JPS62134671A - Image recorder - Google Patents

Abstract

PURPOSE:To reduce the damage of a photosensitive body and to form distinct pictures with a high transfer rate by making the pressing the pressing force between an intermediate transfer body and a pressuring body larger than that between the photosensitive body and the intermediate transfer body and providing a heating means for the intermediate transfer body. CONSTITUTION:A photosensitive body 1, a transfer rolls 2 as the intermediate transfer body, and a pressuring roll 3 as the pressuring body are circumscribed to one another vertically, and a flash lamp 9 provided with a reflecting condensing plate 10 is provided in the transfer roll 2. The pressing force between the transfer roll 2 and the pressuring roll 3 is 60-300kg/cm<2> and is made larger than 5-50kg/cm<2> pressing force between the photosensitive body 1 and the transfer roll 2, and an image is fixed simultaneously with transfer. Thus, the photosensitive body 1 is less pressed to prevent the damage. Since the toner image is not electrostatically stuck to the transfer material but is fixed by the pressure, >=96% transfer efficiency is attained and distinct pictures are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the Invention (Field of Industrial Application) The present invention relates to an image recording apparatus using simultaneous transfer and fixing means.

(Prior art and issues to be solved) A toner image formed on the surface of an image carrier is transferred to a sheet-like transfer material mainly made of paper using electrostatic adsorption force, and then this toner image is supported. Image recording apparatuses that fix and fix toner images by applying pressure or pressure and heat to a transfer material have been widely used to date.

There is no doubt that such a device is useful from a practical standpoint, but since the toner image is electrostatically transferred to the transfer material, it is difficult to form a toner image. The rate at which the toner supplied to the image carrier is actually transferred to the transfer material, the transfer efficiency, is only 80 to 90%, and the equivalent y+1- toner is wasted, and at the same time, the image density inevitably decreases.

Also, what about toner after transfer? Since the toner is only attached to the transfer material by static and aerodynamic forces, the bond between the two is weak, and for this reason, the toner may be scattered due to the electric field existing within the device or vibrations of various parts of the device. However, there was an inconvenience that the toner image was disturbed.

In order to avoid this kind of deficiency, for example,
-134872, U.S. Pat. No. 4,195,927, etc., approximately 200 Kg/
A device that performs transfer open fixing with a pressure of cm' has been proposed, but since such a device uses strong pressure, it is necessary to first transfer a latent image onto the dielectric surface to protect the photoreceptor. This not only leads to an increase in the size of the device, but also has drawbacks such as deterioration of image quality.

Furthermore, after the electrostatic latent image formed on the photoreceptor is visualized, it is transferred to an intermediate transfer member made of silicone rubber or the like, and then this toner image is transferred to a final transfer material by applying heat.
Fixing devices are disclosed in U.S. Pat. No. 3,013,878 and U.S. Pat. No. 3,889,708.

However, in this type of product, a large amount of heat is applied that reaches near the melting point of the toner, and this heat is transmitted to the photoreceptor through the intermediate transfer member, raising the temperature of the photoreceptor and changing its characteristics. There was a risk of damage.

The present invention has been made to address the above-mentioned current situation, and is an image recording method that consumes less energy, has less risk of damaging the photoreceptor and other members, and provides high-quality images with high transfer efficiency. The purpose is to provide a device.

(2) Structure of the invention (technical means for solving the problem) In order to achieve the above object, the present invention includes a photoreceptor for forming a toner image, and a photoreceptor for receiving the toner image by being pressed against the photoreceptor with light pressure. and a pressure member that presses against the intermediate transfer member with a pressure higher than the pressure, and presses and passes a sheet-like transfer material between the intermediate transfer member and the pressure member, and It is characterized in that it is configured to instantaneously apply heat sufficient for fixing at certain positions.

With this configuration, the photoreceptor is not damaged by pressure or heat, and the toner is firmly held on the intermediate transfer body and transfer material by pressure from beginning to end, resulting in a high transfer rate of clear images without image distortion. obtained at a rate.

(Description of Embodiment) FIG. 1 is a schematic side view showing this embodiment of an image recording bag to which the present invention is applied. a photoreceptor l,
A transfer roller 2, which is an intermediate transfer body made of a transparent material such as glass, has a resin film formed on its outer surface, and has a heating source inside, is in pressure contact with this transfer roller. A pressure roller 3 serving as a pressure body is provided between which the sheet-like transfer material is run.

Around the photoreceptor, there is a primary charger 4 for uniformly charging the surface photosensitive layer, an image signal writing means 5 for forming an electrostatic latent image thereon, and a means for visualizing the latent image. developing device 6
, a cleaner 7 for removing residual toner, a static eliminating charger 7a for removing residual charges, a static eliminating lamp 7b, etc. are provided.

