, and an empty ink cartridge is taken out. Next, the new ink cartridge 5 is inserted into the head holder 4 with the side where the ink supply port 51 a is provided facing the joint portion 8 side of the head holder 4. Then, the ink supply port 51 a of the ink cartridge 5 is engaged with the recess 13 a of the seal member 13 of the joint portion 8 of the head holder 4. The ink introduction path 11 of the head holder 4 is in a state where ink supplied to the recording head 3 remains.

  At this time, there is a gap between the front end surface of the ink supply port 51a and the bottom surface of the recess 13a of the seal member 13, and the ink supply port 51a and the seal member 13 are not completely in close contact with each other. The airtightness of 14 has not been secured yet.

  Then, the pressure lever 6 is lowered and locked, and the ink cartridge 5 is fixed at the set position. When the pressure lever 6 is gradually lowered when the pressure lever 6 is locked, first, the outer peripheral surface of the ink supply port 51a and the seal member 13 are fixed. The peripheral surface is brought into close contact with the seal (FIG. 3A), and the air tightness of the ink supply path 14 is ensured. At this time, since there is no ink below the filter 51r in the ink supply port 51a, air is trapped between the filter 51r and the bottom surface of the recess 13a of the seal member 13.

  When the pressing lever 6 is further lowered in this state, the seal member 13 is compressed and the air that is being caught cannot escape to the outside. Then, as shown in FIG. 3B, the film-like member 16 of the pressure increasing and absorbing means 15 swells outward, and the pressure in the ink supply path 14 that rises due to the intrusion of air is absorbed, and the pressure in the ink supply path 14 increases. Therefore, the ink meniscus in the nozzles of the recording head 3 is held and ink leakage is prevented.

  The pressure for inflating the film member 16 is set to be, for example, 3 KPa or less, which is smaller than the pressure for destroying the ink meniscus stretched on the filter 51r or the ink meniscus in the nozzle against the surface tension. Accordingly, the entrained air breaks the meniscus of the filter 51r and does not enter the ink chamber 51b, and the film-like member 16 is deformed without ink leaking from the nozzle.

  The air that has entered the ink supply path 14 in this manner, as is known, sucks ink from the nozzles by suction means that is in close contact with the nozzle plate of the recording head, or ejects ink from the nozzles regardless of the recording data. Can be discharged. Along with this, the film-like member 16 swelled outward is restored and prepared for the next replacement of the ink cartridge 5.

  The pressurization absorbing means 15 of the above embodiment is a type that absorbs the pressurization by utilizing the elongation of rubber, but a member having a small elongation, for example, a film such as polyethylene or polypropylene can also be used.

  When using such a film, as shown in FIG. 4A, the film is attached in a slackened state. As a result, the film-like member 16a loosened by the air trapped when the ink supply port 51a of the ink cartridge 5 is connected to the joint portion 8 of the head holder 4 bulges outward as shown in FIG. 4B. The pressure increase in the ink supply path 14 is absorbed.

  Further, the pressure-absorbing absorption means 15 can be provided by constituting a part of the ink supply path 14 with a flexible tube member. For example, as shown in FIG. 5A, the connecting member 10 that connects the tubular portion 8 a of the joint portion 8 and the tubular member 9 in the above embodiment is replaced with a tube member 16 b that is the pressure increase absorbing means 15. The tube member 16b is flexible (see FIG. 5 (b)), for example, rubber, which expands in the radial direction due to the air entrained when the ink supply port 51a of the ink cartridge 5 and the joint portion 8 of the head holder 4 are connected. A material having flexibility such as elasticity is used.

  Further, the pressure increase absorbing means 15 can be provided on the extension member 17 attached to the ink supply port 51 a of the ink cartridge 5 or the joint portion 8 of the head holder 4. For example, as shown in FIG. 6 (a), a cylindrical extension member 17 having the same diameter is connected to the tip of the joint portion 8 by a joint member 18, and the pressure increase absorbing means 15 is connected to the extension member 17 in the same manner as in FIG. Can be provided. That is, the through-hole 17a is formed in the side wall of the extension member 17, and the film-like member 16c is attached to the outer peripheral surface of the side wall so as to cover the through-hole 17a. In this case, the seal member 13 is attached to the distal end portion of the extension member 17.

