JP2573047B2 - Color image forming equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image forming apparatus using an electrophotographic method, in which toner can be easily supplied to a plurality of developing units.

[Background of the Invention]

2. Description of the Related Art A color image forming apparatus based on an electrophotographic method is roughly classified into two types, that is, a so-called image superposition type and a transfer type, as a method of forming a color image. In each type, at least three types of yellow, magenta, and cyan are used. An image is developed by three developing devices each having a developer, and a color image is formed by combining the developed images.

Each of these developing units is placed in a cartridge together with the image forming body in a state of being normally stacked so as to require high accuracy of image superposition and to facilitate inspection and maintenance. The structure to take off and load is adopted.

Therefore, the replenishing toner to be supplied to each developing unit must also be held and stored in the cartridge. For this reason, the housing of each developing unit is extended rearward, and the portion is formed as a toner box for storing the replenishing toner. The toner is replenished from the toner box to the developing device side in accordance with the consumption of toner accompanying the above.

[Problems to be solved by the invention]

However, the toner box attached to the developing unit is
It is difficult to increase the size of the cartridge from the capacity of the cartridge, so that it is difficult to increase the amount of toner that can be stored.

Therefore, when a large number of color copies are continuously made, the toner must be frequently supplied to the toner box, and there is a problem that the operation is not easy due to the structure of the cartridge.

The present invention solves this problem, and as a result, provides a color image forming apparatus capable of replenishing the toner box of each developing unit with a predetermined amount of toner by a very simple operation simply by pulling out the cartridge from the apparatus main body. It is intended.

[Means for solving the problem]

The object is to allow a process cartridge comprising a rotatable image forming body and a plurality of developing units having different color toners to be drawn out in the direction of the rotation axis of the image forming body, and the plurality of developing units are agitated to stir the developer. Image in which an image forming unit and a toner box having a supply member for supplying toner to the stirring unit are integrally formed in a horizontal direction, and a plurality of image forming units are vertically arranged in parallel at side edges of the image forming body. In the forming apparatus, a cam unit and a regulating unit allow each developing unit to be retracted from the image forming body by a specific distance so that a toner supply port above the toner box is exposed when the process cartridge is pulled out, In the retracted state, the color image forming apparatus is characterized in that toner can be supplied from the upper surface of the developing device.

〔Example〕

As one embodiment of the present invention, Japanese Patent Application Laid-open No.
A color image forming apparatus using a multicolor image forming method based on a toner superposition developing method disclosed in Japanese Patent Publication No. 850 and the like will be described.

FIG. 1 shows a main configuration of a color image forming apparatus, where A is an image reading system, B a laser writing system,
C is an image forming unit, and D is a paper feeding unit, and a color image is formed by the following process.

In the reading system A, reference numeral 11 denotes a document table, and a document stored in the document table 11 is a carriage 12 which slides horizontally and aromaticly.
It is illuminated by a halogen lamp 13 attached to the. Mirrors 16 and 17 are attached to the movable mirror unit 15 and slide in the horizontal direction in the same manner, and a light image of the document is led out to the image reading unit 22 in combination with the mirror 14 attached to the carriage 12. I do.

The carriage 12 and the movable mirror unit 15 are driven via wires (both not shown) connected to a stepping motor, and are slid in the same direction at V and 1/2 V, respectively.

When the image reading unit 22 reads a document placed on the platen glass 11, color separation is performed via the filter 9. The filter 9 includes, for example, a filter R, a filter G, a filter B, and a filter ND. When reading a document, the document is read after passing through any one of the filter R, the filter G, the filter B, and the filter ND. Like that.
Which of the filter R, the filter G, the filter B, and the filter ND is selected is realized by moving the filter 9 in a direction perpendicular to the sheet of FIG. 1 by a filter selecting device. Filter R, filter G, and filter B are respectively red light, green light,
A filter that allows blue light to pass through,
Is a neutral filter, which allows all three colors of light to pass.

The image signal output from the image reading unit 22 is subjected to signal processing in a signal processing unit. In the signal processing section,
A color signal that is color-separated according to the color of the toner is output and input to the laser writing system unit B that is an exposure unit.

In the laser writing unit B, a laser beam generated by a semiconductor laser (not shown)
Is rotated and scanned by a polygon mirror 32 rotated by a mirror, the optical path of which is bent by a mirror 34 via an fθ lens 33, and scans the peripheral surface of the image forming body 30 to which an electric charge is applied in advance by a charger 35 as charging means. .

