1. Field of the Invention
The present invention relates to a recording apparatus and a line type liquid discharge recording apparatus which are provided with a suction unit for keeping the distance between a recording sheet on a platen section and a recording head constant.
2. Description of the Related Art
In an ink jet recording apparatus, keeping the distance between a recording sheet on a platen and a recording head constant is an important task for performing correct impact of ink. For this reason, at the ink jet recording apparatus, a suction section which sucks the recording sheet onto an upper surface of the platen is often provided. The suction section is usually constituted by a plurality of suction openings formed in a surface of the platen and a fan which sucks external air from each suction opening.
In such a configuration in which a plurality of suction openings is provided in order to suck the recording sheet onto the surface of the platen, there is a problem in which suction capability is lowered when a leading end of the recording sheet passes over the platen. When the leading end of the recording sheet passes over the platen, a plurality of suction openings disposed in a transport direction (a sub-scanning direction) is covered by the leading end of the recording sheet in order from the suction opening on the upstream side in the transport direction among the suction openings. That is, while the leading end of the recording sheet is transported, a suction operation is performed in a state where the suction openings close to the paper discharge side are not yet covered by the recording sheet. For this reason, compared to a state where all the suction openings are covered by the recording sheet, negative pressure of the suction openings does not sufficiently rise due to air leakage, so that suction capability is lowered. In such a case, it is difficult to properly keep the distance between the recording head and the recording sheet. For example, in such a case, it is difficult to correct a curl state occurring on the leading end side of the recording sheet. In addition, problems occur such as an increase in noise due to generation of a sound by passage of external air through the suction openings which are not covered by the recording sheet, and lowering of impact precision due to disturbance of discharge of ink by an air current of the suction opening.
In order to solve the problems as described above, in Japanese Unexamined Patent Application Publication No. 2007-152762, a configuration is described in which a plurality of shielding plates which blocks and opens suction openings is provided in the transport direction of the recording sheet and a mechanism is provided which sequentially opens or blocks the suction openings according to movement of a leading end and a back end of the recording sheet.
On the other hand, there is an ink jet printer which can cope with down to the minimum paper width of A4 (210 mm), for example, even in a case where the maximum paper width is a B0 (1030 mm), and perform recording in many types of paper widths between the maximum paper width and the minimum paper width. In such an ink jet printer, when recording is performed on the recording sheet of a width smaller than the maximum paper width, in the suction openings which are not covered by the recording sheet, air is leaked. For this reason, in Japanese Unexamined Patent Application Publication No. 2007-152762, a problem occurs which is similar to the above-described case where the suction openings of a leading end portion of the recording sheet are not blocked.
In Japanese Unexamined Patent Application Publication No. 2004-098319 and Japanese Unexamined Patent Application Publication No. 2007-223139, a shutter is described which corresponds to a plurality of recording sheet widths as well as the transport direction of the recording sheet.
In Japanese Unexamined Patent Application Publication No. 2004-098319, a suction opening on a platen is disposed in a plurality in a linear fashion having inclinations with respect to a main scanning direction and a sub-scanning direction, and a plurality of shutters for blocking the suction openings reciprocates in the main scanning direction, thereby interlocking open and closed states of the suction openings with movement of a leading end and a back end of the recording sheet. Also, in Japanese Unexamined Patent Application Publication No. 2004-098319, with respect to a small paper width, a plurality of shutters is divided into several groups and a shielding plate movement mechanism is provided for each group, thereby individually moving the respective groups.
However, in Japanese Unexamined Patent Application Publication No. 2004-098319, as many shielding plate movement mechanisms as the varieties of widths of the recording sheets are necessary, thereby leading to an increase in the cost of a recording apparatus or an increase in the size of the recording apparatus.
Also, in Japanese Unexamined Patent Application Publication No. 2007-223139, a suction opening of a platen is disposed in a plurality in a linear fashion in a main scanning direction and a sub-scanning direction, and a cylindrical shutter having opened holes is rotated, thereby interlocking open and closed states of the suction openings with movement of a leading end and a back end of the recording sheet. With respect to a small paper width, a countermeasure is made by providing a plurality of holes having a plurality of opening widths at the cylinder. Accordingly, in Japanese Unexamined Patent Application Publication No. 2007-223139, only by a rotation mechanism of the cylindrical shutter, control of opening and closing of the suction openings in the transport direction and the width direction of the recording sheet is performed according to transportation of the recording sheet and the size of the recording sheet.
