JPH0480177A - Receiving device for paper sheet - Google Patents

Abstract

NEW MATERIAL:To eliminate turbulence of alignment property by comparing the size of a paper sheet discharged from an image forming device main body with the size of a paper sheet directly before charging, prohibiting image forming process in the main body when the size is changed from a small one to a large one, and preventing to load a large paper sheet on a small one. CONSTITUTION:When no paper sheet on an upper tray 70 is detected with a sensor SE2, prohibition of printing is released, a paper sheet is printed and received on the upper tray 70. Nextly, the size of this paper sheet is compared with the size of a paper sheet herefrom to be printed, at no change the new one is processed for printing, and received on the tray 70. If there is change, it is received on a lower tray 70a. When there is a paper sheet in the lower tray 70a, the size of this paper sheet is compared with the size of the paper sheet herefrom to be printed, and if the latter is larger, printing process is prohibited. Consequently, a large size paper sheet is not loaded on small one, and alignment property of the paper sheet is not disturbed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a paper storage device, particularly a paper storage device in which sheets that can be ejected from an image forming apparatus body such as an electrophotographic copying machine or a laser printer are stacked and stored on a tray. Regarding equipment.

2. Description of the Related Art Laser printers sometimes perform a large amount of printing at one time, and for this purpose various paper storage devices equipped with large-capacity trays have been proposed.

Generally, this type of paper storage device is equipped with an elevator mechanism that lowers the tray in steps according to the amount of paper loaded, and a mechanism that shifts the tray at a predetermined timing. It is configured to selectively feed paper into each tray.

On the other hand, in the printer itself, printing is performed continuously in order to increase the printing efficiency, and even sheets of different sizes can be ejected continuously. By the way, if paper of different sizes is stacked and stored in the same tray, for example, if large-sized paper is stacked on top of small-sized paper, the large-sized paper will slide off from the small-sized paper, and the alignment of the paper will be disrupted. This has the problem that it is impossible to sort the sheets using the shift mechanism.

Regarding paper size, as described in Japanese Patent Application Laid-Open No. 180680/1983, when a larger size paper is loaded on top of the paper already loaded on the tray, it is possible to change the full load amount depending on the paper size. Are known. However, even in this device, there remains a possibility that the large size paper may slip off from the small size paper.

OBJECTS, STRUCTURES, AND OPERATIONS OF THE INVENTION Therefore, an object of the present invention is to provide a paper storage device that can load and store papers without disturbing the alignment of the papers. Furthermore, an object of the present invention is to ensure the alignment of sheets by focusing on the fact that even if the paper is of a different size, the alignment will not be disturbed when a ``2'' size paper is stored on top of a large size paper. In addition, it is an object of the present invention to provide a paper storage device that can improve the printing efficiency of the printer main body. Furthermore, in addition to the above-mentioned object, it is an object of the present invention to provide a paper storage device that can efficiently use a plurality of trays.

In order to achieve the above object, a paper storage device according to the present invention includes a tray for storing paper, a detection means for detecting the size of the paper, a size of the paper that can be completely ejected from the main body of the image forming apparatus, and a paper storage device that detects the size of the paper that can be completely ejected from the main body of the image forming apparatus. The image forming apparatus includes a comparison means for comparing the size of the ejected paper, and a control means for prohibiting the image forming process in the main body of the image forming apparatus when the comparison means determines that the paper size has been changed.

In the above configuration, when a sheet of a size different from the sheets that have been ejected so far from the main body of the image forming apparatus is completely ejected, image forming processing is prohibited. Therefore, sheets of different sizes will not be completely stacked on the tray, and disturbances in the alignment of the sheets can be prevented.

Further, the paper storage device according to the present invention includes a control unit that prohibits image forming processing in the main body of the image forming apparatus when the comparing unit determines that the paper size has been changed from a small size to a dog size. In this case, disturbances in the alignment of large-sized paper can be prevented, and even if the paper size is changed from dog size to small size (in this case, the paper will not be disordered). The image forming process continues N times, increasing printing efficiency.