On the other hand, when scanning is started, the beam is detected by the index sensor, modulation of the beam by the first color signal is started, and the modulated beam scans the peripheral surface of the image forming body 30. Therefore, a latent image corresponding to the first color is formed on the peripheral surface of the image forming body 30 by the main scanning by the laser beam and the sub-scanning by the rotation of the image forming body 30. This latent image is developed by the developing device 36 loaded with yellow (Y) toner (visual medium) of the developing means, and a toner image is formed on the drum surface. The obtained toner image passes under the cleaning device 39 as a cleaning means separated from the peripheral surface of the image forming body 30 while being held on the drum surface, and enters the next copy cycle.

That is, the image forming body 30 is charged again by the charger 35, and then the second color signal output from the signal processing unit is input to the writing unit B, and the first color signal
The writing is performed on the drum surface in the same manner as in the case of the color signal, and a latent image is formed. The latent image is developed by a developing device 37 loaded with magenta (M) toner as the second color.

The magenta (M) toner image is formed in the presence of the previously formed yellow (Y) toner image.

Reference numeral 38 denotes a developing device having cyan (C) toner, which forms a cyan (C) toner image on the drum surface based on an image signal generated by a signal processing unit. These developing units 36, 37,
AC and DC biases are applied to the sleeve 38, jumping development is performed by a two-component developer as a developing means, and development is performed without contact with the grounded image forming body 30. .

The color image thus formed on the peripheral surface of the image forming body 30 is a recording medium sent from the paper feeding unit D by the paper feeding belt 41 and the feeding roller 42 at the transfer pole 40 provided as a transfer unit. Transferred to recording paper. The recording paper onto which the toner image has been transferred is separated from the drum surface by the separation pole 43, and is conveyed to the fixing device 45 via the transport belt 44 to fix the image.

On the other hand, with respect to the image forming body 30 from which the recording paper is separated from the drum peripheral surface, the blade 39A of the cleaning device 39 contacts and removes the remaining toner. The process for forming a new color image is started.

Next, the layout of each of the above-mentioned main components will be described. As shown in FIG. 1, the image reading system A is mounted on an upper portion of a main body 2 described later housed in an independent dedicated housing 1 and attached. ing.

The main body 2 incorporates an image recording system including the writing system B, the image forming unit C, the paper feeding unit D, and the like. The image reading system A is connected to a flexible cable group connected to the housing 1. Color signal from the camera.

In the main body 2, the image forming body 30 is located substantially at the center, and the developing units 36, 37, and 38 are arranged in a horizontal state facing the right peripheral surface thereof, while the charging unit is disposed on the left peripheral surface. The container 35 and the cleaning device 39 are arranged.

The main body 2 has a so-called clamshell structure that can be divided into two parts, and the image forming body 30, the developing units 36, 37, and 38, and the cleaning device 39 are all provided in the main body 2.
Without being directly attached to a pair of front and rear substrates fixed to the main body, it is mounted on the multicolor process unit 3A which is removably inserted into and removed from the main body 2. Has become.

As shown in FIG. 3, the multi-color process unit 3A is composed of a cartridge capable of storing the image forming body 30, the developing units 36, 37, 38, the cleaning device 39, and the like. The guide member 4 allows easy removal and attachment.

That is, rails 4A are fixed to the left and right side edges of the multicolor process unit 3A, and guide rails 4B are fixed at positions of the main body 2 corresponding to the rails 4A, respectively, as shown in FIG. By engaging with 4B, a pair capable of sliding and being detached is formed.

A pair of left and right reference pins P are attached to the upper surface of the cartridge, and the cartridge is suspended by engaging a hanging portion Q provided inside the main body 2 with a hole provided in the hanging portion Q. In this state, the relative positions of the image forming body 30 attached to the multicolor process unit 3A, the developing units 36, 37, 38 and the main body 2 of the cleaning device 39 are set.

Accordingly, when the handle 5 on the front of the panel is pulled, the multicolor process unit 3A is guided by the rail 4B and is pulled out to the stop position in front of the main body 2, and when the handle 5 is pushed in, the reference pin P is set. The multicolor process unit 3A is again suspended and is stored in the main body 2 by engaging with the hole of the hanging portion Q.

In this manner, the multi-color process unit 3A is held in a suspended state with respect to the substrate of the main body 2, so that the image forming body 3
0, Even if vibrations and shocks transmitted to each developing device or cleaning device are greatly reduced and absorbed, and even if slightly transmitted to the scale, each device receives uniform vibrations and shocks. And the image forming body are held in a relatively uniform state, so that there is no major problem in image formation.

