JPH03186535A - Color image forming device - Google Patents

Abstract

PURPOSE:To improve operational performance by installing a manual paper form feeding plate which has a paper feeding cassette and an outer frame in common and is equipped with a transport means for the manual insertion paper form in replaceable manner and carrying out the mounting/demounting of a paper feeding cassette and the manual paper feed through the operation executed only from one direction. CONSTITUTION:A manual paper feeding plate 30 has an outer frame 31 which is used in common with a paper feeding cassette, and a paper passage 34 consisting of a lower guide plate 32 and an upper guide plate 33 is formed on the upper surface of the outer frame 31. When the paper feeding cassette is pulled out, and the manual paper feeding plate 30 is installed in replacement from a same cassette installation port 141, a manual insertion paper form 39 is inserted from the inlet 34a of the paper form passage 34, and the paper form 39 is transported through the nipping points of the driving rollers 35 and driven rollers 36 in succession, and discharged from the outlet 34b of the paper form passage 34, and passes through the under-side of a paper feeding roller 16 and is supplied to a timing roller 17 through a paper feeding passage 15. In the timing roller 17, the paper form 39 is supplied into a copying part 12 in the adjusted timing with the formation of an image on a photosensitive body belt.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to forming a color toner image on a belt-like image forming member using an electrophotographic method, and transferring the toner image onto a transfer paper to obtain an image. The present invention relates to a color image forming apparatus.

[Conventional technology]

There are various types of color image forming devices, but generally there is a belt-shaped image forming body (also called a photoreceptor belt) between two axes.
A plurality of developing units each containing toner of a different color are arranged along the lower side of the belt, and while the photoreceptor belt is rotated multiple times, an original image is formed on the photoreceptor belt. After forming a latent image according to the number of separated colors and developing with the developer group to form a color image, the color image is fed from a paper feed cassette in a cassette storage chamber provided below the developer group. A color copy can be obtained by transferring the image onto printed transfer paper.

Unlike the photosensitive drum, the photosensitive belt of such a color image forming apparatus has the advantage that it can be made to make a U-turn with a small curvature, so it can be run flat, and space can be used effectively. Further, by providing a separation pole for the transfer paper after transfer at the small diameter curvature portion where the U-turn is made, there is an advantage that separation of the transfer paper is improved.

[Problem to be solved by the invention]

In the case of the above color image forming apparatus, the photoreceptor belt and the paper feed cassette are arranged in layers with the developing device in between.
The paper feed path goes around the outside of the developing device, so it is near one side wall of the apparatus main body. Therefore, if the layout is such that the paper cassette is inserted from the paper feed slot side of the paper cassette, as in a normal image forming apparatus, the distance between the cassette mounting slot and the paper feed roller, which is the starting point of the paper feed path, is becomes longer,
In order to prevent the inability to feed paper due to insufficient insertion, the manual paper feed tray is provided on a side wall separate from the cassette mounting opening, that is, on the installation side of the paper feed path. Therefore, the installation and removal of the paper feeding cassette and the manual feeding of paper must be performed from different directions, which is complicated and troublesome.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a color image forming apparatus in which attachment and detachment of a paper feed cassette and manual paper feeding are unidirectional operations.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a plurality of developing units containing toners of different colors facing the lower side of a belt-like image forming body stretched between two shafts. In the color image forming apparatus, the paper feed cassette is arranged below the developing device, and the paper feed cassette is inserted with the paper feed opening side first. This apparatus is characterized in that the cassette and the outer frame are shared, and that a manual paper feed tray equipped with a means for transporting manual paper is provided in a replaceable manner.

〔Example〕

Next, the present invention will be described based on an embodiment shown in the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a flexible photoreceptor belt which is a belt-shaped image forming member. The photoreceptor belt 1 is stretched between a driving roller 2 and a driven roller 3 and is conveyed in a clockwise direction.

Reference numeral 4 designates a guide member fixed to the main body of the apparatus so as to inscribe the lower side of the photoreceptor heald 1, and reference numeral 5 designates a tension roller that causes the photoreceptor belt 1 to be inscribed in the guide member 4 in a tensioned state. The guide member 4 and the tension roller 5 make it possible to form a stable image forming surface on the photoreceptor belt 1.

