JPH033833A - Sheet feed device - Google Patents

Abstract

PURPOSE:To eliminate the difference between the sheet feeding performances due to types of sheets to exactly feed the sheet by providing a common sheet feed mode for feeding the common sheet selected based on the results obtained by a discriminating means and a thick sheet feed mode for feeding the thick sheet. CONSTITUTION:While a conveying motor 9a is driven, a detecting sensor 15 detects the tip of a sheet to discriminate whether the fed recording sheet 4 is a common sheet or a post card by means of sheet type variables. When the sheet is a common sheet, the sensor 15 is turned on to drive the conveying motor 9a a specified amount corresponding to the common sheet to convey the sheet to a recording means 11, and thus the sheet feeding is completed to start the recording operation. When the supplied sheet 4 is a post card, the sensor 15 is turned on to drive the conveying motor 9a a specified amount corresponding to the post card to convey the sheet to the recording means 11, and thus the sheet feeding is completed to start the recording operation.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a sheet feeding device that feeds a plurality of stacked sheets by changing the feeding mode between normal sheets and thick sheets.

<Prior art> In recording devices such as printers and copying machines, or document reading devices, multiple sheets (recording paper, manuscripts, etc.) are stacked.
Many use a feeding device (so-called cut sheet feeder) for separating and feeding sheets one by one.

There are various types of sheet separation mechanisms for the feeding device, and a typical one uses separation claws. As shown in Figure 6 (8), this is the loading plate 5.
Both sides of the front end in the feeding direction of the sheet 51 stacked on the sheet 5o are held down by the separating claws 52, and the stacking plate 5o is pressed by the pressing spring 53 to press the top layer sheet to the feeding roller 54. When the seat 51 rotates in the direction of the arrow, thrust is applied to the seat 51. On the other hand, since the ends of both sides of the stacked sheets 51 are held down by the separating claws 52, one of the topmost sheets is shown in FIG. 6(B).
A loop is formed between the separating claw 52 and the feeding roller 54 as shown in FIG.

When the feeding roller 54 further rotates, the restoring force causes the sheet 51 to overcome the separating claw 52 and be sent to the conveying roller 55, and as shown in FIG. A loop was created between the roller 54 and the conveying roller 55.

<Problems to be Solved by the Invention> In the conventional feeding method, sheets are fed in the same operation regardless of whether they are plain paper or postcards.

However, since the paper thicknesses of 111 paper and postcards are different, in the same feeding operation, the sheet separation, loop amount, and cue amount may be different due to the difference in paper thickness, and proper feeding may not be performed.

Furthermore, in the conventional example, since the sheet 51 is separated from the separating claw 52 and the feeding roller 54 is continuously rotated until it hits the conveying roller 55 and forms a loop, the sheet 51
was in an unstable state immediately after being separated by the separating claw 52, and was abutting against the conveying roller 55. Therefore, Figure 6 (C)
The formation of the loops shown in Fig. 1 became unstable, which could cause wrinkles and skewing.

The purpose of the present invention is to solve the above-mentioned conventional problems, and by changing the feeding mode for normal sheets and thick sheets, to perform appropriate sheet feeding regardless of the thickness of the sheet, and to feed normal sheets. In some cases, it is an object of the present invention to provide a sheet feeding device that can form a stable loop in separated sheets.

<Means for Solving the Problems> A typical means of the present invention for solving the above problems includes separating claws for pressing both front end portions of the top layer of a plurality of stacked sheets; a feeding means for applying feeding force to the sheet in the uppermost layer; a conveying means for conveying the sheets separated and fed one by one by the cooperative action of the separating claw and the feeding means; Loaded Sea 1~
a discriminating means for discriminating whether a sheet is a normal sheet or a thick sheet; a normal sheet feeding mode for feeding a normal sheet selected according to the result of the discriminating means; and a normal sheet feeding mode for feeding a thick sheet. It is characterized by the provision of a thick sheet feeding mode.

