Title:
PRINTING APPARATUS, PRINTING MEDIUM STORAGE APPARATUS, AND METHOD FOR STORING PRINTING MEDIUM
Kind Code:
A1


Abstract:
The present invention provides a printing medium storage apparatus, a printing apparatus, and a method for storing printing medium which prevent wrinkles and curl of a printing medium while preventing limitation of use according to the size of the printing medium. The printing apparatus performs printing on a sheet, and has a discharging port formed for discharging a sheet on which printing was performed, and a sheet storage apparatus which stores a printing medium on which printing was performed. The printing apparatus includes a sheet support surface which supports a sheet discharged from the discharging port, and a sheet pressing member which presses the sheet against the sheet support surface.



Inventors:
Tamaki, Masatoshi (Tokyo, JP)
Application Number:
12/266168
Publication Date:
05/21/2009
Filing Date:
11/06/2008
Assignee:
CANON KABUSHIKI KAISHA (Tokyo, JP)
Primary Class:
International Classes:
B65H29/00
View Patent Images:
Related US Applications:



Foreign References:
JPH03166157A1991-07-18
JPH0455260A1992-02-21
Primary Examiner:
GOKHALE, PRASAD V
Attorney, Agent or Firm:
Venable LLP (New York, NY, US)
Claims:
What is claimed is:

1. A printing apparatus performing printing on a printing medium, and the printing apparatus comprising: a discharging portion for discharging a printing medium on which printing was performed; a printing medium storage apparatus which stores printing medium on which printing was performed and which was discharged from the discharging portion; a printing medium support surface which supports the printing medium discharged from the discharging portion; and a printing medium pressing member which presses the printing medium against the printing medium support surface, wherein according to the size of the printing medium discharged from the discharging portion, a distance from the front end of the printing medium in the conveyance direction as a direction of conveying the printing medium to a pressing position at which the printing medium pressing member presses the printing medium can be adjusted.

2. The printing apparatus according to claim 1, wherein by changing the timing of pressing the printing medium to be conveyed, the pressing position of the printing medium by the printing medium pressing member is changed and the distance from the front end in the conveyance direction of the printing medium to the pressing position is adjusted.

3. The printing apparatus according to claim 1, to which a printing medium detecting unit for detecting that at least a part of the printing medium has passed through a predetermined position at the downstream of the discharging portion is attached.

4. The printing apparatus according to claim 1, to which a pushing-out member which pushes out a part of the printing medium to change the posture of the printing medium supported by the printing medium support surface into a predetermined posture is attached.

5. The printing apparatus according to claim 4, wherein when the rear end of the printing medium in the conveyance direction as a direction of conveying the printing medium is discharged from the discharging portion, a part of the printing medium is pushed out by the pushing-out member, and the rear end in the conveyance direction of the printing medium is positioned at the opposite side of the discharging portion with respect to the printing medium support surface.

6. The printing apparatus according to claim 5, wherein when a part of the printing medium is pushed out so that the rear end in the conveyance direction of the printing medium is positioned at the opposite side of the discharging portion with respect to the printing medium support surface, the printing medium pressing member withdraws from the printing medium support surface.

7. A printing medium storage apparatus which is attached to a printing apparatus performing printing on a printing medium and including a discharging portion for discharging a printing medium on which printing was performed, from the printing apparatus, and storing a printing medium on which printing was performed, comprising: a printing medium support surface which supports the printing medium discharged from the discharging portion; and a printing medium pressing member which presses the printing medium against the printing medium support surface, wherein according to the size of the printing medium discharged from the discharging portion, a distance from the front end of the printing medium in the conveyance direction as a direction of conveying the printing medium to a pressing position at which the printing medium pressing member presses the printing medium can be adjusted.

