JPH04212973A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent interference with an image exposing means which hinders attaching and removing of an image forming process material made into a unit, when the material is attached to or removed from a device. CONSTITUTION:Interlockingly with a taking-out operation of a process cartridge 30 or an opening action of a door 35 carried out prior to taking out of the process cartridge 30, an image exposing means 7 is retracted so that it is located at a non-interference position at taking out of the process cartridge.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus for forming an image on a transfer material such as a copying machine or a printer.

0002

[Prior Art] In image forming apparatuses such as monocolor analog copying machines using electrophotography and copying machines and printers using semiconductor laser/LED scanning systems, various photoreceptors, developer carriers, and cleaning members with a durable life span are used. A part of the image forming means is made into a cartridge for replenishment and replacement when the developer and toner are exhausted, and the member that integrates the main parts of the image forming means is taken out of the apparatus for maintenance or replacement. It has been proposed that something is configured to do so. 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.

[0003] As a representative configuration of these,
A photosensitive drum, a developing device, a cleaner, etc. are integrally attached to a support member as disclosed in Japanese Patent No. 54392,
A proposal has been made to make the image forming means removable from the main body of the apparatus to facilitate replacement and repair of each unit, and then Japanese Patent Laid-Open Publication No. 154255/1983 proposes a device that integrates the main parts of these image forming means and makes them disposable. Further, a printer configuration using a similar disposable cartridge and forming a latent image on a photosensitive drum by dot exposure scanning and writing using a semiconductor laser is disclosed in Japanese Patent Laid-Open No. 147366/1983. Furthermore, these publications disclose a configuration in which the upper housing of the divided structure is opened to open the transfer material conveyance path and take out the transfer material in the event of a jam, and the above-mentioned Japanese Patent Laid-Open No. 57
Japanese Patent Publication No. 154255 adopts a configuration in which a disposable process cartridge is replaceably disposed in an upper housing having a two-part structure, and attempts to improve the workability of cartridge replacement and ease of jam removal. In addition, with emphasis on ease of replacement of process cartridges, mainly replenishment toner cartridges and cleaning cartridges for recovered toner, the structure is divided into two parts. JP-A-58-1161 discloses an improved method.

[0004] Also, the above structure is vertically shaped, and Japanese Patent Application Laid-open Nos. 63-244058 and 63-244059,
This is proposed in Japanese Patent Application Laid-open No. 63-244064 and Japanese Patent Application Laid-open No. 1-179168, which aims to improve the same direction operation and jam handling.

[0005]

[Problems to be Solved by the Invention] However, especially in devices that use a belt-shaped photoreceptor as the photoreceptor, the photosensitive surface is set at a position slightly recessed from the outer wall of the cartridge due to the layout of each image forming means. When using a light image transmission lens such as the SELFOC lens (product name), which requires placement very close to the photosensitive surface as an image exposure means, it becomes impossible to install and remove the process cartridge in the horizontal direction, making it difficult to operate. decreases significantly. The present invention solves this problem and improves the image forming apparatus, thereby providing an image forming apparatus in which the process cartridge can be easily attached and detached in the horizontal direction without being interfered with by the image exposure means.

[0006]

[Means for Solving the Problems] The above object is such that a process cartridge including at least a belt photoreceptor is removably installed in an apparatus main body, and when the cartridge is installed or removed, the image exposure means is located at a position that does not interfere with the cartridge. This is achieved by an image forming apparatus that is characterized by retracting the image.

[0007]

[Example] Fig. 1 shows an example of the color image forming apparatus of the present invention.
or as shown in FIG.

In FIG. 1, reference numeral 1 denotes a flexible photoreceptor belt serving as a belt-like image carrier. Transported clockwise.

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;
The photoreceptor belt 1 is brought into a tensioned state by the outward biasing action of the rotary roller 3, so that its inner circumferential surface slides against the guide member 4. Therefore, the photoreceptor belt 1
The photoreceptor on the outer circumferential surface of the photoreceptor is always maintained at a constant position relative to the surface of the guide member 4 during transportation, making it possible to form a stable image forming surface.

