JPH05216348A - Separator for transfer paper - Google Patents

Abstract

PURPOSE:To smoothly carry a transfer paper separated from the surface of a photosensitive body to a paper ejecting path by allowing a separating pawl to stand by outside a separating/carrying path. CONSTITUTION:In a transfer type image recorder, the separating pawl 15A arranged on the downstream side of a separating charger 11, advancing from a standby position to a separation position, and separating the transfer paper passing the transfer charger 10 from the surface 1A of the photosensitive body, and a separating pawl moving means 16 advancing the separating pawl to the separation position, or allowing the separating pawl to stand by at the standby position outside the separating/carrying path, are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer paper separating apparatus used in an electrophotographic transfer type image recording apparatus (copying machine, printer, etc.), and more particularly to improvement of a separating claw forward / backward movement and its standby position. ..

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 64-13176 discloses a transfer-type image recording apparatus in which a transfer paper which is in close contact with the surface of a photoconductor is separated by a separation charger and a separation claw on the downstream side thereof. By rotating the separation claw around the support shaft, the separation claw is advanced to the separation position to separate the transfer paper from the surface of the photoconductor, and when the separation claw is retracted from the separation position, the support shaft is rotated in the retracting direction. A separating device that moves and retracts is known.

FIG. 7 is a block diagram showing the functions of exposure, development, transfer and separation on the photosensitive drum of the above conventional apparatus. The photoconductor drum 70 is a drum-shaped image carrier in which a photoconductive substance is laminated on a conductive metal substrate with a constant thickness,
While rotating, its photocathode sequentially passes through a plurality of processing stations. The photoconductor 70 is charged by the charger 71, and the surface of the photoconductor 70 uniformly holds electric charges. When the surface of the rotating photoconductor 70 is irradiated with the optical image 72 of the document, an electrostatic latent image of the document is formed on the irradiated portion of the photoconductor 70. This electrostatic latent image is developed in the developing unit 73 and visualized in the original image shape of the original.

The transfer sheet sent from the sheet feeding section (not shown) is conveyed to the timing roller 75 by the sheet feeding rollers 74A and 74B and stands by there. The transfer paper is sent out from the timing roller 75 to the photoconductor 70 in synchronization so that the front end of the original image area on the photoconductor 70 and the front end of the transfer paper coincide with each other. The transfer paper comes into close contact with the surface of the photoconductor 70, and the toner image of the original is transferred onto the transfer paper P by the transfer charger 76. The transfer paper P that has received the transfer is then separated by the charger 77.
Is separated from the surface of the photoconductor 70. The separated transfer paper is conveyed by the conveyance mechanism 78, reaches a fixing unit (not shown), and is ejected outside the machine.

When the paper detection sensor provided in the cassette paper feed unit (not shown) detects a narrow transfer paper (for example, B5 size vertical paper feed) or thin paper, the separation claw 79 supports the support shaft.
It is rotated counterclockwise about 80 and moved to the separation position shown by the solid line. Narrow or thin transfer paper is difficult to be sandwiched by the timing roller 75 just before the separation charger 77 with sufficient strength, and the original waist strength is not sufficient, so even if it is sandwiched by the timing roller, the apparent waist strength is high. These papers cannot be separated by the separation charger 77 alone because no paper is generated. The portion is separated by the action of the separating claw 79. When the paper detection sensor detects a wide transfer paper (for example, A3 size vertical paper feed) or a thick paper, the control unit rotates the separation claw 79 clockwise to move it to the retracted position indicated by the broken line. Since the wide transfer paper or the thick paper has the above-mentioned waist strength, it can be separated only by the separation charger 77, and as a result, unnecessary contact between the separation claw and the surface of the photoconductor 70 can be avoided. ..

However, the separation claw at the position of the dotted line retracted from the surface of the photoconductor 70 is a conveyance path through which the transfer paper separated by the separation charger 77 is conveyed toward the discharge path.
Since it is inside 81, the transfer paper that is separated and conveyed is
The separation claw protruding into the conveyance path 81 obstructs the course of the separation claw, and prevents proper progress in the direction of the conveyance mechanism 78. Further, the disturbed transfer paper may go around toward the cleaning stage 82 without going toward the transport mechanism 78.

