Processing liquid applying apparatus and image-forming apparatus

A processing liquid applying apparatus includes a processing liquid transfer roller which transfers a processing liquid to a transfer medium while rotating in a predetermined direction; a processing liquid applying section which applies the processing liquid to a surface of the processing liquid transfer roller; a downstream wall which is positioned on a downstream side in a rotating direction of the processing liquid transfer roller with respect to the processing liquid applying section; and a downstream wall moving mechanism which moves the downstream wall between a downstream wall first position at which the downstream wall is positioned when the processing liquid is transferred to the transfer medium and a downstream wall second position at which the downstream wall is positioned when the surface of the processing liquid transfer roller is washed with the processing liquid.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese Patent Application No. 2009-045832, filed on Feb. 27, 2009, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a processing liquid applying apparatus which applies a processing liquid to a surface of a processing liquid transfer roller and transfers the processing liquid to a transfer medium (for example, printing paper and recording sheet), and an image-forming apparatus provided with the processing liquid applying apparatus.

2. Description of the Related Art

For example, in an image-forming apparatus (for example, printer and facsimile) based on the “ink-jet system”, the inks, which are discharged from the nozzles, are adhered or deposited onto the surface of the printing paper. In this situation, the inks are not preferably deposited onto the printing paper depending on the type of the inks or the printing paper, and the image is blurred and/or the color development is deteriorated in some cases. Accordingly, in the case of a conventional technique, as disclosed in Japanese Patent Application Laid-open No. 2006-346534 (FIG. 12), the blurring of the image is avoided, and the deterioration of the color development performance is avoided by previously applying a processing liquid to the surface of the printing paper.

A liquid applying apparatus disclosed in Japanese Patent Application Laid-open No. 2006-346534 includes an applying roller which applies a processing liquid to a sheet member while rotating in a predetermined direction, and a liquid applying section which applies the processing liquid to the surface of the applying roller. The liquid applying section includes a space-forming member which forms a hermetically closed space with respect to the applying roller, an annular abutting member which seals the circumferential edge portion of the hermetically closed space, and a pressing member (spring) which supports the space-forming member and the abutting member and which presses them toward the applying roller. The processing liquid is supplied into the hermetically closed space, the applying roller is rotated, and thus the processing liquid is applied to the surface of the applying roller which constitutes a part of the hermetically closed space.

According to the conventional technique described above, a mechanism, which applies the processing liquid to the surface of the applying roller, can be easily constructed. However, the space-forming member and the abutting member are merely supported by the pressing member (spring). Therefore, the spacing distance between the abutting member and the applying roller cannot be maintained to be constant and/or the spacing distance cannot be appropriately changed. It is impossible to optionally and preferably adjust the applying amount of the processing liquid with respect to the applying roller.

For example, when the applying amount of the processing liquid is excessively increased in the “transfer mode” in which the processing liquid is transferred from the applying roller to the sheet member, it is feared that a long period of time may be required to dry the processing liquid transferred to the sheet member and/or the processing liquid, which remains on the surface of the applying roller, may inhibit the next transfer process. Therefore, it is necessary that the applying amount of the processing liquid should be stabilized to an appropriate amount. In the case of the conventional technique described above, the abutting member is moved in the tangential direction of the applying roller in accordance with the rotation of the applying roller, and the spacing distance, which is provided between the applying roller and the portion of the abutting member positioned on the downstream side in the direction of rotation of the applying roller, is undesirably widened. Therefore, a tendency arises such that the applying amount of the processing liquid is not only stabilized, but the applying amount is also increased undesirably. On the other hand, in the “cleaning mode” in which the applying roller is cleaned, it is desirable that the applying amount of the processing liquid applied to the applying roller is “relatively large” in order to wash out the foreign matter (paper dust or the like) adhered to the applying roller. In the case of the conventional technique described above, it is impossible to appropriately change the spacing distance between the abutting member and the applying roller. Therefore, it is impossible to intentionally increase the applying amount of the processing liquid in the “cleaning mode”, and it is impossible to obtain any sufficient cleaning effect.

SUMMARY OF THE INVENTION

The present invention has been made in order to solve the problem as described above, an object of which is to provide a processing liquid applying apparatus and an image-forming apparatus provided with the processing liquid applying apparatus which make it possible to preferably adjust the applying amount of a processing liquid with respect to a processing liquid transfer roller in the “transfer mode” and the “cleaning mode” respectively.

According to a first aspect of the present invention, there is provided a processing liquid applying apparatus which applies a processing liquid to a transfer medium, including: a processing liquid transfer roller which transfers the processing liquid to the transfer medium while rotating in a predetermined direction; a processing liquid applying section which makes a contact with a surface of the processing liquid transfer roller to apply the processing liquid to the surface of the processing liquid transfer roller; a downstream wall which is positioned on a downstream side in a rotating direction of the processing liquid transfer roller with respect to a contact point at which the surface of the processing liquid transfer roller makes a contact with the processing liquid in the processing liquid applying section; and a downstream wall moving mechanism which moves the downstream wall, in a tangential direction at the contact point of the processing liquid applying section and the processing liquid transfer roller, between a downstream wall first position at which the downstream wall is positioned while the processing liquid transfer roller is transferring the processing liquid to the transfer medium and a downstream wall second position at which the downstream wall is positioned while the surface of the processing liquid transfer roller is being washed with the processing liquid, wherein a distance between the downstream wall positioned at the downstream wall second position and the processing liquid transfer roller, is greater than a distance between the downstream wall positioned at the downstream wall first position and the processing liquid transfer roller.