Furthermore, the paper storage device according to the present invention includes a plurality of trays, a paper transport means for selectively feeding paper into one of these trays, a detection means for detecting the presence or absence of paper in each tray, and a paper storage device for detecting the presence or absence of paper in each tray. a detection means for detecting the size; a first comparison means for comparing the size of the paper that can be ejected from the main body of the image forming apparatus with the size of the paper that was ejected immediately before; and a first comparison means that compares the size of the paper that will be stored in each tray If it is determined that the paper size has been changed by the second comparison means that compares the size of the latest paper stored so far and the first comparison means, the paper is not stored or will be stored in the future. and a control means for controlling the paper transport means so as to send the paper to a tray containing paper of a size larger than the paper.

In the above configuration, the tray into which paper is fed is
The dog size paper is selected so that it is not stacked on top of the IJX size paper and becomes misaligned, and multiple trays are used efficiently to increase print operating efficiency.

Embodiments Hereinafter, embodiments of the paper storage device according to the present invention will be described with reference to the accompanying drawings.

[First embodiment, see Figures 1 to 10] The first embodiment is as follows:
A paper storage unit configured as a dual job stacker consisting of upper and lower paper storage trays each having an independent elevator mechanism and shift mechanism is shown. FIG. 1 shows a state in which this paper storage unit (60) is attached to the laser printer main body (1) via a paper reversing unit (50).

The printer main body (1) is set on a desk (40), and a photosensitive drum (10) is installed approximately in the center so as to be rotatable in the direction of arrow (a). Photosensitive drum (10
) are surrounded by an electrostatic charger (11), magnetic brush developing devices (12), (13), and a transfer charger (14).
), paper separation charger (15), residual toner cleaning device (16), residual charge eraser lamp (17)
) etc. are installed. The image is exposed on the photosensitive drum (10) by the laser beam scanning optical system (2) immediately after the charging process. Note that the printing process using these elements is well known, and the explanation thereof will be omitted.

On the other hand, on the left side of the printer body (1) in the figure, automatic paper feed cassettes (21), (22), and (23) are installed in three tiers, and the desk (40) has an optional elevator-type automatic feed cassette. A paper unit (24) is installed.

The size of the paper loaded in each cassette (21>, (22), (23) and paper feed unit (24) can be detected by sensors (SELL) to (SE14), respectively. ), (22), (23
), from the paper feed unit (24) to each paper feed roller (
25) to (28), the sheets are selectively fed one by one. In the figure, the thick line indicates the paper passing route.

Each sheet of paper is first shredded by a timing roller (30) and sent to a transfer section in synchronization with the image formed on the photosensitive drum (10). After the toner image has been transferred, the paper is conveyed to the fixing device (32) by the conveyor belt (31), where the toner is heated and fixed, and then transferred to the discharge roller (
33) to the outside of the printer main body (1), that is, into the paper reversing unit (50).

The paper reversing unit (50) uses rollers (36) for double-sided printing to print on the other side of paper that has already been printed on one side, or for composite printing to print overlappingly on the same side.
, (37), etc.; face-up paper ejection (non-reversing mode) that transports the paper straight to the paper storage unit (60); and transport that allows the paper to be reversed. It also has the ability to selectively process face-down paper ejection (reverse mode).

In order to achieve the above functions, the paper reversing unit (50
) are the receiving roller (51), the sending roller (52), the forward/reverse switching rollers (53), (54), the paper refeed roller (55), the paper feeding switching claws (56), (57), and the switchback path. (58). Switching claw (56
), (57) can switch the rotation angle between two positions using a solenoid (not shown).

In the non-reversing mode, the paper is completely guided from the receiving roller (51) by the upper surface of the switching claw (56), and completely sent out from the delivery roller (52) to the paper storage unit (60) in a face-up state. In the reversal mode, the paper is guided from the receiving roller (51) to the left side of the switching claw (56), and from the normal rotating roller (53) to the switching claw (5).
7), the leading edge of the paper reaches the switchback path (58) through normal rotation of the roller (54). When the trailing edge of the paper reaches the reversal point (Q),
The rollers (53) and (54) are switched to reverse rotation.

At this point, move the paper with the previous trailing edge at the beginning using the switching claw (
56), and is sent face down from the delivery roller (52) to the paper storage unit (60).

