CN206331237U - A kind of image processing system of electrofax mode - Google Patents

Abstract

The utility model provides an electrophotographic image forming device, comprising: a charging device, including a rotatable charging roller equipped with a voltage applying mechanism, which is in tangential contact with a photoreceptor formed by coating a film on the surface of a circular tube-shaped conductive support to energize it; the voltage applying mechanism includes a DC transformer and an AC transformer, which energizes the photoreceptor by superimposing the DC voltage on the AC voltage, and the frequency Hv of the voltage applying mechanism is between 1.15≦Hv≦1.25kHz , The peak-to-peak voltage Vpp is fixed or variable between 1.0≦Vpp≦1.8kV, and the roller speed of the charging roller is greater than or equal to 225mm/sec. The utility model limits the roller linear speed and voltage frequency of the charging roller, so that the image forming part does not produce image defects such as interference stripes, missing pixels, or latent image flow, and at the same time, it can prevent noise caused by resonance, and can be highly efficient. Fine quality at voltage. In addition, the cost of the image forming apparatus can be reduced by using a structure in which a high-voltage power supply and a photoreceptor cooperate.

Description

An electrophotographic image forming device

technical field

The utility model relates to the field of image formation, in particular to an image forming device in an electrophotographic mode.

Background technique

Most of the existing office spaces use a set of image forming devices (MFP: Multi-Functional Peripheral) as public office equipment. The image forming devices operate through the following steps: The image reading device scans and places on the transparent reading glass through the scanning device. The image data is generated and sent to the image forming unit. The image forming unit charges the surface of the photoreceptor with a charging roller, and the charged photoreceptor absorbs toner of opposite polarity to form a toner image on the surface of the photoreceptor. Then the toner image on the photoreceptor is transferred to the transfer belt device, and the transfer belt device body transfers the toner image to the medium, and the medium with the toner image transferred is pressurized and fixed on both sides of the medium by the fixing device. Heat to fix the toner image to the media, and the fixed media is ejected to the output tray.

In the past, the image forming unit needed to apply a high voltage with a voltage frequency of 0.5-2kHz and a peak-to-peak voltage of 1-3kV to the charging roller to obtain a defect-free, high-quality image.

The cost of the high-voltage power supply in this way is high, and the amount of ozone generated is large. In order to meet the environmental standards, an ozone filter and a fan are required, which increases the cost of the image forming device.

Utility model content

In order to solve the above-mentioned problems in the prior art, the utility model provides an image forming device that can reduce the cost of high-voltage power supply and the amount of ozone generated.

Specifically, an embodiment of the present invention provides an electrophotographic image forming device, which includes:

The charging device includes a rotatable charging roller equipped with a voltage application mechanism, which is in tangential contact with the photoreceptor formed by coating the film on the surface of the cylindrical conductive support to charge it;

An optical device for irradiating light on the photoreceptor to eliminate the charge at a specified position on the photoreceptor to form a specific exposure latent image;

a developing device for imparting toner to the exposed latent image on the photoreceptor through a toner cartridge to form a toner image;

a transfer device, which transfers the toner image to the object to be transferred by using a transfer belt;

a fixing device, which uses a heating roller to fix the toner image on the transferred body and output it;

The voltage applying mechanism includes a DC transformer and an AC transformer, which energizes the photosensitive body by superimposing the DC voltage on the AC voltage, the frequency Hv of the voltage applying mechanism is between 1.15≦Hv≦1.25 kHz, and the peak-to-peak voltage Vpp is between 1.0≦Vpp≦1.8kV is fixed or variable, and the linear speed of the charging roller is greater than or equal to 225mm/sec.

