JPH0246476A - Developing device - Google Patents

Abstract

PURPOSE:To correctly mesh gears even if their tops come into contact with each other by driving a motor in a prescribed length of time after a developing device is moved to a developing position from a non-developing position and rotating a driving idler gear and a developing device gear. CONSTITUTION:When a black developing device 35 moves to the developing position after a color copying action ends, the motor 77 is driven in a prescribed length of time which does not affect a next copying action. Consequently, a 2nd driving idler gear 76 meshes with a gear 75 on the input side of the black developing device 35 rotates in a prescribed length of time just after the black developing device 35 moves to the developing position. Even if the top of the gear 75 on the input side abuts on the top of the 2nd driving idler gear 76 when the black developing device 35 moves to the developing position, the rotating action of the 2nd driving idler gear 76 enables the gear 75 on the input side to correctly mesh with the idler gear 76.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a developing device used in an electrophotographic copying machine capable of performing multicolor copying or multiple copying, and specifically, a developing device that includes a black developing machine and a color developing machine. The present invention relates to a developing device in which one of these developing devices is set at a developing position close to the photosensitive material, and the other is set at a non-developing position away from the photosensitive material.

[Conventional technology]

As a developing device used in an electrophotographic copying machine that performs this type of multicolor and multiple copying, for example, Japanese Patent Laid-Open No. 63-9796
As shown in Publication No. 8, a black developing machine and a color developing machine are arranged so as to be movable toward the photosensitive material, and the black developing machine and the color developing machine are held by springs in a non-developing position away from the photosensitive material. A developing device is known in which one of the developing devices is moved toward the photosensitive material by a cam provided on a cam shaft, thereby bringing it to a developing position close to the photosensitive material.

Specifically, as shown in FIG. 7, the black developing machine 1 and the color developing machine 2 are arranged facing the photosensitive material 3, and are directed towards the photosensitive material 3 by the guide pins 4 and the guide grooves 6 of the placket 5. It is movable forward and backward, and is held in a non-developing position separated from the photosensitive material 3 by a spring 7. First,
Second plate springs 11 and 12 are provided on the backs of the black developing machine 1 and the color developing machine 2, and the camshaft 8 is connected to a motor (not shown) via a spring clutch 13.
The rotation of the camshaft 8 is controlled every 180 degrees by controlling the rotation of the camshaft 3 with a stopper 15 that is swung by a solenoid 14.
Or the first or second leaf spring 11 on the other hand of the second cams 9, 10
．． Press 12 to transfer black developing machine 1 or color developing machine 2 to photosensitive material 3.
, and is moved to a developing position close to the photosensitive material 3 and held there. Normally, the black developing machine 1, which is frequently used, is held at the developing position, and the color developing machine 2 is held at the non-developing position. During color development, the camshaft 8 is rotated 180 degrees to move and hold the color developing machine 2 at the developing position and the black developing machine at the non-developing position, and when the color development is completed, the black developing machine 1 is moved to the developing position and then to the non-developing position. The color developing machines 2 are each moved to a non-developing position and held there.

[Problem to be solved by the invention]

The black developing machine 1 and the color developing machine 2 of this developing device are equipped with a developing roll, an auger, a stirring member, etc., and these are connected by a gear 17 as shown in FIG. It is configured to mesh with a drive idler gear 19 that meshes with a drive gear 18 provided on the machine body side,
When the developing machine is in the non-developing position, the input side gear 17a is separated from the drive idler gear 19, and when the developing machine is in the developing position, the input side gear 17a meshes with the drive idler gear 19.

For this purpose, it is sufficient that the input side gear 17a and the drive idler gear 19 mesh correctly as shown in FIG.
As shown in the figure, if the tooth tips 17b19a contact each other and do not mesh properly, the following problems occur.

In other words, when the tips of the teeth come into contact with each other, the moving distance of the developing device toward the photosensitive material 3 becomes shorter than when they are properly engaged, and the leaf spring is positioned on the cam side, so the leaf spring is strongly suppressed and deformed by the cam. If the above-mentioned condition continues for a long time, the leaf spring will weaken and its elastic force will become weaker, so when the input side gear 17a and the drive idler gear 19 are properly meshed, the force to keep them in the meshed state will be weakened, resulting in skipping. The electrostatic latent image on the photosensitive material may not be developed correctly because the developing machine does not operate properly or the distance between the photosensitive material and the developing roll becomes longer than a predetermined value (hereinafter referred to as "poor shoeking").
Due to a combination of these factors, proper development is not possible, resulting in defects in copy image quality.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a developing device that can solve the above-mentioned problems.

