JPH04184360A - Image forming device - Google Patents

Abstract

PURPOSE:To set each detecting means to a position very close to a photosensitive body by retracting each detecting means from its detection position when a process cartridge is taken out of a device main body. CONSTITUTION:The detecting means S such as a charge electrometer and a density sensor are attached to the lower face of the connection part 103A of a turning lever 103. Their detecting parts an opposed to an opening in the top of the process cartridge 30. On the other hand on the inside of an upper lid 20, a compression spring 106 firmly is in pressurized-contact with the connection part 103A, and the lever 103 is made to abut on a stopper 104 against the energization of a torsion spring 102. Thus, the detecting means S are inserted in the cartridge 30 to be set in a first position where detection is carried out. When the upper lid 20 is opened and the spring 106 is retracted upwards, the lever 103 is released from the pressure, turns by means of the energization of the torsion spring, and is abutted on a pin 105. Consequently, the detecting means S move to the upper part of the cartridge 30 to retract from the first position, so that they are held in a second position. Thus, the device is ready for maintenance work and jam disposal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic image forming apparatus that forms an image on a transfer material, such as a copying machine or a printer.

[Background of the invention]

In image forming devices such as monochrome analog copying machines using electrophotography and copying machines and printers using semiconductor laser and LED scanning systems, various photoreceptors, developer carriers, cleaning members, and developer toners that have a useful life are used. A part of the image forming means is made into a cartridge for replenishment and replacement when it wears out, and the main parts of the image forming means are taken out of the device as a whole for maintenance or replacement. Proposed. Furthermore, various configurations have been proposed in which the conveyance path of the transfer material on which an image is formed by the image forming means is opened to make it easier to take out the transfer material when clearing a jam.

A typical configuration of these is as disclosed in Japanese Patent Publication No. 58-54392, in which the photoreceptor drum, developer, cleaner, etc. are integrally attached to a support member, and the process cartridge is mounted horizontally from the main body of the apparatus as a single process cartridge. An image forming apparatus that can be pulled out has been proposed.

[Problem that the invention seeks to solve]

In addition, when the photoreceptor of the image forming apparatus is provided with various detection means such as a charging electrometer, a toner image reflection density sensor, or a 7-point sensor for detecting the reference position of the photoreceptor, these means are attached to the photoreceptor. Since they are located in close proximity to each other, they are necessarily built into the process cartridge.

However, since each of the above-mentioned detection means is electrically connected to the control section of the main body of the device, incorporating it into a removable process cartridge would complicate the structure of the mechanism and circuitry, resulting in the formation of images. This is also undesirable because it increases the manufacturing cost of the device.

The present invention solves this problem and improves it, thereby providing an image forming apparatus in which each of the above-mentioned detection means installed on the apparatus main body side can be set in a position extremely close to the photoreceptor in the process cartridge. This is the purpose.

[Means for Solving the Problems] The above object is such that when a process cartridge including at least an image bearing member is attached to and detached from the main body of an image forming apparatus, a detection means provided opposite to the process cartridge performs detection. This is achieved by an image forming apparatus characterized in that it moves from a first position to a second position.

〔Example〕

An embodiment of the color image forming apparatus of the present invention is shown in FIGS. 1 to 5.

FIG. 1 shows a first embodiment of the present invention, in which ``■'' is a flexible photoreceptor belt serving as a belt-shaped image carrier, and the photoreceptor belt 1 is installed between rotating rollers 2 and 3. and is conveyed clockwise by the rotation roller 2.

Reference numeral 4 denotes a support member or guide member fixed to the main body of the apparatus so as to be inscribed in the photoreceptor belt 1, and the photoreceptor belt 1 is brought into a tensioned state by the outward biasing action of the rotary roller 3. The inner peripheral surface of the guide member 4
Let it rub.

Therefore, the photoreceptors on the outer circumferential surface of the photoreceptor belt 1 are always maintained at a constant position relative to the surface of the guide member 4 even during conveyance, making it possible to form a stable image forming surface.

Reference numeral 6 denotes a Suflotron charger as a charging means, 7 a laser writing system unit as an image exposure means, and 8 to 11 a plurality of developing means, that is, developing devices each containing a developer of a specific color. The means is disposed facing the outer peripheral surface of the photoreceptor belt l with the guide member 4 on the back side.

