JP2586518B2 - Transfer sheet peeling device for image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is attached to an image forming apparatus such as a copying machine or a printer employing an electrophotographic system and electrostatically adheres to a latent image carrier. The present invention relates to a transfer sheet peeling device for forcibly peeling a transfer sheet, and in particular, forms a toner band having a predetermined width in a non-image forming cycle to lubricate a cleaning member and prevent image disturbance, and cleans the toner band. An object of the present invention is to provide a transfer sheet peeling device which is effective in an image forming apparatus adapted to supply to a member.

[Prior Art] Generally, as shown in FIG. 10, an image forming apparatus such as a copying machine adopting an electrophotographic method includes a latent image carrier 1 such as a photosensitive drum and the latent image carrier 1 charged in advance. Charging device 2,
An optical imaging system 3 for forming a latent image (image portion) based on a light image from a document, for example, on the charged latent image carrier 1, and an inter-image portion of a latent image area formed by the optical imaging system 3 An erase lamp 4 for erasing the charged electric charges of the image forming apparatus, a developing device 5 for developing the latent image formed on the latent image carrier 1 with toner, a corotron for transferring the toner image on the latent image carrier 1 to a transfer sheet 6, etc. A transfer unit 7, a separation charger 8 arranged in parallel with the transfer unit 7 to separate the transfer sheet 6 after the transfer process from the latent image carrier 1, and electrostatically adhering to the latent image carrier 1 And a cleaner 10 including a blade 11 for scraping and removing residual toner on the latent image carrier 1. In FIG. 10, reference numeral 12 denotes a resist roll for positioning and supplying the transfer sheet 6, and reference numeral 13 denotes a transport belt for transporting the transfer sheet 6 after the transfer step to a fixing device (not shown).

By the way, in this type of image forming apparatus, in addition to reducing the frictional resistance between the blade 11 and the latent image carrier 1 to achieve lubrication between the blade 11 and the latent image carrier 1, the components contained in the transfer sheet 6 are also Conventionally, a device provided with a means for preventing non-uniformity of the charging characteristics due to the adhesion to the substrate 1 has already been provided. For example, as shown in the timing chart of FIG. 11, the erase lamp 4 is turned on after the end of the image forming cycle so as to form the inter-image portion, but it is turned off for a predetermined time t during the lighting. For example, the twelfth
As shown in the figure, with the inertial operation of the magnet roll 14 (see FIG. 10) of the developing device 5 that is turned off corresponding to the inter-image section, the residual charging section corresponding to the turning-off time t of the erase lamp 4 A toner band T having a predetermined width is formed by adhering toner to the toner band T.
Is supplied.

[Problems to be Solved by the Invention] However, in such a conventional image forming apparatus, since the amount of the residual toner of the latent image carrier 1 in the image forming cycle is not so large, the peeling claw 9 is Even if it is fixedly provided at a position in contact with the body 1, the residual toner hardly adheres to the tip of the peeling nail 9, but the toner band T as described above has a large amount of toner in the first place. Then, there is a possibility that the toner from the toner band T adheres to the tip of the peeling claw 9. Then, when the transfer sheet 6 comes into contact with the peeling claw 9,
The nail mark of the toner is formed on the transfer sheet 6, which causes the image quality on the transfer sheet 6 to be impaired.

Means for Solving the Problems The present invention has been made in view of the above problems, and an image forming apparatus that forms a toner band on a latent image carrier during a non-image forming cycle is provided. As a prerequisite, an object of the present invention is to provide a transfer sheet peeling device of an image forming apparatus which avoids contamination of a peeling nail due to toner adhesion from a toner band.

In other words, a first invention for achieving the above-described object is to form a toner band T of a predetermined width on a latent image carrier 1 in a non-image forming cycle as shown in FIG.
The transfer sheet 6 electrostatically attached to the latent image carrier 1 is attached to an image forming apparatus that supplies the toner band T to a contact portion of the latent image carrier 1 with the eleventh toner image. A transfer sheet peeling device, which is provided with a peeling claw 9 that is retractably disposed from a sheet peeling position where the leading end abuts on the latent image carrier 1, and moves the peeling claw 9 at least between the sheet peeling position and the retract position A driving means 40 for moving, and a driving control means 70 for controlling the driving means 40 so as to release the peeling claw 9 from the sheet peeling position when the toner band T passes through a portion corresponding to the peeling claw 9. It is provided with.

