JPH01108594A - Lubricating property holding device for blade - Google Patents

Abstract

PURPOSE:To always secure correctly the lubricating property of a blade by allowing a toner to adhere to an inter-image part on a latent image carrying body at every prescribed image forming frequency and supplying it to the blade. CONSTITUTION:When an image forming frequency in a series of image formation processings does not reach a prescribed frequency, a toner 2a is allowed to adhere onto a latent image carrying body 1 until a machine stops after said series of image formation processings is ended, and its toner 2a is supplied to a blade 3. On the other hand, when the image forming frequency in a series of image formation processings is more than the prescribed frequency, whenever the image forming frequency becomes the prescribed frequency in a process of this image formation processing, an intermediate toner adhering means 4 allows a toner 2b supplied to the blade 3 to adhere to inter-image parts I, I. In such a way, when the image forming frequency in a series of image formation processings is extremely frequent, the toner supply quantity to the blade 3 can be increased auxiliary.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a device for maintaining the lubricity of a blade that scrapes off toner remaining on a latent image carrier after transfer in a copying machine or the like. is a cleaning blade slip resistance of a copying machine in which toner adheres to a latent image carrier and is applied to a blade for removing residual toner between the end of a series of image forming processes and the machine's stop. Relating to a holding device.

[Prior Art] In electrophotographic image forming apparatuses such as copying machines and printers, a latent image formed on a latent image carrier such as a photoreceptor is developed with toner, and this toner image is transferred onto paper or the like. Forming the desired image. Furthermore, since toner remains on the latent image carrier after the toner image is transferred, so-called toner cleaning is required in this type of image forming apparatus to remove this residual toner.

There are various methods for this toner cleaning, but if we focus on the blade cleaning method in which the toner adhering to the latent image bearing member is scraped off with a blade, the toner cleaning method is based on the sliding friction between the latent image bearing member and the blade. In order to prevent blade curling, chattering, etc., it is necessary to maintain lubricity between the blade and the latent image carrier.

Therefore, in conventional devices that maintain the lubricity of this blade, for example, in an electrophotographic copying machine, toner is deposited on the photoreceptor between the time when a series of copies of a set number of sheets is completed and the time when the machine stops. The blade is forced to receive the toner by adhering the toner to the blade. This results in
The lubricating component contained in the toner smoothes the sliding property between the photoconductor and the blade, preventing wear on the blade edge, and also prevents the blade from curling up or chattering, thereby reducing the toner flow during the image forming process. It has a reliable scraping effect. In addition, in the case of this type of copying machine, the normal copy size (such as ^4゜84) is usually smaller than the maximum copy size (such as A3),
In this case, there is almost no chance that a toner image will be formed in the area of the photoreceptor corresponding to the difference between the maximum copy size and the normal size, and the supply of residual toner during normal copying cannot be expected. Forced toner supply is especially necessary to maintain blade lubricity.

Forcible adhesion of toner onto the photoreceptor is carried out, for example, by simultaneously turning off a charger and an erase lamp disposed upstream of the developing device after copying is completed and immediately before the machine is stopped.

That is, when the charger and erase lamp are turned off, the photoreceptor between them is charged, and when that area passes through the developing device, toner is attached and supplied to the blade as it is. Therefore, in the conventional apparatus, after a series of copies corresponding to the set number of sheets are completed, a toner image with a width corresponding to the fIm distance between the charger and the erase lamp is formed on the photoreceptor, and a certain amount of the toner image is formed on the photoreceptor. ~ner was to be supplied to the blade.

[Problems to be Solved by the Invention] By the way, as mentioned above, in the conventional apparatus that supplies a fixed amount of toner to the blade after a series of image forming processes are completed, the copy settings of the copying machine cannot be changed. The number of sheets increases, etc.
If the number of image formations in a series of image forming processes increases, the lubricity of the blade may be impaired.