In another embodiment of the present invention, an electrophotographic image forming device is provided, which has:

The charging device includes a rotatable charging roller equipped with a voltage application mechanism, which is in tangential contact with the photoreceptor formed by coating the film on the surface of the cylindrical conductive support to charge it;

An optical device for irradiating light on the photoreceptor to eliminate the charge at a specified position on the photoreceptor to form a specific exposure latent image;

a developing device for imparting toner to the exposed latent image on the photoreceptor through a toner cartridge to form a toner image;

a transfer device, which transfers the toner image to the object to be transferred by using a transfer belt;

a fixing device, which uses a heating roller to fix the toner image on the transferred body and output it;

The conductive support body is composed of an aluminum alloy hollow cylinder with a thickness of more than 1.1 mm, and the voltage applying mechanism includes a DC transformer and an AC transformer, which energize the photoreceptor by superimposing a DC voltage with an AC voltage, and the voltage The frequency Hv of the applying mechanism is greater than or equal to 1.25, the peak-to-peak voltage Vpp is fixed or variable between 1.0≦Vpp≦1.8kV, and the roller speed of the charging roller is above 225mm/sec.

The utility model limits the roller speed and voltage frequency of the charging roller, so that the image forming part does not produce image defects such as interference stripes, missing pixels, or latent image flow, and at the same time prevents noise caused by resonance, and can achieve The fine picture quality at high voltage in the existing technology. In addition, the cost of the image forming device can be reduced by using a structure in which a high-voltage power supply and a photoreceptor cooperate.

Description of drawings

FIG. 1 is a schematic structural diagram of an image forming device according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of an image forming unit according to an embodiment of the present invention;

Fig. 3 is a structural schematic diagram of supplying power to the charging roller in an embodiment of the present invention;

Figure 4 is a schematic diagram of the high voltage output range when the AC transformer uses a ferrite core.

detailed description

Hereinafter, the image forming apparatus according to the embodiment will be described in detail with reference to the drawings. In addition, the same place in each figure is marked with the same symbol.

FIG. 1 is a schematic structural diagram of an image forming apparatus according to an embodiment of the present invention.

In FIG. 1 , the image forming apparatus 100 is, for example, an MFP (Multi-Function Peripherals, multi-function peripherals), a printer, a copier, etc., which are multi-function machines. In the following description, an MFP will be used as an example.

An upper portion of a main body 11 of the MFP 100 has a document table, and an automatic document feeder (ADF) 12 is provided on the document table so that it can be opened and closed freely. In addition, the upper part of the main body 11 is provided with an operation panel 13 . The operation panel 13 has an operation unit 14 composed of various keys and a touch panel-type display unit 15 .

A scanning unit 16 is provided at a lower portion of the ADF 12 inside the main body 11 . The scanner unit 16 reads a document conveyed by the ADF 12 or a document placed on a document table, and generates image data. In addition, the central part of the main body 11 has a printing unit 17, and the lower part of the main body 11 has a plurality of paper feeding cassettes 18 capable of accommodating paper of various sizes.

The printing unit 17 includes a photoreceptor, a laser, etc., and processes image data read by the scanner unit 16 or image data created by a PC (Personal Computer), and forms an image on paper (details will be described later). The printing unit 17 is, for example, a tandem color laser printer, and scans the photoreceptor with a laser beam from an optical scanning device (laser unit) 19 to generate an image.

The printing unit 17 includes image forming units 20Y, 20M, 20C, and 20K for respective colors of yellow (Y), magenta (M), cyan (C), and black (K). The image forming units 20Y, 20M, 20C, and 20K are arranged in parallel from upstream to downstream on the lower side of the intermediate transfer belt 21 .

Toner cartridges 28 for supplying toner to the developing devices 24Y- 24K are provided above the image forming units 20Y- 20K. The toner cartridges 28 include toner cartridges (28Y, 28M, 28C, 28K) for respective colors of yellow (Y), magenta (M), cyan (C), and black (K).

