JPH03177868A - Recorder - Google Patents

Abstract

PURPOSE:To carry out highly reliable image transferring to a transfer material and to eject a transfer material in a face down state by utilizing a transfer roll installed in contact with an upper part of an image carrier. CONSTITUTION:Image transferring is carried out utilizing a transfer roll 17 which is in contact with the upper part of the image carrier 10. Because of this, by having the transfer roll 17 rotate synchronized with the image carrier 10, the function of image transferring and carrying of the transfer material 16 are carried out. Therefore, the state of contact between the image carrier 10 and the transfer material 16 is stabilized. Thus, transferring deviation at the time of image transferring and transfer material jamming at the time of transfer material carrying, etc., can be prevented, the image can be transferred in a lower surface of the transfer material 16, be fixed, and have the transfer material ejected outside the device in that face down state.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) The present invention relates to a recording device, and particularly to a recording device that transfers a developer image formed on an image carrier by pressing it onto a transfer material. The present invention relates to a recording device equipped with a transfer roller.

(Prior Art) Currently, electrophotography is one of the methods for transferring a developer image formed on an image carrier such as a photoconductor or dielectric onto a transfer material such as plain paper. It has been put to practical use in optical printers such as printers. In this method, a toner image is formed on the image carrier through charging, exposure, and development steps, and a corona charger is used from the back of the transfer material to generate a charge opposite to that of the toner, and the image is transferred from the image carrier to the transfer material. Transfer is performed electrostatically.

By the way, in general, in a copying machine, the transfer material is conveyed to the lower part of the image carrier, so that the image is transferred to the upper surface of the transfer material. Thereafter, the toner is fixed on the transfer material within the device, and the transfer material is discharged from the device. Therefore, the image surface of the ejected transfer material is the upper surface.

On the other hand, in an optical printer, the image surface of the ejected transfer material is required to be on the lower surface, that is, in a so-called face-down state.

For this reason, in an optical printer, the transfer material is usually conveyed to the lower part of the image carrier, the image is transferred and fixed on the upper surface of the transfer material, and then the transfer material is turned over and discharged from the apparatus. Therefore, the image surface of the ejected transfer material is the lower surface. but,
This method requires a mechanism for turning over the transfer material within the device, which makes the device complicated, which is very disadvantageous to miniaturization of the device.

Therefore, in the method disclosed in Japanese Patent Application Laid-Open No. 64-20587, a transfer material is conveyed to the upper part of an image carrier, an image is transferred to the lower surface of the transfer material using a corona transfer method, and after fixing,
The transfer material is being ejected from the device with its face down.

(Problems to be Solved by the Invention) However, since this method uses a corona transfer method, the transfer material is only conveyed onto the image carrier and is not fixed. Therefore, the contact state between the image carrier and the transfer material during image transfer becomes unstable.

Therefore, there are disadvantages in that transfer blur and the like occur during image transfer, and transfer material clogs occur within the apparatus when the transfer material is conveyed.

The present invention has been made in view of the above, and an object of the present invention is to provide a recording apparatus that can perform highly reliable image transfer onto a transfer material.

[Structure of the Invention] (Means for Solving the Problems) The present invention includes an image carrier having a developer image on its surface, and an image carrier that is in contact with the upper part of the image carrier and rotates in synchronization with the image carrier. The image forming apparatus is characterized by comprising a transfer roller that presses the transfer material against the image carrier by moving the image carrier, and transfers the development and agent image on the image carrier to the transfer material.

(Function) In the recording apparatus of the present invention, image transfer is performed using a transfer roller that is in contact with the upper part of the image carrier. Therefore, the transfer roller rotates in synchronization with the image carrier, thereby transferring the image and conveying the transfer material. Therefore, the contact state between the image carrier and the transfer material is stabilized. As a result, it is possible to prevent transfer blurring during image transfer, transfer material clogging during transfer material transportation, and the like.

Furthermore, since the recording device of the present invention is provided with a transfer roller above the image carrier, the image is transferred to the lower surface of the transfer material, fixed, and then the transfer material is discharged from the device in a face-down state. can do.

