JPH0635326A - Peeling device - Google Patents

Abstract

PURPOSE:To satisfactorily peel a sheet from a rotary body such as a photosensitive drum irrespective of various sheet widths by providing a means which separates a sheet from the rotary body. CONSTITUTION:A moving separation claw 14 and a fixing separation claw 23 are arranged in the vicinity of the photosensitive drum 11. The moving separation claw 14 reciprocates so as to match the width of a sheet, by the rotation of a rotary rod 12 as a result of the drive of a sparation claw moving motor 13. Therefore, the saparation claws 14 and 23 can be positioned in relation to the photosensitive drum 11 and in the vicinity of both ends of any sheet. When a rotary solenoid 21 excites, a restricting rod 19 turns the prescribed angle, and the front ends 14A and 23A of the separation claws come into contact with the surface of the photosensitive drum 11, so that the sheet is brought into a peelable state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a peeling device for peeling a sheet with a separating claw from a rotating body such as a photosensitive drum, a photosensitive belt and a heat roll (fixing roll) whose surface is rotated. More specifically, the present invention relates to a peeling device capable of favorably peeling sheets of various sizes.

[0002]

2. Description of the Related Art In an electrostatic copying machine or a laser printer, an electrostatic latent image corresponding to an image is formed on a photosensitive member, and this is developed to form a toner image. The toner image is transferred to the paper by the action of the transfer corotron,
After that, the recording sheet is fixed.

In such a recording apparatus, the paper is usually electrostatically adsorbed on the surface of the photoconductor when passing between the photoconductor and the transfer corotron. Therefore, in such a normal state, the sheet comes into close contact with the toner image on the photoconductor. This is preferable for fixing the image.

However, the adsorbed paper may be wound around the photosensitive drum as it is without being peeled off. The next image cannot be formed until the paper is wound around the photosensitive drum. Further, this paper may enter the developing device or the cleaning device, and in such a case, the normal function of these devices is disturbed. Further, even in the heat roll type fixing device, the paper may be wound around the heat roll, and in this case also, there is a problem that the function as the fixing device is hindered.

Therefore, conventionally, one or a plurality of separation claws are slidably contacted with the surfaces of the photosensitive drum and the heat roll. In particular, when a plurality of separation claws are slidably contacted so that the separation claws act on both ends of the paper at the same time, even wide paper or paper that is difficult to peel off can be reliably separated from the rotating body such as the photosensitive drum. be able to.

However, if a plurality of separating claws are constantly brought into sliding contact with, for example, a heat roll in this manner, when a narrow paper is continuously used, a portion where the paper does not pass (hereinafter referred to as a non-paper passing portion). .) Heat accumulates and the temperature of the roll surface rises abnormally. Therefore, there is a problem that the separation claws arranged in this portion are thermally deformed.

In view of this, Japanese Patent Laid-Open No. 64-40871 proposes a fixing device having a control means for separating the separation claw located in the non-sheet passing portion. That is, for example, about three separation claws are arranged on the heat roll at predetermined intervals,
Separation claw driving means for slidingly contacting or separating each of the separation claws is provided. Then, the separation claws located in the non-sheet passing portion are separated according to the detection result of the sheet size. Separating the separation claws in the non-sheet-passing part in this way not only prevents their thermal deformation but also delays the progress of wear of the separation claws themselves, and also scratches the heat roll and the photoconductor. There is also the advantage of reducing the risk of attaching.

[0008]

By the way, in an image forming apparatus such as a general copying machine or a printer, A5 size, A4 size,
It is possible to handle standard size paper such as A3, B5, and B4. Therefore, if the separation claws are made to act on both sheets in the vicinity of both ends, the number of separation claws will be considerably large. Therefore, the number of separating claw driving means for slidingly contacting or separating the separating claws is increased, and the control circuit for controlling them is complicated and the cost of the peeling device for peeling the sheet is considerably increased. there were. Further, since these image forming apparatuses are often adapted to handle atypical paper,
It was practically impossible to arrange the separating claws corresponding to all kinds of papers in terms of cost and arrangement of parts.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a peeling device which is capable of effectively peeling paper having various widths by disposing separation claws with appropriate widths.

[0010]

According to a first aspect of the present invention, there is provided a rotating body such as a photosensitive drum, a photosensitive belt, and a heat roll, the surface of which is rotated, and a sheet supply means for supplying a sheet to the rotating body. , A plurality of separation claws arranged in a line in a direction orthogonal to the rotating direction of the rotating body, each tip of which is in contact with the surface of the rotating body for peeling the sheet, and at least one of these separating claws The separating device is provided with a separating claw moving means for moving in a direction orthogonal to the rotating direction.