In particular, by holding the image forming body 30 and the cleaning device 39 integrally in the multi-color process unit 3A, the blade 39A which must be performed in the cleaning device for superimposed development image formation, for the treatment of toner remaining on the cleaning blade When the second cleaning roller 39B or the like comes into contact with or separates from the substrate or when the second cleaning roller 39B is pressed, a delicate manner of pressing, a pressing state, a load condition, and other adverse effects such as vibrations and shocks are greatly reduced or absorbed.

When the image forming body 30 adopts the image forming process based on the superposition type as described above, the peripheral surface length of the maximum recording body B4 size or A3 size plus a margin for one page is added. It is necessary and its outer diameter dimension is at least 125mmφ or 145mm
It requires a size of about φ, and it is 75 ~ for transfer paper size A4 size equivalent
It requires the size of a photoreceptor drum of 105 mmφ. In this embodiment, which requires a larger diameter when the reading system further moves forward, a drum type image forming body of 110 mmφ is used.

On the other hand, as for the developing units 36, 37 and 38, as will be described later in detail, the outer diameter of the developing sleeve is reduced to 14 mmφ without deteriorating the image performance, and the thickness (height) of each developing unit is reduced to 30 mm.
mm or less, so that three or four developing units, that is, developing units 36, 37, and 38 in the present embodiment, are provided with the outer diameter of the image forming body 30 for color. Can be further integrated and arranged in a horizontal state in a space corresponding to the range.

Therefore, the multi-color process unit 3A affects the layout of the members directly attached to and fixed to the main body 2, particularly the members of the transport system including the upper laser writing diameter B, the lower transfer pole 40, and the separation pole 43. Even if the upper and lower heights are limited to a minimum size enough to cover the image forming body 30, the cleaning device 39 is, of course, equipped with all of the plurality of developing units 36, 37, and 38. It is possible to store the recording paper in a substantially straight line, so that the paper path can be made almost straight. ing.

Each of the developing units 36, 37, and 38 has the following configuration.

Since the developing devices 36, 37, and 38 in this embodiment all use the same functioning developing device, the developing device used in the present invention will be described with reference to the sectional view of the developing device 37 shown in FIG.

In the figure, 30 is an image forming body, 3702 is a housing, 3703
Is a developing sleeve, 3704 is a magnet roller, 3705 is a rigid and magnetic rod (cylindrical bar) that regulates the amount of developer, 3715 is a holder for holding the cylindrical bar 3705, 3706 is a cylindrical bar 3705 and the developing sleeve 3703 The cylindrical rod 3705 is pressed against the developing sleeve 3703 with a constant load in a state where the developer is not interposed therebetween. 3707 and 3708 are first and second stirring members, 3709 is a supply roller, 3710 is a scraper, and 3711 is a stirring partition plate.

Reference numeral 3721 denotes a toner box which is incorporated in the housing 3702 and is integrated with the developing device.
A sponge roller for conveying the toner in the 3721 to the developing device side. The toner in the toner box 3721 is supplied to the developer stirring section by the rotating toner supply rotor 3722 and the sponge roller 3723.

The toner replenished to the stirring section is rotated in the direction indicated by the arrow.
The upper developer D sufficiently stirred and mixed with the carrier is sent to the developing sleeve 3703 via the supply roller 3709 by the stirring member 3707 and the second stirring member 3708 rotating so as to overlap with each other in the opposite direction.

The first stirring member 3707 and the second stirring member 3708 are screw-shaped members having left-handed helical angles rotating in mutually opposite arrow directions, and are conveyed to the back side by the thrust of the second stirring member 3708. The toner and the carrier thus transported sequentially move over the stirring partition plate 3711 whose upper edge is inclined downward in the depth direction of the drawing, move to the first stirring member 3707 side, and are conveyed to the front side of the drawing by the thrust, and the toner between them The developer D is triboelectrically charged by the mixing action of the developer and the carrier, and is adhered in a layer on the peripheral surface of the developing sleeve 3703 by the supply roller 3709 which is spongy and rotates in the direction indicated by the arrow.

In the present embodiment, a fixed magnet roller 3704 and a developing sleeve 3703 rotating outside in a direction indicated by an arrow (clockwise) are shown.
This thin layer of developer adhered on the peripheral surface
At 3712, the latent image on the image forming body 30 rotating in the direction of the arrow is developed in a non-contact manner at intervals to form a toner image.

During this non-contact development, a developing bias containing an AC component is applied to the developing sleeve 3703 from a power source (not shown),
As a result, only the toner in the developer is selectively transferred to and adhered to the surface of the latent image on the developing sleeve 3703.

The developer having consumed the toner component has a high carrier ratio, is conveyed by the developing sleeve 3703, is separated and collected by the scraper 3710, and is mixed again with the developer having a high toner ratio.

The housing 3702 and the toner box 3721 of the developing device 37 are provided with the following auxiliary devices.