6 is a scorotron charger as a charging means; 7
Reference numerals 8 to 11 indicate an image exposure means, and 8 to 11 indicate a plurality of developing units or developing units each containing a developer of a specific color. Disposed facing the outer peripheral surface.

The image exposure means 7 is composed of an LED head 7A and a light image transmission lens section 7B, which is also known as Selfoc Lens (trade name), and the tip of the light image transmission lens section 7B is located at a position extremely close to the photosensitive surface. The settings are made and image exposure is performed. Note that a liquid crystal shutter may be used as the light emitting section of the image exposure means 7 instead of the LED head.

Each of the developing devices 8, 9, 10, and 11 accommodates, for example, yellow, magenta, cyan, and black developers, respectively, and is provided with a developing sleeve that maintains a predetermined gap from the photoreceptor belt 1. It has a function of making the latent image on the photoreceptor belt 1 visible by a non-contact development method. 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 charge eliminating bar, and 13 is a cleaning section, that is, a cleaning device, which includes a blade 13A and a toner conveying roller 13.
B is maintained at a position apart from the surface of the photoreceptor belt 1 during image formation, 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 temporarily 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 LED head 7A, the circumference of the photoreceptor belt 1, which has been charged in advance by a charger 6 serving as a charging means, is It is projected onto the surface and forms an emission 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 1. Therefore, a latent image corresponding to the first color is formed on the circumferential surface of the photoreceptor belt 1 by main scanning by the laser beam and sub-scanning by the conveyance of the photoreceptor belt 1. This latent image is yellow (Y) in the developing means.
The developing device 8 loaded with toner (developing medium) forms a toner image 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 inputted to the image exposure means 7, and the above-mentioned first color signal Writing is performed on the drum surface in the same manner as in the case of , and a latent image is formed. 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.

Further, numeral 11 denotes a developing device containing black toner, which forms a black toner image superimposed on the belt surface by the same process. These developing devices 8, 9, 1
Direct current or even alternating current bias is applied to each sleeve 0 and 11, and jumping development is performed using a two-component developer, which is a developing means, and non-contact development is performed on the photoreceptor belt 1 whose base is grounded. It is about to be done. Note that as the development, non-contact development using a one-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 uppermost 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 photoreceptor belt 1 via the timing roller 17.
It is supplied to the transfer device 12 in synchronization with the above image formation.

The transfer material that has undergone image transfer and static electricity removal is reliably separated from the photoreceptor belt 1, which suddenly changes direction along the rotating roller 2, and is transported upward via the suction type conveyor belt 17A. After the image is fused by the fixing roller 18, the sheet is discharged via the discharge roller 19 onto a tray formed on the upper lid 20.

On the other hand, the photoreceptor belt 1 that has completed the transfer to the transfer material continues to be transported to the cleaning device 1 with the blade 13A and the toner transport roller 13B in pressure contact.
3, the remaining toner is removed, and after the removal is finished, the blade 13A is pulled away again. A little later, after the toner conveying roller 13B smoothes out the toner accumulated on the tip of the blade 13A, the toner conveying roller 13B is removed.
B is separated and a new image forming process begins.

The photoreceptor belt 1, charger 6, developing devices and cleaning device 13 are integrated into an independent process cartridge 30, and are inserted into the device by sliding from the direction indicated by the dashed line. be done.

On the other hand, inside the apparatus below the process cartridge 30, the image exposure means 7 is placed in a guide container 40.

The image exposure means 7 has an LED head 7
A is vertically movably housed in the guide container 40 together with the optical image transmission lens 7B, and is biased upward by a compression spring 41 built in the guide container 40.

Further, sliding plates 42 are provided on the front and rear inner walls of the apparatus main body that sandwich the guide container 40, and are integrated through a connecting portion 42A, each having a pair of elongated holes 42B supported by guide pins 43. At the top, it is biased to slide to the right by a strong tension spring 44.

Further, the slide plate 42 has an inclined groove cam 42C, and the guide container 4 is attached to the groove cam 42C.
The operating pin 7 of the LED head 7A protrudes to the outside of the LED head 7A.
C is engaged in an idle state.