That is, according to the first aspect of the invention, a plurality of separating claws are arranged in a line in the axial direction of the rotating body such as the photosensitive drum, the photosensitive belt, and the heat roll, and at least one of them is the shaft. The position and interval of the separating claws can be arbitrarily changed by enabling the movement in the direction. Thereby, it is possible to deal with peeling of sheets of any width even if two separating claws are used.

According to a second aspect of the present invention, a rotating body such as a photosensitive drum, a photosensitive belt, and a heat roll, the surface of which is rotated, a sheet supply means for supplying a sheet to the rotating body, and a rotating direction of the rotating body. A plurality of separation claws arranged in a line in a direction perpendicular to the direction of contact, each tip of which is in contact with the surface of the rotating body for separating the paper, and at least one of these separation claws is perpendicular to the rotation direction described above. The separating device is provided with separating claw moving means for moving the separating claw in the direction and separating claw separating means for keeping them in contact with the surface of the rotating body while the separating claw is moved.

That is, according to the second aspect of the invention, a plurality of separating claws are arranged in a line in the axial direction of the rotating body such as the photosensitive drum, the photosensitive belt, and the heat roll, and at least one of them is the shaft. The separation claw can be moved in any direction so that the position and the interval of the separation claw can be arbitrarily changed, and the separation claw is separated from the surface of the rotating body while the separation claw is moved. As a result, the position of the separation claw can be adjusted without imposing a burden on the separation claw or the rotating body.

[0014]

EXAMPLES The present invention will be described in detail below with reference to examples.

FIG. 1 shows a main part of a recording apparatus using a peeling apparatus according to an embodiment of the present invention. A rotary rod 12 slightly longer than the length of the photosensitive drum 11 is rotatably arranged in the vicinity of the photosensitive drum 11 of the recording apparatus in the axial direction of the drum, and a male screw is engraved over substantially the entire length thereof. ing. One end of the rotary rod 12 is directly connected to the rotary shaft of the separation claw moving motor 13. The rotary rod 12 is screwed with a female screw portion 15A engraved on the base portion 15 of the moving separation claw 14. The moving separating claw 14 is the rotating rod 1.
It is possible to reciprocate in the drum axial direction 16 with the rotation of 2.

A compression spring 18 is attached to the tip 14A of the moving separation claw 14. As a result, the separation claw 14 for movement has the base 15 as the center, and the photosensitive drum 1
It is given the force to rotate in the direction of 1. A regulation rod 19 for regulating this rotation is in contact with the moving separation claw 14 at a substantially central position. The regulating rod 19 is arranged parallel to the rotating rod 12, and its cross section is elliptical.
One end of the regulating rod 19 is attached to the rotary shaft of the rotary solenoid 21. Instead of the rotary solenoid 21, it is also possible to use a motor such as a pulse motor.

On the other hand, on the left end side of the photosensitive drum 11 in the drawing, a fixing separation claw 23 having its central portion in contact with the regulating rod 19 is arranged. Tip 23A of fixing separation claw 23
A compression spring 24 is attached to the same as in the case of the moving separation claw 14. The base 23B is connected to the rotary shaft 25. Therefore, the fixing separation claw 23 is given a force to rotate in the direction of the photosensitive drum 11 about the rotation rod 25. Both ends of the rotary rod 25 are rotatably held by fixed members (not shown) so that they cannot move in the drum axial direction 16. That is, in the state where the fixing separation claw 23 is positionally fixed in the drum axial direction 16, the rotation position of the tip 23A thereof is regulated by the regulation rod 19.

FIG. 2 shows the positional relationship between the rotation of the fixing separation claw and the surface of the photosensitive drum. Here, the solid line represents the regulating rod 19 and the fixing separation claw 23 in the state where the separation claw 14 for movement shown in FIG. 1 is moved, and the dashed line shows the separation claw 14 for movement after the movement. These states are shown. When the moving separation claw 14 is moving, the rotary solenoid 21 is in the demagnetized state,
At this time, the outer peripheral portion of the regulating rod 19 in contact with the major axis of the ellipse in cross section is brought into contact with the fixing separation claw 23. In this state, the tip 23A of the fixing separation claw is separated from the surface of the photosensitive drum 11 against the compression spring 24.