[0007]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a transfer sheet separating device in which the separation claw is retracted to the outside of the separation conveying path so that the transfer sheet can be smoothly conveyed to the discharge. And

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is a transfer type image recording apparatus, which is arranged downstream of a separation charger and advances from a standby position to a separation position to expose a transfer paper passing through the transfer charger. A separation claw that separates from the body surface and a separation claw moving unit that advances the separation claw to the separation position or waits at a standby position outside the separation conveyance path are provided. Is arranged on the downstream side of the transfer paper and advances from the standby position to the separation position corresponding to the paper width of the transfer paper, and a plurality of separation claws for separating the transfer paper passing through the transfer charger from the surface of the photoconductor and the paper width of the transfer paper. Correspondingly, the separation claw moving means for advancing the separation claw to the separation position or waiting at the standby position outside the separation / conveyance path is provided. On the side of the cleaning stage for cleaning the surface of the drum, the separation claw is set to a position where it stands by from the surface, and the separation claw moving means is arranged so that the tip of the separation claw is perpendicular to the contact surface where the tip is in contact with the photoreceptor surface. The object of the present invention is achieved by a structure having a separating claw guiding means for making it reach the standby position after it is retracted to.

[0009]

When the separation claw comes into contact with the surface of the photoconductor, the tip of the separation claw advances from the standby position outside the separation conveyance path along the trajectory of the cam, and then the tip of the separation claw and the surface of the photoconductor are separated. Contacts the surface of the photoconductor perpendicularly to the contact surface. When the separation claw separates from the surface of the photoconductor, it separates from the surface of the photoconductor along a plane perpendicular to the contact surface where the tip of the separation claw contacts the surface of the photoconductor, and then the outside of the separation conveyance path along the track of the cam. To the standby position.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a main configuration diagram of a transfer type image recording apparatus to which an embodiment of the present invention is applied. The photoconductor 1 is a drum-shaped image carrier in which a photoconductive substance is laminated on a conductive metal substrate with a certain thickness, and is rotatably configured. The surface is adapted to sequentially pass through a plurality of processing stations. The surface 1A of the photoconductor 1 is charged by the charger 2 and uniformly holds the electric charge. Surface 1
The photoconductor 1 uniformly charged with A rotates, passes through the eraser 3, and reaches the exposed portion. An optical image (original reflected light) 4 of a document on a document table glass (not shown) is led out by an exposure optical system 5 such as a lens in an exposure section and is irradiated on the surface 1A of the photoconductor 1. The irradiated portion of the surface 1A discharges electric charge,
An electrostatic latent image of the original is formed on this irradiated portion. This electrostatic latent image is developed by the developing unit 6, and the developing material containing the charged toner particles adheres to this latent image to be visualized in the original image shape of the original.

On the other hand, the transfer paper 7 delivered from a paper feed cassette (not shown) is conveyed to the registration rollers 8 and stands by there. The transfer paper is exposed from the registration roller 8 in synchronization so that the front end of the original image area exposed on the surface 1A of the photoconductor 1 that has passed through the pre-transfer charger 9 and the front end of the transfer paper coincide with each other. Surface 1A of body 1
Sent to. The transfer paper 7 is brought into close contact with the surface 1A of the photoconductor 1 on which the original toner image is formed, and in this state, the original toner image is transferred to the transfer paper 7 by the discharge of the transfer charger 10. The transfer paper 7 on which the original toner image is transferred is subjected to AC corona discharge from the back surface (the surface opposite to the side on which the original toner image is formed) by the separation charger 11 to separate it from the surface 1A of the photoconductor 1. Receive. The transfer paper 7 that has been subjected to the electrostatic separation action is subjected to a mechanical separation action by the separation unit 12 of the present invention, if necessary.

Surface 1A of photoconductor 1 from which transfer paper 7 is separated
The residual toner is removed by the cleaning unit 13. After that, the charge is removed by the charge removing lamp 14, and the state returns to a state where new uniform charging is applied. On the other hand, the transfer paper 7 separated from the surface 1A of the photoconductor 1 is transported by a transport mechanism (not shown) and reaches the fixing section to be fixed. The transfer paper after completion of fixing is discharged to the outside of the machine by a discharge roller.