  Further, as shown in FIG. 6B, a removable extension member 19 is provided in the ink supply port 51a, and the pressure increase absorbing means 15 can be provided on the extension member 19 in the same manner as in FIG.

  The extension member 19 has a cylindrical shape having an ink flow path inside, and one end thereof is fitted into the recess 13 a of the seal member 13 attached to the joint portion 8. The ink supply port 51a has the same shape as the ink supply port 51a, and the other is formed with a recess 19a having the same shape as the seal member 13 so that the ink supply port 51a of the ink cartridge 5 can be fitted. And the through-hole 19b is formed in the side wall of the extension member 19, and the film-like member 16d is attached to the outer peripheral surface of the side wall so that the through-hole 19b may be covered.

  By making the extension member 19 detachable from the ink supply port 51 a of the ink cartridge 5, it is not necessary to provide the extension member 19 for each ink cartridge 5.

FIG. 3 is a cross-sectional view of a head holder mounted on a carriage of the ink jet printer according to the present invention. (A) The A section enlarged view in FIG. (B) The elements on larger scale seen from diagonally upward of the joint part in which the pressure | voltage rise absorption means was provided. FIG. 3 is a partially enlarged view of a joint portion for explaining the operation of the pressure increase absorbing means of FIGS. 1 and 2, and (a) shows a state in the middle of moving an ink cartridge to a set position. (B) A state in which the ink cartridge is fixed at the set position. FIG. 4 is an embodiment of the pressure-absorbing means, (a) a state before the ink cartridge is mounted on the head holder. (B) A state when the ink cartridge is mounted on the head holder. FIG. 4 is an embodiment of the pressure-absorbing means, (a) a state before the ink cartridge is mounted on the head holder. (B) A state when the ink cartridge is mounted on the head holder. FIG. 3 is a cross-sectional view showing an extension member of a joint part, which is an embodiment of the pressure increase absorption means, and (a) the pressure increase absorption means is provided. (B) Sectional drawing which shows the extension member of the ink supply port of an ink cartridge in which the pressure | voltage rise absorption means is provided.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Carriage 3 Recording head 5 Ink cartridge 51b Ink chamber 51a Ink supply port 8 Joint part 8b Through-hole 11 Ink introduction path 15 Pressure | voltage rise absorption means 16 Film-like member

Claims (5)

An ink chamber in the ink cartridge including the ink introduction path by connecting an ink supply port of the ink cartridge and a joint portion communicating with the recording head including a nozzle for ejecting ink through the ink introduction path. In an ink jet printer configured with an ink supply path that communicates with the recording head,
At the connection between the ink supply port of the ink cartridge and the joint portion, the pressure is deformed toward the outside of the ink supply path in response to a pressure increase caused by air intrusion into the ink supply path. boosting absorbing means for suppressing the rise, provided we are in the ink supply path,
The pressure-absorbing absorbing means is a tube member that forms part of the ink supply path, and the tube member swells in the radial direction in response to the pressure increase in the ink supply path. An ink jet printer characterized in that the unit is connected . The inkjet printer according to claim 1, wherein the tube member has elasticity . The ink jet printer according to claim 1 or 2, wherein the boosting absorbing means characterized in that it restored after the post-injection or suction of the ink from the nozzle. The ink introduction path includes a tubular member having one end fixed to an ink introduction port of the recording head, a tubular portion extending from the joint portion, the other end portion of the tubular member, and the tubular portion. It consists of a cylindrical connecting member that connects,
Said tubular member of said boosting absorbing means the ink introduction path, said tubular portion, that any one of claims 1 to 3, characterized in that provided in at least one of the connecting portion and the joint portion the ink jet printer according to. It said ink supply port of the ink cartridge, ink jet printer according to any one of claims 1 to 4, characterized in that it is configured to be connected to the joint portion through a seal member having elasticity .

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