Inkjet printer

Included are a recording medium feeder which feeds a recording medium, a printer which carries out a printing for the fed recording medium by ink discharged from a nozzle surface formed on a print head, and a cleaner (50) which cleans the nozzle surface, wherein the cleaner (50) includes a wiper blade unit (70) which wipes the nozzle surface with a wiper blade (75), and a roller wiper unit (60) which absorbs ink on the nozzle surface by ink absorbers (61b, 62b). The cleaner (50) enables to clean the nozzle surface sufficiently, whereby a good print quality can be maintained.

TECHNICAL FIELD

The present invention relates to an inkjet printer which is equipped with a cleaner.

BACKGROUND ART

It has been essential that an inkjet printer should be equipped with a cleaner which cleans the nozzle surface of a print head for maintaining a good print quality. As a conventional cleaner, as described in Registered Utility Model Publication No. 2543863, there has been a cleaner which wipes a nozzle surface by a plurality of wiper blades placed over a belt.

Patent Literature 1: Registered Utility Model Publication No. 2543863

DISCLOSURE OF THE INVENTION

Problem to be Solved by the Invention

In the cleaning by the wiper blades of such cleaner as mentioned above, however, the nozzle surface of a print head having a minute nozzle diameter cannot be sufficiently cleaned, thereby resulting in a deterioration of a print quality.

Means for Solving the Problem

In order to solve the aforementioned problem, an inkjet printer of the present invention comprises a recording medium feeder which feeds a recording medium, a printer which carries out a printing for the fed recording medium by ink discharged from a nozzle surface formed on a print head, and a cleaner which cleans the nozzle surface, wherein the cleaner includes a wiper blade unit which wipes the nozzle surface with a plurality of wiper blades, and a roller wiper unit which absorbs ink on the nozzle surface by roller members with ink absorbers.

It is preferable that the print head should be movable along a carrier guide which elongates linearly, and that the recording medium feeder and the cleaner should be arranged side by side with each other along a movement direction of the print head.

It is desirable that the roller wiper unit should be placed at a side closer to the recording medium feeder than the wiper blade unit

It is preferable that the roller wiper unit should include a plurality of roller members, and that the plurality of roller members should be placed in such a manner as to allow outer circumferences thereof to be pressure-contacted with one another.

It is preferable that the roller wiper unit should include a first roller member which is so placed as to be able to contact the nozzle surface, and a second roller member placed at a position contacting the first roller member but not contacting the nozzle surface.

It is desirable that the ink absorbers should contain porous materials.

It is preferable that the ink absorbers included in the first roller member and the second roller member should contain porous materials, and that the porous material contained in the ink absorber of the first roller member should be coarser than the porous material contained in the ink absorber of the second roller member.

It is preferable that the roller member should be formed with a gap on the area of the roller member through which a nozzle passes upon contacting the nozzle surface, and it is preferable that the gap should be formed by dividing the roller member along the axial direction thereof, and placing a spacer between divided roller members. The spacer may be detachably placed on the roller member.

It is preferable that the roller member should be able to be driven as the roller member contacts the nozzle surface which moves.

It is preferable that the ink absorbers should be replaceable.

It is preferable that the wiper blade should be so fixed on an endless belt as to face outward, and formed with a recess portion on the area of the wiper blade through which a nozzle passes upon wiping the nozzle surface.

EFFECT OF THE INVENTION

According to the present invention, there is provided an inkjet printer with a cleaner which can sufficiently clean a nozzle surface having a minute nozzle and maintain a good print quality.

EXPLANATION OF REFERENCE NUMBERS

70Wiper Blade Unit

M Recording medium

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment according to the present invention will now be explained with reference accompanying drawings.

As illustrated inFIGS. 1 to 3, an inkjet printer10of the embodiment comprises a recording medium feeder20, a printer30, and a maintenance unit40. In the inkjet printer10, the printer30prints a predetermined character onto a recording medium M supplied from the recording medium feeder20. The maintenance unit40carries out a cleaning for a print head31, a refilling of ink, etc., when the inkjet printer10starts operating, and a user carries out a predetermined control because a print result is poor. At the termination of the inkjet printer10, a nozzle surface34ais capped by a head maintenance apparatus42of the maintenance unit40in order to prevent dryness of a nozzle34b, and the contamination of the nozzle surface34a. As the recording medium M, a film base material, a piece of paper, a cloth or the like can be applied to the present invention.