FIG. 2 is a perspective view showing a separation unit according to an embodiment of the present invention. The separation unit 12 includes a plurality of separation claws 15 that move forward and backward (contact / separation) toward the surface 1A of the photoconductor 1.
It is equipped with A, 15B, 15C and 15D (represented by 15A in FIG. 1). These claws are selectively projected according to the widthwise size of the transfer paper 7 (for example, A4 or A3 size) shown in FIG. Only the two claws located at both ends of the separation claw located within the paper width are made to project, and the other claws are retracted. With this configuration, when these claws separate the corresponding transfer paper, the separation action is started simultaneously from both ends of the transfer paper, and the separation is promoted. 16A, 16B, 16C and 16D are separate claws
A solenoid for driving attachment / detachment of 15A, 15B, 15C, and 15D to / from the surface 1A of the photoconductor 1. Each separation claw and each solenoid corresponding thereto constitute each separation claw drive unit.

FIGS. 3A and 3B are views showing the internal structure of the separation unit 12 shown in FIG. Figure 3 (B)
Is KK in the figure (A) including the unit cover 17.
It is a cross section. Both side surfaces 15A-1 and 15A-2 of the separating claw 15A are slidably held by guide walls 17B and 17C which are provided upright from the inner bottom surface 17A of the unit cover 17. Both sides
Rotating bosses 15A-3 and 15A-4 extending from 15A-1 and 15A-2 toward the guide walls 17B and 17C, respectively, are provided with slot 17D provided in the guide wall 17B and slot (provided in the guide wall 17C ( (Not shown) and are fitted so that they can move smoothly.

A cam convex portion 15A-6 as a cam follower is provided so as to protrude from a lower edge 15A-5 of the separating claw 15A. The cam convex portion 15A-6 is brought into contact with the cam surface 18A of the spring plate 18 against the spring force. The bottom wall 17E having the cam surface 17F is a guide wall
Formed between 17B and 17C (immediately below the separating claw 15A). The base end of the spring plate 18 is firmly inserted between the bottom wall 17E and the inner bottom surface 17A of the unit cover 17. Both sides of separation claw 15A
The gap between the guide walls 17B and 17C where 15A-1 and 15A-2 move smoothly, the slot 17D where the rotation boss 15A-3 moves smoothly, and the rotation boss 15A-4 of this separation claw 15A are smooth. An intersecting void is formed with the moving slot (not shown). An extensible coil spring 19 is placed in this intersecting void. One end of this coil spring 19 has a rotating boss 15A-3, 15 of the separation claw 15A.
It is hung on a protrusion 15A-7 extending from the peripheral portion of the end portion on the side where A-4 is extended toward the above-mentioned intersection void. The other end of the coil spring 19 has an inner bottom surface 17 of the unit cover 17.
Surface 20A of the L-shaped spring retainer 20 sewn on A, which is provided upright
And is hung on the projection 20B extending toward the above-mentioned crossing gap.

The bent portion 21A at the tip of the connecting rod 21 connected to the drive core 16B of the solenoid 16A is engaged with the through hole 15A-8 formed in the center portion of the separation claw 15A in the width direction.

The above is the configuration of the separating claw unit including the separating claw 15A and the solenoid 16A shown in FIG. Separation claw 15
B and solenoid 16B, separating claw 15C and solenoid
The respective separating claw units including 16C, separating claw 15D and solenoid 16D are also configured in the same manner as above. FIG. 4 is a control function block diagram for driving each separation claw unit shown in FIG. The separation pawl drive unit 57 corresponds to the solenoids 16A, 16B, 16C and 16D of the above units shown in FIG.

When electric power is supplied (power switch is turned on),
When the transfer type image device is on standby, the core suction power is supplied to the separation pawl drive unit 57 shown in FIG. 4, that is, the solenoids 16A, 16B, 16C, 16 of the units shown in FIG.
D is applied to each of the separating claws 15A, 15B, 15C and 15D shown in FIG.
It is at the standby position retracted from the surface 1A of the photoconductor 1 shown by the chain line in (B).

