JPH0743553B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus such as a copying machine or a recording apparatus having a plurality of developing devices.

[Conventional example]

Conventionally, an image forming apparatus having a plurality of developing devices has been proposed, and in particular, an electrophotographic image forming apparatus is often used due to its ease of use. The present invention will be described below by taking an electrophotographic copying machine (hereinafter referred to as a copying machine) as an example. In the case of two-color development, normal users have one color (especially black)
It is considered that there are many cases where the user wants to replace the color with various colors, although the frequency of use is much higher than that of other colors, and the other colors are less frequently used.

[Problems to be solved by the invention]

In a copying machine having two developing devices, it is necessary to provide a guide, a safety device, etc. for exchanging the two developing devices so that the two developing devices can be replaced. Induce incarnation.

In this way, in a copying machine having two developing devices, the two developing devices can be exchanged with each other, and there is little advantage in terms of mechanism and usage, and a problem is likely to occur. For this reason, it is preferable in terms of machine construction to fix one developing device to the copying machine and replace the other developing device.

Further, when the developing device is detached, it is preferable to separate the developing device from the latent image carrier in advance so as not to damage the latent image carrier.

Further, it is preferable to provide a sleeve cover in order to prevent scattering of the developer from the developing sleeve and damage to the developing sleeve when the developing device is attached or detached.

However, it is burdensome for the operator to individually perform the operation of moving the developing device toward and away from the latent image carrier and the operation of opening and closing the sleeve cover.

Therefore, an object of the present invention is to automatically move the developing device toward and away from the latent image carrier in conjunction with the operation of rotating and opening and closing the upper housing with respect to the lower housing of the image forming apparatus. An object of the present invention is to provide an image forming apparatus capable of opening and closing a sleeve cover.

[Means for Solving the Problems] An image forming apparatus of the present invention includes a lower housing, a closed position that is rotatably attached to the lower housing, and is closed with respect to the lower housing. In an image forming apparatus provided with an upper housing that is rotatable between an open position opened with respect to a body, the upper housing has a latent image carrier and two first and second latent image carriers. A developing device is provided, and the second developing device is detachably supported by a supporting portion of the upper housing below the first developing device, and the latent image is supported by the supporting portion. It is movable toward and away from the carrier, and the upper casing further includes a second support supported by the support section.
Is provided by a first urging unit that elastically urges the developing device in a direction away from the latent image carrier, and the second developing device includes a first position for covering the developing sleeve and a developing sleeve. A sleeve cover movable between a second position for opening, a second biasing means for elastically biasing the sleeve cover toward the first position, and a biasing force for the second biasing means. A gear for transmitting a driving force for moving the sleeve cover to the second position against the lower housing, wherein the lower housing is a pressing member with a gear part, and the upper housing is in the open position. Is rotated to the closed position, the gear of the second developing device engages with the gear portion and the gear is rotated to move the sleeve cover to the second position. The developing device moves close to the latent image carrier against the biasing force of the first biasing means. As described above, a pressing member with a gear portion for pressing the second developing device is provided, and when the upper housing is moved to the open position, the gear of the second developing device is moved from the pressing member with the gear of the lower housing. By the separation, the sleeve cover is moved to the first position by the urging force of the second urging means, and the second developing device is separated from the latent image carrier by the urging force of the first urging means. An image forming apparatus characterized by the above.

〔Example〕

 The present invention will be described below with reference to examples.

FIG. 5 is a cross-sectional view showing an embodiment of a copying machine for explaining the present invention, which is of a type in which the document placement is moved.

In FIG. 5, the copying machine is a document table 2 composed of a transparent body or the like on which a document to be copied is placed and moved, and a small-diameter image-forming element array (product name self-off) for projecting the document onto the photoconductor 3.
4, irradiation means 5 including a lamp for irradiating the original of the projection unit and a condenser, and two developing devices 6, 7 for forming a toner image on the latent image on the photoconductor 3 arranged around the photoconductor 3. A storage box 8 for paper which is the final image carrier, a paper feeding means 9 for feeding the paper one by one from the storage box 8, and the fed paper to the photoconductor 3 in synchronization with the image corresponding to the original document on the photoconductor 3. 10 pairs of rollers to convey
A charger 11 for transferring the toner image on the photoconductor 3, a charger 12 for separating the paper from the photoconductor, a cleaning device 13 for removing the residual toner on the photoconductor 3, and a charge for giving a uniform charge on the photoconductor 3. Container 14, means for conveying the paper separated from the photoconductor 3
15, a fixing unit 16 for fixing the toner image on the paper, a pair of discharge rollers 17, and a base 18 for stacking the discharged paper.

