JPH0548913B2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a recording device, and particularly to a recording device that mainly records binary images on plain paper, such as a copying machine, a printer, a plotter, etc. used as an output device of a processing system. be.

BACKGROUND ART Conventionally, in contrast recording using light that allows images to be directly recorded on plain paper, recording is performed by applying a relatively high voltage to a large number of needle electrodes arranged in correspondence with pixels. The drive circuit that applies voltage to the needle electrode has a complex configuration because the applied voltage is high, and is therefore expensive.

In order to improve the recording linear density, if the arrangement density of needle electrodes is increased and the number of needle electrodes is increased, the electrode driving portion of the drive circuit must also be increased accordingly, resulting in a more complex configuration and an increase in cost. Rise.

Purpose The present invention solves the drawbacks of the prior art,
It is an object of the present invention to provide a recording device using a contrast recording method that does not require a complicated electrode drive circuit.

Configuration The configuration of the present invention will be described below based on one embodiment.

Referring to FIG. 1, in the recording apparatus of this embodiment, a toner conveying body 100 formed in the shape of an endless belt and having a predetermined width is movably supported by four rollers 10 and 12. The roller 10 is driven by a drive source (not shown) such as a motor, and causes the toner conveying body 100 to run at a predetermined speed in the directions of arrows A1 and A2 shown in the figure.

As can be seen from the cross-sectional view of FIG. 2, the toner transport body 100 includes a photoconductive layer 102 containing a photoconductive material.
and two conductive layers 104 formed on both main surfaces thereof.
and 106, a surface layer 108 containing an insulating material formed on the conductive layer 104, and a surface layer 110 further formed on the conductive layer 106. Surface layer 110 forms a protective layer for conductive layer 106 and advantageously comprises a material transparent to light. Further, for the conductive layer 106, a transparent conductive material including a material transparent to light, such as ITO, is advantageously used.

A photoconductive layer 102 having a resistance RmD in a dark area that is much larger than a resistance RmL in a bright area is advantageously used. In addition, the resistance of the conductive layer 104
The materials are selected so that Rc1 is larger than the resistance Rc2 of the conductive layer 106. That is, Rc2<RmL<Rc1<<RmD (1) On the surface layer 108 side of the toner transport body 100,
A toner adhesion section 200 is provided. As shown in FIG. 3, the toner adhesion section 200 includes a roller 202 that slides on the surface layer 108 of the toner conveying body 100 and rotates in the direction of arrow R, and a doctor blade 204 that slides on the roller 202. roller 20
2 has magnetic poles N and S disposed therein as shown in the figure, and is held at a positive potential by a power source 208 in this embodiment.

Toner 206 is loaded upstream of the doctor blade 204 in the rotational direction R. toner 20
In this embodiment, a single-component magnetic toner having a relatively high resistance is advantageously used. The toner 206 may be any type of high-resistance single-component magnetic toner. In this embodiment, a material that is positively charged by friction with the doctor blade 204 or roller 202 is used. When roller 202 rotates in the direction of arrow R, a layer 210 of positively charged toner is formed on the sleeve of roller 202, typically on the order of tens of micrometers thick.

On the other hand, in this embodiment, a negative potential -V1 is applied to the conductive layer 104 of the toner conveying body 100 from the power source 14 via an electrical connection means 16 (FIG. 1) such as a conductive brush that is in sliding contact with the conductive layer 104. Further, a positive potential is applied to the conductive layer 106 from a power source 18 via an electrical connection means 20 such as a conductive brush that is in sliding contact with the conductive layer 106.
V2 is given. Therefore, the toner transport body 100
When traveling in the direction of arrow A1, the positively charged toner layer 210 is moved to the surface layer of the toner conveying body 100 by an electric field formed between the toner adhering portion 200 and the toner conveying body 100 by the power supplies 208 and 14. 108.

More specifically, the positively charged toner layer 210
Due to the electric field formed between the negative potential of the conductive layer 104 and the positive potential of the roller 202, the toner particles move onto and adhere to the surface layer 108 of the toner transport body 100, forming a toner layer 212. do. In normal cases, when a high-resistance toner is used, it is unavoidable that some amount of toner charged to the opposite polarity will be generated. These usually lead to background stains on the reproduced image. However, in the case of this method, from the roller 202 of the toner adhesion section 200 to the toner conveying body 1
Since an electric field is formed in the direction toward the 00 conductive layer 104, even if negatively charged toner exists, it will not be transferred to the toner transport body 100. Therefore, only positively charged toner is transferred onto the surface layer 108. The toner layer 212 thus deposited is uniformly charged and is transported by the toner transport body 100 while receiving Coulomb force due to the negative potential applied to the conductive layer 104.

