JPS63142365A - Image forming device - Google Patents

Abstract

PURPOSE:To shorten an image formation time by performing image formation on 1st and 2nd surfaces in a process wherein a transfer material is conveyed on a transfer material conveyance path connecting a paper feeding part and a discharge part. CONSTITUTION:The transfer material fed from a transfer material storage part 1 is conveyed toward the discharge part 2 along the transfer material conveyance path 3 at the time of both-surface image formation. The transfer material passes through a 1st image forming means 4, a temporary fixing means 7, a 2nd image forming means 5, and a fixing means 6 successively in said conveying process; and the 1st image forming means 4 forms an image on a 2nd surface (reverse surface) and the 2nd image forming means 5 form an image on a 1st surface (reverse surface). The temporary fixing means 7 fixes (presses and fixes) unfixed toner supplied onto the 2nd surface by the image formation of the 1st image forming means 4 and the fixing means 6 fixes (heats and fixes) the toner image-formed on the 1st and 2nd surfaces by the 1st and 2nd image forming means 4 and 4 securely on the transfer material.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) This emitted 1 is an image type T
In particular, the present invention relates to an image forming apparatus having a double-sided image forming mode.

(Prior Art) FIG. 3 shows an example of a conventional image forming apparatus (copying machine) having a double-sided image forming mode.

In a conventional image forming apparatus, one image forming means is provided in a transfer material transport path 103 that connects a transfer material feeding section (paper feeding cassette) lot and a transfer material discharging section (paper discharge tray) 102, as shown in one example. 104 is provided, and when performing double-sided image formation, this image forming means 104 forms images on the first side and the second side separately. That is, when the transfer material is fed from the feeding section 101, the image forming means 104 first forms an image on the first surface of the upper surface.
Next, the transfer material passes through the fixing device 105 and advances along the conveyance path 106 toward the intermediate paper ejection cassette 107 as shown by the arrow.
The paper is temporarily stored in the intermediate paper ejection cassette 107 with the front and back sides reversed. Then, the transfer material with the :52 side or the top side is returned to the conveyance path 106 again by the paper refeed roller 108 and sent toward the image forming means 104 as shown by the arrow. The image is formed on the second surface of the upper surface.Next, the transfer material passes through a fixing device 105 and is discharged to a discharge section 102 by a paper discharge roller 109.

(Problems to be Solved by the Invention) However, in the case of the conventional method in which images are formed on the first side and the second side by one image forming means 104 provided in the transfer material conveyance path 103, It is undeniable that it takes a certain amount of time to turn the transfer material over from the image formation on the first side to the image formation on the second side, and as a result, image formation in the double-sided image formation mode is rapidly slowed down. There was.

(Purpose of Issue 1!1) Therefore, in view of the above-mentioned supernatant, the present invention aims to significantly shorten the time required to form a double-sided image, and to provide an image forming apparatus that is easy to use. purpose.

(6! Essentials of the Invention) The image forming apparatus according to the present invention includes a first image forming apparatus disposed on the opposite side of the transfer material conveyance path that connects a transfer material feeding section and a transfer material discharge section across the conveyance path. and a second image forming means,
In the process in which the transfer material is conveyed from the feeding section toward the discharge section through the transfer material conveyance path, the first. Among the second image forming means, the first image forming means disposed on the upstream side of the conveyance path forms an image on the first surface, and the second image forming means disposed on the downstream side of the conveyance path forms an image. It is characterized in that it is configured to form an image on the second surface.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows a schematic configuration of an image forming apparatus (copy a) according to the present invention, and in the figure, l is a transfer unit that accommodates a large number of transfer materials and feeds them in response to a feed signal. A material storage section (feeding section); 2 is a discharge section that stores the transfer material after image formation; 3 is a transfer material conveyance path connecting the transfer material storage section l and the discharge section 2; 4.5 is the transfer material conveyance section A second image forming stage f and a second image forming stage are respectively installed in the path 3, 6 is a fixing means (fixing roller) using a heating method, and 7 is a transfer material conveying path 3.
This is temporary adhesion means using a pressure method installed between the first image forming means 4 and the second image forming means 5.

The first image forming means 4 is disposed below the conveyance path and forms an image on the second side ('A side) of the double-sided document on the second side (LA side) of the transfer material conveyed through the transfer material conveyance path 3. The first image forming R&F stage 5 is arranged on the L side of the conveyance path downstream of the first image forming means 4, and forms the :jS1 side (front surface) of the transfer material conveyed through the transfer material conveyance path 3. The first side (front side) of a double-sided original
form an image.