8. A method for storing printing medium for storage a printing medium on which printing was performed by a printing apparatus, into a printing medium storage apparatus, the printing medium storage apparatus comprising: a printing medium support surface which supports a printing medium discharged from the printing apparatus; a printing medium pressing member which presses the printing medium against the printing medium support surface; and a pushing-out member which pushes out a part of the printing medium so as to change the posture of the printing medium supported on the printing medium support surface into a predetermined posture, the printing medium storage method comprising: a printing medium discharging step in which the rear end of the printing medium in the conveyance direction as a direction of conveying the printing medium is discharged from the discharging portion of the printing apparatus; a pushing-out step in which a part of the printing medium is pushed out by the pushing-out member to position the rear end in the conveyance direction of the printing medium at the opposite side of the discharging portion with respect to the printing medium support surface; and a printing medium pressing member withdrawing step in which the printing medium pressing member withdraws from the printing medium support surface.

Description:

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a printing apparatus, a printing medium storage apparatus, and a method for storing printing medium to store a printing medium on which printing was performed and which was discharged.

2. Description of the Related Art

Nowadays, as image output apparatuses, printing apparatuses such as printers, plotters, copying machines, and scanners are widely used. Such printing apparatuses print images on a printing medium based on input image information. As a printing medium, a sheet-like printing medium such as a printing sheet or plastic sheet (hereinafter, referred to as a sheet) or the like is generally used. In some cases, a printing apparatus including a sheet storage apparatus structured so that after printing on the sheet is performed by the printing apparatus, a sheet on which printing was performed is placed on the sheet storage apparatus as a printing medium storage apparatus is used.

As a general sheet storage apparatus in such a printing apparatus, there is one constructed so that a sheet discharged in the horizontal direction or a diagonal direction approximate to the horizontal direction from the printing apparatus is placed on a tray set horizontally or inclined while spread.

A sheet storage apparatus having another construction has, as described in Japanese Patent Laid-Open No. H04-213550 (1992), a sheet conveyance path in which a sheet is discharged horizontally from the printing apparatus and then conveyed in a direction orthogonal to the sheet discharging direction. In this type of sheet storage apparatus, to discharge a sheet, first, the sheet is fed until the sheet front end contacts with a predetermined contact position. Then, by further feeding the sheet from the state where the sheet front end cannot move further, the rear end of the printing medium is pushed out so that the rear end of the sheet is positioned at the opposite side of the front end position of the printing medium with respect to the printing apparatus. By thus rotating the rear end of the printing medium around the front end of the printing medium at a predetermined angle determined according to the shape of the tray, the printing medium is transported to a predetermined stacked position. Thereafter, the printing apparatus continuously discharges a sheet on which printing was performed.

However, in some cases where a conventional sheet storage apparatus having a tray on which a sheet is stacked horizontally or in an inclined state close to horizontal is used, next sheet cannot be stacked in an aligned manner due to undesirable wrinkles and curl caused by the rolled form on a sheet already stacked on the tray. If wrinkles and curl caused by the rolled form remain on a sheet stacked on the tray, before a sheet discharged later reaches the stacking position, it comes into contact with a curl of the placed printing medium, and this obstructs sheet movement. Therefore, it becomes impossible to freely move the subsequent sheet on the conveyance path, and this causes sheet jam.

Further, when a sheet is stacked on the tray arranged horizontally or in an inclined state close to horizontal, the tray requires a space to stack at least equal to or larger than the area of the sheet. Therefore, when an especially large-sized sheet is conveyed and stored, a large space to stack the sheet is inevitably necessary, and the size of the construction of the sheet storage apparatus becomes large as a whole. Thus, when a sheet is stacked on a tray arranged horizontally or in an inclined state close to horizontal, the size of the sheet storage apparatus is determined according to the size of the sheet to be stored. Therefore, in this case, the degree of freedom in design of the sheet storage apparatus is small. Along with an increase in the size of the sheet storage apparatus, it is also necessary to increase the rigidity of the structure in the device for stacking a sheet.

To prevent jam of the printing medium due to wrinkles and curl caused by the rolled form on a sheet, the sheet storage apparatus disclosed in Japanese Patent Laid-Open No. H04-213550 (1992) has been proposed. This disclosed sheet storage apparatus is constructed so that, as described above, the front end of a printing medium contacts with a contact position and, in this state, by pushing out and rotating the rear end of the printing medium, the printing medium is conveyed. When a sheet is stored by using this sheet storage apparatus, it can be prevented that the printing medium becomes uneven due to wrinkles and curl caused by the rolled form of the sheet, and jam of the printing medium at a discharging portion of the printing medium in the printing apparatus can be prevented.