On the other hand, in the duplex print mode, the paper is completely conveyed to the switchback path (58) as in the reversal mode,
When the trailing edge of the paper reaches the reversal point (P), the rollers (54) are switched to reverse rotation. Here, the paper is guided by the lower left surface of the switching claw (57) with the previous trailing edge leading, and is then guided from the paper refeed roller (55) to the paper refeed path (35).
). In the composite print mode, the paper is guided from the roller (53) by the upper left surface of the switching claw (57), and from the refeed roller (55) to the refeed path (35).
sent to.

The paper storage unit (60) has two trays (70
), (70a) and a paper transport section (61),
The trays (70) and (70a) are each movable in a direction perpendicular to the sheet conveyance direction, and can be moved up and down depending on the amount of sheets loaded.

The paper transport section (61) includes transport rollers (62) to (66) and a paper passage switching claw (67) installed between the transport rollers (62) and (63). The switching claw (67) can be switched between two rotational angles by a solenoid (not shown), and its upper surface guides the paper to the conveying roller (63) and stores it in the upper tray (70). Further, the switching claw (67) guides the paper downward with its left side surface and allows the paper to be accommodated in the lower tray (70a) through the conveyance rollers (64) to (66). In addition, a conveyance roller (63),
Immediately after (66), a sensor (SEI>, (SEla) for detecting the passing paper is installed.

The trays (70) and (70a) each have a box (7
1).

The tray (71a) is installed to be shiftable in the direction orthogonal to the paper storage direction and to be movable up and down.
), right below (70a) is a shift motor (73),
(73a) and elevator motor (74), <74a
) is installed, and a shift mechanism and an elevator mechanism (not shown) enable shifting operations and lifting/lowering operations. The shift mechanism has a cam (81) fixed to a support shaft (80) that can transmit rotational force from a shift motor (73).
) is engaged with -IL<85) of the shift plate, and the shift plate is integrally moved with the tray (70) in the arrow (A) and (A') directions (
It is movable in the direction perpendicular to the paper storage direction). In addition, the outer peripheral surface of the cam <81) has notches (
80a).

(80b) are formed, and the actuator (86) of the sensor (SE6) can engage with these notches (80a) and (80b). When the predetermined printing process is completed in the printer body (1), the shift motor (73) is started, the cam (81) is rotated in the direction of arrow (b), and the tray (70) is moved to (A> or (8). When the actuator (86) falls into the notch (80a) or (80b), the sensor (SE6) turns off,
This turns off the shift motor (73). That is, the tray (70) is shifted (
(round trip). On the other hand, the elevator mechanism includes a pinion and a tray (
70), and the details thereof will be omitted.

Note that the configurations of the trays (70) and (70a) themselves and the configuration of their surroundings are exactly the same, and the upper tray (7o) will be described below.
), and regarding the lower tray (70a>), the reference numeral (a) is added in the box, and the explanation thereof will be omitted.

A vertical pair of ejection rollers (75) provided in the box (71) sends out the paper sent from the transport section (61) onto the tray (70>.Ejection roller pair (75)
A paddle wheel (not shown) is installed on the lower roller so that it can rotate integrally with the lower roller, and applies a biasing force in the opposite direction to the storage direction to the rear end of the paper stored on the tray (7o), Align the paper on the tray (7o). The rear end of the paper can be regulated by a back plate located opposite the lower end of the tray (7o). A sensor (SE2) is installed in the tray (7o) to detect the presence or absence of paper on the tray (70).

In order to maintain the proper position (height) of the tray (70), a sensor (SE3) and an actuator (76) are installed to detect the loading surface of the tray (70) itself and the top surface of the stored sheets. There is. The proper position of the tray (70) is defined as a height where the sheets can be accommodated with good alignment by the paddle wheels, specifically, a position from the nip portion of the ejection D-ra pair (75) to the loading surface of the tray (70) or the storage area. This refers to the height to the top of the paper, and there is a certain vertical permissible width. The sensor (SE3) is for detecting the upper limit of the proper position. That is, the actuator (76) is rotatable about the pin (77), and its tip has a shape that follows the outer peripheral surface of the lower roller of the discharge roller pair (75), and the upper surface of the lower end of the tray (70). The rear end portion can be moved forward and backward toward the optical axis of the sensor (SE3).

