JPH01267232A - Image recording device - Google Patents

Abstract

PURPOSE:To provide separability for a recording medium from an image bearer without disturbing a transcribed developer image, by setting the line speed of a feeder part, which delivers recording medium to the image bearer, to a level a little larger than the line speed of the image bearer. CONSTITUTION:The line speed of a feeder part roller 9 is set a little higher than that of a photo-sensitive drum 1. This produces a slack of a recording sheet 14 between the feeder part roller 9 and a transcript pole 5, and the photo- sensitive drum 1 and recording sheet 14 are put in close contact with each other in the transcript region where the transcript pole 5 with high pressure impressed in acting, and thereby the width of the substantially effective transcript region can be increased, and a toner image turned apparent can be transcribed on the recording sheet 14 without generating dust. The slack of recording sheet 14 absorbs variation in the line speed of the photo-sensitive drum 1 and feed roller 9 due to varying load and mechanical vibration, to prevent shift of the recording sheet 14 relative to the photo-sensitive drum 1, and the toner image apparent thereon can be transcribed without disturbance in the image.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image recording device, and particularly to an image recording device having a step of transferring a developer image visualized on an image carrier having a curvature to a recording medium. Regarding equipment.

[Conventional technology]

Image recording apparatuses having a step of transferring a developer image visualized on an image carrier onto a recording medium such as recording paper include electrophotographic copying machines, optical printers, and ion deposit printers.

In the image forming process of electrophotographic copying machines and optical printers, the surface (circumferential surface) of an image bearing member (in this case, a photosensitive drum) is uniformly charged by a charging beam, and in the case of electrophotographic copying machines, an image is formed from the original. By irradiating reflected light, an electrostatic latent image is formed by irradiating an optical printer, especially a laser beam according to the information in the case of a laser beam printer, and a developer such as toner is applied to this electrostatic latent image. The recording paper is brought into contact with the developer and visualized as a developer image, the recording paper is guided from the feeding section to the surface of the image carrier, and the developed developer image is transferred from the back side of the recording paper to which high pressure is applied by the action of a transfer pole. After transferring it onto recording paper by
The recording paper is separated from the surface of the image carrier by the action of a separation electrode or the like to which high-voltage AC power is applied, and the separated recording paper is heated by a conveying section. The developer image is introduced into a fixing device, and the developer image on the recording paper is fixed as a permanent image. The surface of the transfer and minute image carrier is cleaned by a cleaning device, and
Prepare for the next image forming process.

In the transfer process, in order to faithfully transfer the developer image visualized on the image carrier onto the recording paper, it is necessary to must be in close contact with the image carrier, and the line speed between the recording paper and the image carrier (referring to the speed in the moving direction of the recording paper and the speed in the circumferential direction of the image carrier; the same applies hereinafter)
must be in sync.

Further, in the separation process, in order to separate the recording paper onto which the developer image has been transferred from the image carrier without disturbing the developer image, the line speeds of the recording paper and the image carrier must be synchronized.

In conventional image recording devices, the transfer process and separation process are affected by external factors 1 such as load fluctuations, rotational fluctuations of the drive motor, mechanical vibrations of the device, etc. (hereinafter simply referred to as load fluctuations 1 mechanical vibrations, etc.). However, the above-mentioned conditions were not always met.

However, in conventional electrophotographic copying machines and optical printers with low resolution, slight load fluctuations, mechanical vibrations, etc. have not been considered a problem. In other words, if a transfer electric field is applied to an area where the recording paper is not in close contact with the image carrier, some dust may appear around the image such as characters (while the developer moves from the image carrier to the recording paper, some dust may appear around the image). (a phenomenon of scattering) may occur, or
If the line speeds of the recording paper and the image carrier differ, misalignment between the recording paper and the image carrier (hereinafter referred to as paper misalignment) may occur, but conventional electrophotographic copying In the case of printers, this did not pose a problem due to fluctuations in the moving speed of the document table and the poor resolution of the imaging lens, and in the case of low-resolution optical printers, the dot pitch was large.

[Problem to be solved by the invention]

However, due to the miniaturization of image recording devices and the simplification of device configurations, transfer poles have been placed opposite the curved portions of image carriers that have a curvature, and image carriers with smaller diameters have also come to be used. It has become difficult to ensure a sufficiently wide contact width between the recording medium and the image carrier in the transfer area.