Further, as shown in FIG. 1, a second invention for achieving the above-described object has the same principal parts as the first invention, and a peeling device set at a sheet peeling position instead of the driving means 70. A driving means for moving the peeling claw 9 one or more times between the retract position and the sheet peeling position momentarily after the toner band has passed through a portion corresponding to the claw 9;
A drive control unit 80 for controlling the control unit 40 is provided.

In such technical means, the latent image carrier 1 may be appropriately selected as long as it can form a latent image, such as a photoreceptor or a dielectric. , Regardless of the belt shape.

Regarding the formation timing of the toner band T,
As long as it is during a non-image forming cycle, it may be during a continuous image forming cycle or before or after one image forming cycle. As for the toner band T forming means, the lighting timing of the erase lamp may be appropriately controlled after uniformly charging the latent image carrier by the charger. The design may be changed as appropriate, such as by appropriately adjusting the operation timing. When forming the toner band T, the developing device may be turned off to use its inertia, or the developing device may be turned on.

Further, the material and structure of the peeling nail 9 may be appropriately changed as long as it has a function of peeling the transfer sheet. The driving means 40 of the peeling claw 9 may be a device using a linear shift actuator, a motor and a cam, as long as it can move the peeling claw 9 at least between the sheet peeling position and the retract position. The design may be changed as appropriate such as a combination of the above. In this case, if the driving unit 40 is configured so that the contact portion between the peeling claw 9 and the latent image carrier 1 can be displaced along the axial direction of the latent image carrier 1, the latent image carrier The damage caused by the first peeling claw 9 can be dispersed, and the durability of the latent image carrier can be improved. Further, as the drive control means 70, 80, a microcomputer may be provided with the function, or various controllers including a timer and the like may be appropriately combined.

[Operation] According to the above-described first technical means, when the drive control means 70 controls the drive means 40 of the peeling claw 9 in a predetermined mode, the peeling claw 9 becomes latent when the toner band T passes. The sheet moves from the sheet peeling position in contact with the image carrier 1 to the retract position.

Further, according to the second technical means, when the drive control means 80 controls the drive means 40 of the peeling claw 9 in a predetermined mode, the peeling claw 9 to which the toner from the toner band T adheres is moved to the latent image carrier. 1 is instantaneously abutted, and the attached toner is dropped by the impact force at that time.

Hereinafter, the present invention will be described in detail based on an embodiment shown in the accompanying drawings.

Embodiment 1 FIG. 2 shows an example in which the first invention is applied to a two-color copying machine that reproduces a two-color original of red and black.

In FIG. 1, reference numeral 1 denotes a latent image carrier made of, for example, a photosensitive drum, 2 denotes a charger made of a corotron or the like which pre-charges the latent image carrier 1, 3 denotes an exposure lamp 3a, and an optical path of light reflected from the original 20. A plurality of mirrors 3b, an image forming lens 3c for setting an image forming position on the latent image carrier 1, and a color separation filter 3d interposed in the optical path. An optical imaging system for forming an image on the image carrier 1 side, 4 is an erase lamp for erasing the charge on the latent image carrier 1 corresponding to the inter-image section, 5a is a red developing device using red toner, 5b Is a black developing device using a black toner, 6 is a transfer sheet, 7 is a transfer device made of corotron or the like, and 8 is a transfer device 6 arranged in parallel with the transfer device 7 to transfer the transfer sheet 6 after the transfer process to the latent image carrier 1. Charging device for peeling from paper, 9
Is a peeling claw for forcibly peeling off the transfer sheet 6 electrostatically attached to the latent image carrier 1; 10 is a cleaner including a blade 11 for scraping and removing residual toner on the latent image carrier 1;
Is a registration roll for supplying and positioning the transfer sheet 6;
Is a conveyor belt for conveying the transfer sheet 6 after the transfer step.