However, in this sheet storage apparatus, the distance between the discharging portion in the printing apparatus and the contact position is always constant, so that the size of the stackable printing medium is limited. In other words, a printing medium with a size over the distance between the discharging port of the printing apparatus and the contact position cannot be used. Further, even when the sheet storage apparatus disclosed in this Japanese Patent Laid-Open No. H04-213550 (1992) is adopted, there is still a possibility that a large curl is caused by the rolled form depending on the kind and size of the printing medium, and therefore, a case where the printing medium cannot be conveyed to a predetermined stacking space is assumed.

In the sheet storage apparatus of Japanese Patent Laid-Open No. H04-213550 (1992), a part of the printing medium is stacked on a space formed substantially horizontally. Therefore, in this portion, to stack an especially large-sized printing medium, it is inevitable that the sheet stacking device increases in size and the sheet storage apparatus increases in size, as well as in the sheet storage apparatus having a printing medium stacking space formed substantially horizontally as described above. Along with the increase in size of the sheet storage apparatus, it is also necessary to increase the rigidity of the sheet storage apparatus itself.

SUMMARY OF THE INVENTION

In view of the above-described circumstances, and an object thereof is to provide a printing medium storage apparatus, a printing apparatus, and a method for storing printing medium which prevent wrinkles and curl of a printing medium while preventing limitation of use depending on the size of the printing medium. At the same time, another object is to provide a printing medium storage apparatus, a printing apparatus, and a method for storing printing medium in which a space to stack a printing medium is downsized.

The present invention can provide a printing medium storage apparatus, a printing apparatus, and a method for storing printing medium which prevent wrinkles and curl of a printing medium without limiting use depending on the size of the printing medium.

Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a printing section of a printing apparatus and the entirety of a sheet storage apparatus of an embodiment of the present invention;

FIG. 2 is partially sectional view of the printing section of the printing apparatus and the sheet storage apparatus of FIG. 1;

FIG. 3 is partially sectional view of the printing section of the printing apparatus and the sheet storage apparatus of FIG. 1, showing a state during discharging of a sheet;

FIG. 4 is partially sectional view of the printing section of the printing apparatus and the sheet storage apparatus of FIG. 1, showing a state where the sheet is cut with a cutter;

FIG. 5 is partially sectional view of the printing section of the printing apparatus and the sheet storage apparatus of FIG. 1, showing a state where a part of the sheet is pushed out by a sheet pushing-out member and inverted;

FIG. 6 is partially sectional view of the printing section of the printing apparatus and the sheet storage apparatus of FIG. 1, showing a state where the sheet is stored in a sheet storage apparatus; and

FIG. 7 is a flowchart showing a flow of control in the sheet storage apparatus of the present invention.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The same reference numerals denote portions identical to or corresponding to each other among the drawings.

FIG. 1 is a perspective view showing a printing apparatus 200 including a sheet storage apparatus 100 as a printing medium storage apparatus of an embodiment of the present invention. In the present embodiment, the printing apparatus 200 is constructed as a printing apparatus 200 including the sheet storage apparatus 100 by attaching the sheet storage apparatus 100 to a printing section 201 which performs printing in the printing apparatus 200. FIG. 2 is a side view of the printing section 201 in the printing apparatus 200 and a sectional view along the line passing through the central portion of the sheet storage apparatus 100 and extending vertically. FIG. 3 and FIG. 4 show the printing apparatus 200 during conveying of a sheet to the sheet storage apparatus 100, and are a side view of the printing section 201 in the printing apparatus 200 and a sectional view along the line passing through the center of the sheet storage apparatus 100 and extending vertically. FIG. 5 and FIG. 6 show the printing apparatus 200 in which a sheet is placed on the sheet storage apparatus 100, and is a side view of the printing section 201 in the printing apparatus 200 and a sectional view along the line passing through the center of the sheet storage apparatus 100 and extending vertically.

