JPH0373981A - Control method for developing device - Google Patents

Abstract

PURPOSE:To securely catch a developer which does not contribute to development in a developing unit by stopping a developing roller after a 1st bristle cutting process, separating a bristle cutting shutter and then setting it at a bristle cutting position again, and starting a 2nd bristle cutting process. CONSTITUTION:While the bristle cutting shutter 48 is put in operation, a sleeve roller 4 is rotated by about one turn and stopped and the bristle cutting shutter 48 is put back; and the front end sweep member 48b of the bristle cutting shutter 48 is brought into contact with the outer peripheral surface of the sleeve roller 42 and then the sleeve roller 42 is rotated. When the sweep member 48b is put close again for the 2nd time, the sweep member 48b comes into contact in a state wherein toner is removed very much, so the sweep member 48b securely reaches the outer peripheral surface of the sleeve 42 to completely remove and collect a developer from the outer peripheral surface of the sleeve roller 42.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for controlling a developing device that cuts the developer on the outer periphery of the developing roller by controlling the operation of a cutting shutter in the developing device.

Conventional technology To form multicolor images on recording paper, Japanese Patent Laid-Open No. 63-
As shown in Japanese Patent No. 267971, a plurality of developing devices are arranged adjacent to the photoreceptor. In this case 1
When an image of a certain color is being copied using one developing device, it is necessary to stop the operation of the other developing devices.

In addition, it is possible to load both negative and positive film, so that images recorded on these films can be reproduced on recording paper. A developing device for so-called N-P mode for reproducing a positive image on recording paper, and a developing device for so-called P-P mode for reproducing an image on a positive film as a positive image on recording paper, are installed adjacent to the photoreceptor. They are placed separately. In this case as well, when the developer for the N-P mode is operating and the image from the negative film is being reproduced on recording paper, the developer for the P-P mode must be stopped. , if it is operating in the opposite mode, the operation of the N-P mode developer is stopped.

As mentioned above, in an image forming device such as a copying machine or dub link in which a plurality of developing devices are arranged adjacent to each other near the photoreceptor, there are developing devices that do not contribute to development, that is, do not operate. Moving this to isolate it from the photoconductor not only increases the size of the entire image forming device due to the need to secure movement space, but also requires a device to move the developing device, which increases the cost of the device. I will let you do it. Therefore, without having to move each developer,
In order to ensure that the developer is fixed adjacent to the photoreceptor and to prevent the developer in the developer that does not contribute to development from being located opposite the photoreceptor, there is a A brush shutter is provided for wiping off the outer circumferential surface of the developing roller incorporated in the developing roller.

Problems to be Solved by the Invention In order to cut the spikes of developer adhering to the outer peripheral surface of the developing roller in the developing device, which is not involved in development, by using this spike shutter, it is necessary to press the spike shutter against the developing roller. I'm trying to rotate this in the state. but,
The developer adheres strongly to the outer circumferential surface of the developing roller as it is attracted by a permanent magnet built into the developing roller, and the developer attached to the outer circumferential surface is also transported by the rotation of the developing roller. The direction in which the developer is transported acts in a direction that prevents the ear cutting shutter from approaching the developing roller, so the tip of the ear cutting shutter does not easily reach the outer circumferential surface of the developing roller and cuts the developer ears. It will take quite a while to cut it properly.

If this ear cutting takes time, the process time for image formation becomes longer, which conflicts with the function required of an image forming apparatus to quickly reproduce an image. Furthermore, in order to prevent an extension of the image-forming process time, if the time during which the grain cutting shutter is activated is shortened, the developer will not be sufficiently removed from the outer circumferential surface of the developing roller in the developing device, which does not contribute to development. The developer remaining on the outer peripheral surface may scatter. In particular, when a two-component developer consisting of toner and carrier is used as the developer, only the toner remains on the outer peripheral surface of the developing roller.
The toner is no longer subjected to adhesion force due to the magnetism of the developing roller, and becomes easily scattered.

The present invention has been made in view of the above-mentioned problems of the prior art, and is intended to reliably remove developer in the developing devices that do not contribute to development in a developing device having a plurality of developing devices arranged adjacent to a photoreceptor. The purpose is to make it possible to capture it in the developing device.