[Means and effects for solving the problem] (1) A plurality of developing machines are disposed facing the photosensitive material 31 so as to be movable between a developing position and a non-developing position, and each developing machine is connected with an elastic member. The developing machine is moved to the non-developing position and held there, and each developing machine is moved to the developing position and held by a cam and a leaf spring, and the gear on the input side provided in each developing machine is set to the developing position. The drive idler gear is meshed with a drive idler gear connected to a motor 77 provided on the machine body side, and is separated from the drive idler gear when in the non-developing position, so that any one of the developing machines is always in the developing position and the other developing machines At the same time, at the time of different copying operations, one of the developing machines is set to the non-developing position, and only one developing machine corresponding to the copying operation in the other developing machines is set to the developing position. . A developing device in which the motor 77 is driven for a predetermined time when any one of the developing machines is set to the developing position and the other developing machines are set to the non-developing position.

As a result, the motor 77 is driven for a predetermined period of time after the developing machine, which is always held at the developing position, is moved from the non-developing position to the developing position. Even if the tooth tips of the input side gear and the drive idler gear are in contact when the developer is moved to the developing position after rotating for a predetermined period of time, they can be properly engaged by the rotation of the drive idler gear mentioned above. , the leaf spring will never buckle.

Therefore, the developing device, which is always held at the developing position, is always held at the correct developing position and no tacking failure occurs, and good developing operation can always be performed without causing any deterioration in image quality.

2. A plurality of developing machines are disposed so as to be movable between a developing position and a non-developing position, facing the photosensitive material 31, and each developing machine is moved and held by an elastic member to the non-developing position; Each developing machine was configured to be moved to and held at the developing position by a cam and a leaf spring, and a gear on the input side provided in each developing machine was connected to a motor 77 provided on the main body of the copying machine when it was set to the developing position. A developing device which meshes with a drive idler gear and is separated from the drive idler gear when in a non-developing position, and allows an input side gear provided in each of the developing machines to freely rotate by a predetermined angle.

As a result, the input side gear can freely rotate by a predetermined angle, so even if the input side gear's tooth tips and the drive idler gear's tooth tips come into contact when the developing machine moves to the developing position, the input side gear will not rotate. It can rotate freely and engage properly, and the flat springs do not become sagging, which prevents tacking failures.

〔Example〕

First, the overall outline of the electrophotographic copying machine according to the present invention will be explained in the second section.
This will be explained based on the diagram.

A photosensitive material 3] is rotatably provided in the copying machine main body 30, and around it are a charger 32, an LED 33, and a color developing device 34.
, a black developing device 35, a transfer device 36, a peeling claw 37, a cleaner 38, etc. are arranged in this order, and the original image on the platen 39 is transferred to the photosensitive material 3 from between the charger 32 and the LED 33 using an optical system 40.
] to form an electrostatic latent image.

On the other hand, the paper 42 in the tray 41 is sent toward the transfer device 36 by the feed roller 43, and is discharged to the catch tray 45 via the fixing device 44. A paper transport path 46 is provided over the entire area, and by switching the first gate 47, the paper sent out from the fixing device 44 can be fed into the paper transport path 46, and the paper transport path 4
6 is provided with a second gate 48 for reversing the paper, a forward and reverse rotation feed roller 49, a feed roller 50, a paper receiver 51, and a pair of feed rollers 52, which direct the paper that has passed through the fixing device 44 to the transfer device 36 again. It is designed so that it can be transported.

The black developing machine 35 and the color developing machine 34 can move forward and backward toward the photosensitive material 31 and are moved and held between a developing position and a non-developing position. Toner is supplied from the toner box 53 to the auger 5 for replenishment.
It is supposed to be replenished at 4.

Next, the copying operation will be explained.

■The heat developing machine 35 is always held at the developing position, and the color developing machine 34 is held at the non-developing position.During normal copying operations, the black developing machine 35 is used to perform copying operations in the same manner as before, and copies are made. It is discharged onto the catch tray 45. At this time,
The first gate 47 is assumed to be in the posture of the imaginary line.

■In the case of multicolor copying, the sensitive material 31 is uniformly charged with the charger 32, and then imagewise exposed to create an electrostatic latent image. LED33 statue
After erasing the image, the image is developed by a black developing device 35, transferred to a paper 42 fed by a feed roller 43 by a transfer device 36, fixed by a fixing device 44, and sent to a paper conveyance path 46.

