JP2606897B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a laser printer and a copying machine, and more particularly to an image forming apparatus provided with a plurality of developing device storage devices outside a main body.

(Prior Art) The applicant of the present invention has installed a color developing device outside a main body of an image forming apparatus and automatically moves a desired color developing device to a developing operation position inside the main body in order to cope with a need for a wide range of colorization in the image forming apparatus. A plurality of developing device accommodating devices which can be supplied have been proposed (see JP-A-61-256214).

FIG. 3 shows a cross section of a main part of the image forming apparatus 1 having the plural developing device housing device B. The plural developing device housing device B is detachable to the outside of the image forming apparatus main body A, and is inside. It has a storage case 2 that can move up and down. A plurality of storage portions 6, 7, 8 are formed in the storage case 2 by the partition plates 3, 4, 5, and the storage portions 6, 7, 8 store developers of different colors, respectively. Color developing units 9A and 9
B, 9C are stored.

On the other hand, a black developing device 10 containing a black developer and a color developing device 9C selected from the storage section 8 of the storage case 2 are arranged near the photosensitive drum 11 in the image forming apparatus main body A. I have.

A rack 12 is engraved on the upper surface of each color developing device 9A (9B, 9C), and a rack of each color developing device 9A (9B, 9C) is provided near the developing device carry-in port 13 of the image forming apparatus main body A. A transport gear 14 to be meshed with the transport gear 12 is arranged, and the transport gear 14 is driven to rotate by a drive source (not shown).

Further, the color developing device 9C and the black developing device selected as shown in FIG.
A link 16 that is rotated around a shaft 15 is provided between the two ends 10, and one end (lower end) of the link 16 is pinned to the black developing device 10.
The other end (upper end) of the link 16 is engaged with a stopper 18 of the color developing device 9C.

Thus, the transfer of the selected color developing device 9C from the storage case 2 to the main body A and the transfer from the main body A to the storage case 2 are as follows.
This is performed by rotating a transport gear 14 fitted to a rack 12 formed on the upper surface of the color developing device 9C. When the color developing device 9C is pressed against the photosensitive drum 11 as shown by a solid line in FIG. 3, the rack 12 separates from the transport gear 14, and the color developing device 9C as shown by a chain line in FIG. When the pressure on the photosensitive drum 11 is released, the rack 12 is configured to mesh with the transport gear 14.

(Problems to be Solved by the Invention) By the way, as shown by a solid line in FIG. 3, the color developing unit 9C is moved from a state where the photosensitive drum 11 is pressurized to a state where the pressure is released as indicated by a chain line. What is necessary is just to rotate the link 16 in the direction of the arrow around the shaft 15 by a drive source (not shown). Then, the black developing device 10 is pressed against the moving drum 11, and the color developing device 9C
Is formed on the upper surface of the photosensitive drum 11 away from the photosensitive drum 11
The transmission gear 14 acts as a load, and a large driving force is required to rotate the link 16, and if this driving force is insufficient, the black developing device 10
There is a problem that the pressure is not sufficiently increased to 11.

Therefore, it is conceivable that the transfer gear 14 is normally kept free by inserting a clutch or the like at the shaft end of the transfer gear 14, but in this case, although the color developing device 9C returns to the position where the transfer gear 14 is engaged, When returning, the rack 12 of the color developing device 9C and the transport gear 14 come into contact with each other, and a state in which the two are not reliably engaged occurs. When the color developing device 9C is moved to the storage case 2 side in such a state,
In the meshing between the rack 12 and the conveying gear 14 between the front and the back of the color developing device 9C, a shift of one or two teeth may occur. As a result, the color developing device 9C is skewed and caught halfway. The problem arises.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus capable of always and smoothly moving a developing device to a plurality of developing device storage devices. It is in.

(Means for Solving the Problems) An image forming apparatus according to the present invention is a multi-developing device accommodating device having a plurality of accommodating portions accommodating developing devices having a predetermined color developing function, which are attachable to an image forming apparatus main body. A moving mechanism for moving the developing device between any one of the accommodating portions of the plurality of developing device housing devices and the image forming apparatus main body; and a developing device moved into the image forming apparatus main body by the moving mechanism. In the pressurized state of the developing device by the pressing mechanism, the engagement between the moving mechanism and the developing device is released, and the developing device shifts from the pressurized state to the released state. The driving of the moving mechanism is started before the developing device is engaged with the moving mechanism.