Further, in the normal sheet feeding mode, the feeding means is driven to feed the uppermost sheet to the conveying means after a predetermined waiting time after removing it from the separation claw, and the thick sheet feeding mode The feeding mode is characterized in that after the sheet in the most layer is removed from the separating claw, the feeding means is driven so as to feed the sheet to the conveying means without elapse of the waiting time.

Effect> In the above means, the sheet feeding mode of the feeding means changes depending on whether the sheet is a regular sheet or a thick sheet. Therefore, the sheets are accurately fed in a state suitable for each sheet.

In addition, when feeding a normal sheet, the separation claw separates the sheet, the apparatus is stopped for a predetermined period of time, and then the sheet is fed to the conveyance means. In this way, by temporarily stopping the sheet in an unstable state immediately after separation and feeding the sheet to the conveying means after the sheet becomes stable, the sheet forms a stable loop.

<Embodiment> Next, an embodiment of a recording apparatus to which the above-mentioned means is applied will be described with reference to FIGS. 1 to 4.

1(8) to (D) are explanatory views of the sheet feeding state by the sheet feeding apparatus according to the present embodiment, FIG. 2 is an explanatory view of the configuration of the sheet feeding apparatus, and FIG. FIG. 1 is a configuration explanatory diagram of a recording apparatus using a sheet feeding device.

As shown in FIGS. 2 and 3, in this sheet feeding device A, a frame 1 is divided into a left half 1a and a right half 1b, and by moving them along an axis 2, the frame body 1 is divided into a left half 1a and a right half 1b. It is possible to adjust.

By stacking a large number of recording sheets 4 on the mounting plate 3 inside the frame 1, and pressing the mounting plate 3 with a pressing spring 5 toward the feeding roller 6 fixed to the shaft 2. The uppermost layer of the recording sheet 4 is configured to be pressed against the feeding roller 6.

In addition, side guides 7 for guiding the side edges of the recording sheet 4 are provided on the outer walls of the left and right frames], a, and lb, respectively, and side guides 7 for guiding the side edges of the recording sheet 4 are provided on both sides of the front edge. Separation claws 8 for separating the recording sheets 4 are provided respectively. Therefore, when the feed roller 6 is rotated in the direction of arrow a by the feed motor 6a, a thrust is applied to the uppermost recording sheet 4 due to the frictional force of the roller 6. 8 and stops, and the uppermost recording sheet 4 is separated and fed so as to form a loop.

A conveying roller 9 serving as a conveying means is disposed in front of the separating claw 8 in the sheet feeding direction, and the recording sheet 4 separated by the separating claw 8 is fed to the conveying roller 9 after being stopped for a predetermined time. , and is configured to be conveyed by the rollers 9.

A predetermined image is recorded on the recording sheet 4 separated and fed by the sheet feeding device A by a recording device B as shown in FIG. To explain the configuration of this recording device B, pinch rollers 10a and 10b are in pressure contact with the conveyance roller 9,
It is configured to rotate following the rotation of the conveyance roller 9. Therefore, the recording sheet 4 held between the conveyance roller 9 and the pinch roller Oa is conveyed by the conveyance roller 9 rotated in the direction of the arrow by the conveyance motor 9a, and a predetermined record is recorded by the recording means 11.

In this embodiment, the recording means 11 uses an inkjet type, and an inkjet type recording head llc is mounted on a carriage 11b that can be moved by a carriage motor (not shown) along a guide shaft 11a. The nozzles 11c1 are arranged in a vertical line. Therefore, a predetermined image can be recorded on the recording sheet 4 by ejecting ink from the ink nozzle Ilc in accordance with the image signal in synchronization with the movement of the carriage Ilb. Incidentally, lld is a plate-like platen having a built-in heater and whose temperature is adjusted to, for example, about 60° C., and has a function of drying the ink ejected onto the recording sheet 4.

The recording sheet 4 recorded by the recording means 11 is discharged by a discharge roller 12a, and a spur roller 1 which is in pressure contact with the discharge roller 12a and rotates drivenly.
2b to discharge the paper to the stacker 13.

The sheet feeding device A includes a sheet presence/absence sensor 1 for detecting whether or not the recording sheet 4 is on the mounting plate 3.
4 is arranged near the frame 1, and pinch rollers 10a, 1
A sheet detection sensor 15 for detecting the leading edge of the recording sheet 4 is arranged at a predetermined position between 0b and 0b. Further, in this embodiment, a size detection sensor 16 is provided for detecting the position of the side guide 7 and detecting the sheet size. In this embodiment, the size detection sensor 16 has a function of detecting sheet thickness, and detects, for example, a difference between a regular sheet and a thick sheet (such as a postcard) as a difference in size.

Here, a control system for driving and controlling the feeding device A and the recording device B is constructed as shown in the block diagram of FIG.

Specifically, for example, a CPU 17a such as a microprocessor
, a ROM 17b that stores control programs and various data that are operated by the CPU 17a according to the procedure shown in the flowchart of FIG. 5, and an R that is used as a work area for the CPU 17a and temporarily stores various data.
It has a control section 17 equipped with an AM17c, etc., and this control section 1
7 is connected via an interface 18 to an operation panel 19 having a recording start switch, etc., and a sheet presence/absence sensor 14. Signals from the sheet detection sensor 15, size detection sensor 16, image signal input device 20, etc. are input. In addition, signals are sent from the control section 17 via the interface 19 to a motor driver 22 for driving the feed motor 6a, transport motor 9a, and carriage motor 21, and a head dryer 23 for driving the recording heads 1 and c. It is configured to output .

Next, a procedure for feeding the recording sheet 4 by the feeding device A will be explained. In this embodiment, an example will be described in which a postcard is fed as a thick sheet, and plain paper of a different size from the postcard, for example, A4 size, is fed as a normal sheet.

As shown in the flowchart of FIG. 5, when the recording start switch is turned on, the sheet presence/absence sensor 14 detects whether or not there is a recording sheet 4 on the mounting plate 3 in step S1. If yes, that is, when the sensor 14 is on, the process proceeds to step S2, where it is determined whether the recording sheet 4 caught in the size detection sensor 16 and fed is plain paper or a postcard, and if it is plain paper, the normal sheet feeding mode is activated. Feed the sheet according to the instructions.

That is, proceed to step S3 and set F(
g is separated from 1 to 1, and then the process proceeds to step S4, where the feed motor 6a is driven by a predetermined amount (350 steps in this embodiment) to separate only one recording sheet 4.

The driving amount of the feed motor 6a is such that after the feed roller 6 starts rotating (the state shown in FIG. 1(A)), the uppermost recording sheet 14 is looped between the separating claw 8 and the feed roller 6. 1 (B)), the leading edge of the sheet is completely separated from the separating claw 8 due to the stiffness of the sheet 1-4, but the feed amount is such that it does not reach the conveying roller 9. (Figure 1 (C)
condition).

Next, in step S5, the feeding motor 6a is
is stopped for a predetermined period of time (500 m5 in this embodiment), and the feeding of the recording sheet 4 is temporarily stopped. This stabilizes the recording sheet 4, which was in an unstable state immediately after separation. Next, the process proceeds to step S6, where the feeding motor 6a is driven by a predetermined amount (150 steps in this embodiment). This predetermined amount is sufficient for the leading edge of the recording sheet 4 to abut against the two-pronged portion of the conveying roller 9 and the pinch roller 10a to form a loop (the state shown in FIG. 1(D)).

Conventionally, the steps S2 and S4 were performed consecutively (in the example, the feeding motor 6a was
step), the recording sheet 4, which is in an unstable state immediately after separation, is being fed as it is, but by temporarily stopping the feeding as in this embodiment, the recording sheet 4 is
is conveyed to the conveyance roller 9 in a stable state, and then the process proceeds to step S9.

Incidentally, if the recording sheet 4 is determined to be a postcard in step 2, the sheet is fed according to the thick sheet feeding mode.

That is, the process advances to step S7 and the sheet type variable 1 (I'
1. After driving the feed motor 6a by a predetermined amount (450 steps in this embodiment) in step S8,
Proceed to step S9. The amount of motor drive in step S8 is the same as in the case of plain paper in that the uppermost recording sheet is separated by the separating claw 8, but the feed motor 6a continues to rotate and the leading edge of the sheet is separated. The sheet 4 hits the nip between the conveying roller 9 and the pinch roller 10a, and the amount of the sheet 4 is sufficient to form a loop between the nip and the feeding roller 6.

Incidentally, in this embodiment, the amount by which the feed motor 6a is driven in order to feed the plain paper to the nip portion is 500 s t in total.
EP, the amount that the feed motor is driven to feed the postcard to the nip is smaller at 450 seconds, because in the case of postcards, plain paper does not need to form a large loop. It is.

From the state in which the leading edge of the recording sheet 4 hits the nip between the conveyance furnace 9 and the pinch roller 10a and forms a loop as described above, in step S9, the feeding motor 6a is operated for a predetermined period of time (in this embodiment). 500 m5) to stabilize the loop of the recording sheet 4 formed between the conveying roller 9 and the feeding roller 6.

Next, in steps SIO to S14, the transport motor 9
a is driven one step at a time, and the sheet detection sensor 15 detects the leading edge of the recording sheet 4 each time. That is, when the sensor 15 does not turn on, it is assumed that a jam has occurred and a jam message is displayed on the display section on the operation panel 19.

On the other hand, when the sheet detection sensor 15 detects the leading edge of the sheet while the conveyance motor 9a is driven in the 300 s step, the process proceeds to step S15, and it is determined whether the fed recording sheet 4 is plain paper or a postcard based on the sheet type variable, In the case of plain paper, the process advances to step 316 and the sensor 15
From the time when is turned on, the conveyance motor 9a is driven by a specified amount (900 steps in this embodiment) to convey the sheet to the recording means 1, and the sheet feeding is completed and the recording operation is started. Further, in step S15, if the fed sheet 4 is a postcard, the process advances to step S17, and from the time when the sensor 15 is turned on, the conveying motor 9a is driven by a specified amount (902 s step in this embodiment). The sheet is conveyed to the recording unit 1], the sheet feeding is completed, and the recording operation is started.

Here, the drive amount of the transport motor 9a is 9 in the case of plain paper.
00step, while for postcards it is 902s.
The reason why it is different from tep is that correction values are included based on the detection timing of the sheet detection sensor 15 and the conveyance load due to the difference in stiffness of the sheet due to the difference in thickness.

As described above, by detecting the difference between plain paper and postcards and feeding them appropriately, when plain paper is fed, it is no longer fed in an unstable state immediately after separation. Furthermore, when feeding postcards, there is no unnecessary feeding stop time, and the through top of the recording time is not lost. Furthermore, even if there are differences in loop amount, cue amount, etc. due to different sheet types, it is possible to perform appropriate feeding control for each sheet type by inserting correction values for each.

[Other Embodiments] The sheet feeding amount and waiting time shown in the above-described embodiments are merely exemplary, and may be set as appropriate depending on the device dimensions and the like. For example, the longer the distance from the separation claw 8 to the nip between the conveyance roller 9 and the pinch roller 10a, the shorter the sheet waiting time after separation, and conversely, if the distance is short, the recording sheet 4 may fall out. If the condition is poor, it is better to lengthen the sheet waiting time.

Further, the rotational speed of the feeding motor 6a etc. can be driven at a normal speed until the recording sheet 4 is separated, and then the rotational speed can be reduced after separation.
In between, the recording sheet 4 forms a loop more stably.

In addition, as a means for determining the sheet thickness, in the above embodiment, a sensor was used to determine whether plain paper is a postcard based on the difference in sheet size. A text is created, and the host not only transmits the recorded content to the control unit of the recording device, but also sends information regarding the recording sheet. Therefore, the sheet information may be used to determine whether normal sheet recording or postcard recording is being performed during recording, and the sheet feeding mode may be selected in accordance with that information.

Further, the detection may be performed using an optical sensor, for example, regardless of the sheet size.

Specifically, the sheet 4 being fed is irradiated with light from an optical sensor. For example, when the sheet is a regular sheet with a thickness of about 100 μm or less, the light passes through the sheet 4 and the sensor turns on.
In the case of a thick sheet with a thickness of about 200 μm, the sensor may be configured so that light is blocked and the sensor is turned off to determine whether it is a normal sheet or a thick sheet.

Alternatively, a switch may be provided on the operation panel 19 to input whether the sheet is a regular sheet or a thick sheet, and the operator can make a determination based on the information selected by the switch.

Furthermore, in the above-mentioned embodiment, an example was shown in which the feeding roller 6 and the conveying roller 9 were used as feeding means and conveying means, but these do not necessarily have to be limited to roller-shaped ones, and for example, a rotating heald, etc. It may be something.

<Effects of the Invention> As described above, the present invention feeds normal sheets and thick sheets in different modes, thereby eliminating the difference in feeding performance due to differences in one type of sheet and achieving accurate feeding. It can be done.

Furthermore, by providing an appropriate waiting period when feeding a normal sheet, a stable loop can be formed and the occurrence of wrinkles can be effectively suppressed.

[Brief explanation of the drawing]

1 (8) to (1)) are explanatory diagrams showing sheet feeding states by a sheet feeding device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the configuration of the sheet feeding device, and FIG. 3 4 is a block diagram of the control system, FIG. 5 is a flowchart 1 showing the sheet feeding procedure, and FIG. FIG. 2 is an explanatory diagram showing a conventional sheet feeding procedure. 1 is a frame body, 2 is a shaft, 3 is a mounting plate, 4 is a recording sheet, 5 is a pressing blade, 6 is a feed roller, 6a is a feed motor, 7 is a guide, 8 is a separation claw, 9 is a conveyor 10b is a pinch roller, 11 is a recording means, lla is a guide shaft, 11b is a carriage, l
lc is a recording head, lld is an ink nozzle, 12a is a discharge roller, 12b is a spur roller, 13 is a stacker, 14
is a seat presence/absence sensor, 15 is a seat detection sensor, 1
6 is a sheet size detection sensor, 17 is a control unit, 17a
17b is a ROM, 17c is a RAM, 1B is an interface, 19 is an operation panel, 20 is an image signal input device, 21 is a carriage motor, 22 is a motor driver, and 23 is a head driver.

Claims (2)

[Claims] (1) Separating claws for pressing both front ends of the uppermost sheet of a plurality of stacked sheets; feeding means for applying feeding force to the uppermost sheet; and the separating claw. a conveying means for conveying the sheets that are separated and fed one by one by the cooperative action of the conveying means and the conveying means; and a discriminating means for determining whether the stacked sheets are normal sheets or thick sheets; A sheet feeding device comprising: a normal sheet feeding mode for feeding a normal sheet selected according to the result of the determining means; and a thick sheet feeding mode for feeding a thick sheet. (2) In the normal sheet feeding mode, after removing the uppermost sheet from the separating claw, the feeding means is driven so as to feed the sheet to the conveying means after a certain waiting time, and the thick sheet The sheet feeding device according to claim 1, wherein in the feeding mode, after removing the sheet in the uppermost layer from the separating claw, the feeding means is driven so as to feed the sheet to the conveying means without passing the waiting time. .