However, in Japanese Unexamined Patent Application Publication No. 2007-223139, in order to provide openings corresponding to a number of paper widths, the diameter of the cylindrical shutter is increased according to the number of paper widths. For this reason, in Japanese Unexamined Patent Application Publication No. 2007-223139, in the case of coping with a number of paper widths, an increase in size of the recording apparatus is inevitable.
In view of the problems as described above, it is desirable to provide a recording apparatus and a line type liquid discharge recording apparatus, which can prevent lowering of suction power for a recording sheet.
According to an embodiment of the present invention, there is provided a recording apparatus including: a recording head which performs recording onto a recording sheet on the basis of image information; a platen section which guides the recording sheet to a position facing the recording head; a suction unit which includes a plurality of suction openings which is provided at the platen section and sucks and holds the recording sheet, a suction duct which is provided facing the plurality of suction openings, and a suction fan which is connected to the suction duct, and sucks and holds the recording sheet on the platen section through the suction openings; and a shutter mechanism which opens and closes the suction duct.
The shutter mechanism includes a shutter sheet in which at least one exposure opening portion which corresponds to the suction duct and exposes the suction duct is formed corresponding to a width of the recording sheet, and a shutter sheet movement mechanism which makes the shutter sheet travel between the suction duct and a back surface of the platen section.
In the shutter mechanism, when the recording sheet is transported over the platen section, the exposure opening portion of the shutter sheet sequentially opens the suction duct and the suction openings according to a position of a leading end of the recording sheet and the exposure opening portion of the shutter sheet sequentially closes the suction duct and the suction openings according to a position of a back end of the recording sheet.
According to another embodiment of the present invention, there is provided a line type liquid discharge recording apparatus including: a line type liquid droplet discharge head in which nozzles discharging given liquid as liquid droplets are formed over approximately the maximum width of a recording sheet; a platen section which guides the recording sheet to a position facing the line type liquid droplet discharge head; a suction unit which includes a plurality of suction openings which is provided at the platen section and sucks and holds the recording sheet, a suction duct which is provided facing the plurality of suction openings, and a suction fan which is connected to the suction duct, and sucks and holds the recording sheet on the platen section through the suction openings; and a shutter mechanism which opens and closes the suction openings.
The shutter mechanism includes a shutter sheet in which least one exposure opening portion which corresponds to the suction duct and exposes the suction duct is formed corresponding to a width of the recording sheet, and a shutter sheet movement mechanism which makes the shutter sheet travel between the suction duct and a back surface of the platen section.
In the shutter mechanism, when the recording sheet is transported over the platen section, the exposure opening portion of the shutter sheet sequentially opens the suction duct and the suction openings according to a position of a leading end of the recording sheet and the exposure opening portion of the shutter sheet sequentially closes the suction duct and the suction openings according to a position of a back end of the recording sheet.
According to the invention, when the recording sheet is transported over the platen section, the exposure opening portion of the shutter sheet sequentially opens the suction duct and the suction openings according to the position of the leading end of the recording sheet. Also, the exposure opening portion of the shutter sheet sequentially closes the suction duct and the suction openings according to the position of the back end of the recording sheet. Therefore, it is possible to prevent lowering of suction capability at the leading end and the back end of the recording sheet in a simple configuration.
Also, also in the width direction of the recording sheet, by removing suction from the suction openings which are not covered by the recording sheet, it is possible to prevent lowering of suction capability. In addition, it is possible to obtain effects such as suppression of discharge disturbance of ink by an air current which is generated from the suction opening, prevention of a noise caused by the air current, and prevention of drying of nozzle orifices by the air current.
Also, in the invention, also in a case where there are various sizes in the width direction of the recording sheets, it is possible to obtain the above-mentioned effects without necessitating a large space.
Also, in the invention, a recording sheet suction function, an idle discharge receiving function, a capping function, a moisturizing liquid supply function, and an ink mist collection function are provided together in the platen section. Therefore, in the invention, compared to a case where the respective functions are realized by separate components or mechanisms, a reduction in cost by a reduction in the number of components or an improvement in reliability by simplification of a mechanism becomes possible.
Hereinafter, a line type ink jet printer apparatus will be described with reference to the drawings. In addition, application examples are described according to the following order.