The laser writing system unit 7 is housed in a holding casing 70 having a slit-shaped exposure opening 70A on its upper surface, and is incorporated into the main body of the apparatus.

In addition to the optical system shown in the drawings, the laser writing system unit 7 may also include an optical system that integrates a light emitting section and a convergent light transmission body.

The respective developing devices 8,9,10,11 are for example yellow.

It accommodates magenta, cyan, and black developers, and is equipped with developing sleeves that maintain a predetermined gap from the photoreceptor bell (1), and develops the latent image on the photoreceptor bell (1) by a non-contact development method. It has the function of converting Unlike contact development, this non-contact development has the advantage of not interfering with the movement of the photoreceptor belt.

12 is a transfer device; 12A is a static elimination bar; 13 is a cleaning device; a blade 13A and a toner conveying roller 13B of the cleaning device 13 are connected to a photoconductor bell l- during image formation;
The photoreceptor belt 1 is kept at a position apart from the surface of the photoreceptor belt 1, and is pressed against the surface of the photoreceptor belt 1 as shown in the figure only during cleaning after image transfer.

The process of forming a color image by the color image forming apparatus is performed as follows.

First, the formation of a multicolor image according to this embodiment is performed according to the following image forming system. That is, data obtained by a color image data input section in which an image sensor scans an original image is subjected to arithmetic processing in an image data processing section to create image data, which is then stored in an image memory. The image memory is then taken out during recording and input to a recording section, for example, the color image forming apparatus shown in the embodiment of FIG.

That is, when a color signal output from an image reading device separate from the printer is input to the laser writing system unit 7, the laser writing system unit 7 outputs a laser beam generated by a semiconductor laser (not shown). is the driver −
It is rotated and scanned by a polygon mirror 7B rotated by a polygon mirror 7A, and passes through an fθ lens 7C to mirrors 7D and 7E.
, 7F, the optical path is bent, and the light is projected onto the circumferential surface of the photoreceptor belt 1, which has been charged in advance by the charger 6, which is a charging means, to form a bright line.

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 circumferential surface of the photoreceptor belt l. Therefore, a latent image corresponding to the color tEl is formed on the circumferential surface of the photoreceptor belt 1 by the main scanning by the laser beam and the sub-scanning by the conveyance of the photoreceptor belt 1. This latent image is created using yellow (Y) toner (
The toner image is developed by the developing device 8 loaded with a developing medium (developing medium), and a toner image is formed on the drum surface. The obtained toner image, while being held on the drum surface, passes under a cleaning device 13, which is a cleaning means, which is separated from the circumferential surface of the photoreceptor belt 1, and enters the next copy cycle.

That is, the photoreceptor belt 1 is charged again by the charger 6, and then the second color signal outputted from the signal processing section is manually inputted to the writing system unit 7, and the second color signal is inputted to the writing system unit 7, and the second color signal is inputted to the writing system unit 7. In the same manner, writing is performed on the drum surface to form a latent image. The latent image is developed by a developer 9 loaded with magenta (M) toner as a second color.

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

A developing device 10 has cyan (C) toner, and forms a cyan (C) toner image on the drum surface based on a control signal generated by a signal processing section.

Furthermore, 11 is a developing device having black toner, and forms a black toner image superimposed on the belt surface by the same process. These developing units 8.9°10 and 11
A direct current or even an alternating current bias is applied to each sleeve, and jumping development is performed using a 2IR developer serving as a WI imaging means, and development is performed without contact on the photoreceptor belt 1 whose base is grounded. It has become. Incidentally, as the development, non-contact development using a -component developer can also be used.

The color toner image thus formed on the circumferential surface of the photoreceptor belt 1 is transferred to a transfer material fed from the paper feed cassette 14 via the paper feed guide 15 at the transfer section.

That is, the top layer of the transfer material stored in the paper feed cassette 14 is carried out by the rotation of the paper feed roller 16, and transferred to the transfer device 12 via the timing roller 17 in synchronization with the image formation on the photoreceptor belt 1. supplied to.