In this arrangement, the distance between the downstream wall and the processing liquid transfer roller, which is provided when the downstream wall is positioned at the downstream wall second position, is greater than that provided when the downstream wall is positioned at the downstream wall first position. Therefore, the applying amount of the processing liquid to be applied to the surface of the processing liquid transfer roller is increased when the downstream wall is positioned at the downstream wall second position as compared with when the downstream wall is positioned at the downstream wall first position.

The present teaching is constructed as explained above. The applying amount of the processing liquid, with which the processing liquid transfer roller is applied, can be preferably adjusted in each of the “transfer mode” and the “cleaning mode”. In other words, in the “transfer mode” in which the processing liquid is transferred to the transfer medium, the applying amount of the processing liquid with respect to the processing liquid transfer roller can be adjusted to be “relatively small”, for example, in order to quicken the drying of the processing liquid transferred to the transfer medium. On the other hand, in the “cleaning mode” in which the surface of the processing liquid transfer roller is washed, the applying amount of the processing liquid with respect to the processing liquid transfer roller can be adjusted to be “relatively large” in order to wash out the foreign matter (for example, paper dust or paper powder) adhered to the processing liquid transfer roller.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An “image-forming apparatus” according to a preferred embodiment of the present invention will be explained below with reference to the drawings. A “processing liquid applying apparatus” according to a preferred embodiment of the present invention will be referred to as a constitutive part of the “image-forming apparatus” in the description of the “image-forming apparatus”.

First Embodiment

Overall Arrangement of Image-Forming Apparatus

An image-forming apparatus10includes a casing14, a paper feed cassette16, a liquid discharge apparatus18, a transport apparatus20, a processing liquid applying apparatus22, a detecting unit24, and a control unit26, and a processing liquid R (FIG. 4) is applied to the printing paper12as the “transfer medium” or the medium subjected to the transfer, and then the inks as the “liquids” are discharged to the surface of the printing paper12to form an image.

The casing14is a box-shaped member which accommodates the constitutive parts as described above. An opening14athrough which the paper feed cassette16is taken in and out and a printing paper discharge port14bthrough which the printing paper12is discharged are formed on the side surface of the casing14. A paper discharge tray28, which receives the printing paper12discharged from the printing paper discharge port14b, is attached under or below the printing paper discharge port14b.

The paper feed cassette16is a container or vessel which collectively accommodates a plurality of sheets of the printing paper12. A pickup roller30for taking out the printing paper12is arranged over or above the paper feed cassette16.

The liquid discharge apparatus18has an ink discharge head18abased on the “ink-jet system” having a plurality of discharge nozzles. A platen18b, which supports the printing paper12, is arranged at a position opposed to the plurality of discharge nozzles. The ink discharge head18ahas a driving unit (for example, an actuator) which applies the discharge pressure to the ink based on the driving signal given from the control unit26. The ink, to which the discharge pressure is applied, is discharged from the nozzles to the printing paper12. The recording system of the liquid discharge apparatus18is not limited to the “ink-jet system”. The type of the ink is not specifically limited as well. However, the “ink-jet system” is adopted in this embodiment. Therefore, in order to avoid the nozzle clog-up caused by the drying of the ink, the ink, which is obtained by mixing a water-soluble high boiling point solvent (for example, glycol) and a soluble color material with water as the main component, is used. Therefore, the fixation performance of the ink with respect to the printing paper12is not sufficient. In the processing liquid applying apparatus22described later on, a processing liquid R, which is capable of enhancing the fixing of the ink, is applied to the printing paper12.

The transport apparatus20includes transport rollers32which feed the printing paper12taken out by the pickup roller30to the liquid discharge apparatus18via the detecting unit24and the processing liquid applying apparatus22, holding rollers34which hold the printing paper12fed to the processing liquid applying apparatus22, and paper discharge rollers36which discharge the printing paper12formed with the image by the liquid discharge apparatus18from the printing paper discharge port14bto a paper discharge tray28. In this embodiment, a substantially C-shaped transport route M is constructed by the transport apparatus20.

The processing liquid applying apparatus22applies the processing liquid R (FIG. 4) to the printing paper12on the upstream side in the transport direction of the printing paper12with respect to the liquid discharge apparatus18. The present invention has the feature of the arrangement of the processing liquid applying apparatus22. Therefore, the concerning arrangement will be explained in detail later on. In this embodiment, the processing liquid applying apparatus22is arranged in the middle of the transport route M for transporting the printing paper12. Therefore, in the description provided later on, the direction, in which the printing paper12is transported, is referred to as “transport direction X”, and the direction, which is perpendicular to the “transport direction X” is referred to as “printing paper widthwise direction Y”.

The detecting unit24is arranged on the upstream side in the transport direction of the printing paper12with respect to the processing liquid applying apparatus22. The detecting unit24detects the type (for example, thickness, surface smoothness, and hardness) of the printing paper12. The detection result of the detecting unit24is fed to the control unit26.

The control unit26include a central processing unit (CPU) which executes various types of calculation processes, and storage devices (ROM, RAM) which store various types of data and programs. The control unit26controls the operations of, for example, the liquid discharge apparatus18, the transport apparatus20, the processing liquid applying apparatus22, and a stopper driving apparatus96(FIG. 4) described later on. Specified control operation of the control unit26will be explained together with the explanation of the operation of the image-forming apparatus10described later on.

