JP3098656B2 - Developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrophotographic method or the like, and more particularly to a developing apparatus for a multicolor image forming apparatus such as a full-color image.

[0002]

2. Description of the Related Art FIGS. 6 to 11 show a conventional multicolor image forming apparatus for obtaining a multicolor image using an electrophotographic system.

[0006] As shown in FIG. 6, the image forming apparatus has an image carrier 1 at a substantially central portion. An image is exposed on the image carrier 1 by an optical unit 107 so that latent images of respective colors are sequentially formed. It is formed. Each time a latent image of each color is formed, the image carrier 1
Are developed in order by the developing cartridges D of the respective colors, that is, the yellow developing cartridge Dy, the magenta developing cartridge Dm, the cyan developing cartridge Dc, and the black developing cartridge Db disposed around the image carrier 1.
A toner image of each color is sequentially formed thereon.

A transfer drum 103 is provided on the side of the image carrier 1 opposite to the developing cartridge D, and a sheet 102 is fed from the sheet feeding unit 101 to the transfer drum 103. Paper 102
, The tip of the gripper 103 on the outer periphery of the transfer drum 103
The transfer drum 103 is conveyed while being held on its outer periphery by the rotation of the transfer drum 103. The toner images of the respective colors formed on the image carrier 1 are sequentially superimposed and transferred onto a sheet 102 held on the outer periphery of the transfer drum 103 in an image transfer section facing the transfer drum 103, and are transferred to the sheet 10.
Thus, a multicolor image composed of four color toner images on 2 is obtained.

[0005] Paper 102 onto which four color toner images have been transferred
Then, the toner image is separated from the transfer drum 103 and transported to the fixing unit 104, where the toner image is fixed to fix the toner mixture of each color and the paper 102 to form a full-color permanent image. The paper 105 is discharged onto a paper discharge tray 106 via the paper tray 105.

The developing cartridges D of the respective colors are held by a holding member (rotary unit) 108 of the developing cartridge switching means, and are rotated to select a developing cartridge. The rotary unit 108
It has a four-leaf clover shape, and is provided with a storage hole consisting of a substantially semicircular cutout at four locations along the circumferential direction. Each developing cartridge D is stored in the storage hole in the thrust direction. Will be held.

As shown in FIG. 10, each developing cartridge D includes a developing device 12 and a cylindrical shell 13 which covers the developing device 12 and accommodates the developing device 12 in a rotatable (rotatable) manner. At one end of the developing cartridge D, the rotation support shaft 14 of the developing device 12 passes through the shell 13. The developing device 12 is roughly divided into a developer (toner) storage section 19 and a development section 20 adjacent thereto. The toner storage section 19 has a stirring / transporting member 18 for stirring toner and transporting the toner to the development section 20. The developing unit 20 includes a developer carrier 15, a supply / peeling member 17 that supplies toner to the developer carrier 15, and peels off undeveloped toner thereon.
Further, a regulating member 16 that regulates the layer thickness of the toner carried on the developer carrying member 15 and imparts electric charge is provided.

A leg (not shown) is provided on both sides of the shell 13, and the leg is connected to the rotary unit 1 shown in FIG.
The shell 13 is held non-rotatably with respect to the rotary unit 108 in the storage hole by abutting on the step portion 108a provided in the storage hole 08. On the surface of the shell 13 opposite to the leg side, when the developing cartridge D is moved to the developing position, the developer carrier 15 of the developing device 12 in the shell 13 is opposed to the image carrier 1. An opening 13b is provided.

As shown in FIG. 7, on one side of the rotary unit 108, a disc-like shape is rotated around the non-rotating center axis 110 of the rotary unit 108 shown in FIG. Drive side plate 7
Gears 9, 10 that constitute a rotation driving mechanism of the developing device 12 are provided inside the driving side plate 7 in correspondence with the respective developing cartridges D. A gear 8 meshing with the gear 10 is fixedly installed non-rotatably, and the gears 8, 9 and 10 constitute a planetary gear mechanism.

Each of the gears 10 has a member 4 that can rotate integrally with the gear 10 and slide on the gear 10.
8 are provided. The rotation support shaft 14 of the developing device 12 protruding from the shell 13 at one end of the developing cartridge D is fitted and held in the hole 48a of the slide member 48. It is transmitted to the developing device 12. As shown in FIG. 8, the other end of the developing cartridge D is held by the hook member 126 on one side of the rotary unit 108 opposite to the above.