The intermediate transfer belt 21 moves cyclically, and semiconductive polyimide, for example, can be used in consideration of heat resistance and abrasion resistance. The intermediate transfer belt 21 is stretched over the drive roller 32 and the driven rollers 33 and 34 , and the intermediate transfer belt 21 faces and contacts the photoreceptors 22Y- 22K. A primary transfer voltage is applied via a primary transfer roller 25Y to a position where the intermediate transfer belt 21 faces the photoreceptor 22Y, whereby the toner image on the photoreceptor 22Y is primarily transferred to the intermediate transfer belt 21 .

The drive roller 32 over which the intermediate transfer belt 21 is stretched is arranged opposite to the secondary transfer roller 35 . When the paper S passes between the driving roller 32 and the secondary transfer roller 35, a secondary transfer voltage is applied through the secondary transfer roller 35, so that the toner image on the intermediate transfer belt 21 is secondarily transferred to the paper S. superior. A belt cleaner 36 is provided near the driven roller 34 of the intermediate transfer belt 21 .

The light scanning device 19 scans the laser beam emitted from the semiconductor laser element in the axial direction of the photoreceptor 22, and the light scanning device 19 includes a polygon mirror 19a, an imaging lens system 19b, a mirror 19c, and the like.

In addition, as shown in FIG. 1, between the paper feeding cassette 18 and the secondary transfer roller 35, there are provided a separation roller 37 and a conveying roller 38 for taking out the paper S in the paper feeding cassette 18. Between the secondary transfer roller 35, A fixing unit 39 is provided downstream. Further, a conveying roller 40 is provided downstream of the fixing unit 39 , and the paper S is conveyed by the conveying roller 40 and discharged to the paper discharge unit 41 .

Further, downstream of the fixing unit 39, a reverse conveyance path 42 is provided. The reverse conveying path 42 reverses the paper S and guides it toward the secondary transfer roller 35, and is used for duplex printing.

In addition, a finisher (finisher) may be disposed adjacent to the image forming apparatus 100 . In the image forming apparatus 100 connectable to the finisher, another conveying roller is provided downstream of the conveying roller 40 to discharge the sheet S to the finisher. The finisher staples, punches holes, or folds sheets in half and ejects them.

Next, the operation of the image forming apparatus 100 in FIG. 1 will be described. When image data is input from the scanner unit 16 or a PC, images are sequentially formed in the respective image forming sections 20Y- 20K.

Taking the image forming unit 20Y as an example, the photoreceptor 22Y is irradiated with a laser beam corresponding to yellow (Y) image data to form an electrostatic latent image. Furthermore, the electrostatic latent image on the photoreceptor 22Y is developed by the developer 24Y, and a yellow (Y) toner image is formed.

The photoreceptor 22Y is in contact with the rotating intermediate transfer belt 21 and primary transfers a yellow (Y) toner image onto the intermediate transfer belt 21 by the primary transfer roller 25Y. After the photoreceptor 22Y primarily transfers the toner image to the intermediate transfer belt 21, the residual toner is removed by the cleaner 26Y and the paddle 27Y, so that the next image can be formed.

In the same manner as the yellow (Y) toner image forming process, toner images of magenta (M), cyan (C), and black (K) are formed by the image forming sections 20M to 20K, and each toner image is sequentially transferred to the middle. The same position as the yellow (Y) toner image on the transfer belt 21, so that yellow (Y), magenta (M), cyan (C), and black (K) colors are superimposedly transferred onto the intermediate transfer belt 21. Adjust the image to get a full-color adjusted image.

The intermediate transfer belt 21 secondarily transfers the full-color toner image onto the sheet S collectively by the transfer bias of the secondary transfer roller 35 . Simultaneously with the arrival of the full-color toner image on the intermediate transfer belt 21 to the secondary transfer roller 35 , the paper S is supplied from the paper feed cassette 18 to the secondary transfer roller 35 .

The sheet S on which the toner image is secondarily transferred reaches the fixing unit 39, and the toner image is fixed. The paper S on which the toner image is fixed is discharged to the paper discharge unit 41 by the conveyance roller 40 . In addition, after the secondary transfer on the intermediate transfer belt 21 is completed, the residual toner is removed by the belt cleaner 36 .