Means for Solving the Problems In order to achieve the above object, the present invention includes a wiping member that contacts the developing roller in a developing device that has a built-in developing roller and is fixed adjacent to a photoreceptor. In a developing device equipped with a panicle cutting shutter that operates at a panicle cutting position where the members come into contact and a separation position where the members separate, the panicle cutting shutter is operated to the panicle cutting position while the developing roller is rotated, and the wiping member A first ear cutting step of cutting the ears, and after the end of the first ear cutting step, the developing roller is stopped and the ear cutting shutter is moved away, and then the ear cutting shutter is set to the ear cutting position again. A method of controlling a developing device includes a second ear cutting step of rotating the developing roller.

In the present invention, first, in the first ear cutting step, the outer circumferential surface of the developing roller is cut into ears by the wiping member of the ear cutting shutter. After the first ear cutting step is completed, the rotation of the developing roller is stopped, the ear cutting shutter is returned to the separation position, and the ear cutting shutter is set to the ear cutting position again.

At this time, since the wiping member is pressed against the surface of the developing roller that has been cut into ears in the first ear cutting step, the wiping member comes into direct contact with the outer peripheral surface of the developing roller. When the developing roller is rotated in this state in the second ear cutting step, the developer is completely removed from the outer peripheral surface of the developing roller.

EXAMPLE Hereinafter, the present invention will be described in detail based on an illustrated example of the present invention.

FIG. 1 is a schematic diagram showing the internal structure of a reader printer embodying the developing device control method of the present invention.A housing 10 of the reader printer includes a lower housing 10a and an upper housing 10b. A film carrier section 11 for supporting a microfilm F on which an image to be reproduced on paper is recorded.
is provided on the lower housing 10a. In FIG. 1, only the upper and lower film pressure glasses 12, 13 assembled into this film carrier part 11 are shown. A light source 14 is built into the lower housing 10a, and light transmitted from the light source 14 through the microfilm F is irradiated onto a screen 15 installed on the front surface of the upper housing 10b. A projection lens 16 is located above the film carrier section 11, and a prism 17 is located above the projection lens 16 for vertically inverting the image that has passed through the projection lens 16.

A scanning mirror 18 is located above the prism 17 and is rotatable in the direction shown by the arrow.In addition to switching between the reader system optical path and the printer system optical path, the scanning mirror 18 also switches between the reader system optical path and the printer system optical path. sometimes microfilm F
images will be scanned. This scanning mirror 1
A reflecting mirror 19 is fixed to the reader system optical path in order to reflect the image reflected by the image sensor 8 toward the screen 15 . Further, between the photosensitive drum 20 for copying the image on the microfilm F onto recording paper and the scanning mirror 18, there is a reflecting mirror 2L 22 that forms the optical path of the printer system.
．． 23 is installed.

In order to project the image recorded on the microfilm F onto the screen 15 using the reader printer having the above structure, the scanning mirror 18 is rotated to the position of the reader system optical path. As a result, the light from the light source 14 illuminates the microfilm F, and the image recorded on this film is transmitted to the projection lens 1.
6, prism 17, scanning mirror 18, and reflection mirror 1
The image is then projected onto the screen 15.

In order to print the image projected and read on the screen return 15 onto recording paper, the scanning mirror 18 is switched to the printer system optical path position. Thereby, the image of the microfilm F irradiated by the light source 14 is transmitted to the projection lens 16, prism 17, scanning mirror 18, mirror 21 to
The photoreceptor drum 20 is exposed to light through the photoreceptor drum 23. At this time,
The scanning mirror 18 rotates in synchronization with the rotation of the photoreceptor drum 20, and the photoreceptor drum 20 is irradiated with slit light.

Around the photosensitive drum 20, members constituting an image forming device for reproducing an image on the recording paper 25 fed out from the paper feed cassette 24 are arranged. code 26
indicates a main charger, that is, a charging charger, by which the surface of the photosensitive drum 20 is uniformly charged.

On the downstream side of the charging charger 26 in the rotational direction of the rotary drum 20, there is a P-P developing device 27 and an N-P developing device 2.
8 are arranged, and a transfer charger 29 is arranged to transfer the toner image formed on the photoreceptor drum 20 by these developing devices onto the recording paper 25. Further, after the toner image is transferred to the recording paper 25, the photosensitive drum 20
Cleaner 3 to remove the toner remaining on the outer surface of the
0 and an eraser 31 for removing residual charges remaining on the outer peripheral surface of the photoreceptor drum 20 in preparation for the next image formation. The recording paper 25 after the transfer passes through the fixing device 32 and is sent to the paper discharge tray 33.