In order to move the developing cartridge D to the developing position by the rotary unit 108, the motor 8 is connected via a gear 86 connected to a gear 85 provided on the driving side plate 7.
When the side plate 7 is rotated by the
8 rotates about a central axis 110, whereby the gear 8,
The gear 9 and the gear 10 make a planetary motion, and the slide member 4
8 rotates in the opposite direction, and the developing device 12 fitted with the rotation support shaft 14 is maintained in a predetermined constant posture regardless of the movement of the developing cartridge D.

The developing cartridge D moved to the developing position
Is positioned by pressing against the image carrier 1, but the slide direction of the slide member 48 at one end of the developing cartridge D is matched with the direction of the image carrier 1 so that the developing cartridge is held by the slide member 48. It slides in the state where it was done and is positioned. Hook member 12 holding the other end of developing cartridge D on rotary unit 108
Reference numeral 6 denotes a state where the developing cartridge D is opened at a position facing the image carrier 1 so that the developing cartridge can slide.

The pressurizing operation of the developing cartridge D at the developing position is performed by detecting the rotation of the pressurizing control gear 41 by a sensor 43 via a flag 42 provided on the gear 41, as shown in FIG. By controlling the driving of the gear 41 by the driving source 44, a pressurizing control shaft 110 provided at the center of the rotary unit 108 that rotates integrally with the gear 41.
(Which is also the center axis of the rotary unit). The drive source 44 is composed of a stepping motor. After accelerating to a constant speed, rotating at a constant speed at the constant speed, decelerating and stopping, the pressurizing control shaft 110 is pressurized.
Each is rotated 180 degrees in a non-pressurized state.

At the center of the rotary unit 108,
A pressure control mechanism is provided near both ends of the developing cartridge D. As shown in FIG. 10, each of the pressure control mechanisms includes a semi-cylindrical member 123 fixed to the apparatus main body surrounding the pressure control shaft 110, and slides in the half-cylindrical member 123 in the direction of the developing cartridge D. A pressure member 111 having a rectangular cylindrical shape freely housed therein, a cam 125 fixed to the pressure control shaft 110 and housed in the pressure member 111, for sliding the pressure member 111, and a pressure member 111 Springs attached to the semi-cylindrical member 123 so as to urge the pressing member in the direction of the developing cartridge D,
It consists of four.

When the developing cartridge D is not pressurized,
As shown in FIG.
24, the pressing member 111 is in a retracted state separated from the developing cartridge D.
7, the cam 125 is separated from the pressing member 111, and the pressing member 111 is pushed in the direction of the developing cartridge D by the force of the spring 124, so that the developing cartridge D is pressed by the pressing member 111.

When the pressure is released, the slide member 48 of the rotary unit 108
, The force of the hook member 126 returned by the spring 126a, and the weight of the developing cartridge D,
The rotary unit is returned to its normal position.

[0017]

By the way, in the conventional developing apparatus, as shown in FIG.
0, an antenna member 127 for detecting the remaining amount of developer is provided with a specific gap in parallel with the developer carrier 15, and a difference in electric capacity between the developer carrier 15 and the antenna member 127 causes The amount of the developer is detected, and it is detected that the remaining amount of the developer in the developing cartridge D is reduced.

However, in the detection of the remaining amount of the developer by the antenna member 127 as described above, the electric wiring between the developing cartridge D and the apparatus main body for that purpose becomes long.
There is a problem that the S / N ratio cannot be made large because a sliding contact is required.

The differences in the electrical characteristics of the developer of each color between the developing cartridges D, the developer carrier 15 and the antenna member 1
There is also a problem that the detection accuracy of the remaining amount of the developer is reduced due to the variation of the gap between the 27.

An object of the present invention is to provide a developing cartridge of each color which is detachably mounted on a holding member of a switching mechanism and is moved to a developing position to be switched, such as an antenna member and a sliding contact for detecting the remaining amount of the developer. It is an object of the present invention to provide a developing device capable of detecting the remaining amount of the developer in the developing cartridge of each color without providing the electric parts described above and without causing variation between the developing cartridges of each color.