In addition, high-resolution optical printers are required due to the need for reproducibility of gradation images, and it is necessary to ensure adhesion between the recording paper and the image carrier and to synchronize the line speed between the recording paper and the image carrier. It's coming.

For example, in Japanese Patent Application Laid-Open No. 61-212872, the line speed of a conveyance roller that sends a recording paper having a developer image transferred from an image carrier onto a fixing device to a fixing device is slightly faster than the line speed of the image carrier. Although a copying apparatus has been disclosed, the adhesion of the recording paper to the image carrier is insufficient, and the recording paper may slip on the image carrier.
There is also the problem that paper misalignment may occur.

In view of the above-mentioned points, an object of the present invention is to prevent poor adhesion and misalignment between a recording medium and an image carrier when a developer image visualized on an image carrier having a curvature is transferred to a recording medium. It is an object of the present invention to provide an image recording device that can prevent the above phenomenon and transfer a visualized developer image onto a recording medium without disturbing the image.

Another object of the present invention is to prevent misalignment between the recording medium and the image carrier when separating the recording medium to which the developer image has been transferred from the image carrier having a curvature. An object of the present invention is to provide an image recording device that can separate a recording medium from an image carrier without disturbing the image.

[Means for Solving the Problem] In order to achieve the above object, the image recording device of the present invention has the following features:
In an image recording apparatus having a step of transferring a developer image visualized on an image carrier having a curvature to a recording medium, the line speed of a feeding section that feeds the recording medium toward the image carrier is set as described above. It is characterized by being set slightly faster than the line speed of the image carrier.

Further, the image recording apparatus of the present invention is an image recording apparatus having a step of transferring a developer image visualized on an image carrier having a curvature to a recording medium. It is characterized in that the line speed of the feeding and feeding section for feeding out the recording medium separated from the body is set to be slightly slower than the line speed of the 11th image carrier.

[Effect]

In the image recording apparatus of the present invention, by making the line speed of the feeding section slightly faster than the line speed of the image carrier, slack is created in the recording medium between the feeding section and the transfer section, so that the recording medium and the image This prevents the occurrence of dust in the transfer process by bringing the carrier into close contact with the recording medium over a wide range using a transfer electric field, and also absorbs changes in the line speed of the feeding section and image carrier due to load fluctuations, mechanical vibrations, etc. To prevent paper misalignment with an image carrier and to transfer a developer image visualized on an image carrier to a recording medium without causing image disturbance.

In addition, in the image recording apparatus of the present invention, by making the line speed of the conveyance section slightly slower than the line speed of the image carrier, slack is caused in the recording medium between the separation section and the conveyance section, and load fluctuations are caused. Absorbs changes in the line speed of the image carrier and conveyance unit due to mechanical vibrations, etc. to prevent misalignment between the recording medium and the image carrier, and does not disturb the recording medium onto which the developer image has been transferred. Separate it from the image carrier.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a sectional view showing a laser beam printer according to an embodiment of the image recording apparatus of the present invention.

This laser beam printer consists of a photosensitive drum 1 as an image carrier that rotates in the direction of the arrow, a charging electrode 2 that uniformly charges the surface of the photosensitive drum 1, and a laser beam irradiated onto the surface of the photosensitive drum l to staticize it. an optical system 3 that forms an electric latent image;
A developing device 4 that visualizes the electrostatic latent image formed on the photosensitive drum 1 as a toner image, a transfer pole 5 that transfers the toner image on the photosensitive drum 1 to a recording paper 14 that is a recording medium, and a photosensitive drum. a separating unit 6 that separates the recording paper 14 that is in close contact with the photosensitive drum 1 from the photosensitive drum 1; an eraser lamp 7 that removes charges from the surface of the photosensitive drum 1; and a cleaning device 8 that removes toner remaining on the surface of the photosensitive drum 1. , a feeding unit roller 9 that feeds the recording paper 14 toward the photosensitive drum 1, and a conveying unit 1 that feeds the recording paper I4 from the photosensitive drum 1:
A heat roller fixing device 10 that also serves as a J-ra and a paper feed cassette 1
Paper feed section roller 1 that takes out recording paper 14 stacked in 5
1, feeding section guide section +AL2, and conveying section guide member 1
3, recording paper 14, paper feed cassette 15, and paper discharge tray 16. Note that the reference numeral 17 indicates a housing of the laser beam printer.

Next, the operation of the laser beam printer as the image recording apparatus of this embodiment configured as described above will be explained.