Reference numeral 22 denotes a multi-stage sheet feeding tray in which transfer sheets of various sizes are stored in advance, and reference numeral 23 denotes a sheet feeding tray.
A sheet feeding mechanism for conveying the transfer sheet 6 from 22 to the position of the resist roll 12; a fixing device 24 for fixing the toner image on the transfer sheet 6 after the transfer process; Output tray, 26 is double-sided transfer,
A switching member that guides the transfer sheet 6 after fixing to the intermediate tray (not shown) for double-sided transfer and multiple transfer via the return conveyance path 27 when performing multiple transfer.

In this embodiment, as shown in FIGS. 3 and 4, three peeling claws 9 are provided in the axial direction of the latent image carrier 1, and the support mechanism 30 is provided with a mounting frame 30.
A support shaft 32 that is swingable and movable along the axial direction is provided on the support shaft 31, and the central portion of each peeling claw 9 is fixed to the support shaft 32, while the base end side of each peeling claw 9 is connected to a connection plate 33. Are connected by

The driving means 40 of the peeling claw 9 includes a retract driving unit that moves forward and backward between a sheet peeling position P1 where the tip of the peeling claw 9 contacts the latent image carrier 1 and a retracting position P2.
41, and an axial driving unit 42 which moves the peeling claw 9 forward and backward along the axial direction of the latent image carrier 1 by, for example, about ± 12 mm. In this embodiment, the retract driving unit 41 includes a finger actuator 43 composed of an electromagnetic actuator having an operating rod 43a that advances and retreats in the axial direction of the latent image carrier 1, and an operating rod 43a of the finger actuator 43. A driving force transmitting arm 44 for converting the forward / backward movement into a vertical forward / backward movement and transmitting the driving force; a locking plate 45 provided on the connecting plate 33 for transmitting the driving force of the driving force transmitting arm 44 to the connecting plate 33; And an urging spring 46 for constantly urging the locking plate 45 toward the driving force transmitting arm 44 side. On the other hand, the axial drive unit 42 includes a drive motor 47,
Reduction gear for reducing the rotation of the motor shaft of this drive motor 47
48 and an eccentric cam that rotates with the rotation of this reduction gear 48
49 and the eccentric cam 49 erected at one end of the support shaft 32.
, And a biasing spring 51 for biasing the support shaft 32 between the mounting frame 31 and the pressing plate 50.

In this embodiment, the blade of the cleaner 10 is used.
3, is supported by a retractable drive support mechanism 60 that contacts the latent image carrier 1 at the timing when the toner band T passes in the image forming cycle and the non-image forming cycle, as shown in FIG. The toner receiving seal 61 of the cleaner 10 is supported by an interlocking support mechanism 62 that is interlocked with the driving support mechanism 60, and the toner receiving seal 61 is moved by the blade 11 toward and away from the latent image carrier 1. It comes into contact with and separates from the carrier 1. Then, the toner collected in the cleaner 10 is conveyed to a predetermined collecting section by the conveying auger 63.

Further, in this embodiment, the drive control means 70 for controlling the drive means 40 is configured as a microcomputer system shown in FIG.

In the figure, reference numeral 71 denotes a start switch for starting an image forming cycle, and a signal from the start switch 71 is supplied to a CPU 73 via an input interface 72.
To be entered. Based on the input signal, the CPU 73 executes an image forming program stored in advance in the ROM 74, executes a toner band forming program and a peeling claw operation program, and exchanges data with the RAM 75. Is to be performed. The CPU 73 outputs an image forming signal (not shown) from the output interface to control each image forming device. In addition, the CPU 73 operates an erase lamp operation signal Sa, which is an operation signal for forming a toner band, and a magnet roll operation signal. Sb and the peeling claw operation signal Sc are output via the output interface 46, and the respective control signals cause the erase lamp 4, for example, the magnet roll 14 and the finger of the black developing device 5b to be operated, as shown in the timing chart of FIG. The actuator 43 is controlled.

Next, the operation of the transfer sheet peeling device according to this embodiment will be described.

When the start switch 71 shown in FIG. 5 is turned on, first, the CPU 73 executes the image forming program.