This actuator (76) is constantly biased clockwise around the pin (77) by a spring (not shown) and is fully set to the position shown by the solid line in FIG. 1, at which time the sensor (SE3) is in the OFF state. Paper is in the tray (70)
When the upper surface of the paper reaches the upper limit of the proper position, the actuator (76) is biased against the upper surface of the paper and rotates slightly counterclockwise, turning on the sensor (SE3). Based on this ON signal, the elevator motor (74) is turned on in the downward direction, and the tray (70) descends. The actuator (
76) returns in the clockwise direction and the sensor (SE3) is turned off, the elevator motor (74) is turned off. In this manner, the tray (70) is lowered by one step by a predetermined amount when the stacked amount of paper increases and the upper surface of the paper reaches the upper limit height.

If the paper capacity is exceeded, check the sensor (SE4) installed at the bottom of the box (71) or the tray (SE5) that has been lowered.
The determination can be made by detecting 70). When a large size paper can be completely discharged from the printer main body (1), the upper sensor (SE4) is used up, and when a small size paper can be completely discharged, the lower sensor (SE5) is used up. This switching is done by a sensor (SEII) installed in the paper feed section.
This is performed based on the paper size signal from ~(SE14).

When the paper is removed from the tray (70), the tray sensor (SE2) is turned off, and based on this off signal, the elevator motor (74) is turned on in the upward direction, and the tray (70) is turned on until the upper limit sensor (SE3) is turned on. 70) increases,
Return to initial position.

On the other hand, each time the information of the - group is printed out, the shift motor (73) is driven until the sensor (SE6) is turned off, and the tray (70) is moved with the eccentricity of the pin (82) in a direction perpendicular to the storage direction. Moves at a constant pitch according to the amount,
A group of sheets is sorted by this reciprocating movement.

In this embodiment, the upper tray (
70> is used preferentially, and the lower tray (70a) is used after the upper tray (7o) is full or when the paper size has been changed. When changing the paper size, refer to the flowchart and follow the instructions below.
Can be controlled so that dog-sized paper does not fit on top of small-sized paper. If the size of the paper that can be printed on changes from the size of paper that could be printed on up to that point, the paper that is being printed on in the printer main body (1) is large and cannot be placed in either the tray (70) or (70a). If "mono"-size paper is already stored, printing processing is prohibited. On the other hand, if the lower tray (70a) has not yet been filled with paper, subsequent sheets will be stored in the lower tray (70a).
It can be accommodated in 0a). If the lower tray (70a) is full of paper, the paper size is compared with the changed paper size, and the changed paper is stored in the lower tray (70a).
If the size of the paper is smaller than the paper already stored in a), the lower tray (70a) is shifted and the subsequent paper is stored in the lower tray (70a). On the other hand, if the paper size after the change is large, the upper tray (70) should be reviewed6, that is, the size of the paper currently stored in the upper tray (70) can be compared with the paper size after the change, and the size of the paper after the change can be compared. If the subsequent paper is of small size, the upper tray (70) can be shifted and the subsequent paper is stored in the upper tray (70). If the size is large, either tray (70), (
70a), the alignment of the sheets cannot be guaranteed, so printing processing is prohibited.

Note that when the paper size is changed, instead of immediately comparing the paper size on the lower tray (70a), the paper size on the upper tray (70) is compared and the paper size after the change is determined to be small. If so, it may be stored in the upper tray (70).

By the way, in this embodiment, the paper sizes that can be printed by the printer main body (1) are A3 and A4.

B4 and B5, A3 and B4 have only vertical feed, and A4 and BS are divided into vertical feed and horizontal feed. Vertical feeding refers to conveying a sheet with its long side direction parallel to the conveyance direction. Transverse feeding refers to conveying a sheet with its short side direction parallel to the conveyance direction.

Therefore, the same A4. Even if the size is B5, if the conveyance direction is different, the size will be different.

FIG. 3 shows the control circuit of the entire system.