The printing apparatus 200 used in the present embodiment is an ink-jet printing apparatus adapted to a large-sized printing medium. In the present embodiment, the printing apparatus 200 is an apparatus which prints images on a roll paper as a continuous printing medium, and includes a printing unit (printing head), a roll paper feeding mechanism 1, a roll paper and a sheet conveyance mechanism, etc., inside. The printing apparatus to be used in the present invention is not limited to the ink-jet printing apparatus adapted to a large-sized printing medium. The printing apparatus may not be a printing apparatus adapted to a large-sized object. The printing apparatus may not be an ink-jet printing apparatus, and may be a different type of printing apparatus as long as it can perform printing on a printing medium.

A sheet (sheet-like printing medium) drawn out from the roll paper is supplied to a printing head by the roll paper feeding mechanism 1, and images are printed thereon by a printing head not shown while it is conveyed by a sheet conveyance mechanism not shown. The printed sheet 11 is fed out from the discharging port 3 as a discharging portion. Further, inside the discharging port 3 in the printing apparatus 200, a cutter which can cut the rolled sheet at a predetermined position is arranged, and the printed sheet 11 is cut into a predetermined length with the cutter and discharged from the discharging port 3.

The printing head as a printing unit prints images (including characters and symbols) on a printing medium based on image information. When the printing head is an ink-jet type, printing is performed by ejecting inks onto the printing medium from a plurality of ejection ports of the printing head based on the image information. As the printing medium, a sheet-like printing medium such as a printing paper or plastic sheet is generally used. Hereinafter, it is also referred to as a sheet, simply. As the sheet-like printing medium, various printing media such as paper, a plastic sheet, a photographic printing paper, thread, fiber, cloth, leather, etc., can be used as long as images can be printed thereon.

The sheet storage apparatus 100 receives a sheet 11 discharged from the discharging port 3 of the printing apparatus 200 and temporarily stores and holds the sheet 11. The sheet storage apparatus 100 includes a sheet guide 4, a sensor 5, a sheet pressing member 6, a sheet support surface 7, and a sheet pushing-out mechanism 8 as a sheet storage mechanism. The sheet guide 4 guides the front end of the sheet 11 so that the sheet 11 to be discharged is fed out to a predetermined position. The sheet support surface 7 as a printing medium support surface receives the sheet 11 discharged from the discharging port 3 of the printing apparatus 200 and supports the sheet 11 to be stacked. The sheet support surface 7 has a spindle portion 9 on its end portion. In the present embodiment, the sheet support surface 7 which functions as a tray is set in a state where it is slightly inclined and extends in a direction close to the vertical. Therefore, in comparison with a tray formed substantially horizontally, the space necessary for installing the tray is small, so that the sheet storage apparatus 100 can be downsized.

The sensor 5 as a printing medium detecting unit detects passage of at least a part of the printing medium through a predetermined position at the downstream of the discharging port 3. In the present embodiment, the sensor 5 detects passage of the front end of the sheet 11 and detects positioning of the sheet 11 between the sheet guide 4 and the sheet support surface 7. The sheet pressing member 6 as a printing medium pressing member holds the sheet 11 by pressing it against the sheet support surface 7 by pressing the vicinity of the front end of the sheet 11 against the sheet support surface 7. Above the sheet guide 4, a sheet pushing-out mechanism 8 which pushes the sheet 11 out to the opposite side with respect to the printing apparatus 200 in the process of transfer of the sheet 11 to the sheet support surface 7 is arranged. The sheet pushing-out mechanism 8 inverts the sheet rear end by using the spindle portion 9 as a pivot by pushing out the discharged sheet 11 by a pushing-out bar 10. The sheet pushing-out mechanism 8 includes the pushing-out bar 10 as a pushing-out member which moves for inverting the rear end of the sheet 11, and a driving mechanism of the pushing-out bar 10, and a guide mechanism for guiding the movement of the pushing-out bar 10. By pushing-out a part of the sheet 11 by the pushing-out mechanism 8, the posture of the sheet supported on the sheet support surface 7 is set as a predetermined posture.