This is because the amount of toner to be supplied to the blade each time a series of image forming processes is completed is determined based on the assumption that the sliding time between the blade and the latent image carrier corresponds to the appropriate number of image formations. This is because if the sliding time between the blade and the latent image carrier becomes longer than the assumed number of image formations, the set amount of toner will not be able to maintain its lubricity. One way to deal with this is to simply increase the amount of toner that should be supplied at one time, but if the number of image formations in a series of processes is small, this could lead to oversupply of toner and cause dirt inside the machine. Become.

The above-mentioned problem becomes particularly serious in copying machines and the like in which automatic document feeder (ADF) functions have been developed in recent years, and the number of sheets that are continuously copied has increased dramatically.

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to supplementally increase the amount of toner supplied to the blade when the number of image formations in a series of image forming processes is extremely large.

[Means for Solving the Problems] As shown in FIG. 1, the present invention, as shown in FIG. Blade 3 for removing attached and residual toner
The technical means for solving the above problem in the blade lubricity maintaining device is to maintain the lubricity of the blade while a series of image forming processes continues. It is provided with intermediate toner adhesion means 4 for adhering toner 2b to ink image portions I and (2) on the latent image carrier 1 every predetermined number of image formations.

[Operation] If the number of times of image formation in a series of image forming processes does not reach a predetermined number, toner 2a is deposited on the latent image carrier 1 between the end of this series of image forming processes and the stop of the machine. is attached, and the toner 2a is supplied to the blade 3.

On the other hand, if the number of times of image formation in a series of image forming processes is greater than the predetermined number of times, the intermediate toner adhering means 4 is applied to the blade 3 every time the number of image formations reaches the predetermined number of times during the image forming process.
The toner 2b to be supplied to the image area I is attached to the interimage area I.

[Example] Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is a diagram that does not show an example of an image forming apparatus to which the blade lubricity maintaining device according to the present invention is applied.

This is an example of a two-color copying machine,
In FIG. 2, below the platen 11 there are mirrors 13, 14, 15, 17, 18, 19 along with the exposure lamp 12.
and an exposure optical system such as a lens 16 are arranged, and the platen 1
When scanning the original 10 on the original 10, the reflected light from the exposure lamp 12 on the original 10 is reflected by the mirrors 13 and 14.
15, a lens 16, and mirrors 17, 18, and 19 to guide the photosensitive drum 20 to the exposure position. Around the photosensitive drum 20, a charger 21 and a first developer I for red toner are installed to carry out the image forming process. 22
a, a second developing device 22b1 for black toner, a transfer device 23, a peeling corotron 24, and a peeling claw 25 at the rear stage.
, a blade 26a that slides on the surface of the photosensitive drum 20.
A cleaning device 26 having a cleaning device 26 is disposed. Further, an erase lamp 27 for optically eliminating static electricity in the ink image portion of the photosensitive drum 20 is arranged upstream of the first developing device 22a. Then, the paper sent out from the cassette 30 passes through the paper feed conveyance path 32 to a transfer position (transfer device 23
, a peeling corotron 24 arrangement position), and after transferring the toner image, it is sent to a fixing device 35 via a conveyance path 34 where the image is fixed. Thereafter, the paper on which the image has been fixed is discharged to the tray 38 via the discharge conveyance path 36.

Note that an intermediate tray (after the fixing unit 35) is used to store paper that has been image-fixed once for multiple copies or back-side copying.
A return conveyance path 33 is provided for returning to the discharge conveyance path 3 (the illustrated path), and a gate 37 is opened by a command from the control system to the discharge conveyance path 3.
6 and the return conveyance path 33.

FIG. 3 is a block diagram showing an example of the basic configuration of a toner supply control system related to maintaining the lubricity of the blade 26a.

In the figure, 40 is a CPU that performs overall control.
, 41 is a ROM for storing programs, tables, etc.;
2 is a RAM that stores necessary data etc. obtained as a result of calculations by the CPU 40; the CPU 40, ROM 41;
The RAMs 42 are each connected to a bus. Operation signals from a numeric keypad switch 45 and a mode switch 46 provided on the console panel of the copying machine are input to an input interface 43.
It is incorporated into the CP (J40 side) through the CP, so that various modes, copying conditions such as the number of copies, etc. can be recognized.