Now, in the paper size selection console 51 shown in FIG. 4 installed in this image device by the operator, for example,
When A3 size transfer paper is selected, the paper width data 52 of this transfer paper is decoded by the decoder 53, and this decoded data 54 is sent to the drive command unit 55. Transfer paper A3 of separation claw drive unit 57
Solenoid 16 corresponding to the nail that covers the paper width of the size
Electric power to A and 16D (shown in FIG. 2) is cut off by the solenoid drive signal 56 sent from the drive command unit 55, and the drive core 16B is released from the electromagnetic attraction force. As shown in FIG. 3 (A), the coil spring 19 moves the separating claw 15A to the left by its extension force, and as shown in FIG. 3 (B), the separating claw 15A is moved.
The tip of A contacts the surface 1A of the photoconductor 1. The abutting force between the tip of the separating claw and the surface 1A of the photosensitive member 1 resists the elastic force of the leaf spring 18 and is rotated clockwise by the cam convex portion 15A-6 which abuts the cam surface 18A of the leaf spring 18. It is elastic.

When the connecting rod 21 having the bent portion 21A, which is inserted with play into the through hole 15A-8 of the separating claw 15A, moves leftward together with the separating claw 15A, the separating bar shown in FIG. A connecting rod (not shown) having a bent portion that is inserted with play into a through hole (not shown) of the claw 15D also moves leftward together with the separating claw 15D. In this moving process, the projection 15A-6 of the separation claw 15A and the projection (not shown) of the separation claw 15D slide down along the cam surface 17F, and the leaf spring
It slides up along the cam surface 18A of 18 and separates the claws 15A, 15A.
The tip of D traces the movement locus of the chain line indicated by 22 and elastically contacts the surface 1A of the photoconductor 1. Surface 1 of photoconductor 1
This locus of movement in A and its vicinity is
It is along a perpendicular surface 23 perpendicular to the contact surface of the surface 1A at a position where A and the tips of the separation claws 15A and 15D contact each other. Cam surface
18A is configured to obtain the above trajectory.

Next, when the operator selects, for example, an A4 size transfer paper on the paper size selection console 51 shown in FIG. 4, the paper width data 52 of this transfer paper is decoded in the same manner as described above, and FIG. Power to the solenoids 16B and 16C shown in is cut off. These solenoids 16B and 16C are used for the transfer paper A.
It supports nails that cover 4 sizes of paper width. At the same time as the power to the solenoids 16B and 16C is cut off, power is applied to the solenoids 16A and 16D shown in FIG. 2 by the solenoid drive signal 56 sent from the drive command unit 55 shown in FIG. These solenoids 16A and 16D are used for transfer paper A3.
It corresponds to a nail that covers the paper width of the size. Separation claw 15B corresponding to solenoid 16B, 16C whose power is cut off,
15C (separation claw corresponding to the width of A4 size paper) comes into contact with the surface 1A of the photoconductor 1 through the same operation as described above to prepare for separation of the transfer paper A4 size.

The solenoid 16A to which electric power is applied attracts the drive core 16B, and the bent portion 21A of the connecting rod 21 has a separating claw 15A.
Is moved to the right against the extension force of the coil spring 19 shown in FIG. 3 (B). At the same time, the solenoid 16D to which electric power is applied also attracts the driving core (not shown), and the bending portion of the connecting rod causes the separating claw 16D to expand the coil spring (not shown) shown in FIG. 3B. Move to the right against. Separation nail
Projection 15A-6 of 15A and projection of separation claw 15D (not shown)
Slides down on the cam surface 18A of the leaf spring 18 and slides up on the cam surface 17F to move. At this time, these separation claws 15A and 15D
The leading end of 1 moves away from the surface 1A of the photoconductor 1 by drawing a movement locus 22 shown by a chain line, and retreats to a standby position shown by a broken line in FIG. 3B. The separation claw retracted to the standby position (separation claw shown by a broken line in FIG. 3B) is the surface 1A of the photoconductor 1.
To the separation claw (separation claw shown by the solid line in FIG. 3 (B)) that is advancing to the abutting position on the side opposite to the separation conveyance path defined by the separation claw and protruding into the conveyance path. It does not come and does not hinder the conveyance of the separated transfer paper.
The decoder 53 and the drive command unit 55 shown in FIG. 4 can be configured as a control unit 58 including a microcomputer.