[0021]

The above object is achieved by a developing apparatus according to the present invention. In summary, the present invention is capable of detachably mounting a plurality of developing cartridges each including a developer carrying member for carrying a developer and a developer accommodating section for accommodating the developer, and moving the attached developing cartridge to a developing position. Switching means for switching, a light emitting means, and a light receiving means, wherein the light emitted from the light emitting means and passing through the developer accommodating portion is received by the light receiving means to detect a developer amount in the developing cartridge. In the developing device, the light emitting unit and the light receiving unit are provided outside the switching unit, and a light guide member that deflects light emitted from the light emitting unit to pass through the developer accommodating portion to reach the light receiving unit is provided. And a switching device provided for each of the plurality of developing cartridges.

According to one embodiment of the present invention, the light guide member is provided along a longitudinal direction of the developing cartridge, or provided along a direction orthogonal to the longitudinal direction of the developing cartridge. Have been.

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

Embodiment 1 FIG. 1 is a front view showing a method for detecting the remaining amount of a developer in a developing cartridge in an embodiment of the developing device of the present invention, and FIG. 2 is a side view thereof.

In this embodiment, as shown in FIGS. 1 and 2, the center of rotation of the rotary unit 108 as a switching means extends from the drive side plate 7 at one end of the unit 108 to the center in the longitudinal direction of the developing cartridge D. An extended light guide member 134 made of acrylic resin is provided corresponding to each developing cartridge D, and one light emitting LED 129 is provided not on the center of rotation of the rotary unit 108 but on the side plate of the apparatus main body on the drive side plate 7 side. Is the feature.

The light guide members 134 for the respective color developing cartridges D are arranged on the rotary unit 108 at intervals of 90 degrees in the circumferential direction, and when the developing cartridge D is positioned at the developing position, the light guide members 134 are provided. 13
4 so as to correspond to the base end 134a of the LED 1
29 are arranged.

The tip 134b of the light guide member 134 is
The opposite side not facing the light receiving member 128 is cut at 45 degrees, and the light emitted from the LED 129 is transmitted to the light guide member 13.
4 is guided from the base end portion 134a to the front end portion 134b, is reflected at the front end portion 134b by 90 degrees, passes through the developing cartridge D, and is received by the light receiving member 128.

Thus, it is possible to detect the remaining amount of toner in the developing cartridge D without providing any electric parts inside the rotary unit 108, thereby improving the assemblability and maintainability of the unit.

In the above embodiment, since the pressure control shaft 110 for pressing and positioning the developing cartridge D is provided at the rotation center of the rotary unit 108, further deformation of the remaining toner amount detection is impossible. However, the pressurizing mechanism for positioning is the center shaft 11 of the rotary unit 108.
When 0 is not used, or when the pressing mechanism of the developing cartridge is not used for positioning, it is possible to detect the remaining amount of toner by using a configuration in which one light guide member is provided at the center of rotation of the rotary unit 108. It is possible.

Although an acrylic resin member is used as the light guide member 134, a glass member or an optical fiber may be used. When an optical fiber is used, a member for changing the optical path is provided at the center of rotation of the rotary unit 108.

Embodiment 2 FIG. 3 is a front view showing a method for detecting the remaining amount of developer in a developing cartridge in another embodiment of the developing device of the present invention. This embodiment is characterized in that the light guide members 134 of the developing cartridges D of the respective colors are provided on the rotary unit 108 in a direction perpendicular to the longitudinal direction of the developing cartridges D, that is, in the radial direction.

Each of the light guide members 134 is arranged at a 90-degree interval in the circumferential direction of the rotary unit 108 and at a position corresponding to between the developing cartridges D. The proximal end 134a of the light guide member 134 is located outside the outer edge of the rotary unit 108,
4b is located at the center of rotation of the unit 108. Similarly, when the developing cartridge D is positioned at the developing position, one LED 129 is arranged so as to correspond to the base end 134a of the light guide member 134.

According to the present embodiment, the remaining amount of toner in the developing cartridge D can be detected without providing any electric components inside the rotary unit 108, and the assembling and maintenance of the unit are improved.

Embodiment 3 In this embodiment, the presence or absence of the mounting of the developing cartridge D on the rotary unit 108 is detected by using the toner remaining amount detecting means.

FIG. 4 is a block diagram at that time, and FIG. 5 is a flowchart.