The contact pressure between the photoreceptor 1 and the transfer roller 2 is 9.5.
~50 Kg/cm', preferably 5-50 Kg/C
m', the contact pressure between the transfer roller 2 and the pressure roller 3 shall be appropriately determined in the range of 60 to 300 kg/cm'.

As the above-mentioned pressure-contacting means, any known appropriate means can be used, such as placing springs on the bearings at both ends of both the transfer and pressure rollers.

The photoreceptor 1 is constructed by forming a photosensitive layer made of amorphous silicon, amorphous arsenic selenium, an organic semiconductor, etc. on the surface of a metal core made of aluminum, the same alloy, a copper alloy, or the like.

Furthermore, it is preferable to form a photosensitive layer by coating or mixing a silicone resin, a fluororesin, or a block polymer having a functional group thereof on the surface of the photosensitive layer.

The thickness of the surface layer of the photoreceptor is 2 Km or less, preferably IjL
m or less, its surface roughness should be greater than 0.54 m RMS, preferably greater than 0.2 gm RMS.

As mentioned above, the transfer roller 2, which is an intermediate transfer member, is composed of a transparent cylinder made of glass or the like, and a transparent resin such as silicone rubber or urethane rubber is applied to the surface of the cylinder to a thickness of several tens of gm to several mm depending on the pressure. It is formed by forming a film to a thickness of . Further, the glass cylinder is appropriately set in the range of 3 to 7 mm so that it can absorb the pressure with the photoreceptor and the pressurizing body.

A flash lamp 9 equipped with a reflective condensing plate 10 is disposed inside the cylinder, and the light beam projected from the flash lamp 9 is condensed through a slit 12a of a control plate 12 onto a second part N2. As the Franche lamp, for example, a xenon lamp can be used, and the irradiation energy is 0.5
Joule/crn' or more, preferably 1.0 Joule/crn' or more.

The pressure roller 3, which is a pressure body, is made of a compression-resistant material such as acetal, polyimide, or polycarbonate, with a thickness of 2 to 5 mm depending on the pressure contact force with the transfer roller, on the surface of a cylindrical steel core metal. It is made by depositing a resin with excellent properties. Note that a heat source for additional heating is arranged inside the pressure roller, and the temperature of the roller is maintained at about several tens of degrees. This temperature ranges from 70 to i2o'c depending on the type of toner used.
shall be determined as appropriate within the scope of.

Depending on the thickness of the silicone rubber layer of the transfer roller, the pressure roller may be a steel roller with hard chrome plating on the surface or a highly releasable resin such as Teflon with a thickness of several grams to several tens of grams. For baking, it is also possible to use a painted roller or an aluminum roller with anodized finish.

As shown in the figure, on both sides of the pressure nip between the transfer roller 2 and the pressure roller 3, there is a series of means for processing a transfer material such as a sheet of paper, that is, a cassette 13 for storing the transfer material, and a cassette 13 for transporting the transfer material. a conveyance path 14 for transferring, a registration roller 15 for aligning the timing of the toner image on the transfer roller and the transfer material;
A tray 16 and the like for receiving completed copies are arranged.

To briefly describe the operation of the image recording apparatus configured as above, an electrostatic latent image is formed by the image signal writing means 5 on the photosensitive layer charged by the charger 4, and this is supplied from the developing device 6. A visible toner image is formed by the toner.

Next, as the photoreceptor rotates, the toner image reaches the nip portion N1 and is transferred to the transfer roller 2 by the pressure between them.

At this time, the toner that did not contribute to the transfer remains on the photoconductor, and as the photoconductor rotates, it reaches the cleaner 7 and is cleaned.Then, the residual charge is removed by the static elimination charger 7a and the static elimination lamp 7b, and the photoconductor is cleaned. is ready for the next process.

On the other hand, the toner image on the transfer roller reaches the nip portion N2 as the roller rotates.

By this time, the transfer material that has been taken out from the cassette 13, has traveled along the conveyance path 14, and has been temporarily waiting at the position of the registration rollers 15, advances in synchronization with the toner image, reaches the nip portion N2, and reaches the nip portion N2. At the position, the toner image is transferred and fixed onto the transfer material at the same time by pressure from the pressure roller 3, radiant heat from the flash lamp 9, and heat conduction from the pressure roller, completing a copy. As the pressure inner roller rotates, the paper is discharged through the conveyance path 14 and stored in the tray 16.

It is assumed that the toner remaining on the transfer roller 2 without contributing to the transfer is removed by the cleaner 8.