In this case, assuming the black image forming mode, first,
After the charger 2, the erase lamp 4, the black developing device 5b, the transfer device 7, the peeling charger 8 and the cleaner 10 which are peripheral devices of the latent image carrier 1, the main unit of the latent image carrier 1 is operated. The motor is operated as shown in FIG. Then, the timing when the erase lamp 4 is turned off (sixth
In FIG. 2B, a predetermined latent image is formed by the optical imaging system 3, and the latent image is developed with toner by the developing device 5b.
Then, the toner image is transferred to the transfer sheet 6 and the residual toner is removed by the cleaner 10.

In such an image forming process, since the peeling claw 9 is set at the sheet peeling position P1, even if the sheet 6 is not peeled off by the peeling charger 8, the peeling claw 9 is forcibly peeled off. . In particular, in this embodiment, when the multi-transfer or double-sided transfer mode is adopted, the transfer sheet 6 once passes through the fixing device 24. The leading end of the transfer sheet 6 may be easily curled, and the transfer sheet 6 may not be completely peeled off by the peeling charger 8, and forced peeling by the peeling claw 9 increases. Further, in this embodiment, since the peeling claw 9 is advanced and retreated with a predetermined moving margin in the axial direction of the latent image carrier 1, a specific area of the latent image carrier 1 is locally localized during the image forming cycle. It will not be damaged.

When the image forming cycle is completed, the CP
U73 executes the toner band forming program and the peeling claw operating program.

At this time, as shown in FIG. 6 (b), the erase lamp 4 is turned on in response to the inter-image portion based on the erase lamp operation signal Sa, and is turned off for a predetermined time t while being turned on. As shown in FIG. 6 (c), the magnet roll 14 of the developing device 5b is turned off at the timing corresponding to the inter-image section based on the magnet roll operation signal Sb, so that the magnet roll 14 performs the inertial operation of the magnet roll 14. Accordingly, the toner adheres to the residual charging portion corresponding to the turning-off time t of the erase lamp 4 to form a toner band T as shown in FIG.

Then, as shown in FIG. 7, when the toner band T reaches a position where the toner band T passes through the position of the peeling claw 9, the finger actuator 43 causes the peeling claw operation signal to appear as shown in FIG. 6 (d). Based on Sc, it temporarily changes from the ON operation state to the OFF operation state. Then, the driving force for pushing down from the finger actuator 43 is released, and the connecting plate 33 is moved upward by the urging spring urging force. As shown in FIG. The sheet retracts from the sheet peeling position P1 to the retract position P2. In this state, the toner band T moves toward the cleaner 10 without contacting the tip of the peeling claw 9. As a result, the toner from the toner band T does not adhere to the tip of the peeling claw 9, and even if the tip of the transfer sheet 6 contacts the tip of the peeling claw 9 in the image forming cycle,
There is no sticking of toner marks on the transfer sheet 6.

Embodiment 2 In this embodiment, the second invention is applied to the transfer sheet peeling device used in the two-color copying machine according to Embodiment 1, and the basic configuration of this transfer sheet peeling device is Embodiment 1. Drive control means similar to that of the first embodiment, but different from that of the first embodiment.
It has 80.

The drive control means 80 is configured as a microcomputer system corresponding to FIG.
This program is executed to control the finger actuator 43 as shown in the timing chart of FIG.

Next, the operation of the transfer sheet peeling device according to this embodiment will be described.

That is, as shown in FIG. 8B, the finger actuator 43 is in the ON operation state in the image forming cycle and the toner band forming cycle.
The peeling claw 9 is set at the sheet peeling position P1. At this time, as shown in FIG.
, The toner T ′ from the toner band T inevitably adheres to the tip of the peeling claw 9,
In this embodiment, after the main motor of the latent image carrier 1 is stopped, as shown in FIG.
As shown in FIG. 9, since the finger actuator 43 temporarily turns off and then turns on again, the peeling claw 9 temporarily retracts from the sheet peeling position P1 to the retracting position P2 as shown in FIG. Sheet peeling position immediately after
The process returns to P2, and as a result, the peeling claw 9 abuts on the latent image carrier 1. Then, the attached toner T 'at the tip of the peeling claw 9 is dropped and removed by the impact force at that time, and even if the transfer sheet 6 is forcibly peeled by the peeling claw 9 in the next image forming cycle, the transfer is performed. The possibility that the peeling claw 9 is left on the sheet 6 is avoided.