Overall Arrangement of Processing Liquid Applying Apparatus

In this embodiment, the ink, which contains the water-soluble high boiling point solvent (for example, glycol) and the soluble color material, is used as described above. Therefore, it is feared that the high quality is not obtained due to, for example, the blurring of the ink, when the ink is discharged to the unprocessed or untreated printing paper12. Accordingly, in this embodiment, the processing liquid R, which makes it possible to enhance the fixation performance of the ink, is previously applied to the printing paper12by using the processing liquid applying apparatus22. The type of the processing liquid R can be appropriately changed depending on, for example, the type of the printing paper12, the type of the ink, or the purpose of the processing. For example, a liquid containing multivalent metal salt, a cationic surfactant, or a cationic polymer material, which agglutinate or react the color material contained in the ink and which are capable of increasing density or waterproofness of the ink as well as enhancing fixing of the ink, are usable as the processing liquid R. Further, the processing liquid R may contain fine particles such as silica particles, alumina particles, or resin emulsion. In order to perform high-speed printing, a liquid containing organic solvent or surfactant which enhance permeability of the ink is usable as the processing liquid. A liquid to keep the printing paper from curling (especially, a curl occurring immediately after the printing) may be used as the processing liquid R. In order to improve the brightness or whiteness of the printing paper12, a “liquid containing a fluorescent whitener” may be used as the processing liquid R.

As shown inFIG. 1, the processing liquid applying apparatus22includes a processing liquid transfer roller42which transfers the processing liquid R (FIG. 4) to the printing paper12as the “transfer medium” while rotating in the predetermined direction, an applying member44which applies the processing liquid R to the surface of the processing liquid transfer roller42, a support member46which supports the processing liquid transfer roller42and the applying member44, and a processing liquid supply apparatus48which supplies the processing liquid R to the applying member44.

Arrangement of Processing Liquid Transfer Roller

As shown inFIGS. 3 and 4, the processing liquid transfer roller42has a roller body50which has the surface to be coated with the processing liquid R (FIG. 4), and a core member52which is arranged at the central portion of the roller body50. Both end portions of the core member52in the longitudinal direction protrude from both end portions of the roller body50in the longitudinal direction. The roller body50is a substantially columnar member composed of a material (for example, epichlorohydrin rubber) which has a high affinity for the processing liquid R and which has a low affinity for the foreign matter Q (FIG. 4) such as the paper dust or the like. The length of the roller body50is designed to be sufficiently longer than the width of the printing paper12so that the processing liquid R can be transferred to the entire surface of the printing paper12. The core member52is a substantially columnar member composed of a high strength material (for example, stainless steel) which is capable of reinforcing the roller body50. The length of the core member52is designed to be sufficiently longer than the length of the roller body50so that a rotary shaft52acan be constructed at each of the both ends of the roller body50. The processing liquid transfer roller42is arranged so that the processing liquid transfer roller42extends in the printing paper widthwise direction Y and the processing liquid transfer roller42is brought in contact with the surface of the printing paper12between the two holding rollers34in the transport route M.

A rotary driving unit (not shown), which includes a motor and a gear unit, is connected to the rotary shaft52aof the core member52disposed on one side. The direction of rotation of the processing liquid transfer roller42(hereinafter simply referred to as “rotating direction”), which is brought about by the rotary driving unit, is not specifically limited. However, in this embodiment, as shown inFIG. 4, the rotating direction is designed so that the processing liquid R can be transferred to the printing paper12from the upstream side in the transport direction X. In other words, the applying member44described later on applies the processing liquid R to the lowermost portion of the processing liquid transfer roller42in the vertical direction. Starting from this state, the processing liquid transfer roller42is rotated by 180 degrees in the rotating direction, and thus the portion, to which the processing liquid R has been applied, arrives at the uppermost position of the processing liquid transfer roller42in the vertical direction. The processing liquid R is transferred to the printing paper12transported in the transport direction X. After the processing liquid R is transferred to the printing paper12, the processing liquid transfer roller42is further rotated by 180 degrees in the rotating direction. Accordingly, the processing liquid R is applied to the concerning portion by the applying member44again. In this way, the processing liquid transfer roller42repeats the rotation in the rotating direction. Accordingly, the application of the processing liquid R to the processing liquid transfer roller42and the transfer of the processing liquid R from the processing liquid transfer roller42to the printing paper12are continuously performed. In the following description, the “upstream side in the rotating direction” refers to the side on which the surface of the processing liquid transfer roller42exists before the processing liquid R is applied, and the “downstream side in the rotating direction” refers to the side on which the surface of the processing liquid transfer roller42exists after the processing liquid R is applied, based on the lowermost position of the processing liquid transfer roller42in the vertical direction.

Arrangement of Applying Member

As shown inFIGS. 4,5, and6, the applying member44has a processing liquid accommodating cap54which accommodates the processing liquid R (FIG. 4), and a cap holder56which holds the processing liquid accommodating cap54.

The processing liquid accommodating cap54is a groove-shaped member which has an opening80disposed on the upper surface and which applies the processing liquid R to the surface of the processing liquid transfer roller42under or below the processing liquid transfer roller42. As shown inFIGS. 3 and 4, the processing liquid accommodating cap54includes a plate-shaped bottom plate section58which is substantially rectangular as viewed in a plan view and which extends in the printing paper widthwise direction Y, a downstream wall60which is formed to protrude upwardly from the end edge disposed on the downstream side in the rotating direction on the upper surface of the bottom plate section58, an upstream wall62which is formed to protrude upwardly from the end edge disposed on the upstream side in the rotating direction on the upper surface of the bottom plate section58, and side walls64(FIG. 3) which are formed to protrude upwardly from the both end edges in the printing paper widthwise direction Y on the upper surface of the bottom plate section58. As described later on, the downstream wall60functions as the “applying amount-adjusting member” to adjust the applying amount of the processing liquid R with respect to the processing liquid transfer roller42, and the upstream wall62functions as the “cleaning member” which scrapes the foreign matter Q and the remaining processing liquid R off the surface of the processing liquid transfer roller42. The frictional force, which is generated between the upstream wall62and the processing liquid transfer roller42, is designed to be greater than the frictional force which is generated between the processing liquid applying roller42and the foreign matter Q. Accordingly, the foreign matter Q, which is adhered to the surface of the processing liquid transfer roller42, can be effectively scraped off by the upstream wall62which functions as the “cleaning member”.