An image recording device like the one described below uses a photoreceptor made of an organic semiconductor covered with a silicone resin as a photosensitive layer and a transfer roller with a silicone rubber layer formed thereon, and is used to record kneaded materials of low- and medium-molecular-weight polyethylene. When copying was carried out using a mixture of pulverized and classified magnetic material, the nip portion Nl
The transfer rate is 99% at a transfer pressure of 30 Kg/am'.
, Furthermore, at the nip portion N2, the transfer pressure is 80 kg/
crn'', and the surface temperature of the pressurized cola was 90'C!, showing 96% or more.

On the other hand, when electrostatic transfer was performed directly from the photoreceptor to a transfer material under similar conditions, the transfer rate was 88%.

Further, when 100,000 sheets were passed under the above-mentioned conditions, no abnormality was observed in the images, nor was there any damage to the surface of the photoreceptor or deterioration of the characteristics.

Furthermore, if the pressure at the nip portion Nl is less than 6 kg/cm", the transfer rate will drop to less than 60%.

If it exceeds 100 Kg/am', the change in characteristics of the photosensitive layer and the abrasion will be large, and both are not practical.

Additionally, the higher the pressure at the nip N2, the higher the transfer rate, but at 300 Kg/crn' or more,
When paper is used as a transfer material, it becomes transparent or glossy and shortens the life of the transfer cola, which is the intermediate transfer medium. Not good, also 60Kg
/ cm' or less, the transfer rate will be less than 60%, which is not practical.

When transferring and fixing with heat as in the conventional example, it is necessary to heat the relevant part to 180 to 250" O, which increases the surface temperature of the photoreceptor to 80" C or more, and reduces the dark resistance of the photosensitive layer. decreases, making it impossible to obtain a stable latent image.

On the other hand, according to the above-mentioned apparatus, since a quasi-continuous Franche lamp is used, the temperature of the transfer roller does not rise above 40'C even when several hundred sheets are passed, and therefore the surface temperature of the photoreceptor also increases to 40'C. It has been confirmed that toner scattering when the lamp is turned on, which has traditionally been a problem with flash fixing, can be suppressed to about 100% by using pressure to firmly adhere the toner to the transfer material. was able to reduce it significantly.

In order to improve the fixing performance and reduce the energy consumption of flash lamps, the transfer material was preheated to a temperature of 40 to 70% to suppress changes in temperature and humidity of the transfer material due to changes in the external environment.
It is preferable to heat it to about 'C.

FIGS. 2A and 2B show only the relative arrangement of a photoreceptor 1, a transfer roller 2 as an intermediate transfer member, and a pressure roller 3 as a pressure member in another embodiment of the present invention. For example, by appropriately changing the relative positions of these three as shown in FIG. 2A, the 4R configuration, shape, and loading of the transfer material of the entire image recording apparatus can be determined.

The discharge position can be varied in various ways. Further, FIG. 2B shows a case where the intermediate transfer member is formed from two rollers 2a, 2b and a bell 2c wound around these rollers.

This configuration further increases the possibility of changing the configuration of the entire device. Also, flash lamps
It is also possible to configure a plurality of lamps to be turned on in sequence.

(3) Effects of the Invention Since the present invention has the configuration described above, the photoreceptor is suppressed at a relatively low pressure, so the load on the photoreceptor layer is light, and damage to the photoreceptor layer and deterioration of its characteristics can be prevented. can significantly extend the lifespan.

In addition, until the formed toner image is permanently fixed and fixed on the surface of the transfer material, it does not electrostatically adhere to the transfer material, so the image is not disturbed by external conditions. This method has great practical effects, such as reducing toner scattering and increasing image clarity because pressure is applied at the same time as flash fixing.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of an image recording differential according to an embodiment of the present invention, and FIGS. 2A and 2B are diagrams showing other embodiments of the present invention, particularly the relationship among the photoreceptor, intermediate transfer member, and pressure member. FIG. 3 is a schematic diagram showing the arrangement. 1... Photoconductor, 2... transfer roller, 3... pressure roller, 4... repair - next? 1) Electrical equipment, 5... Image signal writing means, 6... Φ developing device, 7 OS cleaner, 9... flash lamp, 14... transport path, 15... registration roller, N1, N2・@-Nip part. Figure 1 ζ10 Figure 2A Figure 2B

Claims (1)

[Scope of Claims] An image bearing member provided with a photosensitive layer and traveling, an intermediate transfer member that is in pressure contact with the image carrier and travels in synchronization, a pressure member that is in pressure contact with the image carrier and travels in synchronization, and the intermediate transfer member. and a means for supplying a sheet-like transfer material between the intermediate transfer body and the pressure body, the pressure contact force between the intermediate transfer body and the pressure body being equal to the pressure contact force between the image carrier and the intermediate transfer body. , and is provided with a means for heating the toner on the transfer material supplied to the pressure area of the intermediate transfer body and the pressure body by applying heat by radiation and conduction at the pressure contact area between the intermediate transfer body and the pressure body. Device.