As shown in FIG. 1, the process cartridge 30
is inserted and the door 35 is closed and locked in a locking device (not shown), the slide plate 42 is inserted into the door 35.
5 is in a position where it is pushed by the pressing pin 36 on the inner surface and slid to the left against the bias of the tension spring 44.

Accordingly, the movement of the grooved cam 42C causes the optical image transmission lens 7 to rise within the guide container 40, and the compression spring 41 also causes the LED head 7A to come into contact with the top of the guide container 40. and set to its upper limit position.

At the upper limit position, the optical image transmission lens 7
The optical image transmission lens section 7B pushes up and opens the shielding lid 30B formed of an elastic material such as Mylar that is attached to the opening of the cartridge 30, and places its tip in the vicinity of a few millimeters from the photosensitive surface of the photoreceptor belt 1. The image exposure is carried out while the image is held at that position.

The door 35 is unlocked and its support shaft 35 is
When the slide plate 42 is opened clockwise to a predetermined angle using A as a fulcrum, the slide plate 42 is released from the pressure by the pressing pin 36 and slides to the right due to the strong bias of the tension spring 44, as shown in FIG. Guided by the cam 42C, the image exposure means 7 descends within the guide container 40 and passes through the optical image transmission lens section 7B.
The distal end of the process cartridge 30 is retracted to a non-interfering position, that is, outside the range of the movement locus accompanying the attachment/detachment operation.

As a result, the process cartridge 30 can be safely and easily taken out of the apparatus via the handle 30A with its opening closed by the elasticity of the shielding lid 30B.

Further, FIG. 3 shows the process cartridge 130.
This is an example of an image forming apparatus in which the image forming apparatus is attached and detached from the front side of the apparatus. In this case, the slide plate 142 that moves the image exposure means 107 up and down is supported directly on the side of the guide container 140, and the protruding The operating pin 107C of the LED head 107A is loosely engaged with a pair of grooved cams 142C.

The operation of the slide plate 142 and the image exposure means 107 by opening and closing the door 135 on the front side of the apparatus is exactly the same as in the previous embodiment, and when the door 135 is closed, the pressing pin Slide plate 1 is pressed by 136.
42 moves to the rear side of the apparatus and raises the image exposure means 107, bringing its optical image transmission lens section 7B close to the photosensitive surface of the photoreceptor belt 101.

When the door 135 is opened, the slide plate 142 moves to the front side of the apparatus by the bias of the tension spring 144, lowers the image exposure means 107 via the groove cam 142C, and prevents the process cartridge 130 from interfering with the slide plate 142. evacuate to position. The opening after the image exposure means 107 is retracted can also be covered with a lid at the same time as it is retracted.

Furthermore, in this embodiment, the image exposure means is retracted in conjunction with opening the door, but it is also possible to configure the retraction in conjunction with the process cartridge removal operation. Included in invention.

[0040]

According to the present invention, the process cartridge can be safely and reliably attached to and removed from the image exposure device without interfering with the image exposure device, and as a result, compact and high-quality images can be produced by selecting the image exposure means. The resulting image forming apparatus is now provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of an image forming apparatus of the present invention.

FIG. 2 is a cross-sectional view showing the door in FIG. 1 opened.

FIG. 3 is an explanatory diagram showing a side cross section of the device.

[Explanation of symbols]

1,101・Photoreceptor belt 6. Charger 7. Image exposure means 7A/LED head 7B・Light image transmission lens 8-11・Developer 12・Transfer device 13.Cleaning device 30,130・Process cartridge 35,135・Door 36,136・Press pin 40,140・Guide device 41,141・Compression spring 42,142・Slide plate 42C, 142C/groove cam 44,144・Tension spring

Claims (2)

[Claims] 1. A process cartridge including at least a belt photoreceptor is removably installed in an apparatus main body, and when the cartridge is installed or removed, the image exposure means is retracted to a position where it does not interfere with the cartridge. Image forming device. 2. The image forming apparatus according to claim 1, wherein the retracting operation of the image exposing means operates in conjunction with opening and closing of a door provided in the apparatus main body.