The sheet storage apparatus 100 is arranged so that the space between the sheet guide 4 and the sheet support surface 7 is positioned below the discharging port 3 for supplying the sheet 11 discharged from the discharging port 3 of the printing apparatus 200 to the space between the sheet guide 4 and the sheet support surface 7. At immediately below the printing section 201, a stand 2 which supports the printing section 201 and the sheet storage apparatus 100 is arranged. To the stand 2, a base 20 extending in parallel to the conveyance direction of the sheet 11 inside the printing apparatus 200 is attached, and to both ends in the conveyance direction of the base 20, wheels 21 are attached. Accordingly, the movement of the printing apparatus 200 is made easy.

Next, a method for storing printing medium until the sheet 11 is received from the printing apparatus 200 constructed as described above and stored will be described with reference to the flowchart of FIG. 7 and the sectional views of FIG. 2 to FIG. 6.

First, when printing information is input into the printing apparatus 200, a sheet size signal, a sheet type signal, and a sheet conveyance signal (feed amount of the conveyance roller and the number of printing passes of the carriage, etc.), etc., are supplied to the sheet storage apparatus 100, and in response to this, the sheet storage apparatus 100 starts operating.

Then, based on the input sheet size signal, it is judged whether the sheet to be discharged from the discharging port 3 of the printing apparatus 200 can be stored in the sheet storage apparatus 100 (S01). At this time, when it is recognized that the sheet cannot be stored in the sheet storage apparatus 100, after printing on the sheet is performed, the sheet is cut, and thereafter, the sheet is not stored in the sheet storage apparatus 100 but is taken out. When it is recognized that the sheet can be stored in the sheet storage apparatus 100, images are printed on the sheet while the sheet is conveyed (S02), and the sheet is conveyed so as to be stored in the storage apparatus 100. Herein, as shown in FIG. 3, the front end of the sheet 11 is fed out from the discharging port 3 and guided temporarily horizontally along the main body tray 12, and then supplied to the sheet storage apparatus 100 downward from the end portion of the main body tray 12.

Then, the sheet 11 is pushed and advanced downward along the sheet guide 4, and the front end of the sheet 11 enters between the sheet guide 4 and the sheet support surface 7. When the sheet thus enters the inside of the sheet storage apparatus 100, the sensor 5 provided in the sheet storage apparatus 100 detects this (S03). Further, by continuously feeding the sheet 11, the printing apparatus 200 reaches a predetermined conveyance distance since the printing apparatus 200 starts printing (S04). Thus, when the sensor recognizes that the sheet 11 has moved by the predetermined conveyance distance and that the sheet has reached a pressing position by the sheet storage apparatus 100, as shown in FIG. 4, the sheet pressing member 6 changes into an operating state from a withdrawn state. In the present embodiment, when the sheet pressing member 6 changes into the operating state, the sheet pressing member 6 rotates and comes into contact with the sheet 11 so as to be able to press the sheet 11. Then, the vicinity of the front end of the sheet 11 is pressed by the sheet pressing member 6. Thus, by pressing the sheet 11 against the sheet support surface 7 by the sheet pressing member 6 at a position between the sheet guide 4 and the sheet support surface 7, the sheet is sandwiched and stopped (S05). The predetermined conveyance distance as a trigger of the operation of the sheet pressing member 6 differs depending on the size of the sheet. For example, in the case of an A2-sized sheet, the predetermined conveyance distance is a conveyance distance until the sheet 11 comes to a position at which the pressing member 6 presses a portion 10 mm inward from the front end of the sheet since the sheet 11 is discharged from the discharging port 3. In the case of an A1-sized sheet, the predetermined conveyance distance is a conveyance distance until the sheet 11 comes to a position at which the pressing member 6 presses a position 100 mm inward from the front end of the sheet 11.

Thus, in the present embodiment, according to the size of the sheet 11 discharged from the discharging port 3 of the printing apparatus 200, the distance from the front end in the conveyance direction of the sheet 11 to the pressing position at which the sheet 11 is pressed by the sheet pressing member 6 can be adjusted. Herein, the conveyance direction is the direction in which the sheet 11 is conveyed by the printing apparatus 200. In the present embodiment, by adjusting the timing of pressing the sheet 11 to be conveyed according to the size of the sheet 11, the pressing position on the sheet 11 by the sheet pressing member 6 is adjusted. Accordingly, the distance from the front end in the conveyance direction to the pressing position of the sheet 11 is changed.