As shown inFIG. 5, grooves62a, which guide the processing liquid R and the foreign matter Q scraped off from the surface of the processing liquid transfer roller42by means of the upstream wall62(FIG. 4) as the “cleaning member” to the processing liquid recovery section S as described later on, are formed on the surface (i.e., the outer side surface) positioned on the upstream side in the rotating direction in relation to the upstream wall62. Further, the water-attracting treatment is applied thereto in order to easily guide the processing liquid R and the foreign matter Q to the processing liquid recovery section S. The material of the processing liquid accommodating cap54is not specifically limited. However, in this embodiment, an elastic material, which includes, for example, rubber or elastomer, is used in order to prevent the surface of the processing liquid transfer roller42from being scratched or damaged.

The cap holder56is a container or vessel which holds the processing liquid accommodating cap54under or below the processing liquid transfer roller42and which recovers the processing liquid R and the foreign matter Q scraped off from the processing liquid transfer roller42. As shown inFIGS. 3 and 4, the cap holder56has a plate-shaped bottom plate section70which is substantially rectangular as viewed in a plan view and which extends in the printing paper widthwise direction Y, and a circumferential wall72which is formed to protrude upwardly from the circumferential edge portion of the upper surface of the bottom plate section70. The outer side surface of the circumferential wall72, which is disposed on the downstream side in the rotating direction, is a fastening surface72ato be fastened by transfer mode stoppers86or cleaning mode stoppers90as described later on. Projections74, which regulate the movement of the cap holder56in the tangential direction of the processing liquid transfer roller42in accordance with the rotation of the processing liquid transfer roller42, are formed to protrude in the printing paper widthwise direction Y on the both outer side surfaces of the circumferential wall72in the printing paper widthwise direction Y. Further, as shown inFIG. 4, a projection76, which regulates the movement of the processing liquid accommodating cap54fixed to the upper surface, is formed at a central portion in the widthwise direction of the upper surface of the bottom plate section70. The side surface of the projection76, which is disposed on the upstream side in the rotating direction, is formed as such an inclined surface that upper portions thereof are more inclined toward the downstream side. In this embodiment, a hard material such as hard plastic or the like is used for the cap holder56so that the processing liquid accommodating cap54can be reliably held. However, the material of the cap holder56is not limited thereto. An absorbing member (not shown), which holds or retains the processing liquid R and the foreign matter Q scraped off by the upstream wall62, may be arranged in the cap holder56.

The processing liquid accommodating cap54is joined (for example, adhered) to the upper surface of the bottom plate section70positioned on the downstream side in the rotating direction with respect to the projection76. Through-holes78(FIG. 3), which continuously penetrate through these components, are formed through the bottom plate section58of the processing liquid accommodating cap54and the bottom plate section70of the cap holder56. As shown inFIG. 4, the opening80of the processing liquid accommodating cap54is arranged under or below the processing liquid transfer roller42in a state in which the processing liquid accommodating cap54is joined to the cap holder56. The lowest point of the processing liquid transfer roller42is positioned within the width of the opening80. The opening80is covered with the surface of the lower portion of the processing liquid transfer roller42. The processing liquid R, which is fed from the processing liquid supply apparatus48(FIG. 1), is supplied from the through-hole78into the processing liquid accommodating cap54. The processing liquid R is retained in the processing liquid accommodating cap54. In this state, the open end of the cap holder56is positioned at a position lower than the upper end of the opening80. Accordingly, the processing liquid accommodating cap54is reliably brought in contact with the surface of the processing liquid transfer roller42.

Therefore, in this embodiment, the processing liquid R accommodated in the processing liquid accommodating cap54corresponds to the “processing liquid applying section” which applies the processing liquid R to the surface of the processing liquid transfer roller42. The downstream wall60of the processing liquid accommodating cap54corresponds to the “downstream wall” which is positioned on the downstream side in the rotating direction with respect to the “contact point at which the processing liquid transfer roller makes a contact with the processing liquid in the processing liquid applying section”. The upstream wall62of the processing liquid accommodating cap54corresponds to the “upstream wall” which is positioned on the upstream side in the rotating direction with respect to the “contact point at which the processing liquid transfer roller makes a contact with the processing liquid in the processing liquid applying section”. The area, which is included in the internal space of the cap holder56and from which the area arranged with the processing liquid accommodating cap54is excluded, is the processing liquid recovery section S which recovers the processing liquid R and the foreign matter Q. Further, the applying member44is moved in a state in which the processing liquid accommodating cap54is brought in contact with the surface of the processing liquid transfer roller42. In other words, the pressing force, which is transmitted from the processing liquid transfer roller42to the processing liquid accommodating cap54by the aid of the frictional force, acts as the “motive power” for moving the applying member44in the tangential direction at the lowermost position in the vertical direction of the processing liquid transfer roller42(hereinafter simply referred to as “tangential direction”), i.e., in the transport direction X. In this way, in this embodiment, the processing liquid transfer roller42functions as the “power source” for the moving mechanism G (FIGS. 2 and 7) described later on.