A wide paper, for example, A3 size is shown in FIG.
The timing roller (not shown) located immediately upstream of the separation charger 11 shown in FIG. 2 causes this paper to be pinched and generate an apparent waist strength.
Can be separated only by 11. In such a case, as shown in FIG. 4, the decoded data 54 of the paper width is sent to the drive command unit 55, and the solenoid driving signal 56 causes the separation claw driving unit 57 to move all the separation claws 16A shown in FIG. It is possible to control 16B, 16C and 16D so that they are in the standby position. In addition, when a naturally strong paper such as thick paper is fed, a paper thickness detection sensor provided in the cassette paper feeding unit (not shown)
The paper thickness is detected by 59, and the detection data 60 is decoded by the decoder 53. All separation claws 16A, 16B, 16
C and 16D are controlled in the same manner as above based on the decoded data 54 of the paper thickness. When controlled in this manner, these separation claws 16A, 16B, 16 which are in the state of being retracted from the separation position
C and 16D do not interfere with the subsequent conveyance of the transfer paper separated from the photoconductor by only the separation charger 11 (FIG. 1), and the surface 1 of the photoconductor 1 of these separation claws
It is possible to avoid unnecessary contact with A (the same figure).

FIG. 5 shows an example of a configuration in which a large number of separation claw units are arranged side by side in the separation unit 12 shown in FIG. Each separation claw unit has a separation claw 60A, 60B, 60C, 60
D, 60E, 60F, 60G, 60H, 60K and their corresponding solenoids 61A, 61B, 61C, 61D, 61E,
61F, 61G, 61H and 61K are configured as shown in FIG. 3 (A) and FIG. 3 (B). Each separating claw is controlled as described above by the control unit shown in FIG. Further, it is possible to control so that a large number of claws act on the selected transfer paper within the width of the transfer paper to perform the separating operation. When controlled in this manner, the separating action is started simultaneously from both ends of the transfer paper, and the separating action is simultaneously started from within the other paper widths, so that the separation is further promoted. Also, the separated paper portion is introduced under the nail at the separation position adjacent to the separated nail. Then
The part separated by the adjacent claw is introduced under the claw in the separation position adjacent to the claw, and the operation is sequentially continued and pushed down one after another, so that the separation can be further promoted.

Among the separation claws located inside the maximum width of the transfer paper, the other separation claws located inside the separation claws located at both ends may be different in number or spacing depending on the quality of the transfer paper used. Can be changed arbitrarily.

The movement locus of the separation claw on the surface 1A of the photosensitive member 1 due to the contacting / separating operation can be configured as shown in FIG. The rotating boss 32A is smoothly inserted into a groove provided between the two walls that are provided upright on the inner bottom portion 17A of the unit cover 17, and rotates while guiding the separation claw 32 to advance and retreat. The end turn portion of the extensible coil spring is inserted in the protrusion 32B with play.

The contact side 32C of the separation claw 32, which contacts the surface 1A of the photoreceptor 1, is formed in the shape of an eagle claw. A driving cam surface 32D is formed on a lower edge 32D between the contact side 32C and the rotating boss 32A.

During the process in which the separating claw 32 moves to the left from the standby position RP and moves to the forward position FP, this lower edge
32D slides down when it comes into cam contact with a driven cam rod 33 fixed in parallel to the rotation axis direction of the photoconductor 1 on a wall (not shown) and slides down to the vicinity where the tip of the separation claw comes into contact with the surface 1A. Go up. This tip follows the movement locus of the one-dot chain line 34 and elastically contacts the surface 1A. Surface 1A
And the movement locus in the vicinity thereof is the surface 1A.
Along a plane 35 perpendicular to the tangent plane that touches.

In the process in which the separating claw 32 moves to the right from the forward position FP and moves to the standby position RP, the separating claw moves in the opposite movement to the above, and the tip of the separating claw moves along the movement locus 34. In contrast to the above, the sheet is separated from the surface 1A of the photoconductor 1 and retracted to the position indicated by the broken line.