6 is a scorotron charger which is a charging means, and 7 is a laser writing system unit which is an image exposure means. 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.

Reference numerals 8.9 and 10.11 designate a plurality of developing devices each containing a developer of a different color, for example, yellow, magenta, cyan, and black.
is arranged to face the photosensitive belt 1 in which the guide member 4 is inscribed. Each of these developing devices 8 to 11 has a phenomenon sleeve 8A, 9A, I which maintains a predetermined gap with the photoreceptor belt 1.
O.A.

11A, and has a function of visualizing the latent image on the photoreceptor belt 1 by a non-contact phenomenon method. Unlike the contact phenomenon, this non-contact phenomenon has the advantage of not interfering with the movement of the photoreceptor belt.

12 is a transfer device, 12A is a static eliminating bar, and 13 is a cleaning device. The blade 13A of the cleaning device 13 and the toner conveying roller 13B are connected to the photoreceptor belt 1 during image formation.
The photoreceptor bell 1-1 is kept in a position apart from the surface of the photoreceptor bell 1-1, and is pressed against the surface of the photoreceptor bell l-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 image forming system shown in FIG. That is, the original image is obtained at the color image data input section (a) scanned by the image sensor;
The image data processing unit (b) performs arithmetic processing on the data to create image data, which is then stored in the image memory (c).

Then, the image memory is taken out during recording and transferred to the recording section (d).
For example, the image data is input to 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, a laser beam generated by a semiconductor laser (not shown) in the laser writing system unit 7 The photoreceptor belt 1 is rotated and scanned by a polygon mirror 7B rotated by a drive motor 7A, the optical path is bent by mirrors 7D and 7E via an fθ lens 7C, and a photoreceptor belt 1 is charged in advance by a charger 6 as a charging means.
is projected onto the circumferential surface 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 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 developed by a developing device 8 loaded with yellow (Y) toner (developing medium) of the developing means, and a toner image is formed on the drum surface. The obtained toner image passes under the blade 13A of the cleaning device I3, which is separated from the peripheral surface of the photoreceptor heald 1 while being held on the drum surface, and enters the next copy cycle.

The photoreceptor belt 1 is charged again by the charger 6, and then the second color signal output from the signal processing section is input to the writing system unit 7, and is processed in the same manner as in the case of the first color signal described above. 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. Magenta (
The M) toner image is formed in the presence of the previously formed yellow (Y) toner image. Similarly, the developing device 10 containing cyan (C) toner produces cyan (C).
A developing device 11 containing black toner further forms a black toner image superimposed on the belt surface.

A direct current or alternating current bias is applied to each sleeve of each of these developing devices 8, 9, 10. 1-1 is designed to be developed in a non-contact manner.

Incidentally, as the development, non-contact development using a non-contact developer can also be used.

As described above, the color toner image formed on the circumferential surface of the photoreceptor belt 1 is transferred to transfer paper. This transfer paper is stored in the paper feed cassette 1 stored in the space below the developing units 8 to 11.
4, the sheets are sent out one by one starting from the top layer by the friction of the paper feed roller 16, and are supplied to the transfer device 12 through the paper feed path 15 and the timing roller 17 in synchronization with the image formation on the photoreceptor belt l.

The paper feed cassette 14 has a paper feed path 15 and a paper feed roller 1.
The cassette can be loaded from a cassette mounting opening 141 provided in the main body side wall B opposite to the main body side wall A on the installation side of No. 6, with the paper feed port 14a first, as shown by arrow a. In this case, although storage means for the paper feed cassette 14 is not shown, it is preferable to use an extendable rail to reach the paper feed position. Of course, other mechanical means are also possible.

When the paper feed cassette 14 is stored to the paper feed position, the paper tray plate 14b is pushed up by the push-up means 142 provided at the bottom of the main body, and the transfer paper is passed through the paper feed port and transferred to the paper feed roller 16 serving as the paper feed means. It is designed to be pressed into contact.

As described above, the transfer paper supplied to the transfer device 12, subjected to image transfer and charge removal, is reliably separated from the photoreceptor belt l, which changes direction abruptly (with a small diameter curvature) along the drive roller 2. After the images are fused upward by the fixing roller 18, the sheets are discharged onto the paper discharge tray 20 via the paper discharge roller 19 and stacked.