In order to prevent the photosensitive drum 20 from being irradiated with a portion of the slit light from the microfilm F that is recorded as a negative image that does not need to be reproduced on the recording paper 25, all shutters and side shutters (not shown) are used. A shutter member is provided in the optical path of the printer system. Further, in order to erase unnecessary portions of the electrostatic latent image formed on the photoreceptor drum by the slit light from the microfilm F recorded as a positive image, an LED for an eraser (not shown) is used. It is arranged adjacent to the photoreceptor drum 20.

2(A) and 2(B) each show the detailed structure of one of the two developing devices 27 and 28 shown in FIG. 1, the NP developing device 28.

A magnetic roller 41 having a permanent magnet defined therein is mounted within the housing 40 of the developing device 28, and a rotary sleeve roller 42 is rotatably fitted around the outer periphery of the magnetic roller 41. The sleeve roller 42 rotates counterclockwise when the photosensitive drum 20 rotates clockwise as shown by the arrow in the figure. A developer tank 44 containing developer 43 is formed within the housing 40 , and the developer 43 therein is stirred by a stirring member 45 . The developer 43 is conveyed toward the photoreceptor drum 20 while being attached to the outer peripheral surface of the sleeve roller 42 by the magnetic force of the permanent magnet as the developing sleeve roller 42 rotates. At this time, the developer 43 is regulated to a constant thickness by the height regulating plate 46 . In addition, a powder smoke prevention plate 47 is provided in front of this height regulating plate 46.

If the developing device that is not selected among the two developing devices, for example, the N-P developing device 28 is not selected, the developing device 28 is not separated from the photoreceptor drum 20.
The sleeve roller 42 is prevented from conveying the developer 43 by the ear cutting shutter 48 . FIG. 2(B) shows a state in which the ear cutting shutter 48 is activated to prevent the developer 43 from being conveyed.

The shape of the ear cutting shutter 48 and the sleeve roller 4
The positional relationship with 2 is shown in FIG. As shown in the figure, there is a shutter frame 48a that is swingable by four swing shafts, and a thickness of 0.0 mm fixed to the tip of the shutter frame 48a.
Wiping member 48b formed of a 5-0.5+ nm polyethylene terephthalate film (trade name Mylar)
It consists of A phosphor bronze plate may be used as the wiping member 48b. This wiping member 48
When the tip of b comes into contact with the outer circumferential surface of the sleeve roller 42, it does not come into line contact with it, but curves into surface contact as shown in FIG. 3. Also,
The radial line R of the sleeve roller 42 at this contact portion
The angle θ between this and the tangent S of the wiping member 48b is 0 to 5.
It is set in the range of 0'. This angle θ is set within the above-mentioned range because if the wiping member 48b comes into contact with the outer peripheral surface of the sleeve roller 42 at an excessively large angle when scraping off the developer, the effect will not be sufficiently obtained.

The drive mechanism of the ear cutting shutter 48 mentioned above is shown in the fourth section.
As shown in the figure, a compression coil spring 51 is attached to the tip of a shutter drive lever 50 fixed to the end of the swing shaft 49, so that the ear cutting shutter 48 is In (B), clockwise direction, that is, the wiping member 4
A spring force is applied in a direction to move 8b away from the surface of the sleeve roller 42. Further, a rotating shaft 52 connected to the stirring member 45 is attached to the housing 40, and the rotating shaft 52 is connected to a motor (not shown) to rotate in the direction shown by arrow A. An ear cutting clutch 53 is attached to this rotating shaft 52, and this clutch 5
3 is connected to a spring clutch 55 that engages with a retaining portion 54 provided on the shutter drive lever 50. Therefore, when the ear cutting clutch 53 is actuated, the claw of the spring clutch 55 is rotated in the direction of arrow B by the rotating shaft 52, and the shutter drive lever 50 is swung in the direction shown by arrow C.

As a result, the ear cutting shutter 48 swings in the direction shown by the arrow in FIG. As a result, the wiping member 48b of the ear cutting shutter 48 is removed from the sleeve roller 4.
The developer is removed from the sleeve roller 42 by contacting the outer circumferential surface of the sleeve roller 2 .

The structure of the ear-cutting shutter 48 in the N-P developing device 28 shown in FIGS. 2 to 4 is substantially the same in the P-P developing device.

In the present invention, from a state in which the reader printer is set to the N-P mode and, for example, an image recorded on microfilm F recorded as a negative image is reproduced on recording paper, When loading a microfilm F that has been recorded as a positive image and reproducing the image on the recording paper, stop the operation of the N-P developing device 28 that had been operating until then. It is necessary to operate the P-P developing device 27. In this case, N-P
The developer 43 can be removed from the surface of the sleeve roller 42 in the developing device 28 without separating the developing device 28 from the photosensitive drum 20.

To do this, first, the ear cutting shutter 48 is operated while the sleeve roller 42 is kept in rotation, and its wiping member 48b is brought into contact with the outer peripheral surface of the sleeve roller 42.

In this state, the sleeve roller 42 is rotated at least one rotation. After this first ear cutting step, the rotation of the sleeve roller 42 is stopped, and the ear cutting clutch 53 is turned off to separate the wiping member 48b of the ear cutting shutter 48 from the sleeve roller 42. Then, the ear cutting clutch 53 is turned on again to remove the wiping member 48b of the ear cutting shutter 48.
After the sleeve roller 42 is brought into contact with the outer peripheral surface of the sleeve roller 42 and the sleeve roller 42 is rotated at least one rotation, the rotation of the sleeve roller 42 is stopped. This completes the second ear cutting step.

In this way, by performing the panicle cutting operation twice by the panicle cutting shutter 48, the developer 43 adhering to the outer peripheral surface of the developing sleeve roller 42 is completely removed. This mountain range is as follows. Even if the ear cutting shutter 48 is operated while the sleeve roller 42 is rotating, the tip of the wiping member 48b of the ear cutting shutter 48 cannot easily reach the outer peripheral surface of the sleeve roller 42, and some developer may be removed. , To be more precise, the toner is the ear-cutting shutter 4.
It passes through the narrow gap between the tip wiping member 48a of No. 8 and the sleeve roller 42. Therefore, after rotating the sleeve roller 48 about one rotation with the ear cutting shutter 48 activated as described above, this rotation is stopped and the ear cutting shutter 48 is returned, and the ear cutting shutter 48 is turned again.
After the tip wiping member 48b is brought into contact with the outer peripheral surface of the sleeve roller 48, the sleeve roller 42 is rotated.

In this way, when the wiping member 48a is brought into contact again by the second operation of the ear cutting shutter 48, the wiping member 48a of the ear cutting shutter 48 comes into contact with a considerable amount of toner removed by the previous wiping action. Therefore, it has been found that at this time, the wiping member 48b reliably reaches the outer circumferential surface of the sleeve roller 42, and the developer is completely removed from the outer circumferential surface of the sleeve roller 42. Note that the second ear cutting step may be repeated multiple times.

FIG. 5 is a diagram showing a control circuit for controlling the operation of the reader printer of the present invention. A control section 60 consisting of a microcomputer or the like includes a print switch 61 for instructing the start of printing, and a control circuit for controlling the operation of the loaded microfilm F. A control signal is sent from a mode changeover switch 62 that selects between -P mode and P-P mode depending on the type. Control signals are sent from this control section 60 to the clutch 53a of the N-P developing device 28 and the motor 63a for driving the sleeve roller, and furthermore, a control signal is sent to the clutch 53a of the N-P developing device 28 and the motor 63a for driving the sleeve roller. 27 clutch 53b,
A control signal is sent to the motor 63b for driving the sleeve roller.

Next, the operating procedure of the developing device in the developing device control method of the present invention will be explained with reference to the flowcharts shown in FIGS. 6 to 8.

FIG. 6 is a diagram showing the main flowchart. When the power of the reader printer is turned on, the microcomputer etc. for controlling it are initialized, and step 7
When set to 1, it becomes a leader state. Next, in step 72, it is determined whether the print switch 61 has been turned on, and in step 73, it is determined whether the mode changeover switch 63 has been set to the NP mode or the PP mode. If the P-P mode is set, the P-P print mode subroutine is executed in step 74, and if the N-P mode is set, the subroutine of the P-P print mode is executed in step 74.
In step 5, the subroutine of the NP print mode is executed.

FIG. 7 is a diagram showing a subroutine of the P-P print mode. When this print mode is executed, the timer Tl in the control section 60 is set in step 81, and the N- The sleeve roller 42 in the P developing device 28 rotates, and in step 83 the clutch 53a in this developing device 28 is turned on, and the ear-cutting shutter 48 is activated to move the wiping member 48b of this shutter to the outer periphery of the sleeve roller 42. make contact with the surface.

When it is determined in step 84 that the time set by the timer Tl has elapsed, the rotation of the sleeve roller 42 is stopped in step 85, the ear cutting shutter 48 is turned off in step 86, and the sleeve roller 42 is stopped in step 85.
away from.