(Operation) According to the present invention, when the developing device shifts from the pressurized state to the release state, the driving of the moving mechanism is started before the developing device is engaged with the moving mechanism. Engagement with the mechanism is always performed reliably, and the movement of the developing device toward the plurality of developing device storage devices is always performed reliably and smoothly.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

1 and 2 are cross-sectional views of a main part of an image forming apparatus according to the present invention. FIG. 1 is a view when a color developing device is in a pressurized state, and FIG. FIG. In FIGS. 1 and 2, the same elements as those shown in FIG. 3 are denoted by the same reference numerals, and the description thereof will be omitted.

In the present embodiment, a channel-shaped holding member 19 is attached to a surface of the plural developing device storage device B facing the device main body A, and a developing device detection sensor 20 is attached to the holding member 19. . Further, an intermediate portion of a developing device detecting lever 22 is provided on a bracket 21 attached to a lower portion of the holding member 19 so as to be rotatable about a shaft 23. As shown in FIG. 1, when the color developing device 9C is in a pressurized state, the illustrated posture is maintained.

Thus, as shown in FIG. 1, the color developing unit 9C is a photosensitive drum.
When the black developing device 10 is pressed away from the photosensitive drum 11 and the latent image formed on the photosensitive drum 11 is color-developed by the color developing device 9C, a color copy is obtained. Rack 12 formed on the upper surface of color developing unit 9C
Are not engaged with the transport gear 14 as shown.

When a command that the above-mentioned color copying is completed is issued, the link 16 is rotated about the shaft 15 in the direction of arrow a in FIG. The color developing device 9C is moved in the direction of arrow c in FIG. 1 to move in the direction of arrow c in FIG. 1 and pressed against the photosensitive drum 11 as shown in FIG.
In this state, the developing device is moved away from the developing device 11 and can be developed by the black developing device 10. At the same time (i.e., at the same time that the color copy end command is issued), the transport gear 14 is driven in the direction of the arrow d in FIG. 1, and the transport gear 14 is disengaged from the rack 12 of the color developing device 9C. Mesh surely. As described above, when the color developing device 9C moves to a position where it engages with the transport gear 14, the second
As shown in the figure, since the color developing device 9C pushes up the developing device detecting lever 22 and rotates it in the direction of arrow e about the shaft 23, the developing device detecting sensor 20 rotates the developing device detecting lever 22. And a signal for stopping the rotation of the transport gear 14 is issued, whereby the rotation of the transport gear 14 is stopped,
At this time, the transport gear 14 and the rack 12 of the color developing device 9C are surely meshed with each other. As a result, the movement of the color developing device 9C to the developing device storage device B side is always performed reliably and smoothly. Become.

(Effects of the Invention) As is apparent from the above description, according to the present invention, in an image forming apparatus having a plurality of developing device storage devices, when the developing device shifts from the pressurized state to the released state, the developing device engages with the moving mechanism. Before starting the driving of the moving mechanism,
Always move the developing device to the multiple developing device storage device side,
In addition, the effect that the operation can be performed smoothly can be obtained.

[Brief description of the drawings]

1 and 2 are longitudinal sectional views of a main part of an image forming apparatus according to the present invention, and FIG. 3 is a longitudinal sectional view of a conventional image forming apparatus. 1. Image forming apparatus, 6, 7, 8 ... Storage section, 9A, 9B, 9C ...
Color developing device, 12 rack, 14 transport gear, 20 developing device detection sensor, 22 developing device detection lever, A ... image forming apparatus main body, B ... plural developing device storage device.

Claims (1)

(57) [Claims] A plurality of developing unit storage devices each having a plurality of storage units that can be mounted on the image forming apparatus main body and have a predetermined color developing function, and one of the storage units of the plurality of developing unit storage devices. A moving mechanism for moving the developing device between the main body of the image forming apparatus and a pressing mechanism for pressing the developing device moved into the main body of the image forming apparatus toward the image carrier by the moving mechanism; When the developing device is pressurized by the mechanism, the moving mechanism and the developing device are disengaged from each other, and when the developing device shifts from the pressurized state to the released state, the moving mechanism is moved before the developing device is engaged with the moving mechanism. An image forming apparatus, which starts driving of the image forming apparatus.