JP2000007187A - Sheet loading device and image forming device provided with this device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent sheet jamming by providing a pair of sheet detection means detecting a sheet tip part at the inside of a pair of location regulating walls performing location regulations of a sheet by being abutted on both the sides of the sheet and deciding an abnormality of a sheet loading state from an output of the sheet detection means at the time of a location regulation of the sheet. SOLUTION: In a sheet loading device 30 provided on a sheet feeding device of a printer, a sheet P is set in a state that the sheet P is abutted on a reference surface E at the inside of a fixing wall 8c on a base 8. In the base 8, recessed parts 8a, 8b for providing a pressure plate spring at an opposed location of a paper feeding roller are formed, a separating pad 28 is provided at a location opposed to a feeding roller of a pressure plate 9 energized upward by the pressure plate spring and a moving wall 7 is freely movably mounted at a location opposed to the fixing wall 8c of this pressure plate 9. At the inside of these location regulating walls 7, 8, optical sensors PS1 and PS2 are provided. When the optical sensor PS1 or PS2 is not operated at the time of a sheet location regulation, the state is decided to be an abnormality of a sheet loading state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet stacking apparatus for stacking sheets to be fed to an image forming apparatus such as a copying machine, a printer, a facsimile or the like and aligning the width of the sheets, and an image provided with the sheet stacking apparatus. And a forming device.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus such as a copying machine, a printer, a facsimile or the like is provided with a sheet feeding apparatus for automatically feeding sheets one by one to the image forming apparatus. The sheet feeding device is provided with a sheet stacking device for stacking sheets to be fed to the image forming apparatus, adjusting the width of the sheets, and regulating the position and orientation of the sheets.

One example of an image forming apparatus is a printer 52 as shown in FIG. The printer 52 includes a sheet feeding device 51 that can be connected to a metal chassis 53 to stack sheets of different sizes, and has an image forming unit that forms an image by an inkjet recording method.

The sheet feeding device 51 provided in the printer 52 will be described.

As shown in FIG. 9, the sheet feeding device 51 includes a sub-tray 54, a feeding roller 55, a separating claw 56, a moving wall 57 which is a position regulating wall for regulating the position of the sheet in the sheet width direction, and a base 58. , A pressure plate 59, a pressure plate spring 60, a separation plate 61, etc., and these components are attached to a base 58 to form a unit.

The moving wall 57 is movably mounted on the pressure plate 59 by its clip portion 57a being pressed against and sandwiching the holder 59c of the pressure plate 59 due to its elasticity.

FIG. 10 shows a view of the sheet feeding apparatus from the direction of arrow S in FIG.

In FIG. 10, a sheet P is a base 58
It is set based on the upper reference plane E. A recess 58 for providing a pressure plate spring 60 is provided on the base 58 at a position substantially facing the roller portion of the feeding roller 55.
a, 58b are formed. The reference plane E is an inner surface of a fixed wall 58c that cooperates with the moving wall 57 to regulate the position of the sheet from the width direction of the sheet.

The pressure plate 59 includes pressure plate shafts 59a,
9b rotatably coupled to the base 58.
A separation pad 78 made of a material having a relatively large coefficient of friction, such as artificial leather, is provided at a position opposing the feed roller 55 of the pressure plate 59 to prevent double feeding of sheets when the number of sheets is reduced. I have.

The pressure plate 59, the moving wall 57 and the fixed wall 58
c and the like constitute the sheet stacking device 80.

The order in which the sheets P are set in the sheet stacking device 80 will be described.

First, the moving wall 57 is moved away from the reference plane E so that the distance between the moving wall 57 and the reference plane E is wider than the width of the sheet P to be set. Next, the sheet P is set between the moving wall 57 and the reference plane E, the moving wall 57 is made to approach the reference plane E, and the sheet P is pressed against the reference plane E by the moving wall 57. As a result, the sheet P is set on the pressure plate 59 with the same width.

[0013]

However, the user,
When the printer 52 is operated without noticing that both ends of the sheet P are in contact with only one of the moving wall 57 and the reference plane E (FIG. 11), the sheet P is indicated by a broken line P ′ in FIG. As shown in the figure, the sheet may be fed to the printer 52 (referred to as skew) in an oblique state.