On the other hand, when the separating claw moving motor 13 shown in FIG. 1 is rotated forward or backward by a predetermined amount to complete the movement of the moving separating claw 14, the rotary solenoid 2 is moved.
1 is excited, the regulating rod 19 rotates 90 degrees, and the outer peripheral portion of which the cross section is in contact with the minor axis of the ellipse is brought into contact with the fixing separation claw 23. At this time, the tip 23A of the fixing separation claw moves in the direction of the arrow 31 while being regulated by the regulation rod 19 according to the pressing force of the compression spring 24, and lightly contacts the surface of the photoconductor drum 11. At this time, the moving separation claw 14 shown in FIG. 1 also performs the same operation, and thus the two separation claws 14,
23 is set on the surface of the photoconductor drum 11.

In the present embodiment, the separation claw moving motor 13 rotates to change the distance between the separation claws 14 and 23 with respect to the photosensitive drum 11, which is slightly shorter than the width of the sheet. To this end, the photosensitive drum 1
It is necessary to detect the width (sheet width) of the sheet sent to the first sheet. Therefore, in this embodiment, the paper width detecting device is used.

FIG. 3 is for explaining the principle of detecting the paper width of the paper width detecting device. A sheet of paper 42 is provided on the conveyance path 41 between the photosensitive drum 11 and a supply tray (not shown).
One elongated sheet width detection device 44 is arranged at right angles to the conveyance direction of. The paper width detecting device 44 includes N optical sensors 46 ₁ to 4 4 at a relatively narrow pitch from a position A to a position B corresponding to the right end of the photosensitive drum 11 shown in the drawing.
6 _N are placed. Here, the position B is the paper 42 fed with the left end of the photosensitive drum 11 and the left end thereof aligned.
This is the right edge of the paper when it is assumed that the paper width is the shortest. Each of the N photosensors 46 _{1 to} 46 _N is composed of a photosensor composed of a pair of a light emitting diode and a photodiode.

In the paper width detecting device 44 having such a structure, when the first photosensor 46 ₁ detects the arrival of the paper 42, the second to Nth photosensors 46 _{2 to} 46 _N after a predetermined time elapses. The detection operation is performed all at once. The detection timings of the _{second to} Nth optical sensors 46 _{2 to} 46 _N are shifted in consideration of the fact that the paper 42 may be conveyed while being obliquely inclined for some reason.

As a result of the detection operation of the _{second to} Nth optical sensors 46 _{2 to} 46 _N , when none of them detects the paper 42, the shortest width (in this embodiment, the photosensitive drum 11 It is determined that the paper having the length from the left end to the first optical sensor 46 ₁ ) has been conveyed. When the paper 42 is detected by all or part of the _{second to} Nth optical sensors 46 _{2 to} 46 _N , the optical sensor 46 located at the rightmost end of them.
It is discriminated that the paper 42 whose right end is is conveyed.
In the example shown in FIG. 3, the first to Mth optical sensors 46 ₁ to 4 4
Since the sheet 42 is continuously detected up to 6 _M, it is determined that the sheet 42 having the width shown by the one-dot chain line has arrived.

FIG. 4 shows the main part of the circuit configuration of this recording apparatus. This recording device includes a CPU (Central Processing Unit) 51. The CPU 51 is connected to various circuit devices via a bus 52 such as a data bus. Of these, the ROM 53 is a read-only memory that stores programs for performing various controls such as control for peeling the paper 42 from the photosensitive drum 11 (FIG. 1). The work memory 54 is a memory that temporarily stores data necessary for performing such control, and is composed of a random access memory. The non-volatile memory 55 is backed up by a battery (not shown) and stores fixed information such as a table relating to rotation control of the separation claw moving motor 13 with respect to the detection operation of the paper width detection device. The service person can change these contents as needed.

The input circuit 56 is an operation panel 57 (not shown).
Connected with. The operation panel 57 is provided with various switches such as a start button for starting the operation of the recording apparatus. The moving motor drive circuit 58 controls driving of the separating claw moving motor 13.
The solenoid excitation circuit 59 is adapted to control the excitation of the rotary solenoid 21. The sensor input circuit 61 is connected to the paper width detection device 44 and other sensors (not shown) and inputs detection signals of these. The main motor drive circuit 62 controls the drive of the main motor 63. The main motor 63 is a motor for driving the photosensitive drum 11 of this embodiment and controlling the conveyance of the paper 42.

FIG. 5 shows the flow of detection of the paper width and movement control of the moving separation claws in this recording apparatus. When the start button is pressed on the operation panel 57 shown in FIG. 4 to start the recording operation (step S101;
Y), the conveyance of the paper 42 (FIG. 3) is started at a predetermined timing. When the first optical sensor 46 ₁ is turned on (step S102; Y), the CPU 51 reads out rotation information representing the rotation state of the separation claw moving motor 13 from the nonvolatile memory 55 (step S103). The separating claw moving motor 13 is composed of a stepping motor,
In a predetermined area of the non-volatile memory 55, the moving separation claw 1
The latest rotation information of the separating claw moving motor 13 is stored in a form corresponding to the position of 4.