Therefore, there is no need for a mechanism for turning over the transfer material, and the apparatus can be made more compact.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing a laser beam printer using an electrophotographic method according to an embodiment of the present invention. 1 in the diagram
is the main body of the laser beam printer device. Device body 1
A photosensitive drum 10, which is an image carrier, is placed inside. A charger 11 is installed below the photoreceptor drum 10 to uniformly charge the photoreceptor drum 10. A laser exposure device 12 that irradiates the charged photoconductor drum 10 with image-modulated laser light is arranged below the photoconductor drum 10 and to the side of the charger 11. A mirror 1 for reflecting the laser beam onto the photosensitive drum 10 on the path.
3 is placed. A developing device 15 that develops an electrostatic latent image formed on the photosensitive drum 10 with toner 14 is arranged above the laser exposure device 12 and on the side of the photosensitive drum 10 . Further, a transfer roller 17 for transferring the toner image on the photoreceptor drum 10 onto the paper 16 conveyed to the upper part of the photoreceptor drum 10 is installed in contact with the upper part of the photoreceptor drum 10 .

Toner 14 remaining on the photosensitive drum 10 after the toner image transfer is placed on the opposite side of the developing device 15 across the photosensitive drum 10.
A cleaner 18 is provided to collect the waste. An LED lamp 19 is arranged below the cleaner 18 for erasing static charges on the photoreceptor drum.

A paper transport path 2 including a transfer roller 17 is formed in the upper part of the apparatus main body 1 . The paper conveyance path 2 includes a paper cassette 20 that stores paper from the upstream side of the transfer roller 17.
a paper feed roller 21 for feeding the paper 16 from the paper cassette 20; a registration roller 22 for transporting the paper 16 fed by the paper feed roller 21 at a predetermined timing; Paper 1
6 to the upper part of the photoreceptor drum 10
The paper 16 after the transfer is sequentially provided downstream of the transfer roller 17.
a second guide 25 that guides the fixing device 2 to the fixing device 24;
A paper ejection roller 26 for ejecting the paper 16 after fixing in step 4 out of the apparatus, and a paper 16 ejected by the paper ejection roller 26.
It is provided with a paper discharge tray 27 for receiving the paper.

On the other hand, below the fixing device 24, an interface 28 is provided for connecting the apparatus main body 1 to a host system such as a word processor or a computer.

Note that although the apparatus main body 1 normally has a drive system for driving the photoreceptor drum 10, it is omitted here.

In such an apparatus, the photoreceptor drum 10 rotates in a direction (in the direction of the arrow) such that charging, exposure, development, transfer, toner removal, and charge erasing are performed thereon in this order.

The above steps are performed as follows. First, the photoreceptor drum 10 is charged with either positive or negative charge by the charger 11 . Photosensitive drum 1 having this charge
0 surface is irradiated with laser light emitted from a laser exposure device 12 via a mirror 13. Since this laser light is image-modulated, an inverted electrostatic latent image is formed on the surface of the photoreceptor drum 10. Next, the obtained electrostatic latent image is developed by a developing device 15 having a toner 14 having a charge of the same sign as the surface potential of the photoreceptor drum 10 biased with a voltage similar to that of the above-mentioned charge. That is, the photosensitive drum 1
The toner 14 adheres to the laser beam irradiated portion on the laser beam. As a result, a visible image is formed on the surface of the photoreceptor drum 10.

On the other hand, the paper 16 is transferred from the paper cassette 20 to the paper feed roller 2.
1, the sheet is conveyed at a predetermined timing by registration rollers 22, and guided between the photoreceptor drum 10 and transfer roller 17 by a first guide 23. At this time, by applying a bias voltage opposite to the charging polarity of the toner to the transfer roller 17, image transfer is performed electrostatically, and an image is formed on the paper 16. Thereafter, the paper 16 on which the image has been transferred is sent to the fixing device 24 via the second guide 25, and the toner image is fixed on the paper 16. After fixing, the paper 16 is ejected from the apparatus by a paper ejection roller 26 and placed on a paper ejection tray 27.
is supplied to

The toner 14 remaining on the photosensitive drum 10 is removed by a cleaner 18. Finally, the static charge on the photoreceptor drum 10 is erased by the LED lamp 19,
The photosensitive drum 10 is reused.