(1) Overall Explanation of Recording Apparatus
(2) Explanation of Platen Section
(3) Explanation of Recording Section
(4) Explanation of Suction Unit
(5) Explanation of Shutter Mechanism
(6) Explanation of Shutter Sheet Movement Mechanism
(7) Explanation of Capping Section
(8) Explanation of Moisturizing Liquid Supply Section
(9) Modified Example
Here, a symbol A in
Next, a sequence of operations from paper feed to paper discharge will be described. The recording sheet 2 which is the roll paper 2b or the cut sheet 2a is fed from a roll paper feed tray 11 in which the roll paper 2b is loaded or a cut sheet feed tray 12 which sets the cut sheet 2a at a predetermined position in a width direction, by a paper feed roller 13 and a paper feed pinch roller 14. The paper feed roller 13 is driven by a driving motor. Then, the capping section 60 is lowered (
If the recording sheet 2 passes an edge sensor 15 which detects a leading end and a back end of the fed recording sheet 2, and then reaches a transport roller 16 and a pinch roller 17, the recording sheet is transported between the recording section 20 and the platen section 30 by the transport roller 16 and the pinch roller 17. Then, the recording sheet 2 is sucked and stuck to the platen section 30 by the suction unit 40. The transport roller 16 is driven by a driving motor. Recording by the recording section 20 is started from a point of time when the sum of a transport amount by the paper feed roller 13 since the time of detection of the leading end of the recording sheet by the edge sensor 15 and a transport amount of the transport roller 16 has reached a predetermined amount.
The recording section 20 is provided with a line type ink jet recording head 21 (hereinafter also simply referred to as a line head) having a width slightly wider than the maximum paper width (in this example, A4) of the recording sheet 2. In a nozzle formation face 20a of the line head 21, in which nozzles that discharge ink facing the recording sheet 2 are formed, a plurality of nozzle rows which respectively discharges ink of different colors is formed. In each nozzle row, electrothermal conversion elements provided in a plurality of minute discharge openings are selectively driven on the basis of image information and ink is discharged from the discharge openings by film boiling pressure generated in the ink by generation of heat.
On the transport roller 16, an encoder and an encoder sensor are mounted. The encoder sensor detects the velocity in a transport direction of the recording sheet 2 and synchronizes discharge timing of the line head 21 with the transport velocity of the recording sheet 2 on the basis of the detection information.
If the back end of the recording sheet 2 passes the transport roller 16 and the pinch roller 17, the recording sheet 2 is transported by a transport roller 18, which is driven in synchronization with the transport roller 16, and a pinch roller 19 which faces the transport roller 18, while being subjected to recording. If the recording is finished, the suction fan is stopped and the recording sheet is transported by the transport roller 18 and the pinch roller 19 as it is. In a case where the recording sheet 2 is the cut sheet 2a, the recording sheet is stored in the paper discharge section 90, whereas in a case where the recording sheet 2 is the roll paper 2b, the recording sheet is cut by the cutter section 80 and then stored in the paper discharge section 90. Finally, a capping member 61 of the capping section 60 is raised, thereby keeping a state where the sealing property of the space portion between the recording section 20 and the platen section 30 is increased (refer to
Next, details of the platen section 30, the suction unit 40, and the shutter mechanism 50 which are distinguishing sections of the invention will be described.
The platen section 30, the suction unit 40, and the shutter mechanism 50 have widths slightly wider than an A4 size width (210 mm). The platen section 30 is constituted by a platen plate 31, an absorber box 32, and an absorber 33. In the platen plate 31, a plurality of circular holes 31a is opened.
In the platen plate 31 which faces the nozzle formation face 20a of the recording section 20, as shown in
In this manner, in the platen section 30, by providing the absorbers 33 so as to face the platen surface from the opening portions for idle discharge 35, it is possible to perform idle discharge which discharges thickened ink beforehand. Also, in the platen section 30, even if ink is discharged to the portions slightly deviated from four sides of the recording sheet in no-margin printing, contamination of the surface of the platen plate 31 by ink can be prevented. Also, a certain amount of moisturizing liquid or ink can be absorbed by the absorbers 33. The position of the opening portion for idle discharge 35 is determined according to the disposition of the head chip 23. Therefore, the suction openings 34 are disposed in a zigzag fashion at the positions avoiding the opening portions for idle discharge 35.
Next, the suction unit 40 will be described. As shown in
Next, the shutter mechanism 50 will be described. As shown in
In the second shutter roller 51b, a compression coil spring is deflected in the axial direction of the second shutter roller 51b, thereby being pressed against the bearing 53b, whereby a moderate load in a rotational direction is applied to the second shutter roller 51b. Due to this, the shutter sheet 54 is transported without being loosened. Also, if the second shutter roller 51b rotates in the clockwise direction, the shutter sheet 54 is wound around the second shutter roller 51b, thereby moving in the direction (the right direction in
The shutter sheet 54 is made as shown in
On the other hand, in a case where the opening of the shutter sheet 54 is not located between the suction opening 34 and the duct opening portion 42d which make a pair located at approximately the same position, communication of the suction fan 41 and the suction opening 34 is cut off, whereby negative pressure is not generated on the surface of the platen plate 31.