Although not shown in this figure, when the power of the recording apparatus is turned on, the CPU 51 controls the moving motor drive circuit 58 to move the moving separation claw 14 to the right end movement limit position, and the nonvolatile This rotation information in the memory 55 is initialized. This is to clear the accumulated error due to the driving of the separation claw moving motor 13.

After a short time t ₁ has passed since the first optical sensor 46 ₁ was turned on (step S104;
Y), the CPU 51 controls the second to Nth optical sensors 46 _{2 to} 46.
The sheet width of the sheet 42 is determined by checking the detection result of _N (step S105). Then, based on the previously determined rotation information and the determined paper width, the number and polarity of drive pulses by which the front end 14A of the moving separation claw is displaced to the left by a predetermined distance from the right end of the paper 42 are calculated and the separation claw is calculated. The drive control of the moving motor 13 is performed (step S106).

The front end 23A of the fixing separation claw is arranged at a position displaced from the left end of the paper 42 to the right by this predetermined distance. In this way, the tips 14A and 23A of the moving separation claw and the fixing separation claw are arranged so as to be moved inward by a predetermined distance from the end of the paper 42 in order to ensure the peeling. is there. The predetermined distance may be set to be narrow, for example, about several mm (millimeter). In this case, there is an advantage that there is no possibility of disturbing the toner image in the case of a normal document.

In step S106, the separating claw moving motor 1
When the drive control of 3 is performed, the rotation information about the new rotation position is written in the non-volatile memory 55 to update its content (step S107), and the work is ended (END).

FIG. 6 shows how the rotary solenoid of this recording apparatus is controlled. CPU shown in FIG.
51, when new rotation information is stored in the memory in step S107 shown in FIG. 5 (step S201; Y), the drive control of the separating claw moving motor 13 is completed at the time before this, so the rotary solenoid The excitation of 21 is started (step S202). As a result, the tips 14A and 23A of the moving separation claw and the fixing separation claw are attached to the photosensitive drum 1.
1 is brought into contact with the surface. As a result, the sheet 42 can be separated by the moving separation claw 14 and the fixing separation claw 23.

In this state, the CPU 51 monitors the completion of the recording operation (step S203), and at the time of completion, controls the solenoid excitation circuit 59 to release the excitation of the rotary solenoid 21 (step S204). That is, in the peeling device of this embodiment, not only when the moving separation claw 14 is moved,
Even when recording is not performed, the moving separation claw 14
The fixing separation claw 23 is separated from the surface of the photosensitive drum 11. Of course, depending on the device, the moving separation claw 14
May be separated from the surface of the photoconductor drum 11 only when moving.

Modification

In the embodiment described above, the sheet width detecting device 44 is used to detect the sheet width one by one, and the moving separation claw 1 is moved.
The case where the movement control of No. 4 is performed has been described. Depending on the device, it is possible to perform such control only for standard size paper.

FIG. 7 shows the positional relationship between a standard size sheet and two separating claws. Here, A5 size,
It shows the case of an apparatus in which five types of sheets of B5 size, A4 size, B4 size and A3 size are used. It is assumed that these sheets are conveyed in the direction of arrow 71 in the figure with one end along the left end side of the photosensitive drum 11 (see FIG. 1). In this case, the fixing separation claw 23 is fixed to the above-mentioned one end side,
The moving separation claws 14 are arranged at the respective positions shown in the drawing (moving separation claws 14 _{1 to} 14 ₄₎ in accordance with the types of these standard size sheets.
Position).

Further, in the embodiment, the rotary rod 12 with a thread
Although the movement control of the moving separation claw 14 is performed by rotating the, the movement control of the moving separation claw 14 may be performed by providing a moving belt.

FIG. 8 shows an outline of a peeling device of a modified example using a conveyor belt. The same parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be appropriately omitted. In the peeling device of this modified example, the moving separation claw 14 is connected to a predetermined position of the endless belt 82 via a connecting tool 81. The endless belt 82 is provided between a rotation shaft of a pulse motor 83 arranged near one end of the photoconductor drum 11 or a pulley 84 connected to the rotation shaft and another pulley 85 arranged near the other end of the photoconductor drum 11. The moving separation claw 14 can be moved in the drum axial direction. Separation claw 14 for movement and separation claw 2 for fixation
The tip of 3 may be separated from the surface of the photoconductor drum 11 if necessary, for example, by providing a mechanism similar to the mechanism shown in FIG.