For example, a revolving flag (not shown) is installed on the rotary unit 108 of FIG. 1, and a revolving position sensor (see FIG. 1) for detecting the rotation (revolving) position of the developing cartridge D around the central axis 110 by the flag on the apparatus body side. Not shown)
Is installed.

Then, the revolution switching motor (motor 87 in FIG. 7) of the developing CRG (developing cartridge D) is rotated by the CPU in FIG. 4, and the rotary unit 108 is driven to revolve the developing cartridge D. When the developing cartridge D is mounted on the rotary unit 108, the light from the light-emitting LED 129 is blocked so that the light-receiving member 128 does not receive the light, as shown in FIG. The toner remaining amount detecting means is operated within a predetermined time, that is, within a time when the developing cartridge is located at the above position.

Thus, the residual detection sensor (light receiving member 12)
8) Whether the developing cartridge is mounted on the rotary unit 108 can be determined from the presence or absence of ON (light reception) in step 8). This is repeated for the other developing cartridges as shown in FIG. It is detected whether or not the developing cartridge is mounted at the position.

[0045]

As described above, according to the present invention, a plurality of developing cartridges each having a developer carrying member for carrying a developer and a developer accommodating portion for accommodating the developer are detachably mounted. A developing unit for switching the developing cartridge to the developing position; a light emitting unit; and a light receiving unit. The light receiving unit receives light emitted from the light emitting unit and passing through the developer accommodating unit. In the developing device that detects the amount, a light guide member that provides the light emitting unit and the light receiving unit outside the switching unit, deflects the light emitted from the light emitting unit, passes through the developer accommodating unit, and reaches the light receiving unit, Since the switching means is provided for each of the plurality of developing cartridges, it is possible to detect the remaining amount of the developer in the developing cartridge without providing electric parts inside the switching means. In addition, the assemblability and maintainability of the apparatus are improved, and it is not necessary to replace the light emitting means and the light guide member every time the developing cartridge is replaced, so that the cost of the developing cartridge can be reduced. This is also advantageous.

[0046]

[Brief description of the drawings]

FIG. 1 is a front view illustrating a method for detecting a remaining amount of a developer in a developing cartridge in one embodiment of a developing device of the present invention.

FIG. 2 is a cross-sectional view showing a detection method.

FIG. 3 is a front view illustrating a method for detecting a remaining amount of a developer in a developing cartridge in another embodiment of the developing device of the present invention.

FIG. 4 is a block diagram showing a method of detecting the mounting of a developing cartridge on a rotary unit using a developer remaining amount detecting means in still another embodiment of the developing device of the present invention.

FIG. 5 is a flowchart showing a developing cartridge mounting detection method.

FIG. 6 is an overall configuration diagram showing a conventional multicolor image forming apparatus.

7 is a front view showing a driving side plate and a developing device automatic control mechanism provided on one side of a rotary unit of a switching unit of the image forming apparatus of FIG. 6;

FIG. 8 is a front view showing a holding portion of the developing cartridge on the other side of the rotary unit.

FIG. 9 is a plan view showing a pressure control mechanism of the developing cartridge.

FIG. 10 is a partially cutaway front view showing a developing cartridge and a pressure member thereof.

11 is a partially cutaway front view showing a state where the developing cartridge is positioned by pressing by the pressing member of FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image carrier 12 Developing device 19 Toner storage part 108 Rotary unit (switching means) 110 Center axis (pressure control axis) 128 Light receiving member (light receiving means) 129 LED (light emitting means) 134 Light guide member D Developing cartridge

Claims (3)

(57) [Claims] 1. A switch for detachably mounting a plurality of developing cartridges each including a developer carrying member for carrying a developer and a developer accommodating portion for accommodating the developer and switching the mounted developing cartridge to a developing position. Means, light emitting means,
A light-receiving means for detecting the amount of developer in the developing cartridge by receiving light emitted from the light-emitting means and passing through the developer accommodating portion by the light-receiving means; Means are provided outside the switching means, and a light guide member for deflecting light emitted from the light emitting means and passing the developer accommodating section to the light receiving means is provided for each of the plurality of developing cartridges. A developing device provided in the switching means. 2. The developing device according to claim 1, wherein said light guide member is provided along a longitudinal direction of said developing cartridge. 3. The developing device according to claim 1, wherein said light guide member is provided along a direction orthogonal to a longitudinal direction of said developing cartridge.