As shown inFIG. 7, the applying member44as described above is arranged movably between the “transfer mode position P1” and the “cleaning mode position P2” under or below the processing liquid transfer roller42. The “transfer mode position P1” herein means the position of the applying member44provided when the processing liquid R is transferred to the printing paper12as the “transfer medium”. The “cleaning mode position P2” herein means the position of the applying member44provided when the remaining processing liquid and the foreign matter Q adhered to the surface of the processing liquid transfer roller42are washed out with the processing liquid R at the timing distinct from that of the “transfer mode”. As shown inFIG. 7, the cleaning mode position P2is positioned on the downstream side in the rotating direction as compared with the transfer mode position P1on the basis of the central portion in the transport direction X of the bottom plate section58of the processing liquid accommodating cap54.

As described above, the opening80, which is the “processing liquid applying section”, is arranged under or below the processing liquid transfer roller42. The lowest point of the processing liquid transfer roller42is positioned within the width of the opening80. Therefore, when the applying member44is moved toward the downstream side in the rotating direction in the tangential direction, the distance D between the forward end60aon the upper side in the vertical direction of the downstream wall60and surface of the processing liquid transfer roller42(hereinafter simply referred to as “distance D between the downstream wall60and the processing liquid transfer roller42) is increased. On the contrary, when the applying member44is moved toward the upstream side in the rotating direction in the tangential direction, the distance D between the downstream wall60and the processing liquid transfer roller42is decreased. When the applying member44is moved toward the downstream side in the rotating direction in the tangential direction, the contact pressure between the upstream wall62and the processing liquid transfer roller42is increased. On the contrary, when the applying member44is moved toward the upstream side in the rotating direction in the tangential direction, the contact pressure between the upstream wall62and the processing liquid transfer roller42is decreased.

Arrangement of Support Member

As shown inFIG. 2, the support member46has a bearing section82which rotatably supports the processing liquid transfer roller42, and a sliding section84which slidably supports the applying member44. The support member46supports the processing liquid transfer roller42and the applying member44. Further, the support member46constitutes the moving mechanism G which moves the applying member44in cooperation with the processing liquid transfer roller42.

As shown inFIG. 2, the bearing section82has two support plates82awhich are arranged in parallel to one another while being separated from each other by a spacing distance in the printing paper widthwise direction Y. As shown inFIG. 6, bearing holes82b, which rotatably support the rotary shaft52aof the processing liquid transfer roller42, are formed mutually opposingly through the two support plates82arespectively. Slotted holes82c, which are long in the tangential direction and which support the projections74of the applying member44movably in the tangential direction of the processing liquid transfer roller42, are formed mutually opposingly. The sliding section84is arranged somewhat under or below the slotted holes82cbetween the two support plates82a.

As shown inFIGS. 6 and 7, the sliding section84is a plate-shaped member which is substantially rectangular as viewed in a plan view and which extends in the printing paper widthwise direction Y. A central portion of the upper surface of the sliding section84in the tangential direction is a smooth surface84aon which the applying member44is slidably placed. A plurality of (three in this embodiment) through-holes88, into which transfer mode stoppers86are inserted in conformity with the arrangement position of the applying member44, are formed while being separated from each other by spacing distances in the printing paper widthwise direction Y at the central portion of the sliding section84in the tangential direction. A plurality of (two in this embodiment) cleaning mode stoppers90are formed while being separated from each other by a spacing distance in the printing paper widthwise direction Y on the downstream side in the rotating direction as compared with the transfer mode stoppers86. Further, a plurality of (four in this embodiment) support projections94, which support coil springs92, are formed while being separated from each other by spacing distances in the printing paper widthwise direction Y on the downstream side in the rotating direction as compared with the cleaning mode stoppers90.

The transfer mode stoppers86are projections which position the applying member44at the “transfer mode position P1”. The transfer mode stoppers86are moved upwardly and downwardly and they are moved in the tangential direction by the stopper driving apparatus96(FIG. 4) arranged under or below the sliding section84. In other words, the transfer mode stoppers86are constructed so that the positions can be adjusted in the both directions of the “vertical direction” and the “tangential direction” by means of the stopper driving apparatus96. The cleaning mode stoppers90are projections which position the applying member44at the “cleaning mode position P2”. In this embodiment, the cleaning mode stoppers90are formed integrally with the sliding section84. The coil springs92constitute the “restoring mechanism” which pushes and returns the applying member44positioned at the “cleaning mode position P2” toward the upstream side in the rotating direction as compared with the “transfer mode position P1”. One end of the coil spring92is fixed to the support projection94, and the other end is fixed to the applying member44. The length of the coil spring92is designed so that the applying member44is positioned on the upstream side in the rotating direction as compared with the “transfer mode position P1” in the natural state. The cleaning mode stoppers90may be also constructed so that the positions can be adjusted in the “tangential direction” by means of a stopper driving apparatus (not shown).

In this embodiment, the coil spring92is used as the “restoring mechanism”. However, the arrangement of the “restoring mechanism” is not specifically limited. For example, it is also allowable to use any other elastic member including, for example, plate spring, rubber, and elastomer. It is also allowable to use any driving apparatus including, for example, motor and electromagnetic solenoid. It is also allowable to use any arrangement in which the restoration is effected manually. Further, the applying member44may be allowed to function as the “restoring mechanism” by forming a part or all of the applying member44with an elastic material including, for example, rubber and elastomer. However, when the “restoring mechanism” has an urging means for urging the applying member44toward the upstream side in the rotating direction, it is desirable to provide such a design that the frictional force, which is generated between the processing liquid accommodating cap54and the processing liquid transfer roller42, is greater than the urging force of the “restoring mechanism” to be exerted on the applying member44in order to move the applying member44to the “transfer mode position P1”.