An exposure opening portions 54c are openings for preventing interference of the threaded boss holes 42e of the upper duct 42a, a moisturizing liquid supply tubes 71, and gears 52a and 52b for driving the first and second shutter roller 51a and 51b, which will be described later.
As the material of the shutter sheet 54, a material having a thin thickness (in the order of 10μ to 100μ), flexibility, a certain amount of strength is preferable, and a film made of resin such as polyethylene terephthalate, polypropylene, or polyimide is appropriate.
Next, movement of the shutter sheet 54 and the recording sheet 2 will be described with reference to
In order to accomplish this, a shutter sheet position detection sensor 56 provided with a light emitting portion and a light sensing portion, as shown in
In addition, in a case where the recording sheet 2 is the roll paper 2b, since the back end is not present, the shutter sheet 54 may be in the state of
After the recording sheet 2 has escaped from the platen section 30, driving of the suction fan 41 is stopped. Thereafter, the shutter sheet 54 is moved to an initial position. This is performed by moving the shutter sheet 54 in the opposite direction to the transport direction of the recording sheet 2 and then moving the shutter sheet by a predetermined amount after detection of a marker on the shutter sheet 54 by the shutter sheet position detection sensor 56.
In the above explanation of the operations of the shutter sheet 54 and the recording sheet 2, the line C of the leading end of the recording sheet 2 and the line D connecting the outer circumferences on the downstream side in the transport direction of the exposure opening portions 54a of the shutter sheet 54 approximately correspond with each other when viewing from the direction vertical to the recording sheet 2. However, strictly, it is more preferable that the line C and the line D be deviated from each other by a constant amount.
Although
Similarly, as shown in
In the above explanation, a case where the recording sheet 2 has an A4 size which is the width of the platen section 30 has been described. In the invention, in the case of the recording sheet of a size smaller than this, for example, the case of an A5 size, it is preferable if the exposure opening portion 54b shown in
In addition, an initial position of the shutter sheet 54 having the exposure opening portions corresponding to a plurality of recording sheet widths varies according to the width of the recording sheet 2 which is recorded. Movement of the initial position of the shutter sheet 54 in this case is performed as follows. Specific markers are respectively provided at the respective exposure opening portions. Then, the shutter sheet 54 is moved in the transport direction of the recording sheet 2 or the opposite direction to the transport direction according to the width of the recording sheet which is recorded, and then moved by a predetermined amount after detection of an objective marker by the shutter sheet position detection sensor 56.
Although the shutter sheet 54 of
The exposure opening portions 54a and 54b of the shutter sheet 54 may be connected in the main scanning direction, as show in
In addition, although in this example, the width of the platen section 30 is set to be an A4 width, it is not to be limited thereto, but an A0 width or an A1 width is also acceptable.
On the other hand, in particular, in the printer apparatus 1 in which the width of the sheet is wide, for a reduction in size of the printer apparatus 1, there is a case where it is preferable to install a plurality of small fans rather than a single large fan. Also, in the invention, by providing the patterns of the exposure opening portions corresponding to a number of paper widths, a shutter in the width direction of the recording sheet is realized. However, when the number of patterns of the exposure opening portions is increased, a possibility arises that worsens a throughput due to the time it takes to set up the shutter sheet 54 at an appropriate initial position corresponding to the sheet width when continuous recording of the recording sheets of different widths is instructed.
As described above, in a case where a reduction in size of the apparatus or an improvement in throughput of continuous printing of the recording sheets of different widths is demanded, for example, when the maximum width of the recording sheet width is an A0, as shown in
All the above examples are for the sheet widths which approximately correspond to multiple numbers of the A4 width. However, a case where a recording sheet of another width, for example, an A1 size (width: 594 mm), is transported is as follows. That is, the suction fans 41 of adjacent three suction units 40 are driven and adjacent two suction units of the three suction units 40 use the exposure opening portions 54a of the shutter sheets 54 of the corresponding shutter mechanisms 50. Then, the remaining one suction unit uses the exposure opening portions having no opening of about 36 mm (=210 mm×3-594 mm) width of the shutter sheet 54 of the corresponding shutter mechanism 50. In this manner, by installing a plurality of suction units 40 and (or) a plurality of shutter mechanisms 50, a number of patterns of the exposure opening portions may not be provided in one shutter sheet 54.