As the photosensitive drum 1 rotates, the charged electrode 2
charge the surface uniformly. The photosensitive drum 1 charged in the negative direction is selectively exposed to a laser beam from the optical system 3, and an electrostatic latent image is formed on its surface. This electrostatic latent image is visualized as a toner image by the developing device 4.

On the other hand, the recording paper 14 stacked in the paper feed cassette 15 is
The paper is taken out by the feeding unit roller 11 and then transferred to the feeding unit roller 9.
The photosensitive drum 1 and the transfer pole 5 are fed into the opposing transfer section via the feeding section guide member 12, and the transfer pole 5 electrostatically charges the photosensitive drum 1 by the electric charge on the back surface of the recording paper 14. The toner images that have been superimposed and developed on the photosensitive drum 1 are transferred to the surface. Thereafter, the recording paper 14 is separated from the photosensitive drum 1 by applying an alternating current electric field to its back surface by the separation electrode 6.

The recording paper 14 separated from the photosensitive drum 1 is guided via the conveyance section guide member 13 to a thermal roller fixing device IO that also serves as a conveyance section roller, is thermally fixed, and is discharged onto a paper discharge tray 16.

After the recording paper 14 has been separated, the photosensitive drum 1 has its remaining charges erased by an eraser lamp 7, and then its remaining toner is removed by a cleaning device 8, in preparation for the next image forming process.

In the above configuration, as a result of various experiments, the inventors of the present invention set the line speed of the feeding section roller 9 to be slightly faster than the line speed of the photosensitive drum 1, thereby achieving a value as shown in the second threshold. , a slack is created in the recording paper 14 between the feeding section roller 9 and the transfer pole 5, and the photosensitive drum l and recording i14 are brought into close contact with each other in the transfer area where the transfer pole 5 applied with high pressure acts. It was confirmed that the width of the effective transfer area could be widened and that the developed toner image could be transferred onto the recording paper 14 without causing dust. In addition, load fluctuations 2 due to slack in the recording paper 14 between the feeding roller 9 and the transfer pole 5 absorb changes in the line speed of the feeding roller 9 and the photosensitive drum l due to mechanical vibrations, etc. It was confirmed that paper displacement of the recording paper 14 against the paper can be prevented, and that the toner image developed on the photosensitive drum 1 can be transferred to the recording paper 14 without disturbing the image.

Further, as a result of various experiments, the inventors of the present invention and others have found that by setting the line speed of the heat roller fixing device 10, which also serves as a conveyor roller, to be slightly slower than the line speed of the photosensitive drum l, as shown in FIG. In addition, slack is created in the recording paper 14 between the photosensitive drum 1 and the heat roller fixing device 1o, and load fluctuations 2 that occur when the recording paper 14 is conveyed are absorbed, such as mechanical vibrations, etc. It was confirmed that misalignment could be prevented and that the recording paper 14 to which the toner image was transferred could be separated from the photosensitive drum 1 without disturbing the toner image.

In the above embodiment, a laser beam printer was used as an example of the image recording device, but even in an electrophotographic copying machine that requires high resolution, the line speed of the feeding section is set slightly higher than the line speed of the image carrier. Set up fast,
It goes without saying that similar effects and effects can be obtained by setting the line speed of the conveyance section to be slightly slower than the line speed of the image carrier.

FIG. 3 is a sectional view of a main part showing a modification of the image recording apparatus of the embodiment shown in FIG. The image recording apparatus of this example is the same as the image recording apparatus shown in FIG. 1, except that the conveying section roller 18 is provided separately from the heat roller fixing device 10 (not shown in FIG. 3). Even in such an image recording apparatus, the same operation and effect as in the case of the image recording apparatus of the embodiment shown in FIG. 1 can be obtained.

Further, as shown in FIG. 4, based on the information, the recording head 42 applies electric charges to the surface of the dielectric drum 41, which is an image carrier, to form an electrostatic latent image, and this electrostatic latent image is developed. An ion deposit printer in which an image is visualized with a developer by a device 43, and the visualized developer image is transferred and fixed onto a recording paper 45 by a transfer fixing roller 44 having both transfer and fixing functions to obtain a permanent image. Also, the line speed of the feeding section roller 46 is set slightly faster than the line speed of the dielectric drum 41, and
By setting the line speed of No. 7 slightly slower than the line speed of dielectric drum 41, it is possible to obtain the same functions and effects as in the case of the image recording apparatus of the embodiment shown in FIG.