Therefore, the conventional sheet stacking apparatus has a problem that the sheet is jammed.

Another problem is that the sheet is wrinkled.

Further, a printer (image forming apparatus) having a conventional sheet stacking apparatus has a problem that an image is formed on a sheet on which wrinkles have occurred, so that a disturbed image is formed on the sheet.

Further, the printer has a problem in that an image is formed on an oblique sheet, and the left and right margins are different in the length direction of the sheet (FIG. 12), and image processing with poor appearance is performed. For example, in an A4 size sheet,
While the right margin is about 3 mm at the leading end Pa, it is only about 1 mm at the trailing end Pb, and the margin becomes uneven in the sheet length direction.

(Object) An object of the present invention is to provide a sheet stacking apparatus capable of reliably regulating the position and orientation of a sheet, and an image processing apparatus having the sheet stacking apparatus, which forms an image with uniform sheet margins and provides good-looking image processing. It is an object of the present invention to provide an image forming apparatus that can perform the operation.

[0019]

The above object is achieved by the following sheet stacking device.

In a sheet stacking apparatus provided with a pair of position regulating walls, at least one of which is capable of moving at least one of the sheets stacked on a sheet stacking table provided on a base member to regulate the position of the sheet by abutting on both sides thereof, A pair of sheet detecting means disposed inside both of the position regulating walls for detecting the end of the sheet, and a sheet stacking state abnormal when at least one of the sheet detecting means does not operate during the sheet position regulating. And a notifying means for notifying that

Further, one of the position regulating walls is fixed,
The other is movable, one of the pair of sheet detecting means is provided on the base member or the sheet stacking table, and the other sheet detecting means is provided on the other position regulating wall.

The detecting means is a reflection type optical sensor.

The detecting means is a limit switch that can contact the sheet.

Further, the above problem is solved by the following image forming means.

The apparatus includes any one of the sheet stacking apparatuses described above and image forming means for forming an image on a sheet sent from the sheet stacking apparatus.

(Operation) The sheet is set on the sheet stacking table, and at least one of the pair of position regulating walls is made to approach the other, and both sides of the sheet are sandwiched by the pair of position regulating walls to regulate the position and orientation of the sheet. I do. At this time, the notifying means does not operate because the sheet detecting means can detect both ends of the sheet.

However, if both sides of the sheet are not reliably sandwiched between the pair of position regulating walls, the position regulating wall and either one of the position regulating walls or one of the position regulating walls may not be sandwiched. A gap is formed between the sheet and the end of the sheet, and both the sheet detecting means or the sheet detecting means on the side where the gap is generated cannot detect the sheet, and thus does not operate.

Therefore, either the sheet detecting means has not detected the sheet, or one of the sheet detecting means has detected the sheet, but the other has not detected the sheet. To inform that the seat orientation and position are not regulated.

When the user is notified of the abnormal state by the notification means, the user moves the position regulating wall again to correct the direction and the position without fail.

Further, the image forming apparatus forms an image on a sheet fed with its position and orientation being precisely regulated by the image forming means.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS.

In the embodiment of the present invention, as shown in FIG. 1, a printer 2 is taken as an example of an image forming apparatus.

The printer 2 is provided with a sheet feeding device 1 which is capable of stacking sheets of different sizes connected by a metal chassis 2 and has an image forming means for forming an image by an ink jet recording system.

The sheet feeding device 1 will be briefly described in advance.

The sheet feeding device 1 includes a sheet stacking device 30
The sheet stacking device 30 can stack sheets of different sizes (in this embodiment, sheets having a width of about 240 mm or less).

The sheet feeding device 1 is attached to the metal chassis 3 at a predetermined angle. The sheet P on which an image is formed by the printer 2 is discharged substantially horizontally.

As shown in FIG. 1, the sheet feeding device 1
A sub-tray 4, a feeding roller 5, a separation claw 6, a moving wall 7, a base 8, a pressure plate 9 as a sheet stacking table, a pressure plate spring 10, a separation plate 11, and the like are provided. Normally, the sheet P is separated from the feed roller 5 because a release cam (not shown) pushes the pressure plate 9 down to the position shown in FIG.