The recording medium feeder20includes two sheets of bottom boards21,22which are in parallel with each other, and face each other in the X-direction (print head movement direction) inFIGS. 1 to 3, aluminum-made rollers23,24,25, both ends of shafts23a,24a,25athereof respectively fixed to bottom boards21,22, and a platen26in a roller shape, ends of a shaft26athereof fixed to the respective bottom boards21,22, in the same way.

The rollers23,24,25have cylindrical rotation sections23b,24b,25bslidably and rotatably placed on outer circumferences of the shafts23a,24a,25a, respectively, and the platen26has a cylindrical rotation section26bslidably and rotatably placed on an outer circumference of the shaft26a. As illustrated inFIG. 3, the rollers23,24,25, and the platen26are arranged in the order of the roller23, the platen26, the roller24, and the roller25from their upstream sides in a recording-medium-feed-direction (Y-direction), and in the Z-direction (height direction, up-and-down direction), the roller23and the roller25are arranged at the same height, the roller24is placed on a position higher than the roller23and the roller25, and the platen26is placed on a position higher than the roller24. When the recording medium M is rolled up by the rollers23,24,25, and the platen26arranged thus way, and the roller25is rotated around the shaft25ain the arrow A direction (FIG. 3) by a predetermined angle, the roller24, the platen26and the roller23can be driven to the arrows B, C, and D directions, respectively, and a predetermined tension is applied to the recording medium M along the Y-direction. When the roller25is further rotated, the recording medium M moves through directions represented by the arrows E and F, and fed to the Y-direction.

As illustrated inFIGS. 1 to 3, the printer30includes the print head31, a print head carrier32which detachably holds the print head31, and a carrier guide33. The carrier guide33is a member which is formed in an approximately rectangular shape elongating in the X-direction, and both ends thereof are fixed to the bottom board21and a support plate44by welding, through an aperture22aof the bottom board22.

As illustrated inFIGS. 1 to 4, the print head31is an inkjet print head, wherein a head body34, an ink channel (not illustrated) and an ink tank (not illustrated) are accommodated in a case31aformed in an approximately rectangular shape. As illustrated inFIG. 4, the nozzle surface34awhich is the bottom surface of the head body34is fitted into and engaged with an opening31cformed in the center of a bottom surface31bof the approximately rectangular case31a, and the nozzle surface34adownward protrudes from the bottom surface31b. The nozzle surface34a, formed in an approximately rectangular shape and water-repellent-finished, is formed with a plurality of nozzles34bfor ink injection in a line along the longitudinal direction of the nozzle surface34aat predetermined intervals.

The print head31detachably attached to the print head carrier32in such a manner as to allow the nozzle surface34ato face downward, and the print head carrier32is movable along a guide rail33awhich is formed on the upper surface of the carrier guide33.

Below the nozzle surface34aof the print head31, attached to the print head carrier32, the platen26is placed along the movement direction (X-direction) of the print head31. When ink is downward injected from the predetermined nozzles34bof the nozzle surface34aby a driving apparatus (not illustrated), a predetermined print is carried out onto the recording medium M sliding the upward of the cylindrical rotation section26b. The print head31of the embodiment is a print head which carries out a printing at a predetermined position of the carrier guide33when placed at the predetermined position, but the present invention is applicable to one type of an inkjet printer that the print head31carries out a printing while moving in the X-direction.

As illustrated inFIGS. 1 and 2, the maintenance unit40includes a head maintenance apparatus42and a cleaner50. The head maintenance apparatus42and the cleaner50are aligned each other along the X-direction, and fixed to a base plate43which has one end face vertically fixed to a lateral surface of the bottom board22, and elongates in the X-direction, and the support plate44is fixed to the other end face of the base plate43in such a manner as to be parallel to the bottom boards21,22.

The head maintenance apparatus42includes a suction opening42a, made of hollow rubber with its upper portion opened, in the upper surface thereof. The inside of the suction opening42ais vacuumed by a pump (not illustrated) provided in a main body unit42bof the head maintenance apparatus42, thereby negatively pressurized. By pressing the suction opening42aagainst the nozzle surface34a, it is possible to vacuum and remove a contaminant and vacuum excessive ink, on the nozzle surface34a.