On the printer side, there are a control processor (100) that controls the printer main body (1), a control processor (101) that controls the laser beam optical system (2), and a paper reversing unit (
a control processor (102) that controls the paper storage unit (60); and a control processor (103) that controls the paper storage unit (60).
). Print information is printed on the host computer (110)
The data can be sent from the host interface (111) to the image creation controller (112). The image creation controller (112) sends image information to be printed to the optical system control processor (113) via the video line (113).
101), and also sends the print mode, etc. to the interface control processor (115) via the control line (114). This interface control processor (115) has a serial interface (11
6) communicates with each processor (100) to (103) in various modes. That is, the interface control processor (115) controls each processor (100) to (1
03) receives various information such as paper size, paper jam, paper passage, etc., and each processor (100) to (10
3) Send the necessary information to. Then, the interface control processor (115) turns on the display section (117) of the operation panel on the printer body (1).

Control off. The display section (117) displays each processor (10
0) to (103) are displayed externally based on instructions from the processor (115).

FIG. 4 shows a schematic configuration of a processor (1o3) that controls the paper storage unit 1-(60).

This processor (103) is mainly composed of CPU (120), RAM (121), and FROM (122).
It is equipped with RAM (121) is stored in the upper tray (70
) and a C memory that stores the empty data of the lower tray (70a), a C memory that stores the latest paper size data of the upper tray (70), an E memory that stores the latest paper size data of the lower tray (70a), and a processor (1).
15), which stores the paper size data currently being transmitted from 15). Connected to the output port of the CPU (120) are drive circuits for the switching claw (67) drive solenoid, paper transport motor, shift motors (73), (73a), and elevator motors (74), (74a). In addition, each sensor (SEI) to (SE5), (SEla) is connected to the input port of the CPU (120).
~(SE5a), tray (70).

(70a) shift position sensor (SE6), (
SE6a) is connected.

Next, the control procedure of the processor (103) that controls the paper storage unit (60) will be explained with reference to FIGS. 5 to 10.

FIG. 5 shows the main routine of the CPU (120). When the power is turned on and the program starts, initial settings are first performed in step (Sl), and various flags, timers, and counters are reset. Next, step (52),
(53) through the serial interface (116) to other processors (100), (101), (1
02).

(115), and if it is determined in step (separate) that sequence control of print processing has started, a subroutine for paper storage processing is executed in step (B5).

FIG. 6 shows a subroutine for the sheet storage process that can be executed in step (B5).

First, in step (511), a tray to accommodate paper is selected. In steps (512) and (513), the tray is lowered/raised to set the tray height to an appropriate position. In step (514), the tray is shifted to separate the sheets, and in step (515), sequence control of sheet conveyance, paper jam detection, etc. is processed.

FIG. 7 shows a subroutine for tray selection processing executed in step (Sll).

In steps (521) to (525), a print prohibition flag for prohibiting print processing is reset to "rO". When the print prohibition flag is set to ``1'', the print process that is about to be performed in the printer body (1) is prohibited, and when it is reset to ``0'', the print process is permitted.

First, in step <521>, the sensor (SE2) is turned on.

By turning off, it is determined whether there is paper on the upper tray (70), and if there is no paper, the print prohibition flag is reset to "rO" in step (522), and the process moves to step (526). If there is paper on the upper tray (70), it is determined in step (523) whether or not the print prohibition flag is "0." If it is reset to '0', the process directly proceeds to step (526). If the print prohibition flag has been set to "rl", the sensor (5
The presence or absence of paper on the lower tray (70a) is determined by turning on or off E2a). If there is no paper, go to step (5)
In step 25), the print prohibition flag is reset to "0" and the process moves to step (526). If there is paper on the lower tray (70a), this subroutine is immediately ended.

That is, here, the upper tray (70) can be selected preferentially.

Next, in step (526), the size of the sheet to be ejected (printed) from now on is compared with the size of the sheet ejected immediately before to determine whether or not it has been changed. If there is no change in size, this subroutine ends immediately. Therefore, NO in step (521) and step (5
If YES in step 23), the paper is stored in the upper tray (70). Also, if No at Ste/B (524),
The paper is stored in the lower tray (70a). If there is a change in size, the presence or absence of paper on the lower tray (70a) is determined in step (527) by turning on and off the sensor (SE2a). If there is no paper [No in step (527)], the switching claw (67) is set to the lower guide position in step (531), and this subroutine is ended.