As shown in FIGS. 2 and 3 , in the image forming unit 20 of the present invention, the charging roller 202 has a voltage applying mechanism 204 for applying a specified voltage and frequency to the charging roller 202 . The charging roller 202 is tangent to the photoreceptor 201, and is in press contact with the surface of the photoreceptor 201 under the control of the pressing mechanism. The photoreceptor 201 is generally formed by coating the outer surface of the cylindrical conductive support 203.

When the photosensitive body 201 rotates, it will drive the charging roller 202 to rotate drivenly, so that the charging roller 202 and the photosensitive body 201 rotate together. At this time, a high voltage is applied to the charging roller 202 by the voltage applying mechanism 204, and discharge occurs in a small space near the contact between the charging roller 202 and the photoreceptor 201, thereby charging the photoreceptor 201. The high voltage here is generally the self-contained high voltage realized by superimposing the DC voltage generated by the DC transformer with the AC voltage generated by the AC transformer. By alternating discharge of the AC component, the DC component is concentrated and stable charging is obtained.

Here, as parameters of the AC component, it is necessary to control its frequency and peak-to-peak voltage. The frequency affects the discharge interval. Compared with the linear velocity when the image is formed, if the frequency (that is, the discharge interval) is longer, then, in the discharge interval, you can see the unevenness of the image. And if the frequency exceeds a certain frequency value, it will resonate with the micro-vibration of the photoreceptor 201 or the exposure device, thereby causing interference fringes on the image. Therefore, a specific frequency range must be selected relative to a specific linear velocity.

Based on the above conditions, in this embodiment, when the linear velocity of the charging roller 202 is limited to be greater than or equal to 225 mm/s, the voltage frequency Hv of the voltage applying mechanism 204 is between 1.15≦Hv≦1.25 kHz, and the peak-to-peak voltage Vpp is between 1.15≦Hv≦1.25 kHz. 1.0≦Vpp≦1.8kV is fixed or variable, and this range is the voltage frequency and peak-to-peak voltage applied to the charging roller by the voltage application mechanism. The unevenness of the toner image and the phenomenon of noise streaks caused by the discharge interval can be avoided by the above arrangement.

In another embodiment of the present invention, the iron core of the AC transformer that applies pressure to the charging roller 202 may use a ferrite system. The iron core of the AC transformer is conventionally made of a ferrite system or a metal system, and the metal system core can output a large peak-to-peak voltage. When the peak-to-peak voltage becomes larger, the charging can also be averaged and image defects can be prevented, but the cost of this method is relatively high. Ferrite cores, on the other hand, are not commonly used because of the lower voltage generated.

As shown in Figure 4, in this embodiment, the frequency of the charging roller 202 is selected between 1.15-1.25kHz, and when the peak-to-peak voltage is between 1.0-1.8kV, a low-cost ferrite core can be used. The iron core can obtain a good image effect within the above range, and at the same time realize the cost reduction of the high-voltage power supply.

In another embodiment of the present invention, the cutting pitch of the conductive support 203 of the photoreceptor 201 is less than 400 μm.

In another embodiment of the utility model, the conductive support 203 of the photoreceptor 201 may be formed of a hollow aluminum alloy cylinder with a thickness of 1.0 mm or less. Generally, the diameter of the photoreceptor is larger than that of the charging roller to increase the formation area of the toner image.

In an embodiment of the present utility model, the conductive support body 203 of the photoreceptor 201 may also be composed of a hollow aluminum alloy cylinder with a thickness of 1.1 mm or more.

In one embodiment of the present utility model, when the charging width in the charging process by the charging roller is X (mm), and the amount of ozone generated around the contact nip line between the charging roller and the photoreceptor is Y (ppm), X/ Y×1000≦9.2. This limitation mode can reduce the amount of ozone generated by the image forming apparatus.