The cleaner50will now be explained with reference toFIGS. 5 to 11. The cleaner50includes a main body unit51, a roller wiper unit (ink absorbing unit)60, and a wiper blade unit70. The cleaner50arranges the roller wiper unit70and the wiper unit60, in sequential order from the recording medium feeder20side, at a halfway position in which the print head31, positioned upward of the recording medium feeder20, is moving toward the head maintenance apparatus42, and excessive ink on the nozzle surface34acan be absorbed and wiped by just passing the print head31through the shove of cleaner50.

As illustrated inFIGS. 5 to 7, the roller wiper unit60comprises the same shaped two of roller member61(first roller member) and roller member62(second roller member) with shafts61a,62athereof arranged in the Z-direction. The shafts61a,62aformed by molding plastic material. The roller members61,62respectively have urethane-made cylindrical ink absorbers61b,62bwhich are rotatable while sliding around the shafts61a,62a. One ends of the shafts61a,62aare fixed to a backing plate52of the main body unit51, and the other ends thereof are fixed to cylindrical members61c,62c, and the ink absorbers61b,62bare retained by the cylindrical members61c,62c, respectively. The arrangement interval of the shaft61aand the shaft62ais set as to be smaller than the sum of the radius of the ink absorber61band that of the ink absorber62b. Accordingly, the ink absorber61band the ink absorber62bare pressure-contacted with each other, and contacted in deformed conditions by their elasticity. Meanwhile, the roller members61,62may not be formed in the same shape, and for instance, when the roller member62, having a larger external diameter than the roller member61, is adopted, much ink can be held in the roller member62. The shaft61aand the shaft62amay not be arranged in the Z-direction as long as the roller members61,62contact each other and the shaft61ais placed at a higher position than the shaft62ain the Z-direction. The number of roller members to be placed may be more than or equal to three. The ink absorbers61b,62bmay be made of material other than urethane, as long as it is porous material. The ink absorbers61b,62bmay be structured such that predetermined areas, from their outer circumferences in their radial directions, are made of porous material, and the other portions are made of material other than porous material.

Both ink absorber61band ink absorber62bare respectively separated into a first ink absorber61b1, second ink absorber61b2and first ink absorber62b1, second ink absorber62b2, at the centers of their axial directions. Plastic-made circular spacers61d,62dare placed between the first ink absorber61b1and the second ink absorber61b2, and the first ink absorber62b1and the second ink absorber62b2, respectively. The spacers61d,62dare formed by molding plastic material. The spacers61d,62dare formed in the same external shape, and concentrically fixed to the shafts61a,62a, respectively, in bonded manners. The movements of the second ink absorbers61b2,62b2toward the directions of shafts61a,62aare limited by the spacers61d,62d, and a gap of minimum clearance L1is formed between the first ink absorber61b1and the second ink absorber61b2, and a gap of minimum clearance L2(L1=L2) is formed between the first ink absorber62b1and the second ink absorber62b2. When the cylindrical members61c,62care so arranged as to contact the first ink absorber61b1and the first ink absorber62b1, respectively, the movements of the first ink absorber61b1and the first ink absorber62b1toward the shafts61a,62aare limited. Accordingly, the clearances between the first ink absorber61b1and the second ink absorber61b2, and between the first ink absorber62b1and the second ink absorber62b2can be held in constant values (L1, L2). Meanwhile, the spacers61d,62dmay be an integral member of the respective shafts61a,62aformed by molding.

In a halfway in which the print head31moves to the head maintenance apparatus42along the carrier guide33for maintenance, and moves to the above of the recording medium feeder20after the maintenance for printing, the nozzle surface34amoves toward a predetermined direction while pressure-contacting the ink absorber61b. The ink absorber61b, pressure-contacted by the moving nozzle surface34a, is driven and rotated, and in accordance with this, the ink absorber62bis driven and rotated. The spacer61dis so arranged as to be placed at a path through which the nozzle34bpasses when the nozzle surface34aand the ink absorber61bare pressure-contacted (refer toFIG. 11). L1is set as larger than the nozzle34bby a predetermined magnitude. Accordingly, when the nozzle surface34amoves while pressure-contacting the ink absorber61b, the ink absorber61bdoes not contact the lined nozzles34band an area with a predetermined width from that line. Therefore, it is possible to prevent that a contaminant is mixed into the nozzle34band the nozzle34bis scratched, by preventing the ink absorber61bfrom no directly pressure-contacting the nozzle34b, and excessive ink on a portion, away from the nozzle34b, of the nozzle surface34acan be absorbed. As the ink absorber61bis formed in a rotatable roller shape, a portion of the ink absorber61b, which is to contact the nozzle surface34ain turn, is a different portion from a portion used for the previous absorbing of ink and thus it is possible to absorb ink smoothly. Likewise, as the ink absorber62bis formed in a rotatable roller shape, a portion of the ink absorber62b, which is to contact the ink absorber61bin turn after the absorbing of ink is a different portion from a portion used for the previous absorbing of ink, and thus it is possible to absorb and hold ink smoothly.

The ink absorber61band the ink absorber62bare made of porous urethane material, but sizes of pores of the ink absorber61bare larger than those of the ink absorber62b. That is, the ink absorber61bhas more rough porosity than the ink absorber62b. Accordingly, the ink absorber61bhaving larger pores is likely to absorb excessive ink from the nozzle surface34a, the ink absorbed by the ink absorber61bis transferred to the ink absorber62b, and the ink absorber62bis likely to hold ink as their pores are small. The ink absorbers61b,62bcan be replaced by, for instance, removing the cylindrical members61c,62cand pulling out from the shafts61a,62a, after absorbing a predetermined amount. Of course, it is possible to replace either one of the ink absorbers61b,62b.

As illustrated inFIGS. 5,6and8, the wiper blade unit70includes ad rive roller71, a dependent drive roller72, a rubber-made endless belt73which is rolled up to the outer circumferences of the drive roller71and the dependent drive roller72, a motor74for rotary driving the drive roller71and a plurality of scrapers (wiper blades)75, which are so arranged on the endless belt73at predetermined intervals as to face outward. The drive roller71and the dependent drive roller72are arranged in the X-direction with shafts71a,72a, rotatably supported by the backing plate52and a front plate53, be in the Y-direction. The plurality of scrapers75are tabular members made from approximately rectangular rubbers, one edges thereof are fixed to the endless belt73via fixtures76, and they are arranged at predetermined intervals one another. Each of the plurality of scrapers75is fixed to the endless belt73in a perpendicular manner. When a force is supplied to the drive roller71from the motor74, the drive roller71rotates around the shaft71a, and thus the endless belt73rolled up the drive roller71starts moving, and the dependent drive roller71starts driving and rotating.

As illustrated inFIG. 8, among four edges of the scraper75, the center of an edge75a, farthest from the endless belt73, is provided with a recess portion75bwhich concaves toward the endless belt73with a predetermined width L3. In a halfway in which the printhead31moves to the head maintenance apparatus42along the carrier guide33for maintenance, and moves to the above of the recording medium feeder20after the maintenance for printing, the nozzle surface34amoves toward the predetermined direction while rubbed by the plurality of moving edges75ain a slide manner or pressed against them. The recess portion75bis so arranged as to be placed at the path through which the nozzle34bpasses when the nozzle surface34ais rubbed by the edge75ain a slide manner (refer toFIG. 11). L3is set as larger than the nozzle34bby a predetermined magnitude. Accordingly, when the nozzle surface34amoves while rubbed by the edge75ain a slide manner, the edge75adoes not contact the lined nozzles34band an area with a predetermined width from that line. Therefore, it is possible to prevent that a contaminant is mixed into the nozzle34band the nozzle34bis scratched, by allowing the edge75ato pressure-contact it, and excessive ink on a portion, away from the nozzle34b, of the nozzle surface34acan be absorbed.

As explained above, the cleaner50is provided with the roller wiper unit60and the wiper blade unit70, whereby excessive ink and a contaminant on the nozzle surface34acan be absorbed by the roller member61and wiped by the scraper75, and the nozzle surface34acan be in a clean condition. As the roller wiper unit60is arranged closer to the recording medium feeder20than the wiper blade unit70, even if excessive ink and a contaminant remain on the nozzle surface34aafter the maintenance at the head maintenance apparatus42and the scraping of excessive ink and a contaminant at the wiper blade unit70, the roller member61can absorb them. Therefore, the print head31can be sent to the recording medium feeder20with the nozzle surface34acleaned, and a high print quality can be realize.

In the inkjet printer10structured thus way, when a printing start signal is transmitted to the print head31from a control circuit (not illustrated), the print head carrier32moves toward the X-direction along the carrier guide33and stops at a predetermined print position. A detection of the position of the print head carrier32is carried out by a well-known optical detection apparatus (not illustrated).

Next, a printing is carried out for the recording medium M, moved the below of the print head31by the recording medium feeder20, by ink discharged from the print head31.

When the print quality is poor and the maintenance is required for the print head31, the user allows the print head32, holding the print head31, to move toward the X-direction along the carrier guide33by carrying out a predetermined operation, and the maintenance such as the vacuuming of a contaminant on the nozzle surface34aand the refilling of ink is carried out at the head maintenance apparatus42. After the maintenance is finished and the printing is to restart the pint head carrier32is returned to the above of the recording medium feeder20again. When the print head carrier32is moved to the head maintenance apparatus42from the above of the recording medium feeder20this way, as illustrated inFIGS. 9 and 10, the nozzle surface34afirst pressure-contacts the roller member61(FIG. 9), and then rubbed by the scraper75in a slide manner (FIG. 10). When the print head carrier32is moved to the recording medium feeder20from the maintenance apparatus42, it is first rubbed by the scraper75in a slide manner and then pressure-contacted with the roller member61.

As the spacer61dis placed between the first ink absorber61b1and the second ink absorber61b2, when the ink absorber61bare pressure-contacted with the nozzle surface34a, the first ink absorber61b1and the second ink absorber61b2contact the nozzle surface34aat outer areas36,37of a nozzle-neighborhood area35(FIG. 11) including the nozzles34band having a predetermined width, but the ink absorber61bdoes not contact the nozzle-neighborhood area35. As the recess portion75bis placed at the center of the edge75a, when the scraper75is pressure-contacted with the nozzle surface34a, the edge75acontacts the nozzle surface34aat the outer areas36,37of the nozzle-neighborhood area35(FIG. 11) including the nozzles34band having the predetermined width, but the edge75adoes not contact the nozzle-neighborhood area35. Accordingly, excessive ink on the outer areas36,37, away from the nozzle34bat predetermined distances, can be scraped by the scraper75or absorbed by the ink absorber61b, and a contaminant on the outer areas36,37can be scraped by the scraper75. In contrast, ink on the nozzle-neighborhood area35is pulled back to the inside of the nozzle34bby the water-repellent finish applied to the nozzle surface34aand the interfacial force of ink, or it flows into the outer regions36,37, scraped by the scraper75or absorbed by the ink absorber61b.

The present invention is explained with reference to the aforementioned embodiment, but the present invention is not limited to the aforementioned embodiment and can be improved or modified for the purpose of the improvement or within the scope of the present invention. For instance, in the aforementioned embodiment, an example that the spacers61d,62dare fixed to, in bonded manners, or integrally formed with the shafts61a,62a, but the spacers61d,62dmay be detachably attached to the shafts61a,62aby, for instance, screwing. For instance, the spacers61d,62dmay be formed in shapes like screw nuts, and the shafts61a,62amay be formed with threads. The spacers61d,62dare detachable from the shafts61a,62athus way, whereby the replacements of the second ink absorber61b2,62b2, which position at the backs of the spacers61d,62din viewing from the cylindrical members61c62csides, become easy.

Threads of the shafts61a,62amay be formed on predetermined regions which include adjustment regions for the attachment positions of the spacers61d,62d. When the attachment position of the spacer61dis adjustable, the spacer61dis placed so that it can precisely position on the path through which the nozzle34dpasses.

The cylindrical members61c,62cmay be detachably attached to the shafts61a,62ain screwing manners. For instance, the cylindrical members61c,62cmay be formed in shapes like screw nuts, and the shafts61a,62amay be formed with threads. When the cylindrical members61c,62care detachable, the replacements of the ink absorbers61b,62bbecome easy.

The present invention is based on Japanese Patent Application No. 2003-356125 filed on Oct. 16, 2003. The specification, claims and drawings of the Japanese Application are hereby entirely incorporated in the present specification by reference.

INDUSTRIAL APPLICABILITY

The present invention can also be adapted to an inkjet printer which has a nozzle surface with a minute nozzle diameter.