That is, when the paper size is changed, the lower tray (70
a) If no paper is stored above, subsequent papers can be stored in the lower tray (70a).

On the other hand, if there is paper on the lower tray (70a) [YES in step (S27)], in step (528) the size of the paper stored in the lower tray (70a) is compared with the changed paper size. do. Here, as shown in FIG. 8, in step (541) the currently transmitted (changed) paper size data is called from the F memory in the RAM (121), and in step (542) it is read from the lower stage of the E memory. Recall the latest paper size data in the tray (70a). These data are stored as positive numbers that increase in size from small to large as shown in Table 1 below. Large size and small size are relative concepts considering the difference in paper conveyance direction.
And so.

[Margin below] Next, in step (543), data F and data E are compared, and if the changed paper size (data F) is less than or equal to the size of the paper already stored (data E), [step YES in step (543)], flag A is reset to 10 in step (544), and if the dog size has been changed [NO in step (543)], step (54)
In step 5), flag A is set to 11. Flag A is “0”
．． When the paper is reset to the lower tray (70a)
), and when set to ``1'' prohibits it.

Said steps (543), (544), (545)
When the process is completed, the process returns to FIG. 7 and goes to step (529).
) to determine whether flag A is 11. If it has been reset to "0", the changed paper size is smaller than the size of the paper currently stored on the lower tray (70a), so the lower shift flag is set to 1 in step (530).
1", and in step (531) turn the switching claw (67
) to the lower guide position, and this subroutine ends.

On the other hand, if flag A is determined to be "1" in step (529), the changed paper size is larger than the size of the paper currently stored on the lower tray (70a), so step (532) Upper tray (70) below
Check. That is, in step (532) the sensor (
The presence or absence of paper on the upper tray (70) is determined by turning on or off SE2), and if there is no paper, the process proceeds to step (53).
6), set the switching claw (67) to the upper guide position,
End this subroutine. That is, the upper tray (70
), the subsequent sheets can be stored in the upper tray (70). Upper tray (7
0) If there is paper on top [YES in step (532)]
In step (533), the size of the paper stored in the upper tray (70) is compared with the changed paper size. Here, as shown in FIG. 9 (basically the same as the flowchart in FIG. 8), in step (551), the changed paper size data is called from F memory, and in step (552), the changed paper size data is called from D memory. The latest paper size data in the upper tray (70) is called from. Subsequently, in step (553), these data F and D (see Table 1 above)
and if the changed paper size (data F) is less than or equal to the already stored paper size data (data D) [YES in step (553)], step (554)
If the size has been changed to large, set flag B to rO in step (553) and set flag B to rl in step (555). Flag B
is reset to "0", the paper is placed in the upper tray (
70), and when set to ``1'' prohibits it.

Said steps (553), (554), (555)
When the process is completed, the process returns to FIG. 7 and goes to step (534).
) to determine whether flag B is 11. If it has been reset to "0", the paper size after the change is smaller than the size of the paper currently stored on the upper tray (70), so the upper shift flag is set to rl in step (535).
”, and in step (536) turn the switching claw (67).
is set to the upper guide position, and this subroutine ends.

On the other hand, if it is determined that the flag B is "1" in the step (534), the paper size after the change is larger than the size of the paper currently stored on the upper tray (70), so in this case, the paper tray (70).

(70a) is not appropriate, and the print prohibition flag is set to "1" in step (537). With this, printing processing in the printer main body (1) is prohibited.

FIG. 10 shows the tray shift subroutine that can be executed in step (514).

First, in steps (560) and (565), it is determined whether the upper shift flag or the lower shift flag is 11.
If each is set to "1", step (561
) to (564) and (566) to (569) to shift the upper tray (70) or lower tray (70a). That is, the shift motors (73) and (73a) are turned on in steps (561) and (566), and step <56
2), shift detection sensor (SE6) at (567).

(SEaa) (7) If on-edge (switching from off to on) is confirmed, step (563), <5
68) to turn off the shift motors (73) and (73a), and step (S64).