On the other hand, the photoconductor bell (1) which has completed the transfer to the transfer paper continues to be conveyed to the blade 13A and the toner conveying roller 13B.
The remaining toner is removed in the cleaning device 13 which is brought into pressure contact with the toner. After cleaning is completed, the blade 13A is pulled away again, and a little later, the toner supply roller 13B smoothes the toner accumulated on the tip of the blade 13A, and then the toner transport roller 13B is pulled away, and a new image forming process begins.

FIG. 3 is a partially cutaway front view when the paper feed cassette 14 is removed and a manual paper feeder is installed as a replacement from the same cassette mounting opening 141, and FIG. 4 is a perspective view of the manual paper feeder.

The manual paper feeder 30 has a common outer frame 31 with the paper feed cassette 14.
A paper path 34 consisting of a lower guide plate 32 and an upper guide plate 33 is provided on the upper surface of the outer frame 31. 35
36 is a drive roller exposed through a hole in the lower guide plate 32;
is a driven roller that passes through the groove of the upper guide plate 33 and rides on the drive roller 35. The drive roller 35 is fixed to three shaft rods 35a that are mounted between the side walls of the outer frame 31.

These three shaft rods 35a have shaft ends 35b outside the outer frame connected by an endless body 35c. One of these drive rollers 35 is connected to a main body drive gear 37 via a gear train 35d when the manual paper feeder 30 is mounted on the main body of the apparatus. Further, the driven roller 36 is fixed to a shaft rod 36a which is vertically freely supported by a long hole between the side walls of the outer frame 31, and a spring 38
It is pressed against the drive roller 35 by the tensile force of .

Therefore, when the paper feed cassette 14 is removed and the manual paper feeder 30 is installed as a replacement from the same cassette mounting port 141, the manual paper 39 is inserted into the entrance 3 of the paper path 34.
4a, the paper 39 is conveyed one after another through the nipping points between the drive roller 35 and the driven roller 36, is ejected from the exit 34b of the paper path 34, passes under the paper feed roller 16, and is fed The paper is fed to the tie shortening roller 17 via a path 15, and is transferred to the transfer unit 12 at the timing roller 17 in time with the image formation on the photoreceptor belt.
The paper will be fed to.

(Effects of the Invention) As described above, the present invention includes a plurality of developing units containing toner of different colors arranged opposite to the lower side of a belt-like image forming body stretched between two shafts, and the developing units In a color image forming apparatus in which a paper feed cassette is arranged lower and the paper feed cassette is inserted with the paper feed slot side first, an outer frame is shared with the paper feed cassette. ,
In addition, since the manual paper feeder equipped with a manual paper conveying means is provided in a replaceable manner, it is possible to attach/detach the paper feed power center and manually feed paper from only one direction, which improves operability. improves.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a color image forming apparatus according to the present invention, and FIG.
The figure is a block diagram showing the image forming system. Figure 3 is a partially cutaway front view when the paper feed cassette is removed and a manual paper feeder is installed as an exchange from the same cassette installation slot. Figure 4 is a partially cutaway front view of the manual paper feeder. FIG. 1... Photoreceptor belt 2... - Drive roller 3 - Followed roller 4... Guide member 5 - Tension roller 6 - Charger 7 - Laser writing system unit 8 9. 10, 11 - Developing device 12 - Transfer device 13 - Cleaning device 14 - Paper feed cassette 141 - Cassette mounting port 15 - Paper feed path 16 - Paper feed roller 17 - Timing roller O - Manual paper feeder 1 - Outer frame 2 - Lower guide plate 3...-Upper guide plate 4-Paper path 5--Drive roller 6-Followed roller 7--Main body side drive gear 8--Spring 9--Manual paper feed

Claims (1)

[Claims] A plurality of developing devices containing toner of different colors are arranged opposite to the lower side of a belt-like image forming body stretched between two shafts,
In a color image forming apparatus, in which a paper feed cassette is arranged below the developing device, and the paper feed cassette is inserted with the paper feed slot side first, the paper feed cassette and the outer frame are connected to each other. What is claimed is: 1. A color image forming apparatus, characterized in that a manual paper feeding tray having a common paper feeding tray and a conveying means for manually feeding paper is provided in a replaceable manner.