The transfer material that has undergone image transfer and static electricity removal is transferred to the rotating roller 2.
The image is reliably separated from the photoreceptor belt 1, which suddenly changes direction along the direction of the photoreceptor belt 1, and is passed through the adsorption type conveyor belt 17A to the upper side, where the image is fused by the fixing roller 8, and then passed through the paper ejection roller 19 to the upper cover. It is discharged onto a tray formed at 20.

On the other hand, the photoreceptor belt 1 that has completed the transfer to the transfer material continues to be conveyed to the blade 13A and the toner conveying roller 13B.
The remaining toner is removed in the cleaning device 13, and the blade 13A is separated again at the end of the process, and a little later, the toner conveying roller 13B removes the toner accumulated on the tip of the blade 13A. After that, the toner transport row 213B is separated and a new image forming process begins.

The photoreceptor bell l-1, the charger 6, each developing device, and the cleaning device 13 are an independent process cartridge 3.
0, and is then inserted and installed into the device by sliding from the direction indicated by the - dotted chain line.

That is, the process cartridge 30 has a rail member 3 having a convex cross-sectional shape on both sides thereof, as shown in FIG.
1, and is attached to the device by being inserted into and engaged with a guide member 32 having a concave cross-sectional shape built inside the device.

The installed process cartridge 30 is covered by the upper lid 20, which is opened and closed using the shaft 20A, which is the upper exterior member, as a fulcrum, and the insertion opening of the process cartridge 30, that is, the right side of the main body of the apparatus, is connected to the shaft 60A, which is the exterior member.
It is closed by a side cover 60 that is opened and closed using the fulcrum as the fulcrum.

A frame body integrally forming a symmetrical side plate 100 is fixed inside the apparatus main body above the process cartridge 30, and a support shaft 101 installed between the side plates 100 is biased counterclockwise by a torsion spring 102. A rotating lever 103 is pivotally mounted.

The rotating levers 103 are arranged in front and rear pairs with the connecting portion 103A at the center, and the reference position of the charging electrometer, toner image reflection density sensor, or photoreceptor bell 1 is provided on the lower surface of the connecting portion 103A. The mounting supports any detection means S such as a 7-auto sensor. The detection means S
The detection portion faces an opening hole 30A provided on the central axis of the upper surface of the loaded process cartridge 30.

On the other hand, a conical compression spring 106 is provided on the inner surface of the upper lid 20.
When the upper cover 20 is closed and locked by a locking member (e!!l not shown), the compression spring 10 is fixedly attached at one end as shown in FIG.
6 presses the connecting portion 103A of the rotary lever 103 with the other free end, and rotates the rotary lever 103 clockwise against the bias of the torsion spring 102 to close the stopper 10.
41: Abutting.

Thereby, the detection means S is inserted into the process cartridge 30 and set at a first position, that is, a predetermined detection position, where detection is performed close to the outer peripheral surface of the photoreceptor belt l.

When the upper lid 20 is opened, the detection means S set at the first position is activated by opening the opening hole 3OA of the process cartridge 30.
More escapes.

That is, as shown in FIG. 3, when the compression spring 106 is retracted upward due to the counterclockwise rotation of the top cover 20, the rotation lever 103 is released from the compression and rotated counterclockwise by the bias of the torsion spring. /< then comes into contact with the hanging bottle 105 and occupies the illustrated position.

As a result, the detection means S detects the process cartridge 3.
0 and is retracted from the first position, and is held at a second position where the process cartridge 30 can be attached and detached.

Furthermore, the detection means S can be moved from the first position to the second position by opening the side cover 60, which is the other exterior member.

In FIG. 4, a cylinder member 200 is fixed to the main body of the apparatus on the central axis above the process cartridge 30,
A movable member 201 having a detecting means S mounted inside the cylinder member 200 and supporting it is biased by a compression spring 202 to insert the detecting means S into the opening hole 30A of the cartridge. Note that the movable member 201 has a penetrating bottle 203.
is inserted through the elongated hole 200A of the cylinder member 200, and its rotation is restricted.

On the other hand, a pair of symmetrical sliding plates 205, which are slidably supported by engaging a pair of guide bins 204 in their elongated lengths, are mounted on the inner wall of the main body of the apparatus above the cartridge, and are opposed to each other with the cylinder member 200 interposed therebetween. It is provided.