Also, the power supply I! of the main motor 48 of the aircraft body! ! 7. High-voltage power supply 49 for charger 21, power supply 50 for erase lamp 27,
Furthermore, the CPU 4 is used for the second development 122b for black toner.
0 side through the output interface 44 to the photosensitive drum 2.
A control signal related to toner image formation on the 0 is provided.

Next, the operation will be explained according to the flowchart shown in FIG.

When a start operation is performed after performing operations related to the number of copies, density, magnification, etc. using the ten key switch 45 and the mode switch 46, the copying process is started under the set conditions and mode. The internal counter N is incremented each time - copies of the copying process are completed (each copy), and it is checked whether the set number of copies has been completed and whether the internal counter N has reached the predetermined value S. Check.

Here, if a series of copies of the set number of sheets is completed before the internal counter N reaches the predetermined value S, the final toner adhesion control is performed, and the toner is deposited on the photosensitive drum 20 between the time the copy ends and the machine stops. After applying toner, remove the blade 26.
supply to a. Specifically, as shown in FIG. 5, the high-voltage power source 49 of the charger 21 and the power source 50 of the erase lamp 27 are simultaneously cut off at time ts until the machine is stopped. Then, at the time ts when the power is cut off, as shown in FIG. 6, an area having a width l formed between the charger 21 and the erase lamp 27 on the photosensitive drum 20 remains in a charged state. Then, the timing t immediately before the rotation of the photosensitive drum 20 is expected to cause the area to reach the second developing device 22b position.
The mag roll is temporarily driven at o, and in that state the area is in the second current @l! When the toner passes through the position 22b, the black toner in the developing device 22b adheres to an area having a width p, and is supplied to the blade 26a of the cleaning device 26 as the photosensitive drum 20 rotates. After that, time te
At the point in time, the power supply 47 to the main motor 48 is cut off and the aircraft stops.

On the other hand, if the set number of copies is large, in the process shown in FIG.
When the internal counter N reaches the predetermined value S, the 7 lag F of the inter-image lamp Δto cut is set and the internal counter N is cleared (N13). Then, when the flag F is confirmed when the erase lamp 27 is irradiated with light to eliminate the charge in the ink image area before the start of the next copying process, the erase lamp 27 is turned off for only ΔtO. Thereafter, the internal counter is incremented every time one copying process is completed, and the same process as described above is repeated every time the value N reaches a predetermined value. Therefore,
Until the series of copies of the set number of sheets are completed, as shown in FIG. 5, the erase lamp 27 that irradiates light at the inter-image section is shut off by ΔtO every time a predetermined number of eight copies are completed. As a result, a charged area with a width ΔtO·V (V is the circumferential speed of the photosensitive drum 20) is formed in the interimage area on the photosensitive drum 20 due to the above-described off operation of the erase lamp 27, and this area is covered by the second developing device 22b. When passing through the position, the toner is developed and reaches the blade 26a without being transferred.

That is, until a series of copies is completed, a black streak area with toner attached is formed on the intermediate image portion of the photosensitive drum 20 every eight times a predetermined number of times, and the toner is sequentially supplied to the blade 26a. . Then, when a series of copies of the set number of sheets is completed while performing the above processing, the final toner adhesion control as described above is similarly executed.

The above predetermined value S and the cut time Δt of the erase lamp 27
o, that is, the amount of toner that should be supplementarily supplied to the blade 26a during continuous copying is determined based on the lubricity of the blade for a series of copies, taking into consideration the final toner adhesion amount to be supplied, the properties of the toner used, etc. The amount of toner is determined so that the toner can be supplied in just the right amount to maintain the amount of toner.

Incidentally, when the paper is supplied to the transfer position, it is subjected to the feeding action of a feed roll or the like, and due to the friction between the roll and the paper surface, paper dust is likely to be generated at the position where the paper comes into contact with the roll. Then, when the paper is supplied to the transfer position, this paper powder adheres to the photosensitive drum 20, and when it further reaches the blade 26a of the cleaning device 26, the lubricity of the blade decreases. In order to prevent this paper powder from reducing the lubricity of the blade, control is added to the final toner adhesion control described above to increase the supply of toner onto the photosensitive drum 20 corresponding to the a-ru contact position of the paper. be done.