(569) sets the upper shift flag and lower shift flag to 1.
0'' and end this subroutine.

In the above control procedure, in order to ensure the alignment of dog-sized paper on the tray, large-sized paper is stored on top of small-sized paper based on the size criteria shown in [Table 1]. I avoided that.

However, as mentioned above, size is only relative, and assuming the tray is shifted, if the center of gravity of the paper to be accommodated later is on the paper already accommodated, then The paper that can be accommodated (after changing the size) will not shift. Therefore, if the paper sizes have such a relationship, there will be no problem even if the changed paper is stacked on top of the already stored paper without setting flags A and B to "1". Does not occur. [Table 2] shown below shows the paper size after the change, the size of the paper already stored in the tray, and the flag A.

This shows the relationship B. Therefore, steps (543), (544), (545) based on the above [Table 1]
) or (553), )554), or (555), compare the paper sizes based on [Table 2] and cerat or reset flags A and B to "1." or "0". Good too.

[Referring to the margin below, in the above control procedure, when the change in paper size is confirmed in step (526), the lower tray (7
0a), but instead, the state of the upper tray (70) is checked [step (532),
(533) When flag B is set to "1", check the state of the lower tray (70a) and [
Steps (527) and (528), flag A is 11
``, the print prohibition flag may be set to ``rl''.

[Second Embodiment, see FIGS. 10 and 11] This second embodiment is provided with only one tray, and the device includes the middle lower tray (70a) and the switching claw (67) in FIG. ) and the paper transport section to the lower tray (70a) can be used.

Here, when the size of paper that can be ejected from the printer main body (1) is changed, in order to ensure the alignment of the paper after the change on the tray (70), the printer main body (1) is
1) Prohibits print processing.

Specifically, in addition to the flowcharts in FIGS. 5 and 6 in the first embodiment, control is performed based on the flowcharts in sections 11 and 12.

The tray selection subroutine executed in step (511) in FIG. 6 is executed as a paper acceptance determination subroutine shown in FIG. That is, step (5101
) to determine whether flag C is 11.

When the flag C is reset to "rO", it is allowed to feed the paper into the tray (70), and when it is set to "1", it is prohibited. If flag C is reset to 10, the printer body (1
) to compare the size of the paper that can be printed from now on with the size of the paper that was ejected immediately before. Step (5
The processing at step 102) is similar to the processing at the subroutine shown in FIGS. 8 and 9 in the first embodiment. That is, as shown in FIG. 12, steps (5111), (5
112), the paper size data that will be accommodated from now on and the paper size data that was accommodated immediately before are called from the F memory and D memory, and the data F is read in step (5113).
, D. The pigs are the same as those shown in [Table 1] above, and if the paper size is not changed, [Step (5)
113), flag C is set in step (5114).
Reset to 10. On the other hand, if the paper size has been changed [Step (5113) TNO, Step <5115) Set T7 Lug C to "1."

Now, returning to FIG. 11, in step (5103) it is determined whether the flag C is rl. rl", the paper size has been changed, so step (51)
In step 04), the print prohibition flag is set to "1" and subsequent print processing is prohibited. This eliminates the possibility that the alignment of the sheets will be disturbed. On the other hand, if flag C has been reset to "0" [No in step (5103)],
Or, even if flag C is set to ``1.'', YES in E step (5101)], step (5105).
), the tray (70
), and if there is no paper, there will be no paper alignment problem, so flag C is reset to "0" in step (5106), and step (5107) is performed.
The print prohibition flag is reset to "0." and print processing is permitted.

[Third Embodiment, see FIG. 13] This third embodiment also has only one tray, and the same device as in the second embodiment is used. Here, when the size of the paper ejected from the printer main body (1) has been changed from small size to dog size, in order to ensure the alignment of the changed dog size paper on the tray (70), the printer main body (1) ) is prohibited from printing.

Specifically, among the flowcharts that can be used in the second embodiment, control can be performed based on the subroutine shown in FIG. 13 instead of the paper size comparison subroutine shown in FIG. In the 13th Ward, Step (5121),
In step (5122), the paper size data that will be accommodated from now on and the paper size data that was accommodated immediately before are called from the F memory and D memory, and in step (5123), data F and D are compared. The data is the same as that shown in [Table 1] above, and there is no change in paper size (F=D).
If the size has been changed from dog size to small size (F<D), flag C is reset to 10'' in step (5124).