In addition, although in the above example, the suction unit 40 and the shutter mechanism 50 are made in an A4 width unit, for example, a combination in which the suction unit 40 is made in an A2 unit and is two pieces and the shutter mechanism 50 is made in an A4 unit and is four pieces is also possible. That is, the widths of the suction unit 40 and the shutter mechanism 50 do not have to correspond with each other and the appropriate respective widths may be appropriately selected according to the specifications of a recording apparatus demanded.
Next, a movement mechanism of the shutter sheet 54 will be described. As shown in
To the first shutter roller 51a, the gear 52a is concentrically fixed, and to the shutter roller 51b, the gear 52b is concentrically fixed. The gear 52a is engaged with an idler gear 57a and the idler gear 57a is engaged with an idler gear 57c. Similarly, the gear 52b is engaged with an idler gear 57b and the idler gear 57b is engaged with an idler gear 57d.
On the other hand, a motor gear 57f is fixed to a rotary shaft of a stepping motor 57e and engaged with a reduction gear 57g. The reduction gear 57g is constituted by a large gear and a small gear which are integrated with each other, and the small gear is engaged with a pendulum gear 57h. A pendulum 57i is oscillated around the central axis of the reduction gear 57g and engaged with the idler gear 57c or the idler gear 57d according to an oscillation direction. If the stepping motor 57e is driven in the clockwise direction, the reduction gear 57g rotates in the counterclockwise direction and the pendulum 57i is oscillated in the counterclockwise direction, so that the pendulum gear 57h is engaged with the idler gear 57c. Then, the pendulum gear 57h is rotated in the clockwise direction, so that subsequent connection is made. The idler gear 57c, the idler gear 57a, and the gear 52a are rotated in the counterclockwise direction, the clockwise direction, and the counterclockwise direction, respectively, and the first shutter roller 51a to which the gear 52a is fixed is rotated in the counterclockwise direction.
Also, if the stepping motor 57e is driven in the counterclockwise direction, the reduction gear 57g rotates in the clockwise direction and the pendulum 57i is oscillated in the clockwise direction, so that the pendulum gear 57h is engaged with the idler gear 57d. Then, the pendulum gear 57h is rotated in the counterclockwise direction, so that subsequent connection is made. The idler gear 57d, the idler gear 57b, and the gear 52b are rotated in the clockwise direction, the counterclockwise direction, and the clockwise direction, respectively, and the shutter roller 51b to which the gear 52b is fixed is rotated in the clockwise direction.
As described above, driving of the first shutter roller 51a and the second shutter roller 51b can be changed over by changing a rotational direction of the stepping motor 57e, so that a moving direction of the shutter sheet 54 can be controlled.
Next, the capping section 60 will be described using
The capping member 61 is made into a frame shape which surrounds the platen section 30, and has cam followers 61a at one side surface portion. In
When printing is not performed, a state as shown in
Next, the moisturizing liquid supply section 70 will be described with reference to
In addition, the moisture sensor may be provided at the nozzle formation face 20a of the recording section 20 or the upper surface of the platen plate 31 of the platen section 30, which constitute the hermetically-sealed space portion 65. Also due to this, the moisture sensor can detect a moist state of the hermetically-sealed space portion 65.
Supply of the moisturizing liquid to the absorber 33 is performed, for example, when the capping member 61 is lifted by the tension coil springs 62, so that the hermetically-sealed space portion 65 is formed by the nozzle formation face 20a of the recording section 20 and the upper surface of the platen plate 31 of the platen section 30, as shown in
On the other hand, all or a portion of the duct opening portions 42d is opened by one of the exposure opening portions 54a and 54b of the shutter sheet 54. Then, by driving the suction fan 41 corresponding to the opened shutter sheet 54, it is possible to suck out ink mist in the vicinity of the platen and the head from the suction openings 34 to the suction duct 42. Due to this, a dedicated ink mist collection mechanism may not be used. In addition, collection of ink mist may be performed either when the hermetically-sealed space portion 65 is formed by the capping member 61 or when it is not formed. When the hermetically-sealed space portion 65 is formed, ink mist in the hermetically-sealed space portion 65 can be efficiently collected. When the hermetically-sealed space portion 65 is not formed, a wider range of ink mist can be collected.
In the above example, the line type ink jet printer apparatus 1 has been taken and described as an example. However, the invention can also be applied to a serial type printer apparatus in which the recording head is moved in the direction perpendicular to the transport direction of the recording sheet.
The present application contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2009-298740 filed in the Japan Patent Office on Dec. 28, 2009, the entire contents of which are hereby incorporated by reference.
It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.
Number | Date | Country | Kind |
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P2009-298740 | Dec 2009 | JP | national |