Again, in step 87, the ear cutting shutter 48 is turned on, and in step 88, the timer 12 in the control section 60 is turned on.
Set. After the sleeve roller in the N-P developing device 28 is rotated in step 89 for the time set by the timer T2, steps 91 and 92 are executed to perform P-P development using the P-P developing device 27. -P printing is performed in step 93. In other words, a positive image is reproduced on the recording paper 25 with respect to the microfilm F recorded as a positive image. The set values of the timers T1 and T2 described above are set to the time required for the sleeve roller 42 to rotate at least one revolution.

Note that even before printing is done in step 93,
If printing in P-P mode is executed, the ears have been completely cut at that time, so it is unnecessary to execute each step shown in FIG. 7, and printing is executed immediately. Ru.

That is, the above-described steps are executed when the reader printer is started and when the NP print mode is executed in the previous process.

Similarly, if the print that has already been done is a P-P mode print and the N-P print mode is subsequently set or the reader printer is activated, the N-P print shown in FIG. mode is executed. This subroutine is almost the same as the procedure shown in FIG. 7, and in FIG. 8, steps corresponding to those shown in FIG. ing. Note that the stirring member 45 in the developing device that is not used for development may or may not be rotated when not in use, but it is preferable that it not be rotated.

In the embodiment described above, the present invention is applied to a reader printer that operates in N-P print mode and P-P print mode, but it is also possible to apply the present invention to a copier having a similar copying function or to print multicolor images on copy paper. The present invention is basically applied to an image forming apparatus having a plurality of developing units, such as a copying machine. However, the present invention can also be applied to a case where there is only one developing device.

In such a case, the toner is not transferred to the photosensitive drum, but the developer 43 is controlled to be stirred by the stirring member 45.

In this embodiment, the sleeve is rotatable and the magnetic roller is fixed, but the sleeve may be fixed and the magnetic roller is rotatable, and the magnetic roller may be rotated instead of the leaf roller in the illustrated embodiment. Further, the sleeve roller and the magnetic roller may be rotated simultaneously.

Effects of the Invention As described above, according to the present invention, after the outer circumferential surface of the developing roller is cut into ears by the wiping member of the ear cutting shutter in the first ear cutting step, the rotation of the developing roller is stopped and the ear cutting shutter is turned off. After returning to the separation position, the ear-cutting shutter was set to the ear-cutting position again, and the second ear-cutting process was activated by rotation of the developing roller. The wiping member is pressed against the cut surface of the developing roller, and the ears are cut while the wiping member is in direct contact with the outer peripheral surface of the developing roller. Therefore, as the developing roller rotates in this second panicle cutting step, the developer is completely removed from the outer circumferential surface of the developing roller, and as a result, the developer attached to the outer circumferential surface of the developing roller is reliably removed in a short time. It becomes possible to remove it. In addition, since the developer can be removed reliably, the ears can be cut sufficiently without increasing the surface precision of the contact part of the wiping member provided on the ear-cutting shutter, which reduces the cost of the developing device. It has also become possible to achieve.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the internal structure of a reader printer according to an embodiment of the present invention embodying the developing device control method of the present invention, and FIG. FIG. 2(B) is a sectional view showing the details of the N-P developing device shown in FIG. 1; FIG. 2(B) is a sectional view similar to FIG. FIG. 3 is a perspective view showing the ear cutting shutter and sleeve roller shown in FIGS. 2(A) and (B), and FIG. 4 is a part of the developing device shown in FIGS. 2(A) and (B). 5 is a block diagram showing the control circuit of the present invention, FIG. 6 is a main flowchart showing the control procedure of the present invention, and FIG. 7 is a block diagram showing the control circuit of the present invention.
FIG. 8 is a flowchart showing the subroutine of the NP print mode in FIG. 6. 20... Photosensitive drum, 27... P-P developing device, 2
8... N-P developing device, 42... Developing sleeve roller, 48... Ear cutting shutter, 48b... Wiping member.

Claims (1)

[Scope of Claims] A developing device having a built-in developing roller and fixed adjacent to a photoconductor includes a wiping member that contacts the developing roller, and has a corner cutting position where the wiping member contacts and a separating position where the wiping member comes into contact. a first ear cutting step of operating the ear cutting shutter to an ear cutting position with the developing roller rotated and cutting the ears with the wiping member; After the first ear cutting process is completed, the developing roller is stopped and the ear cutting shutter is separated, and then the ear cutting shutter is set to the ear cutting position again and the developing roller is rotated.
A method for controlling a developing device including a step of cutting the ears.