Both the first image forming means 4 and the second image forming means 5 charge the surface of the photosensitive drum (A-Si photosensitive tram) 8.8'' and the photosensitive drum 8.8' to about +450V, for example. The drum surface of the photosensitive drum 8,8' is irradiated with the modulated image signal read by the chargers 9 and 9' and the document reading units 15 to 17, and the electric charge in the image signal portion is erased to form a latent image pattern. A laser light source 10.10' that performs the formation, a developing device 11.11' that visualizes the charge dissipation pattern using a reversal development method using, for example, Φ toner with a particle size of approximately 10 g, and a transfer material that is in close contact with the photosensitive drum 8.8'. A transfer charger 12.12" that applies a transfer charge of e from the back side to the photosensitive drum 8.
．． It is equipped with a separation static eliminator 13.13' that separates the transfer material that is in close contact with the drum surface of 8' from the drum surface, and a cleaner 14.14'' that cleans the drum surface of photosensitive drum 8.8'. The configuration is as follows.

As shown in FIG. 2, the temporary attachment means 7 is constituted by a pair of pressure rollers 18 and 19 that face each other and are in contact with each other.

Such a roller 18,19 has a surface roughness of 0.3, for example.
A metal roller polished to ~0.7μ and applied with a linear pressure of approximately 5 to 15 g/cm is used. Further, the temporary adhesion means 7 includes an oil application device 20 that applies oil (silicone oil) to prevent toner from adhering to the surfaces of the rollers 18 and 19, and an oil application device 20 that scrapes toner adhering to the rollers 18 and 19. A scraper 21 for scraping is attached. The oil application device 20 includes a container 22 containing a predetermined amount of oil and oil rollers 18 and 1 inside the container 22.
9 and a web 23 to be applied in a small amount.

Next, the double-sided image forming mode of the present image forming apparatus having the above-described configuration will be described.

In this image forming apparatus, during double-sided image formation, the transfer material fed from the transfer material storage section 1 is transported along the transfer material transport path 3 toward the discharge section 2 as shown by the arrow. During this conveyance process, the transfer material is sequentially transferred to 1 image forming means 4 and temporary attachment means 7.
．． It passes through the second image forming means 5 and the fixing means 6. Then, the first image forming means 4 forms an image on the second side (back side), and then the second image forming means 5 forms an image on the first side (front side).
An image is formed on the image. Further, in the temporary adhesion means 7, the unfixed toner image-formed on the second side by the first image forming means 4 is fixed (pressure-fixed) onto the transfer material to such an extent that no image disturbance occurs during conveyance, and the fixing means 6, the first image forming means 4
The toner images formed on the first and second sides by the second image forming means 5 are reliably fixed (heated and fixed E) on the transfer material.

As described above, in the case where the temporary attachment means 7 is provided between the first image forming means 4 and the second image forming means 5, the first image forming means at the former stage is formed at the transfer separation section of the second image forming means 5 at the rear stage. Flying toner adhering to the transfer material during image formation in means 4
(Preventing scattering due to deformation when the transfer material contacts and separates from the photosensitive drum 8', scattering due to wind blowing toward the photosensitive drum 8' from the transfer charger 12" and separation static eliminator 13' side (so-called corona wind), etc.) Therefore, the charger 9
This means that contamination of the transfer charger 12' and the transfer charger 12' by scattered toner is minimized, and stable image formation can be performed over a long period of time.

In addition, in the case of illustration, the first image forming means 4? Although the second image forming means 5 is arranged below the conveying path and the second image forming means 5 is arranged above the conveying path, conversely, the first image forming means 4 is arranged above the conveying path and the second image forming means 5 is arranged above the conveying path. It may also be placed below the conveyance path. Furthermore, although the pressurizing method is used for the temporary attachment means 7, a heating method may also be used.

(Effects of the Invention) As explained above, according to the image forming apparatus of the present invention, the first and second surfaces of the transfer material are This has the advantage of significantly shortening and speeding up image formation in a double-sided image forming mode in which the first and second sides of a single-sided original are simultaneously transferred.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a schematic vertical cross-sectional view showing one embodiment of the present invention;
The figure is a schematic vertical cross-sectional view showing details of the temporary attachment means used in the same embodiment, and FIG. 3 is a schematic vertical cross-sectional view showing a conventional image forming apparatus. 1... Transfer material storage section (feeding section), 2... Discharge section, 3
... Transfer material conveyance path, 4... First image forming means, 5.
. . . second image forming means; 7-. temporary attachment means;

Claims (1)

[Claims] 1) In the transfer material conveyance path connecting the transfer material feeding section and the discharging section,
A process in which the transfer material is conveyed along the transfer material conveyance path from the feeding section toward the discharge section, comprising a first image forming means and a second image forming means disposed on opposite sides with a conveyance path in between. Among the first and second image forming means, the first image forming means disposed on the upstream side of the conveyance path forms an image on the first surface, and the second image forming means disposed on the downstream side of the conveyance path forms an image on the first surface. An image forming apparatus characterized in that an image forming means is configured to form an image on the second surface. 2) Between the first image forming means and the second image forming means of the transfer material conveyance path, toner attached to the transfer material that has passed through the first image forming means is assumed to be on the transfer material. 2. The image forming apparatus according to claim 1, further comprising temporary attachment means for attaching the image.