On the other hand, if the paper size has been changed from the small size to the large size (FED), the flag C is set to "1" in step (5125).

After that, the subroutine shown in FIG. 11 explained in the second embodiment is processed, and if flag C is set to "1", the print prohibition flag is set to "1" in step (5104).
” to prevent paper alignment from being disturbed when the paper is changed from small size to dog size.

Note that also in the third embodiment, step (5123)
, (5124), and (5125), the paper sizes may be compared based on Table 2 and the flag C may be set or reset to "rl" or "rO".

Effects of the Invention As is clear from the above description, according to the present invention, when the size of paper that can be ejected from the image forming apparatus main body is changed, image forming processing in the image forming apparatus main body is prohibited. This eliminates the problem that large size paper cannot be stacked on top of ``\'' size paper and its alignment is disturbed.

Further, according to the present invention, when the size of paper ejected from the image forming apparatus main body is changed from /J\ size to large size, image forming processing in the image forming apparatus main body is prohibited. Similarly to the above, the inconvenience that large-sized sheets are stacked on small-sized sheets and their alignment is disturbed is eliminated.

Furthermore, according to the present invention, when the size of paper that can be ejected from the image forming apparatus main body for a plurality of trays is changed, no paper is accommodated or a paper of a size larger than the paper that can be accommodated in the future is accommodated. Since the paper is fed into the tray, it is possible to eliminate problems such as large-sized paper being stacked on top of small-sized paper and disrupting the alignment, and also to improve the efficiency of the printing process by efficiently using multiple trays. be able to.

[Brief explanation of drawings]

1 to 10 show a first embodiment of a paper storage device according to the present invention, FIG. 1 is an overall configuration diagram of a system including a printer, and FIG. 2 is a perspective view showing main parts of a tray shift mechanism. 3 and 4 are block sections of the control circuit, and the fifth section, FIG. 6, FIG. 7, FIG. 8, FIG. 9, and FIG. 10 are flowcharts showing control procedures. FIGS. 11 and 12 are flowcharts showing the control procedure in the second embodiment. FIG. 13 is a flowchart showing the control procedure in the third embodiment. (1)...Printer body, 60)...Paper storage unit, (67)...Switching claw, (70), (70
a) Tray, (103) Accommodation unit control processor, (115) Interface control processor, (120) Microcomputer, (
121)...Random access memory.

Claims (1)

[Scope of Claims] 1. A paper storage device that sequentially stacks and stores sheets discharged one by one from an image forming apparatus main body, comprising: a tray for storing sheets; and a detection means for detecting the size of the sheets. and a comparison means for comparing the size of the paper ejected from the image forming apparatus main body with the size of the paper ejected immediately before that, and when the comparison means determines that the paper size has been changed, the image forming apparatus main body A paper storage device comprising: a control means for prohibiting image forming processing; 2. A paper storage device that sequentially stacks and stores sheets discharged one by one from the image forming apparatus main body, which includes: a tray for storing the sheets; a detection means for detecting the size of the paper; and an image forming apparatus main body. a comparison means for comparing the size of the paper ejected from the paper and the size of the paper ejected immediately before; and when the comparison means determines that the paper size has been changed from the small size to the large size, the image forming apparatus main body A paper storage device comprising: a control means for prohibiting image forming processing. 3. A paper storage device that sequentially stacks and stores sheets of paper discharged one by one from the main body of the image forming apparatus, including a plurality of trays for storing sheets of paper, and selectively feeding sheets of paper into one of the trays. A paper transport means, a detection means for detecting the presence or absence of paper in each tray, a detection means for detecting the size of the paper, and a size of the paper ejected from the image forming apparatus main body and the size of the paper ejected immediately before. a first comparing means for comparing the size of the paper to be stored from now on and the latest size of the paper stored so far for each tray; control means for controlling the paper transport means to send the paper to a tray that does not contain any paper or contains paper of a size larger than the paper that will be stored in the future, when determining that the paper size has been changed; A paper storage device characterized by comprising: