JP2539235B2 - Image forming device developing device - Google Patents

Description

The present invention relates to a developing device equipped in an image forming apparatus such as an electrostatic photocopier and a facsimile.

[Conventional technology]

As the developing device described above, for example, as shown in Japanese Patent Laid-Open No. 62-65048, two developing devices for accommodating developers of different colors are provided in the developing section so that they can be inserted and removed separately, Position switching means for switching the other developing device to a non-developing position in cooperation with the switching of the developing device to the developing operation position, and the driving device for switching the position of the developing device is interlocked with the position switching device. There is.

According to such a developing device, so-called mono-color development can be performed by selecting either one of the developing devices, or so-called superposition development can be performed by sequentially using the two developing devices. Since the two developing units can be inserted into and removed from the developing unit separately, various maintenance can be easily performed on the developing unit by removing the developing unit from the developing unit.

Here, the position switching means is composed of two rotary cams that switch the developing device to the two positions separately with rotation and a gear interlocking mechanism that interlocks and connects the two rotary cams. Is composed of a drive gear that transmits rotational power to the gear interlocking mechanism via a clutch.

By the way, when the developing device is pulled out from the developing section or the developing device is reset to the developing operation position while the developing device is in the developing operation position, the developing device may damage the photoconductor.

In this case, by switching the developing device in the developing operation position to the developing non-operation position by the driving means, it is possible to prevent damage to the photoconductor properly. When the cover is open (or the upper case is open in a shell-type image forming device), the safety switch that stops the drive of the device is turned off. Each time it was switched to the inoperative position, it was necessary to close the front cover and drive the device.

In order to eliminate this troublesome operation, the above-mentioned developing device has a manual operation for switching only the developing device in the developing operation position to the developing operation inactive position without moving the developing device in the development inoperative position. A switching operation means is provided.

The manual switching operation means is provided between the drive gear and the cam shaft between a cam shaft of a rotary cam that is linked to one developing device and a gear of the gear interlocking mechanism that transmits rotational power to the cam shaft. Is provided with a one-way clutch for transmitting rotational power to the cam shaft, and a manual operation tool is attached to the cam shaft. When the one developing device is in the developing operation position, the driving force is transmitted to the cam shaft by the driving means. The developing device can be switched to the non-developing position by rotating the developing device by half rotation in the opposite direction.

[Problems to be solved by the invention]

However, when pulling out the developing device from the developing unit, there is a fear that the photoconductor is unexpectedly damaged by forgetting to switch the developing device at the developing operation position to the development inoperative position.

Alternatively, it may be forgotten to reset the extracted developing device to the original position and then switch the developing device to the developing operation position. In this case, the two developing devices are both in the development inoperative position. Therefore, development itself becomes impossible,
Alternatively, when the driving means is operated to select the development by the other developing device, both developing devices are exposed to the developing operation position, so that there is an inconvenience that development in which two color developers are mixed is performed. .

Further, as another configuration of the manual switching operation means, there is disclosed one in which a 180-degree play is provided between the cam shaft and the gear, instead of providing a one-way clutch between the cam shaft and the gear. However, even with such a configuration, there is no change in that the photoconductor is damaged or the development cannot be performed due to the failure to perform the above operation.
Although there is an advantage that the developing device can be returned to a predetermined developing mode by repeating the operation of selecting the developing device twice based on the occurrence of the situation where the developing cannot be performed, the operation is troublesome and It takes time, and furthermore, due to the play portion, the relative positional relationship between the cam shaft and the gear is likely to deviate due to the vibration of each part of the device, and further, it is linked to the cam shaft. Since the developing device is displaced and the gap between the developing sleeve of the developing device and the photoconductor changes, there is an inconvenience that the desired development cannot be achieved.

The above-mentioned inconvenience is caused by temporarily moving one of the two developing units, which requires maintaining the relative positional relationship at 180 degrees,
Alternatively, it is caused by the one developing device unexpectedly moving and the relative positional relationship between the two developing devices being displaced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to eliminate the above-mentioned conventional drawbacks by an extremely simple improvement.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a developing device of an image forming apparatus having two developing devices that can be inserted into and removed from a developing portion separately, and is capable of switching one developing device to a developing operation position. Position switching means for interlockingly switching the other developing device to the developing inoperative position is provided, and driving means for position switching of the developing device is interlockingly connected to the position switching means, and the driving means is connected to the position switching means. A manual switching operation means for manually switching the position switching means in the state where the transmission of the drive means to the drive source is cut off is provided in the middle of the transmission system to reach the developing device. A structural feature is that an insertion / extraction check means for checking insertion / extraction is provided.

[Action]

According to the above-mentioned characteristic structure, since the insertion / extraction of the developing device at the developing operation position is restrained by the insertion / extraction restraining means, when the developing device is pulled out or the developing device is reset to the original position, the photoconductor is unexpectedly opened. Does not hurt.

Then, while the relative positional relationship between the two developing devices is maintained at 180 degrees by the position switching means that sets the other developing device in the developing inoperative position when the other developing device is in the developing operation position, Since the two developing devices are switched to the two positions in a contradictory manner by manual operation, a situation in which both the developing devices are not shown in the development inoperative position or the development operating position does not occur. Inconveniences caused by the conventional play, that is, the developing device is not displaced and the gap between the developing sleeve of the developing device and the photoconductor does not change.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
4 and 5 schematically show a shell type electrostatographic copying machine as an example of an image forming apparatus, in which a copying machine case 3 provided with a document placing table 1 and a document pressing plate 2 is vertically divided into two parts. The upper case 3A therein is connected to the lower case 3B so as to be openable and closable around the horizontal axis 4 on the side of the paper discharge section, and the movable optical system exposure device 5 is provided in the upper case 3A while the front and rear housings 6 are provided. A static elimination lamp 8 is provided around the photoconductor 7 that is horizontally mounted on the
The charging device 9, the blank cut lamp 10, the developing device 11 and the cleaning device 14 are arranged to form an image forming unit U, and the image forming unit U has one end side thereof via the support shaft a and the lower case 3B. Roller b on the other end side
Is rotatably supported on the rail 3a on the upper case 3A side, and further, the transfer device 12 and the sheet separating device 13 are mounted on the lower case 3B at a position corresponding to the photoconductor 7 when the upper case 3A is closed. The transfer device 12 and the paper separating device 13 are provided.
Is left on the lower case 3B side, the image forming unit U can be lifted up and swung around the support shaft a in conjunction with the opening of the upper case 3A.

Then, in the lower case 3B, a paper feed / conveyance device 17 for feeding the paper from the manual feed unit 15 or the paper feed cassette 16 to the transfer device 12, and the paper after transfer / separation from the fixing device 18 to the paper ejection tray 19. A sheet discharging and conveying device 20 for discharging a sheet, and a double-sided copying mechanism section for performing double-sided copying as necessary (a switchback mechanism 21 and a sheet after completion of one-sided copying in which the front and back sides are reversed by the switchback mechanism 21 An intermediate tray 22 for temporarily stocking, and a re-feeding mechanism 23 for re-feeding the stocked sheets) 24 are arranged.

Next, a specific example of the developing device 11 will be described.
As shown in FIGS. 1 and 6 to 11, a small-capacity type first developing device 25 for accommodating a color developer other than black, which is generally infrequently used, and a black color developer, which is frequently used. A large-capacity type second developing device 26 for accommodating the above is arranged around the photoconductor 7 in a vertically insertable and removable state. Specifically, the first and second developing devices 25 and 26 are The toner replenishment form and the storage capacity are different, and both have the same structure, and a developing case 29 in which a toner replenishing hopper 28 is continuously provided is provided with a developing opening at a portion corresponding to the photoconductor 7. A stirrer for forming a developing sleeve 30 and incorporating the developing sleeve 31 into the developing case 29 so as to face the developing opening 30 and to stir the developer and pump it up to the developing sleeve 31.
32, a brush cutting member 33 that controls the height of the brush of the magnetic brush of the developer formed on the sleeve peripheral surface, and a return plate 34 that circulates the developer after the brush cutting onto the stirring tool 32. And the first developing device 25 has an opening / closing lid at the top.
28a is opened to replenish the toner from the toner bottle, and the second
The developing device 26 is configured such that toner is replenished by replacing the toner cartridge C.
Two supporting pins (one is also used as the rotating shaft of the developing sleeve 31) d and d are provided on both sides in the longitudinal direction of the developing case 29 (both sides in the axial direction of the photoconductor 7). It is lined up.

On the other hand, a pair of upper and lower brackets in which elongated holes g, which engage with the fixing pins f, f of the housing 6 are formed on the inner surface sides of the front and rear housings 6, respectively (as shown in FIG. The housing 6 on the rear side cannot be seen, and the one attached to the housing 6 on the rear side is the drawing target.)
Is provided so as to be movable in the perspective direction with respect to the photoconductor 7 within the range of the elongated holes g, g, and supports the support pins d of the developing devices 25 and 26 so as to be vertically insertable and removable. The two pin support parts e, e are formed on the brackets 35, 35, and the pin support parts e on the photoconductor 7 side are made to correspond to each other and the photoconductor 7
The housing 36 is provided with insertion / withdrawal restraint means 37, 37 for restraining the withdrawal of the support pin d from the pin support portion e of the bracket 35 that has been moved closer to the photoconductor 7 side.

A gear-type interlocking mechanism 44 in which upper and lower three gears are meshed with each other is provided in the housing 6, and the upper and lower gear shafts 38 and 39 of the gear-type interlocking mechanism 44 are provided with a phase of 180 degrees. With the rotating cams 40, 40 connected in series, and one of the developing devices 25, 26 supported by the brackets 35, 35 positioned at the developing operation position X and the other at the developing non-operation position Y, The rotary cams 40, 40 are engaged and connected to the cam followers 41, 41 provided on the brackets 35, 35, respectively.

Further, as shown in FIGS. 2 and 3, the lower gear shafts 39, 39 of the gear type interlocking mechanism 44 are connected to each other, and the connecting shaft is projected from the housing 6 on the front side. The projecting shaft is used as an input shaft 42, which is subjected to split circle processing (so-called D cut), and at the same time, the input shaft 42 and the output shaft 43 of the motor M.
Are linked by a gear interlocking mechanism G.

The input side gear G ₁ of the gear interlocking mechanism G is slidably provided on the input shaft 42, and the input side gear G ₁ is provided.
A manual operation tool 46 for releasing the engagement of G _{1 with} the output side gear G ₂ against the biasing tool 45 is provided slidably on the input shaft 42 in a state of being prevented from coming off by the E ring h. This cam body 47 is provided on the input shaft 42.
Is provided with a sensor S for stopping the orbit of the motor M by detecting the half rotation of the motor.

When the developing device selection switch (not shown) is operated to drive the motor M, the developing devices 25 and 26 both move in antipathy, and the sensor S detects half rotation of the cam body 47. At that time, the driving of the motor M is stopped, and as shown in FIGS. 8 and 9, one of the first developing devices 25, which has been in the developing operation position X up to then, is in the developing non-operation position Y and the other one. The second developing device 26, which was in the development inoperative position Y, can be switched to the development operating position X.

That is, a gear-type interlocking mechanism 44 that is rotated with the rotation of the input shaft 42, and a gear-type interlocking mechanism 44 that is connected to the gear-type interlocking mechanism 44.
Mainly with the individual rotating cams 40, 40, both the developing devices 25, 26
A position switching means A for switching between the developing operation position X and the developing non-operation position Y in a contradictory manner, and the input shaft 42 and the motor M for the interlocking mechanism 44, and the output shaft 43 of the motor M. A gear interlocking mechanism G extending between the input shaft 42 and the input shaft 42 constitutes a drive unit B for switching the positions of the developing devices 25 and 26 via the position switching unit A.

When any one of the developing devices 25 and 26 is switched to the developing operation position X, the state of the position switching is detected by the sensor S and the driving of the motor M is stopped. S and the cam body 47
Thus, the drive stopping means C for detecting the switching of the developing device 25 (or 26) on one side to the developing operation position X and stopping the drive of the driving means B is constituted.

Further, while the driving of the motor M is stopped, the gear engagement of the gear interlocking mechanism G is released by the manual operation tool 46, and the manual operation tool 46 is half-rotated to switch the position switching means A. Therefore, the developing device 25, 26
The position switching means A can be manually operated, that is, the position switching means A can be operated in a state in which the transmission with the drive means B is cut off by the gear G ₁ which can be disengaged and the manual operation tool 46 which operates the gear. The manual switching operation means D that can be manually switched is configured.

According to the above configuration, when the upper case 3A is opened and the developing devices 25 and 26 are pulled out, for example, when the first developing device 25 is in the developing operation position X shown in FIG. 8, it is shown in FIG. As described above, since the support pin d of the first developing device 25 on the side of the photoconductor 7 is in the extraction and restraint state by the insertion / extraction restraining means 37, the first developing device 25 is removed from the developing portion (that is, the bracket 35). This prevents the photosensitive member 7 from being accidentally damaged by the developing sleeve 31 because it cannot be pulled out upward.

Here, the position changeover means A is manually changed over by the manual changeover operation means D in a state where the transmission with the drive means B is cut off, and as shown in FIG. By switching to the development inoperative position Y,
As shown in FIG. 11, the withdrawal restraint of the first developing device 25 is released, and thus the first developing device 25 is easily withdrawn from the developing portion while the photoconductor 7 is prevented from being scratched. It is possible.

Next, the first developing device 25 is pulled out, and then the second developing device is removed.
When the 26 is pulled out from the developing section, if the above-mentioned position switching is still left, the withdrawal of the second developing device 26 is also restrained by the insertion / extraction restraining means 37, so that the withdrawal is impossible. By manually switching the position switching means A by the switching operation means D, the second developing device 26 can be operated without damaging the photoconductor 7.
Can be extracted from the developing section.

Then, predetermined maintenance is performed to reset the developing devices 25 and 26 to the original positions. At this time, the second
The developing unit 26 can be set easily and easily.

On the other hand, with respect to the set of the first developing device 25, the position switching operation of the position switching device A is performed by the manual switching operation device D, so that the photosensitive member 7 of the first developing device 25 is set.
The insertion of the side support pin d into the pin support portion e is restrained by the insertion / extraction restraint means 37, and thus the first developing device
Since it is impossible to set 25, in this case also the first
The developing device 2531 prevents the photoconductor 7 from being damaged.

Therefore, the position switching operation of the position switching means A is performed by the manual switching operation means D, and the first developing device 25
However, in the state where the first developing device 25 is set again in this way, the second developing device 26 containing the black developer, which is frequently used, is definitely used. The developing operation position X is shown. this is,
This is because the positions of both the developing devices 25 and 26 are switched while the relative positional relationship between the developing devices 25 and 26 is always maintained at 180 degrees by the manual switching operation means D.

By the way, by rotating the input shaft 42, and hence the rotating cams 40, 40 by 180 degrees by the manual switching operation means D, the developing devices 25, 26 are initially set in the initial posture (developing operating position X and developing inoperative). Although it can be returned to the position Y), its operation is very difficult, and originally, there is a disadvantage that the gap between the photoconductor 7 and the development sleep 31 is changed and the predetermined development cannot be performed. is there.

However, the drive stopping means C causes the one developing device 25 to
(Or 26) is configured to detect the position switching to the developing operation position X and stop the driving of the driving means B. Therefore, by driving the position switching means A by the driving means B, The developing devices 25, 26 can be easily shown in the initial position, that is, it is not necessary to rotate the input shaft 42 by the manual switching operation means D severely.

In the embodiment, the drive means B is detected by detecting the position switching of one developing device 25 (or 26) to the developing operation position X.
Drive stop means C for stopping drive is provided, but this is omitted and, for example, as shown in phantom in FIG.
The aim i is provided in the vicinity of the manual operation tool 46, and the two pointers j, j are formed by giving a phase of 180 degrees to the manual operation tool 46, and the pointer j is aligned with the aim j. By rotating the manual operation tool 46, both the developing devices 25, 26
It is not indispensable to perform the manual switching operation between the two positions X and Y accurately, that is, to provide the drive stopping means C.

In the embodiment, the copying machine case 3 is divided into upper and lower parts,
The so-called three-division type shell type copier in which the image forming unit U is connected across the upper and lower cases 3A and 3B has been described, but the copier case 3 is divided into upper and lower parts.
A so-called two-division type shell type copier that connects A and 3B,
A copying machine of a type in which the image forming unit U can be pulled out to the front side in the axial direction of the photoconductor 7 without dividing the copying machine case 3 as it is, and other facsimiles, printers, etc. can be embodied in the present invention.

〔The invention's effect〕

As described above, according to the present invention, since the developing device in the developing operation position is restrained by the inserting / extracting inserting / removing restraining means, it is unexpected when the developing device is pulled out or the pulled-out developing device is reset to the original position. It is surely prevented that the photoconductor is damaged.

Then, the two developing devices are positionally switched so that the two developing devices are switched to the two positions by a manual operation while keeping the relative positional relationship of the two developing devices constant. By interlocking with each other, when one developing device is in the developing operation position, the other developing device is always shown in the developing non-operation position. There is no room for switching to the position, and since both developing devices are still interlocked by the position switching means, the gap size between the developing sleeve of the developing device in the developing operation position and the photoconductor is always constant. Therefore, it is possible to provide a developing device that is useful in terms of use because of the extremely simple and rational improvement as a whole. Than it was.

[Brief description of drawings]

FIG. 1 is a perspective view showing various means (position switching means, driving means, drive stopping means, manual switching operation means and insertion / extraction check means), FIG. 2 is a perspective view mainly showing manual switching operation means, and FIG. It is an exploded perspective view of a manual switching operation means. FIG. 4 is a vertical sectional side view of a shell type electrostatic photocopier as an example of the image forming apparatus, and FIG. 5 is a vertical sectional side view of the electrostatic photocopier showing an opened state of the upper case. FIG. 6 is a side view of the image forming unit showing a state where the first developing device is pulled out, and FIG. 7 is a perspective view of two developing devices. FIGS. 8 and 9 are sectional views showing the position switching state of the developing device, and FIGS. 10 and 11 are explanatory views showing the movement state of the bracket for switching the position. 25,26 …… Developer, 40 …… Rotating cam, 42 …… Input shaft, 43
...... Output shaft, 44 …… Interlocking mechanism, 46 …… Manual operation tool, A…
... position switching means, B ... position switching drive means, D ...
... Manual switching operation means, G ... Gear interlocking mechanism, M ... Drive source (motor), X ... Development operating position, Y ... Development inoperative position.

Claims (2)

(57) [Claims] 1. A developing device of an image forming apparatus, wherein two developing devices are separately inserted into and removed from a developing unit, and the other developing device is interlocked with switching of one developing device to a developing operation position. Is provided with a position switching means for switching to the developing inoperative position, and the position switching driving means of the developing device is interlocked with the position switching means, and in the middle of the transmission system from the driving means to the position switching means, A manual switching operation means is provided for manually switching the position switching means in a state where the transmission of the drive means to the drive source is cut off, and further, insertion / withdrawal restraint for restraining insertion / removal of the developing device in the developing operation position. A developing device of an image forming apparatus including means. 2. The position switching means comprises two rotary cams for individually switching the developing device to the two positions according to rotation, and an interlocking mechanism for interlockingly connecting the two rotary cams.
The drive means is composed of a motor and an input shaft for the interlocking mechanism, and a gear interlocking mechanism extending between the input shaft and the output shaft of the motor, and the manual switching operation means is for engaging the gears of the gear interlocking mechanism. The developing device for an image forming apparatus according to claim 1, comprising a manual operation tool for releasing and operating the input shaft in the disengaged state.