At the same time, when the charging roller 202 imparts charges to the photoreceptor 201, its roller linear speed is at least 225mm/sec, the frequency can be less than or equal to 1.15HV, and the peak-to-peak voltage can be 1.0-1.8kV.

Through the above structure, the present embodiment provides an image forming apparatus that does not generate image defects such as interference fringes, missing pixels, latent image flow, etc., avoids noise caused by resonance, and can reproduce fine image quality. In addition, the cost of the image forming apparatus can be reduced through the cooperative structure of the high-voltage power supply and the photoreceptor.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the present invention. These new embodiments can be implemented in various other forms, and various omissions, substitutions, combinations, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the present invention, and are included in the present invention described in the claims and its equivalent scope.

Claims (7)

1. a kind of image processing system of electrofax mode, possesses:

Charging system, including possess the rotatable charged roller of voltage applying mechanism, with being applied on tubular conductive support body surface The photoreceptor of film formation is tangent to be contacted to assign electricity to it；

Optical devices, form special on the photoreceptor by light irradiation to eliminate the electric charge of specified location on the photoreceptor Fixed exposure sub-image；

Developing apparatus, is assigned by toner cartridge and exposed on the photoreceptor sub-image with toner, form toner picture；

The toner picture, is transferred on transfer printing body by transfer device using transfer belt；

Fixing device, carries out exporting after being fixed using heating roller to the toner picture on the transfer printing body；

It is characterized in that,

The voltage applying mechanism includes DC transformers and AC transformers, and it gives the photoreceptor by the overlapping AC voltages of D/C voltage Assign electricity, the frequency Hv of the voltage applying mechanism between 1.15≤Hv≤1.25kHz, between peak value voltage Vpp in 1.0≤Vpp Fixed or variable between≤1.8kV, the roller linear velocity of the charged roller is more than or equal to 225mm/sec.

2. image processing system according to claim 1, it is characterised in that,

The cutting pitch of the conductive support body is less than or equal to 400 μm.

3. image processing system according to claim 1 or 2, it is characterised in that,

The Optical devices are laser scan units, carry out following sub-images and are formed, that is, when forming the exposure sub-image of uniform concentration Sub-image structure is to be made up of the continuous of the line with specific pitch or site.

4. image processing system according to claim 3, it is characterised in that,

The iron core for producing the AC transformers of the AC voltages is ferrite system iron core.

5. image processing system according to claim 4, it is characterised in that,

It is X (mm), the charged roller pressure of the contact with the photoreceptor by the powered width in the powered process of the charged roller When the ozone amount for printing the generation of line periphery is Y (ppm), X/Y × 1000≤9.2.

6. image processing system according to claim 5, it is characterised in that,

The hollow aluminium alloy cylinder that the conductive support body is less than or equal to 1.0mm by thickness is constituted.

7. a kind of image processing system of electrofax mode, possesses:

Charging system, including possess the rotatable charged roller of voltage applying mechanism, with being applied on tubular conductive support body surface The photoreceptor of film formation is tangent to be contacted to assign electricity to it；

Optical devices, form special on the photoreceptor by light irradiation to eliminate the electric charge of specified location on the photoreceptor Fixed exposure sub-image；

Developing apparatus, is assigned by toner cartridge and exposed on the photoreceptor sub-image with toner, form toner picture；

The toner picture, is transferred on transfer printing body by transfer device using transfer belt；

Fixing device, carries out exporting after being fixed using heating roller to the toner picture on the transfer printing body；

It is characterized in that,

The conductive support body is made up of more than thickness 1.1mm aluminium alloy hollow cylinder, the voltage applying mechanism bag DC transformers and AC transformers are included, it assigns electricity, the voltage applying mechanism by the overlapping AC voltages of D/C voltage to the photoreceptor Frequency Hv be more than or equal to 1.25, voltage Vpp fixed or variable, charged rollers between 1.0≤Vpp≤1.8kV between peak value Roller linear velocity in more than 225mm/sec.