That is, the housing 3702 has a pair of front and rear moving rollers 3750 on the bottom surface thereof, and is mounted on a later-described developing device support base 3760 provided inside the cartridge when being incorporated in the multicolor process unit 3A. And can be moved freely in the horizontal direction.

In the housing, a projection 3740 is integrally formed at the front and rear of the right side surface, and regulating pins 3740A are planted on the respective inner side surfaces so as to face each other.

On the other hand, the toner box 3721 has a toner supply port 3721A opened at an upper part thereof, and the toner supply port 3721A is hinged.
It is opened and closed by a shielding plate 3730 attached via 3730A.

When the developing device 37 is housed in the cartridge of the multi-color process unit 3A, as shown in FIG. 3, a tension spring 3761 stretched between the housing 3702 and the cartridge.
Urged in the direction of the image forming body 30 by the action of the developing unit 3760 to move to the left on the developing device support base 3760 so that the abutting roller 3703A provided coaxially with the developing sleeve 3703 is brought into contact with the surface of the image forming body 30. The interval between the development areas 3712 is set accurately.

The cartridge is provided with a rotating shaft 3762 that is inserted into the front and rear walls.
A pair of cam plates 3763 forming 63A are fixed with the same phase in the rotation direction.

The groove cam 3763A engages with the restriction pin 3740A of the projection 3740, and its counterclockwise end is the restriction pin 3740A.
The groove width is slightly widened so that the 3740A can float.

In FIG. 3, the rotating shaft 3762, ie, the cam plate
3763 is rotated counterclockwise and the groove cam 3763A
This shows a state in which the developing device 37 moves rightward via the restriction pin 3740A due to a change in the radius of curvature formed by the control device 3 and is retracted from the surface of the image forming body 30.

On the other hand, as for the developing devices 36 and 38 located above and below the developing device 37, the cam plates 3663 and 3863 are in the clockwise rotated positions, so that none of the developing devices is subject to the position regulation by the respective cam plates, so It is urged and moved in the direction of the forming body 30 to set a developing area.

As a result, only the toner box 3721 of the developing device 37 protrudes rightward, so that the shielding plate 3730 can be opened, and toner can be supplied.

FIG. 4 shows a state in which toner is supplied to the developing device 37. The rotation of the cam plate 3763 is performed by operating an operation lever 3764 integral with the rotation shaft 3762 provided on the front surface of the cartridge.

Similarly, toner supply to the developing units 36 and 38 is performed individually via the operating lever 3664 or 3864.

As described above, in the color image forming apparatus of the present invention, the toner of the designated color is replenished to each developing device at any time by a very simple operation while each developing device is housed in the cartridge of the process unit. Therefore, the capacity of the toner box integrated with each developing device can be reduced accordingly, so that the process unit and thus the apparatus itself can be made compact.

〔The invention's effect〕

The present invention provides a structure in which a main image forming member is housed in a single cartridge and is detachable from a main body of the apparatus as a process unit. Development of a very simple toner replenishment method for each of the developing units housed in the printer makes it possible to make the process unit compact, and as a result, a small and useful color image excellent in handleability and maintenance. A forming apparatus has been provided.

[Brief description of the drawings]

1 (a) and 1 (b) are cross-sectional views of a color image forming apparatus of the present invention, FIG. 2 is a cross-sectional view of a developing device used in the apparatus, and FIG. 3 is a multicolor process unit of the apparatus. FIG. 4 is a perspective view of the unit. 3A: Multicolor process unit 4A: Rail, 4B: Guide rail 5: Handle, 30: Image forming body 36, 37, 38: Developing device, 3721: Toner box 3721A: Toner supply port, 3730 ... Shielding plate 3740A ... Regulatory pin, 3760 ... Developer support base 3761 ... Tension spring, 3763 ... Cam plate 3764 ... Operation lever, P ... Reference pin Q ... Hanging part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shizuo Morita 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation Inspector Masayuki Mori

Claims (1)

(57) [Claims] 1. A process cartridge comprising a rotatable image forming body and a plurality of developing units having different color toners can be pulled out in the direction of the rotation axis of the image forming body, and the plurality of developing units stir the developer. A stirrer and a toner box having a supply member for supplying toner to the stirrer are integrally formed in a horizontal direction, and a plurality of stirrers are vertically arranged in parallel at a side edge of the image forming body. In the color image forming apparatus, each developing device can be retracted by a specific distance from the image forming body by a cam unit and a regulating unit so that a toner supply port above the toner box is exposed when the process cartridge is pulled out. A color image forming apparatus wherein toner can be supplied from the upper surface of the developing device in the retracted state.