The group of parts located in the unit cover 17 for activating the separating claws constitutes the separating claw moving means. Further, among the components constituting the separating claw moving means, the part for moving the tip of the separating claw back to the standby position after retracting the tip of the separating claw in the direction perpendicular to the contact surface in contact with the surface of the photosensitive drum is separated. It constitutes the nail guiding means.

[0031]

As described above, in the present invention, the separation claw that is not involved in the separation operation is electrostatically separated because it is at the standby position outside the subsequent conveyance path of the electrostatically separated transfer paper. Subsequent conveyance of the transfer paper is not hindered. Further, since unnecessary contact between the separation claw and the surface of the photoconductor is avoided, deterioration and damage of the image forming layer of the photoconductor and the tip of the separation claw can be prevented, and their life can be extended.

[Brief description of drawings]

FIG. 1 is a main configuration diagram of a transfer type image recording apparatus to which an embodiment of the present invention is applied.

FIG. 2 is a three-dimensional perspective view of a separation unit that is an embodiment of the present invention.

3A and 3B are a top view showing an internal configuration of a separation claw unit that is an embodiment of the present invention and a partial side sectional view of a separation claw unit that is an embodiment of the present invention.

FIG. 4 is a block functional diagram showing a configuration of a control unit of the present invention.

FIG. 5 is a three-dimensional perspective view of another embodiment of the separation unit of the present invention.

FIG. 6 is a view showing another embodiment of the separation claw of the present invention.

FIG. 7 is a diagram showing a configuration of a main part of a conventional technique.

[Explanation of symbols]

1, 70 ... Photoconductor, 6 ... Developing unit, 11, 77 ... Separation charger, 10, 76 ... Transfer charger, 12 ... Separation unit, 13 ... Cleaning unit, 15A, 15B, 15C, 15
D, 60A, 60B, 60C, 60D, 60E, 60F, 60G, 60
H, 60K, 79 ... Separation claw, 16A, 16B, 16C, 16D, 61
A, 61B, 61C, 61D, 61E, 61F, 61G, 61H, 61K
... Solenoid (separation claw moving means), 17 ... Unit cover, 17A ... Inner bottom surface, 17B, 17C ... Guide wall, 17D, 17E
… Slots, 17F… Cam surface, 18… Leaf springs, 18A… Cam surface, 19
… Coil spring, 20… L-shaped spring retainer, 21… Connecting rod, 21A…
Bending section, 23, 34 ... Movement locus, 33 ... Followed cam rod, 51 ... Paper size selection console, 53 ... Decoder, 55 ... Drive command section, 57 ...
Separation claw driving unit, 58 ... Control unit including microcomputer, 59 ... Paper thickness detection sensor, 73 ... Developing unit, 74A, 74B ... Paper feeding roller, 75 ...
Timing roller, 78 ... Transport mechanism, 80 ... Support shaft, 81 ... Transport path, 82 ... Cleaning stage.

Claims (4)

[Claims] 1. An electrophotographic transfer-type image recording apparatus, which is disposed downstream of a separation charger, advances from a standby position to a separation position, and separates the transfer paper passing through the transfer charger from the surface of the photoconductor. An apparatus for separating a transfer sheet, comprising: a claw; and a separation claw moving unit that advances the separation claw to the separation position or waits at the standby position outside the separation conveyance path. 2. In an electrophotographic transfer image recording apparatus, a transfer paper which is disposed on the downstream side of a separation charger, advances from a standby position to a separation position according to the paper width of the transfer paper, and passes through the transfer charger. A plurality of separation claws for separating the separation claws from the surface of the photoconductor, and separation claw moving means for advancing the separation claws to the separation position or waiting at the standby position outside the separation conveyance path in accordance with the paper width of the transfer paper. A transfer paper separating device characterized by the above. 3. A standby position outside the separation / conveyance path is on a cleaning stage side for cleaning the surface of the photosensitive drum after transfer, and is a position where the separation claw is retracted from the surface of the photosensitive drum. The transfer paper separating device according to claim 1 or 2. 4. The separation claw moving means includes separation claw guiding means for moving the tip of the separation claw back to the standby position after retracting the tip of the separation claw in a direction perpendicular to the contact surface in contact with the surface of the photosensitive drum. The transfer paper separating device according to claim 1 or 2, characterized in that: