JPH0640230B2 - Image recorder - Google Patents

Description

The present invention relates to an image recording apparatus that records an image on a recording sheet using an electrophotographic process.

[Conventional technology]

The conventional electrophotographic process was used in 1938 by American CF
Many applications of the Carlson method invented by Carlson include a xerographic device as an example of a typical image recording device.

FIG. 3 is a schematic side view showing a conventional image recording apparatus utilizing such an electrophotographic process.

In the figure, reference numeral 1 denotes a photoconductor configured by providing a photosensitive layer on the outer peripheral surface of a cylindrical conductive base material. Along the outer peripheral surface of the photoconductor 1, a charging unit 2, a developing unit 3, a developing unit 3 and A casing 5 containing the toner 4, a transfer charging unit 6, a fixing unit 7, a discharging unit 8, and a cleaning unit 9 are arranged in the order of the recording process.

The developing means 3 includes a sleeve 3a disposed inside the opening of the container 5 facing the photoconductor 1 and a sleeve 3a.
It is constituted by a magnet roll 3b which is rotatably arranged in a non-contact manner therein, wherein the magnet roll 3b is divided into a plurality of N poles and S poles alternately in the circumferential direction. It has a structured structure.

Reference numeral 10 denotes a recording sheet sent from a sheet feeding unit (not shown) between the photoconductor and the charging transfer unit 6, and the charging unit 2
An arrow L between the developing means 3 and the developing means 3 is a light beam for exposure from an optical writing means (not shown).

FIG. 4 is an explanatory diagram showing a basic recording process of the conventional image recording apparatus having the above-mentioned configuration, and the operation will be described with reference to this figure.

First, as shown in FIG. 3, the photosensitive member 1 is rotated at a constant speed in an hourly manner in a dark environment, and the charging unit 2 uniformly charges the surface of the photosensitive member 1 by corona discharge or frictional charging. Let

After that, when the surface of the photoconductor 1 is selectively irradiated with the light beam L at the image writing position for exposure, the charge escapes from the surface of the photoconductor 1 in the area exposed to the light, and in the part not exposed to the light. Since the electric charge remains, an electrostatic latent image is formed on the surface of the photoconductor 1 by this.

The electrostatic latent image thus formed is sent to the developing position by the rotation of the photoconductor 1. At the developing position, the toner 4 in the container 5 is conveyed on the sleeve 3a so as to come close to the surface of the photoconductor 1 by the relative rotation of the sleeve 3a and the magnet roll 3b forming the developing means 3. Toner 2
Is attached to the electrostatic latent image portion by an electric attraction force to be developed, so that the electrostatic latent image is visualized, that is, a toner image.

Then, this toner image is sent to the transfer position, and the electric attraction force generated by the charge transfer means 6 is applied to the surface of the recording paper 10 sent between the photoconductor 1 and the charge transfer means 6 at this transfer position. Alternatively, by a method other than the charge transfer means 6, the transfer is performed by using, for example, an adhesive substance.

The transferred toner image is sent to the fixing means 7 together with the recording paper 10, and is fixed on the recording paper 10 by applying heat or pressure by the fixing means 7.

On the other hand, the photosensitive member 1 after the transfer of the toner image continues to rotate, and after the electrostatic latent image residual image is erased by the discharging unit 8, the surface of the photosensitive member 1 is cleaned by the cleaning unit 9 such as a fur brush or a blade. By removing the residual toner and cleaning the same, one recording process is completed.

[Problems to be solved by the invention]

As described above, the conventional image recording apparatus employs a method of selectively adhering toner to the electrostatic latent image portion formed on the photoconductor and transferring the toner to the recording medium which is the final medium. However, according to this, a so-called edge effect phenomenon occurs in which the development density of the boundary portion where the electric field strength of the electrostatic latent image is strong becomes high, and therefore it is difficult to obtain a good recorded image. Atsuta

In addition to this, recently, for example, JP-A-59-154874.
As shown in Japanese Patent Laid-Open Publication No. 2004-242242, a photoconductor comprising a photoconductive layer, a transparent conductive layer and a transparent support is used, and an optical writing means is provided so as to face the developing means with the photoconductor sandwiched therebetween. An apparatus has been proposed which performs development immediately after writing the electrostatic latent image on the photoconductive layer of the photoconductor by the writing means, but this apparatus is basically the same as the above-mentioned image recording apparatus, and therefore the same. Has the drawback of.

The present invention has been made to solve such a problem, and an object of the present invention is to realize an image recording apparatus capable of obtaining a good recorded image without causing an edge effect phenomenon.

[Means for solving problems]

In order to achieve this object, the present invention provides a photosensitive member formed by stacking a transparent conductive layer and a photoconductive layer, a charging unit for uniformly charging the photoconductive layer of the photosensitive member, and a charging unit after the charging step. Toner applying means for applying toner to the entire surface of the photoconductive layer,
An optical writing system for selectively irradiating the photoconductive layer from the transparent conductive layer after the toner applying step, and a backside of the recording sheet for transferring the toner of the irradiated portion to the recording sheet surface after the light irradiating step. It is characterized by comprising a transfer charging means for applying a potential having the same polarity as that of the charging means, and a cleaning means for removing the toner remaining on the surface of the photoconductive layer after the transfer step.

Further, in addition to the above configuration, the invention of the present application arranges the toner applying unit and the cleaning unit inside an opening located in front of and behind the charging unit and removes the toner removed by the cleaning unit. It is characterized by comprising a housing provided with a toner guide which is returned to the toner applying means side.

[Action]

According to the above-mentioned means, the insulating toner is uniformly applied by the toner applying means to the entire surface of the photoconductive layer of the photoconductor uniformly charged by the charging means, and then the optical writing system is applied from the transparent conductive side. By writing an electrostatic latent image on the photoconductive layer by means of a toner, the toner in the electrostatic latent image portion is discharged, and then at the transfer position from the back surface of the recording paper by the transfer charging means the same as the charging means. A toner image can be obtained on the surface of the recording paper by applying a polar potential and transferring the toner in the electrostatic latent image portion onto the recording paper.

Therefore, according to this, it is possible to form a toner image of uniform density with less edge effect phenomenon on the surface of the recording paper, so that by fixing this toner image on the recording paper, a good recorded image can be obtained, and the charging Since the photoconductive layer of the photoconductor is uniformly charged by the means, it is possible to simply supply the toner to the photoconductive layer of the photoconductor by the toner application means in the toner application step without applying voltage. The toner can be applied to the entire surface of the photoconductive layer of the photoconductor in a uniform thickness, and the applied toner is reliably held by the charging potential of the photoconductive layer. Bring good results.

Further, according to the present invention, the cleaning means and the toner applying means are arranged in the same housing, and after the transfer process is completed, the toner removed from the surface of the photoconductive layer of the photoconductor by the cleaning means is returned to the toner applying means side and re-used. Since the toner is used, the toner can be used without waste.

〔Example〕

 Embodiments will be described below with reference to the drawings.

FIG. 1 is a schematic side view showing an embodiment of an image recording apparatus according to the present invention, in which the same parts as those in FIG. 3 are designated by the same reference numerals.

In the figure, reference numeral 11 denotes a photoconductor used in this embodiment, which is formed by stacking a photoconductive layer 11b on an outer peripheral surface of a cylindrical transparent electrode layer 11a, and the photoconductive layer 11b side of the photoconductor 11 is formed. The charging means 2, the toner applying means 12,
The transfer charging unit 6, the fixing unit 7, and the cleaning unit 9 are arranged in the order of the recording process.

Further, on the inner side of the photoconductor 11, that is, on the side of the transparent conductive layer 11a, an optical writing system 13 including, for example, a laser oscillator, an fo lens, a rotary polygon mirror, a reflecting mirror, and the like, a charge eliminating unit 14 such as a charge eliminating lamp, and the like. A reflection plate 15 is provided, and the optical writing system 13 is set so that light is emitted from the transparent conductive layer 11a side to the photoconductive layer 11b at a position between the toner applying means 12 and the transfer charging means 6. Further, the discharging means 14 cooperates with the reflecting plate 15 to irradiate the photoconductive layer 11b after the transfer process from the transparent conductive layer 11a side as well.

Reference numeral 16 denotes a housing that accommodates the toner 4 that is insulative and has magnetic properties. The housing 16 has openings in front of and behind the charger 2 and the toner applying means is provided inside the openings. 12 and a cleaning means 9 such as a fur brush are arranged, and a toner guide 17 for scraping off the toner 4 from the cleaning means 9 and returning it to the toner applying means 12 side is provided in the housing 1.

The toner applying means 12 is composed of a sleeve 12a and a magnet roll 12b as in the developing means 3 shown in FIG. 3, and the magnet roll 12b is divided into N and S poles alternately in the circumferential direction. It has a structured structure.

FIG. 2 is an explanatory diagram showing a basic recording process of the image recording apparatus having the above-mentioned configuration, and the operation will be described with reference to this figure.

First, the photoconductor 11 is rotated clockwise in a dark environment as shown in FIG. 1, and the photoconductive layer 11b is charged by the charging means 2.
Is uniformly charged.

Thereafter, at the toner application position, the toner 12 conveyed on the sleeve 12a is electrically moved so as to be close to the surface of the photoconductive layer 11b by the relative rotation of the sleeve 12a of the toner application means 12 and the magnet roll 12b. The toner 4 is attracted to the surface of the photoconductive layer 11b by a suction force, and thereby the toner 4 is sequentially applied to the entire surface of the photoconductive layer 11b.

The toner 4 thus applied to the surface of the photoconductive layer 11b is
The photoconductor 11 is rotated to be transported to the transfer position.
In the meantime, the light writing system 13 selectively irradiates the photoconductive layer 11b from the transparent conductive layer 11a side with the light beam L to perform exposure, whereby the toner 4 in the irradiated portion, that is, the portion to be a recorded image is discharged. .

In this state, from the back surface of the recording paper 10 sent between the photoconductor 11 and the transfer charger 6 from a paper feeding unit (not shown), the potential of the same polarity as the charged toner, that is, the potential of the same polarity as the charging means 2 is obtained. Then, the toner 4 that has been discharged as described above is transferred to the surface of the recording paper 10.

As a result, a toner image of the transferred toner 4 is obtained on the surface of the recording paper 10, so that the recording paper 10 is sent together with this toner image to the fixing means 7, and the fixing means 7 fixes the toner image on the recording paper 10. This completes the recording of the image.

On the other hand, a considerable amount of the toner 4 remains on the surface of the photoconductive layer 11b of the photoconductor 11 even after the transfer of the toner 4 is completed.
The remaining toner 4 is sent to the charge eliminating position by further rotation of the photoconductor 11, and the photoconductive layer 11b is entirely irradiated with the charge eliminating light by the charge eliminating means 14 and the reflecting plate 15 from the transparent conductive layer 11a side. Therefore, the residual charge is erased, that is, the charge is removed, so that the adsorption force is weakened.

After that, these toners 4 are removed from the surface of the photoconductive layer 11b by the cleaning means 9, whereby the photoreceptor 11 is removed.
The toner 4 is further scraped from the cleaning means 9 by the toner guide 17 and returned to the toner applying means 12 side to be reused.

In addition, in the above-described embodiment, the transparent conductive layer 11a of the photoconductor 11 has Au or ITO on the surface of the polyester film.
A material obtained by vapor deposition of (isodium tin oxide) or the like can be used, and the photoconductive layer 11 formed by coating on the vapor deposition surface side.
As b, ZnO, Se, Se ₂ As ₃ ,
It is possible to use a photoconductive material such as Se-Te or A-Si.

Further, in the above-described embodiment, a charge eliminating lamp is used as the charge eliminating means 14, and this lamp is used together with the reflecting plate 14 in the photoreceptor 11.
However, the charge may be removed from the outside of the photoconductor 11, that is, from the photoconductive layer 11b side by using a charge removing unit that performs AC corona discharge. The discharging unit 14 may be omitted if there is a time for discharging the charges held by the toner 4 remaining on the surface of the conductive layer 11b.

〔The invention's effect〕

As described above, according to the present invention, the toner is uniformly applied to the entire surface of the photoconductive layer of the photoconductor uniformly charged by the charging means, and then the photoconductive layer is selectively applied by the optical writing system. Since the toner of the light-irradiated portion is transferred to the recording paper by the transfer charging means after that, it is possible to form a toner image of uniform density with less edge effect phenomenon on the recording paper surface. By fixing this toner image on the recording paper, it is possible to obtain the effect of obtaining a good recorded image.

Further, since the photoconductive layer of the photoconductor is uniformly charged by the charging means, the toner is simply supplied to the photoconductive layer of the photoconductor by the toner applying means without applying voltage in the toner applying step. The effect that the toner can be applied to the entire surface of the photoconductive layer of the photoconductor with a uniform thickness is obtained, and the applied toner is reliably held by the charging potential of the photoconductive layer. Therefore, also in this respect, it is possible to obtain the effect of producing a good result in recording the image.

Further, according to the present invention, the cleaning unit and the toner applying unit are arranged in the same housing, and after the transfer process is completed, the toner removed from the surface of the photoconductive layer of the photoconductor by the cleaning unit is returned to the toner applying unit side and re-used. Since the toner is used, there is an effect that the toner can be used without waste.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an embodiment of an image recording apparatus according to the present invention, FIG. 2 is an explanatory view showing the basic recording process, and FIG. 3 is a schematic side view of a conventional image recording apparatus. FIG. 4 is an explanatory diagram showing the basic recording process. 2 ... Charging means, 4 ... Toner, 6 ... Transfer charging means, 7 ... Fixing means, 9 ... Cleaning means, 10 ...
... recording paper, 11 ... photoreceptor, 11a ... transparent conductive layer, 1
1b ... Photoconductive layer, 12 ... Toner coating means, 13 ...
Optical writing system, 14 ... static elimination means, 16 ... housing, 17 ...
… Toner guide

Claims (2)

[Claims] 1. A photoconductor comprising a transparent conductive layer and a photoconductive layer, a charging means for uniformly charging the photoconductive layer of the photoconductor, and an entire surface of the photoconductive layer after the charging step. Toner applying means for applying toner, an optical writing system for selectively irradiating the photoconductive layer from the transparent conductive layer side after the toner applying step, and the toner of the irradiated portion after the light applying step on the recording paper surface. For transferring, a transfer charging means for applying a potential of the same polarity as that of the charging means from the back surface of the recording paper, and a cleaning means for removing toner remaining on the surface of the photoconductive layer after the transfer step are provided. Characteristic image recording device. 2. A photosensitive member formed by stacking a transparent conductive layer and a photoconductive layer, charging means for uniformly charging the photoconductive layer of the photosensitive member, and the entire surface of the photoconductive layer after the charging step. A toner applying means for applying toner, an optical writing system for selectively irradiating the photoconductive layer from the transparent conductive layer side after the toner applying step, and a toner of the irradiated portion after the light applying step is applied to the recording paper surface. Transfer charging means for applying a potential of the same polarity as the charging means from the back surface of the recording paper, a cleaning means for removing the toner remaining on the surface of the photoconductive layer after the transfer step, and the charging means. The toner applying unit and the cleaning unit are respectively arranged inside the openings located in front of and behind them, and a casing provided with a toner guide for returning the toner removed by the cleaning unit to the toner applying unit side is provided. The image recording apparatus characterized by the.