At this time, the first gate 47 is at the solid line position.

The paper sent into the paper conveyance path 46 is sent to the forward/reverse rotating feed roller 49 at the second gate 48, and when it is bitten by the forward/reverse rotating feed roller 49, it is reversed and at the same time passes through the second gate 4.
8 to turn the paper upside down and send it out to the feed roller 50.
The sheet is conveyed toward the paper receiving roller 50 and sent out to the paper receiver 51 by the feeding roller 50. Thereafter, the sheet is conveyed by the pair of feed rollers 52 to the sending side of the feed roller 43 and sent to the transfer device 36 in the same manner as normal paper feeding.

At this time, the side of the paper that has been copied first faces the photosensitive material 31.

On the other hand, during the above-described operation, an electrostatic latent image is again formed on the photosensitive material 31, the black portion of the electrostatic latent image is erased by the LED 33, and only the color portion is developed by the color developing device 34. At this time, the heat developing machine 35 is moved to the non-developing position and held there, and the color developing machine 34 is moved to the developing position and held there.

Thereafter, the visible image developed by the color developing device 34 is transferred onto the paper, fixed by the fixing device 44, and then discharged onto the catch tray 45. At this time, the first gate 47 is in the posture of the virtual line.

■The case of multiple copying is also the same as the above-mentioned multicolor copying.

Next, details of the developing device will be explained.

As shown in FIG. 3, the color developing machine 34 includes a developing roll 61, first and second augers 62 in a developing machine housing 60.
．． 63, a stirring member 64, a third auger 65, and a toner stirring member 66 are provided, and the supporting shaft 6 of the developing roll 61
1a, the support shafts 62a, 6 of the first and second augers 62.63
3a.

Support shaft 64a1 of stirring member 64 Support shaft 6 of third auger 65
5a, the support shafts 66a of the toner agitating member 66 are connected to each other via a gear 67 as shown in FIG.
It is designed to mesh with 8.

As shown in FIG. 3, the heat developing machine 35 includes a developing roll 71, first and second augers 7 in a developing machine housing 70.
2.73, a stirring member 74 is provided, and the supporting shafts 71a, 7
2a, 73a, and 74a are connected to each other via a gear 75, as shown in FIG.

The first and second drive idler gears 68 and 76 are rotatably supported on the copying machine main body 30 side, and mesh with drive gears 78 connected to the output shaft of a motor 77 mounted on the copying machine main body 30 side. are doing.

Next, a device for moving the developing machine will be explained.

As shown in FIGS. 4 and 5, the negative side plate 80a and the other side plate 80b
A planar U-shaped bracket 80 connected by a connecting plate 80c.
is disposed facing the photosensitive material 31, a hole 81 formed in the negative side plate 80a fits into the support shaft 31a of the photosensitive material 31, and a sliding piece 82 provided on the connecting plate 80C is placed on the copying machine main body 30 side. The bracket 80 is placed on a guide rail 83 provided on the photosensitive material 31 and is slidably supported in position with the photosensitive material 31. A heat developing machine 35 is disposed within the bracket 80, and the developing machine \ Guide pin 84 provided on the housing 70
Guide groove 85 formed in one side plate 80a1 and the other side plate 80b
The thermal developing device 35 can freely move forward and backward toward the photosensitive material 31 with respect to the bracket 80, and is moved and held at a non-developing position separated from the photosensitive material 31 by the spring 86. , is attached to the rear side of the housing 70 of the developing machine so as to face the pair of left and right first plate springs 87° 87 or the pair of opening windows 88° 88 formed in the connecting plate 8C, and a handle is attached to one side plate 80a of the bracket 80. There are 8 or more installations.

Since it is like this, hold the handle 89 and remove the bracket 80.
The heat developing machine 35 and the heat developing machine 35 are pulled out from inside the copying machine main body 30, making it easier to inspect and repair the heat developing machine 35. When pushing the bracket 80 into the copying machine main body 30, the receiver provided on the copying machine main body 30 side is pushed along the material 89a as shown in FIG.

At this time, the replenishment auger 54 gets in the way, but the replenishment auger 54 is rotatable around a support shaft 53a supported on the toner box 53 as shown in FIG.
Opening 8 formed in one side plate 80a of the bracket 80
Since it is detachably connected to the upper part of the second auger 73 protruding from 0d and relatively displaceable in the axial direction, the replenishment auger 54 can rotate upward about the support shaft 53a and interfere with the bracket 80. I try not to do that.

a developing machine housing G of the color developing machine 34;

A movable guide rail 90 is provided on the upper surface, and this movable guide rail 90 is slidably fitted into a fixed guide rail 92 provided on a movable bracket 91, and the color developing machine 34
can be pulled out from the copying machine main body 30, and the movable bracket 91 is formed with a long hole 94 facing a guide pin 93 provided on the copying machine main body 30 side, and moves forward and backward toward the photosensitive material 31 together with the color developing device 34. The color developing device 34 is moved and held at a position separated from the photosensitive material 31 by the springs 95, so that the color developing device 34 is moved and held at a non-developing position.

A lever 96 facing the back surface of the housing 60 of the color developing device 34 is swingably supported by a U-shaped support frame 87a that supports the first plate spring 87, and the lever 96 has a first plate spring 87. The two-plate spring 97 is provided so as to face the opening window 88.

Connecting plate 8 of the bracket 80 in the copying machine main body 30
．． A support bracket 98 is provided at a position facing Oc, and cam shafts 99 are horizontally supported on this support bracket 98, and a pair of first cams 100 and a pair of second cams are mounted on the nine cam shafts. The cams 101 are disposed at positions shifted by 180 degrees in the rotational direction and shifted in the axial direction, and the pair of first cams 100 face the first leaf spring 87,
A pair of second cams 101 face the second leaf spring 97, and the camshaft 99 is connected to a drive gear 103 via a spring clutch 102, and this drive gear 03 is connected to the output side of the motor 77. In addition, the spring clutch 102 has first and second stop pawls 1.05 and 106 provided on the collar 104 with a phase shift of 1.80, and a stop lever on the first and second stop pawls 105 and 106. By bringing the solenoid 107 into contact with the solenoid 108, the rotation of the camshaft 99 is regulated every 180 degrees, and the solenoid 108 is constantly demagnetized so that the stopper lever 107 is in a position where it comes into contact with the first stopper pawl 105.
As a result, the first cam 100 or the first plate spring 8 is attached to the cam shaft 99.
7, the black developing device 35 is moved and held at the developing position, and the color developing device 34 is brought to the non-developing position by the spring 95, and when color developing, the solenoid 108 is energized. The nine camshafts are set at the second cam 1 with the stop lever 107 in a position where it contacts the second stopper claw 106.
01 is in contact with the second plate spring 97, whereby the black developing device 35 is moved and held in the non-developing position by the spring 86, and the color developing device 34 is moved and held in the developing position.

Next, first and second drive idler gears 68 according to the present invention.
76, the input side gear 67 of the color developing device 34, and the input side gear 75 of the black developing device 35 are always properly engaged with each other.

First, as described above, the black developing machine 35 is always held at the developing position, the color developing machine 34 is held at the developing position, and the color developing machine 34 is moved and held at the developing position only when color copying is performed. In addition, the black developing device 35 is moved and held in a non-developing position, and when the color copying operation is completed, it is automatically returned to the above-mentioned state.

The motor 77 that drives the drive gear 78 is dedicated to driving an independent developing machine, and is driven only during the developing process during the copying operation, and the black developing machine 35 moves to the developing position after the color copying operation is completed. Motor 7 immediately after being held
7 is driven for a predetermined time that does not interfere with the next copying operation, for example, about 1 second.

As a result, the second drive idler gear 76 that meshes with the gear 75 on the input side of the black developing machine 35 rotates for a predetermined period of time immediately after the black developing machine 35 moves to the developing position. Even if the tooth tips of the input side gear 15 and the second drive idler gear 76 are in contact with each other when the input side gear 15 and the second drive idler gear 76 are moved to the position, the input side gear 75 and the second drive idler gear 76 rotate. The drive idler gear 76 meshes properly.

Therefore, when the black developing device 35 is not used for a long time, for example, when there is no copying operation for a long time, the input side gear 75 and the second drive idler gear 76 are in a state where their tooth tips are in contact with each other. Since the first leaf spring 87 does not become loose and is securely engaged, the black developing device 35 can be held at the correct developing position at a predetermined distance from the photosensitive material 31. This can prevent tacking failure.

Further, since the color developing device 34 moves to the developing position during color copying, the copying operation starts immediately after moving to the developing position, so that the input side gear 67 and the first drive idler gear 68 are activated so that the motor 77 is immediately driven. The time during which the tooth tips are kept in contact with each other becomes extremely short, and the second leaf spring 97 does not become flattened as described above, so there is no need to drive the motor 77 in particular.

In the above examples, a color developing machine and a black developing machine were used.
The same applies when using multiple color developing machines and black developing machines, or multiple color developing machines; the key is to always use one of the developing machines as the developing position and the remaining developing machines as the non-developing position. , when one of the remaining developing machines is placed in the developing position, any one of the developing machines held at the developing position is set to the non-developing position, and any one of the developing machines is placed in the non-developing position again.
It is sufficient to drive the motor for a predetermined period of time after moving one developing machine to the developing position.

Next, a second embodiment of the present invention will be described.

As shown in FIG. 6, a pin 110 is provided on the support shaft 71a of each developing port of the black developing device 35, and a pair of radial grooves 11 are provided in the boss hole 111 of the gear 75 on the input side.
2, 11.2, and the pin 110 is loosely fitted into this pair of grooves 112, 112, and the grooves]]2 and pin 1]0
The gear 75 on the input side can freely rotate with respect to the support shaft 7 ], a by the amount of play.

In this way, when the black developing device 35 is moved to the developing position, even if the tooth tips of the input-side gear 75 and the tooth tips of the second drive idler gear 76 come into contact, the input-side gear 75 remains on the support shaft. 71a
It rotates a little freely against the shaft and meshes naturally and correctly. Incidentally, the gear on the input side of the color developing machine may be made in the same manner.

〔Effect of the invention〕

(2) The motor 77 is driven for a predetermined time after the developing machine, which is always held at the developing position, is moved from the non-developing position to the developing position, so that the drive idler gear is connected to the input side gear provided in the developing machine for a predetermined time. Even if the tips of the teeth of the input side gear and the tips of the drive idler gear are in contact when the developing machine is moved to the developing position, they can be properly engaged by the rotation of the drive idler gear mentioned above, and the plate The spring will never flatten.

Therefore, the developing device, which is always held at the developing position, is always held at the correct developing position and no tacking failure occurs, and good developing operation can always be performed without causing any deterioration in image quality.

2. Since the gear on the input side can freely rotate by a predetermined angle, even if the tips of the teeth of the gear on the input side and the tips of the drive idler gear come into contact when the developing machine moves to the developing position, the gear on the input side will not rotate. It can rotate freely and engage properly, and the plate springs do not become sagging, which prevents tacking failures.

[Brief explanation of the drawing]

1 to 6 show embodiments of the present invention, FIG. 1 is a front view showing a gear train of a developing machine, FIG. 2 is a schematic explanatory diagram of an electrophotographic copying machine, and FIG. 3 is a diagram of a developing machine. A sectional view, FIG. 4 is a perspective view,
5 is a front view, FIG. 6 is a partial perspective view of another embodiment, FIG. 7 is a perspective view of a conventional example, FIG. 8 is an explanatory diagram of the gear train of the developing machine, and FIGS. 9 and 10. The figure is a diagram illustrating a malfunction. 77 is a motor.

Claims (2)

[Claims] (1) A plurality of developing machines are arranged so as to be movable between a developing position and a non-developing position, facing the photosensitive material 31, and each developing machine is moved and held by an elastic member to the non-developing position. , each developing machine is moved to and held at a developing position by a cam and a leaf spring, and a gear on the input side provided in each developing machine is connected to a motor 77 provided on the main body of the copying machine when it is set to the developing position. The drive idler gear meshes with the drive idler gear and is spaced apart when in the non-developing position, and
One developing machine is always in the developing position and the other developing machine is in the non-developing position, and at the time of different copying operations, any one of the developing machines is in the non-developing position and corresponds to the copying operation in the other developing machine. The motor 77 is driven for a predetermined time only when one of the developing machines is set to the developing position again and the other developing machine is set to the non-developing position. A developing device characterized by: (2) A plurality of developing machines are disposed so as to be movable between a developing position and a non-developing position, facing the photosensitive material 31, and each developing machine is moved and held by an elastic member to the non-developing position. , each developing machine is moved to and held at a developing position by a cam and a leaf spring, and a gear on the input side provided in each developing machine is connected to a motor 77 provided on the main body of the copying machine when it is set to the developing position. The developing device is characterized in that the gear on the input side provided in each of the developing machines is able to freely rotate by a predetermined angle, the gear being meshed with a drive idler gear and separated from the drive idler gear when in a non-developing position.