In order to realize this control, a plurality of erase lamps 27 are provided.
The LEDs are arranged in the axial direction of the photosensitive drum 20, forming a so-called ED array structure. In such an erase lamp 27, the LED at the position corresponding to the position where the paper roll contacts on the photosensitive drum 20 is, for example, L in FIG.
E D (i) to LED (inn) (n pieces), and
Unlike other LEDs, such as LED (inn) (n pieces) from L E D (j), which turn off at the same timing as the off timing ts of the charger 21, the LEDs turn off at the timing ts' before this ts. It will be turned off. As a result, from the above L E D (i) to L E D (inn),
And the charged area width at the position corresponding to L E D l to L E [) (inn) increases by V・(tS-TS'), and as shown in FIG. 8, the toner area width increases by the corresponding amount. As a result, the amount of toner supplied to the blade 26a at that position is increased. This makes it possible to reliably maintain lubricity, especially at the blade position corresponding to the paper roll contact position, which is easily affected by paper dust.

Although the above control is carried out in addition to the final toner adhesion control, it may also be taken into account in the control for adhering toner to the ink image portion every predetermined number of copies as described above.

In the above control, in which toner is supplied to the blade at the end of a series of copies, in principle, when starting up a copier that has been stopped for a long time and making the first copy, toner has not been supplied to the blade for a long time. Copying will be performed in this state. To compensate for the lubrication of the blade during the first copy after such a long standstill,
In an actual copying machine, in addition to the various controls mentioned above, for example, the charger and erase lamp are simultaneously turned off immediately before the machine stops during the warm-up cycle when the power is turned on, and the amount of toner is adjusted based on the off timing. may be supplied to the blade 26a.

Although the above embodiments have been described using a copying machine as an example, the present invention can also be applied to an electrophotographic printer or the like.

[Effects of the Invention] As described above, according to the present invention, toner is attached to the latent image carrier and supplied to the blade between the end of the series of image forming processes and the stop of the machine. Based on this assumption, toner is attached to the ink image area on the latent image carrier and supplied to the blade every predetermined number of image formations, so the number of image formations in the series of image formation processes is extremely large. In this case, the amount of toner supplied to the blade can be increased as a supplement. Therefore, even if the number of image formations in a series of image forming processes increases, the lubricity of the blade is not affected, and the lubricity of the blade is always maintained at an appropriate level.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of the present invention, FIG. 2 is a diagram showing a structural example of an image forming apparatus in which the blade lubricity retaining device according to the present invention is adopted, and FIG. 3 is a diagram showing the structure of the blade lubricity retaining device. A block diagram showing an example of the basic configuration of the control system, Fig. 4 is a flowchart showing the flow of processing, Fig. 5 is a timing chart showing the operation of each part, and Fig. 6 is a diagram showing the positional relationship between the charger and the erase lamp. , Figure 7 shows the erase lamp LE.
FIG. 8 is a timing chart showing an example of control timing when configured with a D array. FIG. 8 is a diagram showing the state of the toner area formed on the photosensitive drum by the operation of the erase lamp according to the timing chart shown in FIG. be. [Description of symbols] 1...Latent image carriers 2a, 2b...Toner 3, 26a...Blade 4...Intermediate toner adhesion means 20...Photosensitive drum 21...Charger 22a...・First developing machine 22b...Second developing machine 26...Cleaning device 27...Erase lamp Patent applicant Fuji Xerox Co., Ltd. Agent
Patent attorney Tomohiro Nakamura (2 others) Figure 6

Claims (1)

[Claims] A blade that attaches toner (2a) onto the latent image carrier (1) between the end of a series of image forming processes and the time the machine stops, and applies the toner (2a) to the blade (3) for removing residual toner. In the lubricity maintaining device, toner (2b) is applied to the intermediate image area (I ・ I) on the latent image carrier (1) every predetermined number of times of image formation while the series of image forming processes described above is continued. A blade lubricity maintaining device characterized by comprising intermediate toner adhesion means (4) for adhering toner.