Each sliding plate 205 has an inclined bent portion 2 at its left end.
05A is bent in the central axis direction so that the penetrating pin 203 is located below both ends protruding to the outside of the cylinder member 200, and the bent part 205B, which is formed outward at the right end, is the side cover. It is in contact with a pressure contact lever 61 that is integrated with 60.

When the side cover 60 is closed and locked by a locking member (not shown), each sliding plate 205 moves to the left against the bias of the tension spring 206, as shown in FIG. 4(a). The respective bent portions 205A are kept at positions spaced apart from the through pins 203, thereby setting the detection means S at the first position where detection is possible.

The detection means S set at the first position escapes from the opening hole 30^ of the process cartridge 30 by opening the side cover 60.

That is, as shown in FIG. 4(b), when the side cover 60 is rotated clockwise and each of the sliding plates 205 slides to the right under the force of the tension spring 206, the sliding plates 205 are bent. The portion 205A is the through pin 203
, the movable member 201 is raised against the bias of the compression spring 202, and the detection means S is connected to the process cartridge 3.
0 and retracted to the second position.

Further, FIG. 5 shows that the detection means S follows the process cartridge 30 in accordance with the ejecting operation and moves from the first position to the second position.
2 shows a second embodiment configured to move to a different position.

In this case as well, a cylinder member 300 similar to that in the previous embodiment is provided, and the elongated hole 300 of the cylinder member 300
A movable member 301 having a through-hole 303 inserted through the movable member 301 is built in, and is biased by a compression spring 302 so as to project downwardly the detection means S attached and supported at its lower end.

Further, a pair of symmetrical rotating plates 305 rotatably supported by a shaft 304 are provided on the inner wall of the main body of the apparatus above the cartridge.

The bent portion 305^ at the tip of each rotating plate 305 is connected to the elongated hole 300 of the cylinder member 300 of the through bottle 303.
It is bent in the direction of the central axis so as to be located below both ends protruding to the outside of A, and is biased counterclockwise by a torsion spring 306 to abut against a stopper 307, thereby leaving the through-hole bottle 303 in a free state. It is located in

Therefore, the detection means S is inserted into the opening hole 30A in the upper part of the process cartridge 30 by the bias of the compression spring 302, and is set at the first position where detection is possible.

-1 A pair of cam rails 30B are formed on the upper surface of the process cartridge 30.
When the cam seal 30B is moved in the direction to remove it from the main body of the apparatus as shown by the solid line in FIG. 5(b), the cam seal 30B
Push up the protrusion 305B of No. 5 and rotate the rotating plate 305 clockwise.

As a result, the bent portion 305A of the rotary plate 305 comes into contact with the penetrating bottle 303 and pushes up the movable member 301, and the detection means S escapes from the opening hole 30A at the top of the process cartridge 30 and retreats to the second position. do.

〔Effect of the invention〕

The present invention is configured so that various detection means arranged near the shoulder surface of the photoreceptor are automatically moved and retracted in accordance with maintenance or jam removal preparation work, resulting in higher quality images. Now, an image forming apparatus that can realize a combination of a process material unit and a process material unit has been provided.

[Brief explanation of drawings]

WgI Figure 1 Figure 1 Cross-sectional structure of the betrayal invention image forming device! Figure R and Figure 2 are perspective views of the main parts, and Figures 3 to 5 are explanatory views of the main parts. l...Photoreceptor belt 20...Top lid 30...Process cartridge 30A...Opening hole 30B...Cam rail 31...
Rail member 32... Guide member 60... Side cover 61... Pressing lever 103... Rotating lever 106, 202, 302... Compression spring 20
0.300... Cylinder member 201.301... Movable member 203.303...
Penetration bottle 205...Sliding plate 205A, 205B, 305A...Bending portion 3
05...Rotating plate 305B...Protrusion S...
Detection means

Claims (3)

[Claims] (1) When a process cartridge including at least an image bearing member is attached to or detached from the main body of an image forming apparatus, the detection means provided opposite to the process cartridge moves from the first position where detection is performed to the second position retreated. An image forming apparatus characterized by moving with. (2) The image forming apparatus according to claim 1, wherein the detection means moves in conjunction with an opening operation of the exterior member. (3) The image forming apparatus according to claim (1), wherein the detection means moves in conjunction with the ejecting operation of the process cartridge.