When the transport roller 12 is started with the sheet P set, the feed roller 5 and a release cam (not shown) operate. When the release cam separates from the pressure plate 9, the pressure plate 9 is pushed by the pressure plate spring 10 and rises, and the sheet P is pressed against the feed roller 5. The sheets P are picked up by the rotation of the feeding roller 5 and separated one by one by the separation claws 6. The separated sheet P is sent to the supply inlet 14. The feed roller 5 and the release cam rotate once until the sheet P is fed into the nip portion between the feed roller 12 and the pinch roller 13, and the drive is turned off from the feed roller 12 again with the pressure plate 9 separated from the feed roller 5. The state shown in FIG. 1 is maintained.

The printer 2 will be described.

The PE sensor lever 1 is connected to the supply inlet 14.
7, a PE sensor 18, a lower guide 19, and the like. The transport unit 15 includes a transport roller 12, a pinch roller 1
3, a pinch roller guide 16, a platen 20, and the like.

The PE sensor lever 17 is a lever that detects the leading edge of the sheet P and obtains a recording position on the sheet P. The pinch roller 13 is provided with a pinch roller guide 16.
Of the sheet P is urged by a pinch roller spring (not shown) to generate a conveying force of the sheet P.

The sheet P sent by the feed roller 5 is
A roller pair 12 rotated by a transport motor (not shown),
13, the recording head 21 forms an image based on predetermined image information. The recording head 21 is formed integrally with the ink tank 22 and has a structure that can be easily replaced.

The printer 2 has a recording head 21
An ink jet recording system is used in which ink is ejected from the ink to perform recording. That is, the recording head 21 generates a fine liquid ejection port (orifice), a liquid path, an energy action section provided in a part of the liquid path, and droplet forming energy to act on the liquid in the action section. Energy generating means.

As an energy generating means for generating such energy, a recording method using an electromechanical transducer such as a piezo element or the like, an electromagnetic wave such as a laser is irradiated to generate heat, and droplets are discharged by the action of the heat. There is a recording method using an energy generating unit that causes the liquid to be heated, or a recording method using an energy generating unit that discharges the liquid by heating the liquid with an electrothermal converter such as a heating element having a heating resistor. Among them, a recording head used in an ink jet recording method in which a liquid is ejected by thermal energy has a high density of liquid ejection ports (orifices) for ejecting recording droplets to form ejection droplets. Therefore, high-resolution recording can be performed. A recording head using an electrothermal transducer as an energy generating means has advantages such as easy downsizing, easy high-density mounting, and low manufacturing cost.

Further, in the embodiment of the present invention, as an ink ejection structure, an electric current is supplied to the electrothermal transducer in accordance with a recording signal, and bubble growth generated in the ink by utilizing film boiling generated in the ink by the thermal energy is performed. The recording is performed by discharging the ink from the discharge port by contraction.

The recording head 21 integrally having the ink tank 22 is removably attached to the carriage 23. The carriage 23 reciprocally scans in the direction orthogonal to the sheet P conveyance direction by the guide shaft 24. Therefore, an image is formed on the sheet P conveyed on the platen 20 by scanning the recording head 21 integrally with the carriage 23.

The discharge unit includes a discharge roller 25 and a transmission roller 26 for transmitting the drive of the transport roller 12 to the discharge roller 25.
And a spur 27 for assisting discharge.

A transport motor (not shown) for driving the transport rollers 12 and the like and a carriage motor (not shown) for driving the carriage 23 are provided with a predetermined angle according to a signal sent from a driver (not shown). A rotating stepping motor is used.

The feed roller 5 is provided with a sensor plate (not shown) having a diameter smaller than the diameter of the feed roller rubber attached to the feed roller 5. A part of this sensor plate (not shown) is cut out, and only when the feed roller 5 and the release cam are at the initial position where the press-contact with the pressure plate 9 is released, a photo-interrupter or the like directly provided on the electric board is used. The roller sensor (not shown) is in a light-transmitting state without being shielded from light. By detecting the state of the sensor plate, it is possible to detect the angular position of the feed roller 5 and the angular position of the release cam that is synchronized with the phase of the feed roller 5 and is interlocked. Control timing can be set.

The sheet feeding device 1 will be described again.

The sheet feeding device 1 is unitized by mounting each component on a base 8. As shown in FIG. 2, the sheet P comes into contact with the reference plane E inside the fixed wall 8c on the base 8. The base 8 is formed with concave portions 8a and 8b for providing the pressure plate springs 10 at positions substantially opposed to the roller portion of the paper feed roller 5.

The pressure plate 9 is rotatably connected to the base 8 by pressure plate shafts 9a and 9b at upper ends of both ends. A separation pad 28 made of a material having a relatively large friction coefficient, such as artificial skin, is provided at a position of the pressure plate 9 opposite to the feeding roller to prevent double feeding when the number of sheets is reduced. A movable wall 7 that can slide left and right is mounted on the pressure plate 9 so that sheets P having different sizes can be placed on the sheet reference plane E.
It can be set to.

The pressure plate 9, the movable wall 7, the fixed wall 8c and the like constitute a sheet stacking device 30.

As shown in FIG. 1, the moving wall 7 is
The clip portion 7a is movably attached to the pressure plate 9 by being pressed into the holder 9c of the pressure plate 9 with its elasticity. In the present embodiment, the moving wall 7
Is set to about 250 to 1000 g.

As shown in FIG. 2, the moving wall 7 has an inner surface F for regulating the end of the sheet P, and a set surface 7b on which the sheet P is set perpendicular to the inner surface.
Means for detecting the positional relationship between the moving wall 7 and the sheet P is provided on the set surface 7b. The detecting means is the optical sensor PS1. This optical sensor PS1 is a reflection type optical sensor including a light emitting element and a light receiving element. The optical sensor PS1 can move together with the moving wall 7 in the direction of the arrow, and can detect the end of the sheet according to the position of the moving wall 7.

On the other hand, a similar reflection type optical sensor PS2 is also provided on the base 8 near the surface on the sheet reference side E. The pressure plate 9 has a notch 9d formed around the optical sensor PS2.

The optical sensor PS1 is, as shown in FIG.
Distance L from sheet abutting surface F of moving wall 7 (where L =
The optical sensor is installed such that an axis connecting the centers of the light emitting element and the light receiving element of the optical sensor is located at a distance (about 1.5 mm). Similarly, the other optical sensor PS2 is located at a position away from the sheet abutting surface E of the fixed wall 8c by a distance L (not shown) (cause L = about 1.5 mm). It is installed so that the axis connecting the centers of the elements is located.

The optical sensors PS1 and PS2 are connected to an exclusive OR circuit 31, as shown in FIG. The exclusive OR circuit 31 is a circuit connected to the notifying means 32 and operating the notifying means 32 only when a signal indicating that the sheet is set in a normal state is received from one of the optical sensors. Therefore, when the exclusive OR circuit 31 receives a signal from both optical sensors that the sheet is set in a normal state, the exclusive OR circuit 31 does not operate the notification means 32. The notifying unit 32 can notify the user of the abnormal state by sound or light.

In the above configuration, as shown in FIG.
When both ends of the sheet are reliably sandwiched between the fixed wall 8c and the moving wall 7 and the position and orientation of the sheet are accurately regulated, the light receiving elements of the optical sensors PS1 and PS2 receive the reflected light and receive both lights. A signal indicating that there is a sheet is output from the optical sensors PS1 and PS2. For this reason, the notification means 32 does not operate.

However, as shown in FIGS. 5 and 6, when one end of the sheet is separated from one of the fixed wall 8c and the moving wall 7 by a distance L or more, the farthest one is. Since the sensor PS1 (or PS2) does not receive the reflected light,
Only one of the optical sensors receives the reflected light. For this reason, the notifying means 32 operates to notify the user by sound or light that the sheet is not set in a normal state. The user resets the sheet to a normal state.

The order of the quality of the position setting of the moving wall 7 as described above is as shown in the flowchart of FIG. That is, when the sheet P is set in the sheet feeding device 1 and the signals from the optical sensors PS1 and PS2 both output a signal indicating that a sheet is present, the moving wall 7 is set. Is determined to have been performed normally, and a state of waiting for a feed instruction is left as it is.

On the other hand, if a signal is output that recognizes that there is no sheet in both or one of the optical sensors PS1 and PS2, the NAND circuit 31 determines that there is no proper positional relationship between the sheet P and both walls. Is determined, and the user is notified by the notification means 32.

Therefore, the user can easily recognize that the positional relationship between the sheet edge and the regulating wall in the sheet feeding device is inappropriate.

The optical sensor PC1 on the fixed wall 8c side is provided on the base 8, but may be provided on the pressure plate 9.

The fixed wall 8c may be a movable wall.
In this case, the optical sensor PS2 is provided on the moving wall.

In the above embodiment, a non-contact sensor such as an optical sensor is used as a means for detecting the end of the sheet. A simple contact sensor may be used.
Therefore, the sheet detecting means in the present invention includes not only a non-contact sensor but also a contact sensor.

The numerical values shown in the above description are numerical values shown for reference, and the present invention is not limited to these numerical values.

[0068]

According to the present invention, it is possible to inform the user that the positional relationship between the end of the sheet set in the sheet stacking apparatus and the position regulating wall for regulating the end is inappropriate. So, set the sheet again,
It is possible to restrict the position and the orientation to a normal position, and it is possible to prevent the skew of the sheet which occurs in an improper setting state, the sheet jam due to the skew, and the unfavorable image processing by the image forming apparatus.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a sheet feeding apparatus and an image forming apparatus including a sheet stacking apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of the sheet stacking device of FIG.

FIG. 3 is a plan view of the optical sensor.

4 is an operation explanatory view, and is a cross-sectional view taken along the arrow 3-3 in FIG. 2;

FIG. 5 is an operation explanatory view, and is a sectional view taken along arrow 4-4 in FIG. 2;

FIG. 6 is an operation explanatory view, and is a cross-sectional view taken along line 5-5 in FIG. 2;

FIG. 7 is a block circuit diagram.

FIG. 8 is an operation flowchart.

FIG. 9 is a front sectional view of a sheet feeding apparatus and an image forming apparatus including a sheet stacking apparatus of a conventional example.

FIG. 10 is a plan view of the sheet stacking device of FIG. 9;

FIG. 11 is a plan view of the sheet stacking device when sheets are set diagonally in the sheet stacking device.

FIG. 12 is a plan view of an oblique sheet when an image is applied to the sheet.

[Explanation of symbols]

 P sheet PS1, PS2 Optical sensor (sheet detecting means) 1 Sheet feeding device 2 Printer (image forming device) 5 Feeding roller 6 Separation claw 7 Moving wall (position regulating wall) 8 Base (base member) 8c Fixed wall (position) Regulating wall) 9 pressure plate (sheet stacking table) 21 recording head (image forming unit) 30 sheet stacking device 32 notification unit

Continued on the front page F term (reference) 2H072 AA07 AA09 AA12 AA22 AB29 BA03 BA06 BA17 CA01 3F048 AA02 AA04 AA05 AB01 BA08 BC00 BC03 CB06 CC05 DC04 DC14 3F343 FA02 FB02 FB03 FB04 HA33 HD07 HE02 HE20 HE22 MA03 MA09 MA26 MA55

Claims (5)

[Claims] 1. A sheet stacking apparatus having a pair of position regulating walls, at least one of which is capable of moving at least one of the sheets stacked on a sheet stacking table provided on a base member to regulate the position of the sheet by abutting on both sides thereof. A pair of sheet detecting means disposed inside the both position regulating walls to detect the end of the sheet, and when at least one of the sheet detecting means does not operate at the time of regulating the sheet position, the sheet stacking state is changed. A notifying means for notifying that the sheet is in an abnormal state. 2. One of the position regulating walls is fixed and the other is movable, one of the pair of sheet detecting means is provided on the base member or the sheet stacking table, and the other sheet detecting means is provided on the other side. 2. The sheet stacking device according to claim 1, wherein the sheet stacking device is provided on the position regulating wall. 3. The sheet stacking apparatus according to claim 1, wherein the detection unit is a reflection type optical sensor. 4. The sheet stacking device according to claim 1, wherein the detection unit is a limit switch that can contact the sheet. 5. An image comprising: the sheet stacking device according to claim 1, 2, 3 or 4; and an image forming means for forming an image on a sheet sent from the sheet stacking device. Forming equipment.