FIG. 9 shows another mechanism for bringing the separating claw into contact with and separating from the surface of the photosensitive member. In this modified example, the separation claw 91
Is rotatably arranged with the rotating shaft 92 as a fulcrum,
A solenoid 93 is attached to the base side thereof. In this mechanism, when the plunger of the solenoid 93 is pushed out, the separation claw 91 comes into contact with the surface of the photoconductor, and when it is retracted, it separates from the surface of the photoconductor.

In the above-described embodiments and modifications, the recording device (the recording device for corner registration) in which the position of one edge (the left edge in FIG. 1) of the paper is always fixed has been described. The present invention can be similarly applied to a recording apparatus that performs center registration with the center position of the paper being the center position of the photoconductor. However, in this case, both of the two separating claws may be movable. Of course, you don't have to have two separate claws at all times,
If necessary, it can be additionally arranged at other places such as the central portion of the paper.

Further, although the peeling device for peeling the paper from the photosensitive drum has been described in the embodiment, the present invention can be applied to a device for peeling the paper from other photoconductor such as a photoconductor belt. Further, the peeling device of the present invention is not limited to the photoconductor, and it is needless to say that the peeling device can be similarly applied to the case of peeling a sheet from another rotating body such as a heat roll.

[0041]

As described above, according to the first and second aspects of the invention, a plurality of separation claws are arranged in a line in a direction orthogonal to the rotation direction of the rotating body, and at least one of them is arranged. Since it is moved in the direction orthogonal to this rotation direction, the peeling position of paper of various sizes can be arbitrarily set, for example, by specifying both ends of normal paper and places where preprinted paper is not printed. The peeling operation can be performed. Therefore, as compared with the case where the peeling of several sheets is shared at one fixed position of the separation claw, the image before fixing is not damaged. Further, even with a heat roll, the peeling can be performed at the most efficient position for peeling, so that the paper is not damaged or deformed at the time of peeling.

According to the second aspect of the invention, since the separation claw is not in contact with the surface of the rotating body during its movement, the rotating body and the separation claw itself are damaged or deformed during the movement. It has the effect of never happening.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main part of a recording device using a peeling device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the positional relationship between the rotation of the fixing separation claw and the surface of the photosensitive drum in the present embodiment.

FIG. 3 is a principle diagram showing a paper width detection principle of the paper width detection device in the present embodiment.

FIG. 4 is a block diagram showing a main part of a circuit configuration of a recording apparatus using the peeling apparatus of this embodiment.

FIG. 5 is a flowchart showing a flow of detection of a sheet width and movement control of a moving separation claw in the present embodiment.

FIG. 6 is a flowchart showing how the rotary solenoid is controlled in this embodiment.

FIG. 7 is a plan view showing a positional relationship between a standard size sheet used in a modified example of the present invention and two separation claws.

FIG. 8 is a schematic configuration diagram showing a peeling device using a conveyor belt as another modification of the present invention.

FIG. 9 is a side view showing a mechanism for bringing a separation claw into contact with and separating from a surface of a photoconductor according to still another modification of the present invention.

[Explanation of symbols]

11 ... Photosensitive drum, 12 ... Rotating rod, 13 ... Separation claw moving motor, 14 ... Movement separation claw, 14A, 23A ... (separation claw) tip, 18, 24 ... Compression spring, 19 ... Restriction rod,
21 ... Rotating solenoid, 23 ... Fixing separation claw, 25 ... Rotating shaft, 42 ... Paper, 44 ... Paper width detecting device, 46 ₁ to 4
6 _N ... Optical sensor, 51 ... CPU, 53 ... ROM, 54 ...
... Working memory, 55 ... Non-volatile memory, 57 ... Operation panel, 63 ... Main motor, 91 ... Separation claw, 93 ... Solenoid

Claims (2)

[Claims] 1. A rotator for rotating its surface, a sheet feeding means for feeding a sheet to the rotator, and a row arranged in a line in a direction orthogonal to the rotating direction of the rotator, each of which has its leading end. A peeling device comprising: a plurality of separation claws that are in contact with the surface for separation; and separation claw moving means that moves at least one of these separation claws in a direction orthogonal to the rotation direction. . 2. A rotator for rotating its surface, a sheet feeding means for feeding a sheet to the rotator, and a sheet arranged in a line in a direction orthogonal to the rotating direction of the rotator, each of which has its leading end. A plurality of separation claws that are in contact with the surface for peeling, a separation claw moving unit that moves at least one of the separation claws in a direction orthogonal to the rotation direction, and a separation claw during movement of the separation claws. A peeling device comprising: a separating claw separating means that is not in contact with the surface of the rotating body.