FIG. 2 is a schematic explanatory diagram of the transfer roller 17.

The transfer roller 17 includes a cylindrical core material 17a and a core material 17a.
The elastic layer 17b is provided in a cylindrical shape around the elastic layer 17b, and the resistance layer 17c is provided on the elastic layer 17b. Here, the core material 17a is made of metal such as stainless steel. The elastic layer 17b is made of soft conductive urethane rubber or the like having a resistivity of about 10<6 >[Omega]. The resistance layer 17c is made of a fluororesin or the like having a resistivity of about 10<9>Ω·(1), and has a thickness of about 100 μm. The resistance value per unit area between the core material 17a and the resistance layer 17c is approximately 107Ω/cd. The hardness of this transfer roller 17 is 10° according to JIS-A.
It is. Furthermore, two bias power supplies that apply bias voltages opposite to the toner charging polarity are connected to the transfer roller 17.

With the bias voltage applied to the transfer roller 17,
Approximately 30g is applied to the photoreceptor drum 10 by a spring material (not shown).
It is pressurized with a constant pressure of /cI11 (linear pressure per 1CI11 in the axial direction of the roller) and rotates following the photosensitive drum 1°.

Test Example A specific test example in which an image was printed using the laser beam printer shown in FIG. 1 will be shown below.

The photoreceptor drum 10 is made by coating an organic photoreceptor (OPC) on the surface of an aluminum tube, and has an outer diameter of 30I.
I11 and is rotating at a circumferential speed of 48 am/see. The charger 11 is a scorotron charger, and the voltage of the photosensitive drum 1o is approximately -560V (development position).
is charged with electricity. In the laser exposure device 12, the amount of exposure is adjusted so that the potential of the photoreceptor drum 10 irradiated with laser light becomes approximately -70V. Further, a developing bias of -450 V is applied to the sleeve of the developing device 15, and magnetic toner which is tribo-charged with FII to a negative polarity is stored inside. The transfer roller 17 has an outer diameter of -18
m+s is used.

Under the above conditions, the weight is between 30 g / rrr and 120
A paper passing test was conducted on paper of g/rrr. As a result, no paper jams occurred at all. Further, the toner image transferred onto the paper had no transfer blur and was of high quality.

The dimensions of the above laser beam printer are width 280++
It is an extremely small device with a depth of 240 mm, a depth of 240 mm, and a height of 120 mm.

The present invention is not limited to what has been described in the examples. For example, an example in which the material and configuration of the transfer roller is modified;
Methods include forming an electrostatic latent image using an ion projection head that uses a dielectric drum as an image carrier, and a method in which paper is fed from the bottom of the device body to the top of the image carrier. It is inclusive.

[Effects of the Invention] As explained above, according to the recording apparatus of the present invention, by using the transfer roller disposed in contact with the upper part of the image carrier, highly reliable image transfer can be performed on the transfer material.
In addition, it is possible to discharge the transfer material in a face-down state.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a laser beam printer using an electrophotographic method according to an embodiment of the present invention, and FIG. 2 is a schematic explanatory diagram of a transfer roller. 10... Photosensitive drum, 11... Charger 12
...Laser exposure device, 13...Mirror 14...
Toner 15...Developing device, 17...Transfer roller,
17a...Core material, 17b...Elastic layer, 17c...
Resistance layer, 18... Cleaner 19... LED lamp, 24... Fixing device, 29... Bias power supply.

Claims (1)

[Claims] An image carrier having a developer image on its surface, and a transfer material that is brought into pressure contact with the image carrier by contacting above the image carrier and rotating in synchronization with the image carrier to carry the image. A recording device comprising: a transfer roller that transfers a developer image on a body onto a transfer material.