Here, the position on the photoconductor on which the document is projected is arranged above the cylindrical photoconductor 3, and the contact point of the paper on which the toner image is transferred with the photoconductor is arranged below the photoconductor. . Since the developing device 27 for forming the toner image must be located between the above two, it is arranged next to the photoconductor 3 as shown in FIG. 1, and in order to arrange the two developing devices. A vertical relationship occurs at that position. In the embodiment shown in FIG. 5, the developing device 7 is a red developing device, the developing device 6 is a black developing device which is frequently used,
The developing device 7 is arranged below the developing device 6. The toner in the developing device 6 is replenished from outside the apparatus through the upper surface of the machine.

Further, the developing device 7 does not have a mechanism for replenishing the developer to the apparatus and is configured to be replaced when the developer is used up.

FIGS. 2 and 3 show a state in which the upper and lower housings are opened and the upper housing is opened in the copying machine of the embodiment shown in FIG.

The embodiment of FIG. 2 shows a state in which the upper part is rotated around a point 19 near the fixing device 16 as a swing center and opened, and the embodiment of FIG. It shows a state in which the upper casing is rotated about the swinging center to be opened. In both FIGS. 2 and 3, the upper housing of the paper feed roller 9 and the transport roller pair 10 prevents the paper transport means from being soiled due to the scattering of toner during development and the dropping of toner during replacement of the developing device. A cover 21 is provided. The method of replacing the developing device 7 will be described below in the case of the embodiment shown in FIG. 2, but it is also applicable to the embodiment shown in FIG.

FIG. 4 shows the state in which the machine is closed and the developing unit 7 is pressed against the photoconductor 3, and FIG. 1 shows the state in which the developing unit 7 is separated from the photoconductor 3 and It shows a state in which the upper housing is opened.

In FIG. 4, the developing device 7 attached to the upper housing is
It is swingably supported with respect to the hinge 22, and the hinge 23
The developing device 7 is brought into contact with and separated from the photoconductor 3 by a pressing mechanism composed of a lever 24 and a roller 25 which rotate around the center of the developing device 7.

FIG. 1 shows a state in which the upper housing is opened, and in this state, the developing device 7 is in a state of being separated from the photoconductor 3. When the developing device 7 is brought close to the photoconductor only when the color of the developing device is selected, the developing device 7 is separated and contacted by rotating the lever 24 by a driving means such as a solenoid. In this case, by opening the upper casing of the machine, the drive means can be electrically connected.
When turned off, the lever 24 may be rotated counterclockwise by the spring 26 to release the pressure.

Further, as shown in FIG. 7, it is also possible to open and close the main body so that the developing device 7 is separated and contacted. The mechanism of FIG. 7 will be described later. In Figure 1, the frame of the developing machine
27 and a lever 29 that can be swung about a hinge 28 are shaped so as to sandwich the swing center of the developing device 7 and
The developing device 7 is swingably held by the hinge 22 by the spring 30 urging the spring 29 to apply a force in the direction of pressing the lever 29 to the frame 27. The engaging portion 27a between the hook 29a of the lever 29 and the hinge of the frame 27 has a slight clearance with respect to the center 7 as shown in FIG. The connection and disconnection is carried out. Further, the frame 27 and the lever 29 have guide portions 27b and 29b for facilitating attachment to the main body of the developing device 7.

The force of the developing device 7 in the separating direction may have a means such as a spring for performing the force, or may be proportional to the developing device 7 due to its own weight.

When the developing device 7 is taken out from the main body of the machine, the lever 29 and the hinge 22 are disengaged by manually pushing the knob 29c of the lever 29 to the developing device frame 27 side as shown in FIG. It is done in. The frame 27 is provided with a handle portion 27c for releasing the frame 27 to facilitate the above operation. Furthermore, this handle 27c or lever 29
The knob portion 29c has a handle shape that facilitates holding of the developing device. Further, the developing sleeve 31 of the developing device 7 is provided with a protective cover 32 so that the toner on the sleeve 31 does not stain the operator when the developing device 7 is taken out from the main body of the machine. The cover 32 is opened and closed in conjunction with the opening and closing of the upper housing.

A mechanism for simultaneously pressing the developing device 7 and opening and closing the cover 32 by opening and closing the upper casing will be described with reference to the embodiment shown in FIG. Further, it is possible to inform the main body of the presence or absence of the developing device 7 and further the color in the developing device by the detecting means 33. In the embodiment of FIG. 7, in conjunction with the opening and closing of the machine upper casing,
An example is also shown in which the developing device 7 is brought into and out of contact with the photoconductor 3 and the sleeve cover 32 is automatically opened and closed.
In the figure, the sleeve cover 32 is rotatably supported around a hinge 34, and an outer peripheral portion thereof forms a partial gear 32a. This gear 32a is a hinge 35 provided on the developing device 7.
It engages with a gear 36 that is rotatably supported about. This gear 36 is a hinge provided on the lower housing of the machine.
It is arranged at a position where it engages with a partial gear 38a of a lever 38 which is swingably supported around 37. A force in the direction of arrow A is applied to the lever 38 by an urging means 39 such as a spring, and when the lever 38 is not engaged with the gear 35 of the developing device 7, the lever 38 stops at the position where it abuts against the stopper 40.

This FIG. 7 shows a state in which the upper casing of the machine is closed. In the state in which the upper portion is opened, the gear 36 is disengaged from the gear-shaped portion 38a of the lever 38, and the cover 32 is moved by the spring 41 to form an arrow. It rotates in the opposite direction to B and hits the stopper 43 and stops with the sleeve covered. Further, the developing device 7 is rotated in the direction opposite to the arrow C away from the photoconductor 3 by the urging means 45 such as a spring provided between the developing device 7 and the part 44 of the upper casing of the machine. In this way, the developing device 7 is separated from the photoconductor 3 and the sleeve cover 32 is positioned so as to cover the sleeve when the upper housing is opened, which facilitates the attachment and detachment of the developing device.

The state in which the upper casing of the machine is closed is the reverse operation to the above. When the gear 36 engages with the gear 38a of the lever 38, a force greater than the force of the spring 45 is applied from the lever 38, and the developing device 7 is exposed. Close to the body 3. At the same time, the gear 36 is a gear
When driven by 38a, it rotates in the direction of arrow D, and further rotates the sleeve cover 32 in the direction of arrow B. In this way, the sleeve cover 32 of the developing device 7 is removed from the sleeve when the upper and lower casings of the machine are closed, and the developing device is ready for development. Reference numeral 42 in FIG. 7 denotes a member that engages with the spring 41 provided in the developing device 7. As described above, it is easy to automatically perform separation / contact of the developing device 7 with respect to the photoconductor 3 and automatic opening / closing of the sleeve cover in conjunction with opening / closing of the upper casing of the machine.

In addition to the photoconductor, the use of an insulator may be applied as the image carrier. Further, the developing system of the developing device and the color of the toner are not limited to those in this embodiment.

〔The invention's effect〕

As described above, in the image forming apparatus having the two developing devices of the present invention, when the two developing devices are arranged so as to have a vertical relationship, the lower one is made detachable and replaceable. As a result, it is possible to completely prevent color mixing due to toner scattering during replacement falling to the developing device below.

Further, in an image forming apparatus such as a split-type copier or a recording device having upper and lower casings, the developing device belongs to a casing that is opened upward, and in the opened state, the developing device is disposed below the upper and lower developing devices. The developed developing device is located at a position where the user can directly touch the hand, and it is easy to remove the lower developing device from the opened upper housing. In this way, arranging the replaceable developing device in the split rotary type device below facilitates the replacement. In addition, since the second developing device is automatically moved toward and away from the latent image carrier and the sleeve cover is automatically opened and closed in conjunction with the opening and closing of the upper housing, the operation burden on the operator is increased. Is reduced. Also, the above 2
Since one operation is performed in common with the pressing member with the gear unit provided in the lower housing, the configuration of the device is simplified.

[Brief description of drawings]

FIG. 1 is a partial side view showing an embodiment of an example of taking out the developing device of the present invention, FIGS. 2 and 3 are sectional views of a copying machine to which the present invention is applied, and FIG. 4 is an example of the operation of the developing device. Showing a partial side view,
FIG. 5 is a sectional view of a copying machine to which the present invention is applied, FIG. 6 is a partial side view showing a part of a pressing mechanism, and FIG. 7 is a side view showing an opening / closing mechanism of a developing sleeve cover. In the figure, 3 is a photoreceptor which is an image bearing member, and 6 and 7 are developing devices.

Claims (1)

[Claims] 1. An image forming apparatus capable of dividing a first unit and a second unit with a conveyance path as a boundary, wherein the first unit is an image carrier, a black developing device assembled to the first unit, and a black developing unit. A color developing device provided on the transport path side of the developing device, the black developing device is configured to replenish the developer from outside the device through the first unit, and the color developing device has a mechanism for replenishing the device with the developer. An image forming apparatus characterized in that it is exchanged without it.