Further, in each of the above embodiments, a case is explained in which rollers are used as both the feeding section and the conveyance section, but it is also possible to apply an image recording apparatus that uses a heald feeding system as the feeding section and the conveyance section. The invention can be applied in the same way.

〔Effect of the invention〕

As described above, according to the present invention, in an image recording apparatus that has a step of transferring a developer image visualized on an image bearing member having a curvature to a recording medium, the line speed of the feeding section is adjusted to an image. By setting the line speed slightly faster than the line speed of the carrier, ■ The slack of the recording medium that occurs between the feeding section and the transfer section allows the image carrier and the recording medium to be spread over a wide width within the transfer area where the transfer pole acts. This allows for close contact and effectively prevents dust from forming.

■ The slack in the recording medium that occurs between the feeding section and the transfer section can absorb the load fluctuation 1 mechanical vibration that occurs when feeding the recording medium, and prevent paper misalignment. The developed developer image can be transferred to the recording medium without disturbing the image. ■ Even if the diameter of the image carrier is reduced in response to the miniaturization of image recording devices, the feeding section and transfer The slack of the recording medium that occurs between the recording medium and the image carrier allows for a wide contact width between the recording medium and the image carrier, so the rolling performance is not degraded. ■ Even at the leading edge of the recording medium. , due to slack in the recording medium that occurs between the feeding section and the transfer section, the recording medium and the image carrier can be spread over a wide KM? Since it can be kneaded to bring it into close contact, sufficient transfer performance can be obtained even at the leading edge of the recording medium. ■ Even with stiff recording media, the slack in the recording medium that occurs between the feeding section and the transfer section makes it possible to record. Since the medium and the image carrier can be brought into close contact over a wide range, stable transfer performance can be ensured.

Further, according to the present invention, in an image recording apparatus having a step of transferring a developer image visualized on an image carrier having a curvature to a recording medium, the line speed of the conveying section is set to the line speed of the image carrier. By setting the setting slightly slower than 1, the load fluctuation caused by the slack of the recording medium between the separating section and the conveying section 1 mechanical vibrations that occur during conveyance of the recording medium can be absorbed and the paper between the recording medium and the image carrier can be Misalignment can be prevented, and the recording medium to which the developer image has been transferred can be separated from the image carrier without disturbing the developer image. It is possible to absorb the load fluctuation 2 mechanical vibrations that occur during transport of the recording medium due to slack in the recording medium that occurs between the recording medium and the image carrier, and prevent misalignment between the recording medium and the image carrier. The recording medium onto which the image has been transferred can be separated from the image carrier without disturbing the developer image. ■ Even if the recording medium is stiff, the recording medium can be loosened due to the slack in the recording medium that occurs between the separation section and the conveyance section. It is possible to prevent paper misalignment between the recording medium and the image carrier by absorbing load fluctuations 9 mechanical vibrations etc. that occur during conveyance, so the recording medium to which the developer image has been transferred can be moved without disturbing the developer image. There are effects such as being able to separate it from the image carrier.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a laser beam printer according to an embodiment of the image recording device of the present invention, FIG. 2 is a cross-sectional view of essential parts for explaining the operation of the laser beam printer shown in FIG. 3 is a sectional view of a main part showing a modification of the image recording device shown in FIG. 1, and FIG. 4 is a sectional view of a main part showing an ion deposit printer according to another embodiment of the image recording device of the present invention. . In the figure, 1... Photosensitive drum, 2... Charging electrode, 3... Optical system, 4... Developing device, 5... Transfer pole, 6... Separation pole, 7... Eraser. Lamp, 8...Cleaning device, 9...Feeding section roller, 10...Heat roller setter which also serves as a conveying section, 11...
Paper feed section roller, 18... Conveyance section roller, 14... Recording paper, 41... Dielectric drum, 42... Recording head, 43... Developing device, 44... Transfer fixing roller, 45... Recording paper, 46... Feeding unit roller, 47... Conveying unit roller. Patent issuer

Claims (2)

[Claims] (1) In an image recording apparatus having a step of transferring a developer image visualized on an image carrier having a curvature to a recording medium, a line of a feeding section that feeds the recording medium toward the image carrier. An image recording apparatus characterized in that the speed is set slightly faster than the line speed of the image carrier. (2) In an image recording apparatus having a step of transferring a developer image visualized on an image carrier having a curvature to a recording medium, the record separated from the image carrier after the developer image is transferred; An image recording apparatus characterized in that a line speed of a conveying section for sending out a medium is set to be slightly slower than a line speed of the image carrier.