The distance from the front end in the conveyance direction to the pressing position of the sheet 11 can be adjusted according to the size of the sheet 11, so that the sheet storage apparatus 100 can store more type of printing media with comparatively less limitation according to the size of the printing medium. Therefore, the sheet storage apparatus can be widely applied. The size of the printing medium allowed to be stored by the sheet storage apparatus is comparatively less limited, so that when designing the sheet storage apparatus, it can be designed without limitation according to the size of the printing medium to be stored, and the degree of freedom in design is increased.

In the sheet storage apparatus like a conventional sheet storage apparatus in which a sheet contacts with a contact position and is stored, according to the distance between the sheet discharging portion in the printing apparatus and the contact position in the sheet storage apparatus, the size of the sheet which the sheet storage apparatus can store is limited. However, in the sheet storage apparatus of the present embodiment, it is possible to change the position at which the sheet pressing member 6 presses the sheet against the sheet support surface 7, so that the limitation on the sheet when pressing the sheet against the sheet support surface 7 is less.

To adjust the position of pressing the sheet by the sheet pressing member 6, the attaching position of the sheet pressing member 6 to the sheet storage apparatus 100 may be shifted and adjusted. Further, the adjustment of the timing of pressing the sheet and shifting of the attaching position of the sheet pressing member 6 can be adopted concurrently. By adopting these concurrently, the pressing position on the sheet can be more flexibly adjusted, so that more type of printing media can be stored. In addition, the degree of freedom in design of the sheet storage apparatus is further increased. In the present embodiment, the sheet pressing member 6 is a rotation type, however, the present invention is not limited thereto, and the sheet pressing member 6 may be a slide type or other types.

Further, as shown in FIG. 4, when the printing is finished (S06) and the sheet 11 is conveyed by a predetermined distance, the rear end of the sheet 11 is cut with a cutter while the vicinity of the front end of the sheet 11 is sandwiched (S07). Thus, in the sheet discharging step (printing medium discharging step), the sheet 11 is cut and the rear end in the conveyance direction of the sheet 11 is discharged from the discharging port 3 of the printing apparatus 200. When the sheet 11 is cut, a sheet pushing-out bar 10 included in the sheet pushing-out mechanism 8 temporarily moves from the withdrawn position shown in FIG. 4 to the maximum extended position of the sheet pushing-out bar 10 shown in FIG. 5. As shown in FIG. 5, when the sheet 11 is cut and the rear end of the sheet 11 in the conveyance direction is discharged from the discharging port 3, a part of the sheet 11 is pushed out by the sheet pushing-out bar 10. Thus, in the pushing-out step, to position the rear end in the conveyance direction of the sheet 11 to the opposite side of the discharging port 3 of the printing apparatus 200 with respect to the sheet support surface 7, a part of the sheet 11 is pushed out by the sheet pushing-out bar 10. In the present embodiment, the vicinity of the portion of the sheet 11 corresponding to the spindle portion 9 of the sheet support surface 7 when the sheet 11 is placed on the sheet support surface 7 is pushed out.

Then, as shown in FIG. 6, the sheet pushing-out bar 10 is returned to the withdrawn position. By the series of operations of the sheet pushing-out mechanism 8, the rear end of the sheet 11 is inverted around the spindle portion 9 as a pivot provided on the sheet support surface 7, and is positioned at the opposite side of the discharging port 3 across the spindle portion 9 as a pivot. In other words, the sheet 11 turns into a posture in which the rear end in the conveyance direction of the sheet 11 is positioned at the opposite side of the discharging port 3 with respect to the sheet support surface 7. Thus, the sheet 11 is stacked in a predetermined posture at a predetermined position of the sheet support surface 7 (S08). The predetermined posture in the present embodiment is a posture in which a region from the front end to a substantially central portion in the conveyance direction of the sheet 11 is supported on the sheet support surface 7 and the rear end in the conveyance direction of the sheet 11 is positioned at the opposite side of the discharging port 3 with respect to the sheet support surface 7. In this case, the sheet 11 is bent at the substantially central portion of the sheet 11 which corresponds to the spindle portion 9 of the sheet support surface 7, and has a V-shape.

As shown in FIG. 6, when the sheet 11 is placed at the predetermined position on the sheet support surface 7 in the predetermined posture, the sheet 11 is positioned away from the sensor 5, so that the sensor 5 does not detect the sheet 11 (S09). Thus, when a part of the sheet 11 is pushed out so that the rear end in the conveyance direction of the sheet is positioned at the opposite side of the sheet support surface 7 with respect to the printing apparatus 200, the sheet pressing member 6 stops pressing the sheet 11, and withdraws so as to separate from the sheet support surface 7. Thus, in the sheet pressing member withdrawing step (printing medium pressing member withdrawing step), the sheet pressing member 6 withdraws from the sheet support surface 7 and changes into a withdrawn state from the operating state. In this state, the sheet storage apparatus 100 recognizes that the sheet pressing member 6 has changed into the withdrawn state from the operating state, and the operation of the sheet storage apparatus 100 is completed (S10). It is detected by using the sensor 5 that the sheet 11 has been placed at the predetermined position of the sheet storage apparatus 100 in the predetermined posture. When the sheet 11 is not placed at the predetermined position in the predetermined posture, subsequent printing operations of the printing apparatus 200 are suspended. Accordingly, it is prevented that a next sheet is supplied when the sheet is not placed at the normal position in the normal posture and causes paper jam and a stacking failure, etc., in the printing apparatus 200.

By pushing-out a part of the sheet 11 by the sheet pushing-out bar 10, the rear end of the sheet 11 is inverted around the spindle portion 9 as a pivot, so that the sheet 11 is bent in a direction opposite to the direction in which wrinkles and curl usually occur on the printing medium. Accordingly, wrinkles and curl of the sheet 11 after the sheet 11 is stored in the sheet storage apparatus 100 are prevented.

In the present embodiment, the sensor 5 is provided, however, the present invention is not limited to this, the sensor 5 may not be provided as long as paper jam and a stacking failure, etc., are allowed. In the present embodiment, to invert the rear end of the sheet 11, the sheet pushing-out mechanism 8 is provided and, particularly taking a sheet having a large curl due to the rolled form into consideration, assists the inversion of the sheet. However, the present invention is not limited to this, and the sheet pushing-out mechanism may not be provided when the curl due to the rolled form are disregarded.

The series of operations for storage the sheet on which printing was performed by the printing section 201 of the printing apparatus 200 into the sheet storage apparatus 100 are as described above. Then, when a sheet is continuously stored and stacked into the sheet storage apparatus 100, by continuing the series of operations, a plurality of sheets can be continuously stored. Herein, in the present embodiment in which the first sheet is stored, the sheet pressing member 6 presses the sheet for the first time when the sheet reaches the pressing position. For sheets supplied second and subsequently, by simply repeating the above-described process, the sheet storage apparatus can store the sheets continuously. However, when storage the second and subsequent sheets, to hold the sheets stored previously, the sheet pressing member 6 is allowed to press the sheets stored previously immediately before the next sheet reaches the pressing position. Then, the sheet pressing member is allowed to temporarily withdraw immediately before the next sheet reaches the pressing position, and then press the sheets again when the next sheet reaches the pressing position. Accordingly, the time for pressing and holding the previously stored sheets by the sheet pressing member 6 becomes long, so that the previously stored sheets are more stably held by the sheet storage apparatus.

As described above, in the present embodiment, the printing apparatus 200 is constructed as a printing apparatus 200 including the sheet storage apparatus 100 by attaching the sheet storage apparatus 100 to the printing section 201 which performs printing in the printing apparatus 200. However, the printing apparatus and the sheet storage apparatus of the present invention are not limited to this, and the sheet storage apparatus may be constructed separately. This sheet storage apparatus may be constructed so as to be attached to various printing apparatuses. It is also allowed that the printing section which performs printing of the printing apparatus and the sheet storage apparatus are formed integrally and constructed as one printing apparatus 200.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

This application claims the benefit of Japanese Patent Application No. 2007-297266, filed Nov. 15, 2007, which is hereby incorporated by reference herein in its entirety.