In this embodiment, the vibration of the peeling claw 9 is performed only once in order to remove the adhered toner T 'on the peeling claw 9, but the vibration may be performed a plurality of times. Further, in this embodiment, the vibration operation of the peeling claw 9 is performed on the stopped latent image carrier 1, but the vibration operation of the peeling claw 9 is performed on the rotating latent image carrier 1. Is also good.

[Effects of the Invention] As described above, according to the transfer sheet peeling device of the image forming apparatus according to the first and second inventions, the toner band is formed for the purpose of lubricating the cleaning member and making the charging characteristics uniform. Even in the case of the forming type, it is possible to effectively avoid a situation in which the toner from the toner band is kept in a state of being adhered to the peeling nail, and accordingly, the toner is not transferred to the transfer sheet and the transfer of the nail is prevented. Good image quality of the sheet can be maintained.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an outline of a transfer sheet peeling device of the image forming apparatus according to the first and second inventions, and FIG. 2 is an explanation showing an embodiment of the image forming apparatus to which the first invention is applied. Figure,
3 and 4 are a front view and a perspective view showing details of a transfer sheet peeling device according to the embodiment. FIG. 5 is a block diagram showing a specific example of drive control means of the transfer sheet peeling device according to the embodiment. FIG. 6 is a timing chart showing the operation of the transfer sheet peeling device according to the embodiment, FIG. 7 is an explanatory diagram showing the operation process at that time, and FIG. 8 is a transfer sheet of the image forming apparatus according to the second invention. FIG. 9 is a timing chart showing the operation of the embodiment of the peeling device, FIG. 9 is an explanatory diagram showing the operation process at that time, and FIG. FIG. 11 is a timing chart showing the operation of the conventional image forming apparatus when forming a toner band, and FIG. 12 is an explanatory diagram showing the operation process at that time. [Explanation of Symbols] T toner band 1 latent image carrier 9 peeling claw 11 blade (cleaning member) 40 driving means 70, 80 drive control means

Claims (4)

(57) [Claims] A latent image carrier (1) in a non-image forming cycle
A toner band (T) having a predetermined width is formed on the image forming apparatus, and the toner band (T) is supplied to a contact portion of the cleaning member (11) with the latent image carrier (1). ,
Transfer sheet (6) electrostatically attached to latent image carrier (1)
A transfer sheet peeling device for forcibly peeling off the peeling claw, wherein a peeling claw (9) disposed so as to be retractable from a sheet peeling position whose leading end contacts the latent image carrier (1); A driving means (40) for moving at least between the sheet peeling position and the retracting position, and the toner band (T) at a position corresponding to the peeling claw (9).
And a drive control means (70) for controlling the driving means (40) so as to release the peeling claw (9) from the sheet peeling position when the sheet passes. 2. The apparatus according to claim 1, wherein said driving means includes an axial driving section for moving said peeling claw along said axial direction of said latent image carrier. The transfer sheet peeling device for an image forming apparatus according to claim 1. 3. A latent image carrier in a non-image forming cycle.
A toner band (T) having a predetermined width is formed on the image forming apparatus, and the toner band (T) is supplied to a contact portion of the cleaning member (11) with the latent image carrier (1). ,
Transfer sheet (6) electrostatically attached to latent image carrier (1)
A transfer sheet peeling device for forcibly peeling off the peeling claw, wherein the peeling claw (9) is disposed so as to be retractable from a sheet peeling position whose leading end contacts the latent image carrier (1); Means (40) for moving at least between the sheet peeling position and the retract position, and after the toner band (T) has passed through a location corresponding to the peeling claw (9) set at the sheet peeling position. An image forming apparatus comprising: a drive control means (80) for controlling the drive means (40) to move the peeling claw (9) one or more times between the retract position and the sheet peeling position instantaneously. Transfer sheet peeling device of the device. 4. The driving means (40) includes an axial drive section (42) for moving the peeling claw (9) back and forth along the axial direction of the latent image carrier (1). The sheet transfer / peeling device of the image forming apparatus according to claim 3.