Arrangement of Processing Liquid Supply Apparatus

As shown inFIG. 1, the processing liquid supply apparatus48includes a tank100which stores the processing liquid R, a supply tube102awhich connects the tank100and one of the through-holes78, a recovery tube102bwhich connects the tank100and the other through-hole78, and a pump104which is arranged at an intermediate position of the recovery tube and which sucks or pressurizes the processing liquid R contained in the processing liquid accommodating cap54. The liquid amount of the processing liquid R in the processing liquid accommodating cap54is properly retained by circulating the processing liquid R by means of the pump104.

Operation of Image-Forming Apparatus

When the image is formed on the printing paper12by using the image-forming apparatus10, the image signal is inputted into the control unit26from the external device such as a personal computer or the like. Accordingly, the control unit26drives the transport apparatus20. The printing paper12, which is accommodated in the paper feed cassette16, is taken out by the pickup roller30, and the printing paper12is fed to the processing liquid applying apparatus22via the detecting unit24. The detecting unit24detects the type (for example, thickness, surface smoothness, and hardness) of the printing paper12transported through the transport route M, and the detection result is given to the control unit26.

Transfer Mode

When the processing liquid applying apparatus22is operated in the “transfer mode”, the transfer mode stoppers86are moved upwardly by the stopper driving apparatus96in the state in which the applying member44is positioned on the upstream side in the rotating direction as compared with the through-holes88of the sliding section84, and the transfer mode stoppers86are allowed to protrude from the upper surface of the sliding section84. In the state in which the applying member44is positioned on the upstream side in the rotating direction as compared with the through-holes88, the lengths of the coil springs92are in the natural state, and the urging force is not generated in the coil springs92which press the applying member44toward the upstream side in the rotating direction. Therefore, when the processing liquid transfer roller42is thereafter driven and rotated, the pressing force, which is directed toward the downstream side in the rotating direction in the tangential direction, is applied by the aid of the frictional force to the upstream wall62from the surface of the processing liquid transfer roller42. The pressing force is greater than the urging force of the coil springs92. Therefore, the entire applying member44is moved toward the downstream side in the rotating direction in the tangential direction, and the fastening surface72aof the applying member44is allowed to abut against the transfer mode stoppers86. In other words, the applying member44is positioned at the “transfer mode position P1” by means of the transfer mode stoppers86.

When the applying amount of the processing liquid R is adjusted depending on the type of the printing paper12, the stopper driving apparatus96is controlled by the control unit26which serves as the “stopper control unit” based on the detection result obtained by the detecting unit24. The transfer mode stoppers86are moved in the tangential direction. In other words, the “transfer mode position P1” is positionally adjusted in the tangential direction so that the preferred applying amount is obtained depending on the type of the printing paper12. For example, if the control unit26judges that “the liquid absorption performance of the printing paper12is high” based on the detection result obtained by the detecting unit24, it is necessary that the applying amount of the processing liquid R with respect to the processing liquid transfer roller42should be increased. In this case, the transfer mode stoppers86are moved toward the downstream side in the rotating direction, and thus the “transfer mode position P1” is moved toward the downstream side in the rotating direction. The distance D between the downstream wall60and the processing liquid transfer roller42is increased. In the “transfer mode”, the applying member44is positioned by the transfer mode stoppers86. Therefore, the distance D between the downstream wall60and the processing liquid transfer roller42is stable at a constant distance. The applying amount of the processing liquid R with respect to the surface of the processing liquid transfer roller42is not undesirably varied or fluctuated. In other words, the downstream wall60functions as the “applying amount adjusting member” which adjusts the applying amount of the processing liquid R.

The processing liquid R, which has been applied to the surface of the processing liquid transfer roller42from the applying member44, is transferred to the surface of the printing paper12brought in contact with the surface of the processing liquid transfer roller42. The printing paper12, to which the processing liquid R has been transferred, is fed to the liquid discharge apparatus18. The image is formed on the surface of the printing paper12, and then the printing paper12is discharged from the printing paper discharge port14bby means of the paper discharge rollers36. The processing liquid R, which remains on the surface of the processing liquid transfer roller42, is scraped off toward the outer side surface of the upstream wall62by means of the upstream wall62upon the contact with the upstream wall62. In other words, the upstream wall62functions as the “cleaning member” which scrapes the foreign matter Q and the processing liquid R remained on the surface of the processing liquid applying roller42. Also in the “transfer mode”, the foreign matter Q, which is removed by the upstream wall62, may be washed out with the processing liquid R by feeding the processing liquid R to the upstream wall62without transferring the processing liquid R to the printing paper12in the same manner as in the “cleaning mode” described below.

Cleaning Mode

For example, when the printing operation is not performed for a long period of time, then the remaining processing liquid R is deposited on the surface of the processing liquid transfer roller42in some cases, and the viscosity of the remaining processing liquid R is increased, resulting in the adhesion to the surface of the processing liquid transfer roller42together with the foreign matter Q or the like in other cases. When the printing operation is repeatedly performed in the “transfer mode”, then the remaining processing liquid R or the foreign matter Q (hereinafter referred to as “foreign matter Q or the like”) are adhered and accumulated on the surface of the processing liquid transfer roller42and the outer side surface of the upstream wall62, the foreign matter Q or the like is interposed and accumulated between the upstream wall62and the processing liquid transfer roller42, and/or the foreign matter Q or the like enters the interior of the processing liquid accommodating cap54in some cases. If the transfer operation is continued without removing the foreign matter Q or the like in such situations, the performance of the processing liquid applying apparatus22is conspicuously deteriorated, because any new processing liquid R is not transferred to the portion of the surface of the processing liquid transfer roller42to which the foreign matter Q or the like is adhered. When any gap appears between the upstream wall62and the processing liquid transfer roller42due to the foreign matter Q or the like interposed between the upstream wall62and the processing liquid transfer roller42, it is feared that the air may enter the interior of the processing liquid accommodating cap54due to the negative pressure for sucking the processing liquid R, and/or the processing liquid R contained in the processing liquid accommodating cap54may leak to the outside due to the positive pressure for supplying the processing liquid R into the processing liquid accommodating cap54. Further, when the foreign matter Q or the like enters the interior of the processing liquid accommodating cap54, it is feared that any “uneven application or coating” of the processing liquid R may be caused in the step of applying the processing liquid R to the surface of the processing liquid transfer roller42.

In view of the above, in order to remove the foreign matter Q or the like, for example, from the processing liquid transfer roller42, the user starts the “cleaning mode”, for example, by operating a mode selection switch. In the “cleaning mode”, the transfer mode stoppers86are moved downwardly by means of the stopper driving apparatus96, and the transfer mode stoppers86are retracted downwardly from the upper surface of the sliding section84. Therefore, when the processing liquid transfer roller42is driven and rotated, then the upstream wall62is pressed toward the downstream side in the rotating direction in the tangential direction by the surface of the processing liquid transfer roller42, and thus the entire applying member44is moved toward the downstream side in the rotating direction. The fastening surface72aof the applying member44is allowed to abut against the cleaning mode stoppers90. In other words, the applying member44is positioned at the “cleaning mode position P2” by means of the cleaning mode stoppers90. When the process proceeds from the cleaning mode to the transfer mode again, the rotation of the processing liquid transfer roller42is stopped. When the rotation of the processing liquid transfer roller42is stopped, the pressing force, which is exerted from the surface of the processing liquid transfer roller42, is not exerted on the upstream wall62. Therefore, the coil springs92, which have been compressed, are restored to the natural state. Accordingly, the applying member44is moved to the upstream side in the rotating direction as compared with the through-holes88of the sliding section84. In this state, the transfer mode stoppers86are allowed to protrude from the upper surface of the sliding section84again, and the processing liquid transfer roller42is rotated. Accordingly, the transfer mode is started.

In this embodiment, the upstream wall62is formed integrally with the applying member44. Therefore, the upstream wall62is also moved in accordance with the movement of the applying member44. It is assumed that the position of the upstream wall62is referred to as “upstream wall first position P3” when the applying member44is positioned at the “transfer mode position P1”. It is assumed that the position of the upstream wall62is referred to as “upstream wall second position P4” when the applying member44is positioned at the “cleaning mode position P2”. On this assumption, the contact pressure between the upstream wall62and the processing liquid transfer roller42is great when the upstream wall62is positioned at the “upstream wall second position P4” as compared with when the upstream wall62is positioned at the “upstream wall first position P3”. Therefore, the force, with which the foreign matter Q adhered to the surface of the processing liquid transfer roller42is scraped off, is increased in the “cleaning mode”, i.e., when “the upstream wall62is at the upstream wall second position P4” as compared with the “transfer mode”, i.e., when “the upstream wall62is positioned at the upstream wall first position P3”.

In this embodiment, the downstream wall60is formed integrally with the applying member44. Therefore, the downstream wall60is also moved in accordance with the movement of the applying member44. It is assumed that the position of the downstream wall60is referred to as “downstream wall first position P5” when the applying member44is positioned at the “transfer mode position P1”. It is assumed that the position of the downstream wall60is referred to as “downstream wall second position P6” when the applying member44is positioned at the “cleaning mode position P2”. On this assumption, as shown inFIG. 7, the distance D between the downstream wall60and the processing liquid transfer roller42is increased when the downstream wall60is positioned at the “downstream wall second position P6” as compared with when the downstream wall60is positioned at the “downstream wall first position P5”. Therefore, the applying amount of the processing liquid R with respect to the surface of the processing liquid transfer roller42is increased in the “cleaning mode”, i.e., when “the downstream wall60is positioned at the downstream wall second position P6” as compared with the “transfer mode”, i.e., when “the downstream wall60is positioned at the downstream wall first position P5”.

Therefore, in the “cleaning mode”, the foreign matter Q or the like can be efficiently scraped off owing to the large contact pressure of the upstream wall62with respect to the processing liquid transfer roller42, and it is possible to effectively prevent the foreign matter Q or the like from entering the space between the upstream wall62and the processing liquid transfer roller42. Further, the foreign matter Q or the like, which has been scraped off by the upstream wall62, can be efficiently washed out with the large amount of the processing liquid R. The grooves62a, which guide the foreign matter Q or the like to the processing liquid recovery section S, are formed on the outer side surface of the upstream wall62, and the water-attracting treatment is applied. Therefore, the foreign matter Q or the like can be efficiently washed out with the processing liquid R, and the foreign matter Q or the like can be recovered by the processing liquid recovery section S. Further, when the cleaning mode stoppers90are also constructed so that the cleaning mode stoppers90can be positionally adjusted in the “tangential direction” by means of the stopper driving apparatus (not shown), the applying member44can be positioned at the position appropriate to remove the foreign matter Q or the like depending on the type of the foreign matter Q or the like.

In this embodiment, the “moving mechanism G”, which moves the applying member44between the “transfer mode position P1” and the “cleaning mode position P2”, is constructed by the processing liquid transfer roller42, the support member46, the coil springs92, the transfer mode stoppers86, and the cleaning mode stoppers90. The downstream wall60and the upstream wall62are formed integrally with the applying member44(processing liquid accommodating cap54). Therefore, “the operation for adjusting the applying amount of the processing liquid R with respect to the processing liquid transfer roller42” and “the operation for adjusting the force (contact pressure) to scrape off the foreign matter Q or the like” can be simultaneously performed by means of the “moving mechanism G”. The operations can be performed easily and quickly.

Second Embodiment

In a processing liquid applying apparatus108according to a second embodiment, as shown inFIG. 8, rotary shafts110of a applying member44are formed at both end portions in the printing paper widthwise direction Y of the applying member44, and a motor (not shown) is connected to the rotary shaft110. The angle of rotation of the motor is controlled by the control unit26, and thus the “transfer mode (solid lines shown in FIG.8)” and the “cleaning mode (two-dot chain lines shown in FIG.8)” are switched. In other words, the distance D between the downstream wall60and the processing liquid transfer roller42in the “cleaning mode” is greater than the distance D in the “transfer mode”. Further, the contact pressure of the upstream wall62with respect to the processing liquid transfer roller42in the “cleaning mode” is smaller than the contact pressure in the “transfer mode”. In this way, in the second embodiment, it is possible to more finely adjust the “distance” D between the downstream wall60and the processing liquid transfer roller42and the “contact pressure” between the upstream wall62and the processing liquid transfer roller42merely by controlling the angle of rotation of the motor.

Third Embodiment

In a processing liquid applying apparatus112according to a third embodiment, as shown inFIG. 9, a pressing member114, which includes, for example, an electromagnetic solenoid or an air cylinder and which presses the applying member44toward the side of the processing liquid transfer roller42, is arranged under or below the applying member44. In the “waiting state” in which the drying and the increase in viscosity of the processing liquid R accommodated in the processing liquid accommodating cap54is avoided to preferably maintain the viscosity of the processing liquid R when the printing operation of the image-forming apparatus10is not performed, the applying member44is pressed by the pressing member114. Accordingly, the forward ends of the respective walls60,62,64of the applying member44are allowed to abut against the surface of the processing liquid transfer roller42in a capping state in a liquid-tight manner. Therefore, in the “waiting state”, it is possible to prevent the processing liquid R contained in the processing liquid accommodating cap54from any contact with the external air or the outside air, it is possible to avoid the drying and the increase in viscosity of the processing liquid R, and it is possible to always preferably maintain the viscosity of the processing liquid R. Even when the processing liquid transfer roller42is rotated in the “waiting state”, it is possible to avoid the leakage of the processing liquid R from the processing liquid accommodating cap54.

The position of arrangement in the tangential direction of the applying member44in the “waiting state” is not specifically limited. However, in order to allow the forward ends of the respective walls60,62,64to reliably abut against the surface of the processing liquid transfer roller42, it is desirable that the position of arrangement in the tangential direction of the applying member44in the “waiting state” is slightly deviated toward the upstream side in the rotating direction as compared with the “transfer mode position P1”. When the downstream wall60and the upstream wall62have the same height, it is desirable that the lowest point of the processing liquid transfer roller42is positioned at the center in the widthwise direction (tangential direction) of the opening80in order to obtain the equivalent contact pressure in relation to the processing liquid transfer roller42, the downstream wall60, and the upstream wall62in the “waiting state”.

Other Embodiments

In the respective embodiments described above, the downstream wall60and the upstream wall62, which constitute the processing liquid accommodating cap54, are formed integrally. Therefore, the “downstream wall moving mechanism” which moves the downstream wall60between the “downstream wall first position” and the “downstream wall second position” and the “upstream wall moving mechanism” which moves the upstream wall62between the “upstream wall first position” and the “upstream wall second position” are unified into one “moving mechanism G”. However, the downstream wall60and the upstream wall62may be moved distinctly by distinctly forming the downstream wall60and the upstream wall62.

In the respective embodiments described above, the processing liquid R is accommodated in the processing liquid accommodating cap54. However, for example, a porous member such as sponge or urethane, in which the processing liquid R is absorbed, may be accommodated in the processing liquid accommodating cap54. In this case, the porous member and the processing liquid R absorbed in the porous member correspond to the “processing liquid applying section”.

In the respective embodiments described above, the present invention is applied to the “ink-jet printer”. However, the present invention is also applicable to any “image-forming apparatus” of another type including, for example, the “facsimile” and the “multifunction machine”. Further, the present invention is also applicable to any recording system including, for example, the “thermal transfer system”, the “electronic photograph system”, and the “silver salt photograph system” in addition to the “ink-jet system”.

In the respective embodiments described above, the “processing liquid transfer” is performed by the processing liquid applying apparatus22before the “image formation” by the liquid discharge apparatus18. However, the “processing liquid transfer” may be performed after the “image formation”, or the “processing liquid transfer” may be performed both before and after the “image formation”.

In the respective embodiments described above, the printing paper12is used as the “transfer medium”. However, the type of the “transfer medium” is not specifically limited. For example, when a transmission type manuscript is prepared, it is also allowable to use a plastic sheet composed of polyethylene terephthalate or the like.