Toner transport body 10 with toner layer 212 transferred thereto
The part marked 0 travels in the direction of arrow A1 and reaches the recording section 3.
It reaches 00. A recording section 300 is provided downstream of the toner adhering section 200, as shown in FIG. An exposure section 302 is provided on the side of the transparent surface layer 110 of the toner transport body 100. Exposure section 3
02 has a number of light emitting means corresponding to the number of vertical pixels constituting one character line, for example, and is scanned in the width direction of the toner conveying body 100, that is, in the direction perpendicular to the paper surface of FIG. good. Of course, instead of doing this, it is necessary to
It is also possible to use a device in which light emitting means are arranged corresponding to each pixel constituting a character line. As shown in FIG. 4, light 304 from the exposure section 302 is irradiated onto the toner transport body 100 from the transparent surface layer 110 side.

As the light emitting means of the exposure section 302, a light source such as a light emitting diode or a laser that has a switching function and can perform line scanning is advantageously used. Alternatively, the light from a light source that emits light constantly may be controlled by a light control element having a light shutter function, such as a liquid crystal or an electro-optic effect element such as PLZT. In any case, when the present apparatus is applied to a copying machine, the exposure section 302 is configured to irradiate image light from a document onto the toner conveying body 100 from the side of the transparent surface layer 110 using, for example, an optical fiber. Further, when applied to an output device of a processing system, the light emitting state thereof is modulated by an output information signal from the processing system, thereby emitting image light.

As shown in FIG. 4, a facing roller 310 that rotates in the direction of arrow S is disposed on the surface layer 108 side of the toner conveying body 100, facing the exposure section 302. As shown in FIG. The opposing roller 310 is electrically maintained at a reference potential, such as ground air. A recording medium 312 such as paper is interposed between the opposing roller 310 and the toner conveying body 100, and this is indicated by the arrow A2.
The toner transport body 100 travels in the direction of arrow A3 at substantially the same speed as the toner transport body 100 that travels in the direction of arrow A3. As shown, the opposing roller 310 is disposed such that the recording medium 312 is very close to the surface layer 108 of the toner transport body 100, and a gap 314 is formed.

The resistance of the recording medium 312 is Rp, the capacitance is Cp,
If the capacitance of the air gap 314 is Cg, the capacitance of the surface layer 108 is Cs, and the capacitance of the photoconductive layer 102 is Cm, the electrical equivalent circuit of the exposure section 300 shown in FIG. The result will be as shown in the figure.

Therefore, regarding the potential of the conductive layer 104 in the portion of the toner conveying body 100 immediately below the opposing roller 310, the potential VoD of the unexposed portion has a resistance value RmD that is much larger than Rc1, etc., as described above. Therefore, the voltage of power supply 14 is approximately -
equal to V1, i.e. VoD~−V1 (2). Also, the potential VoL of the exposed part
is expressed by the following equation because its resistance value RmL is comparable to the resistances Rc1 and Rc2. In other words, VoL=[Rc1・V2 − (Rc2+RmL)V1]/(Rc1+Rc2+RmL)
(3) As can be seen from these equations, toner transport body 1
Since the toner in the portion corresponding to the dark area on 00 has the potential VoD, that is, approximately equal to the negative potential of the power source 14, the surface of the toner conveying member 100 is caused by the electric field formed between the conductive layer 108 and the roller 310 It remains attached to layer 108. However, the toner in the area corresponding to the bright area is absorbed by the conductive layer 1 in that area.
Since the potential of 04 has the value shown by equation (3), the toner is repelled from the toner transport body 100 side by the electric field formed from the conductive layer 106 further below to the roller 310, and is transferred to the recording medium 312. toner 31
6 is attached to this. In other words, the voltage values of the power supplies 14 and 18 are selected so that the positive polarity toner 212 is repelled from the toner conveying body 100 by the bright area potential VoL defined by equation (3). is advantageous. In other words, it is desirable to select so that the numerator of formula (3) is positive.

In this way, toner in a portion corresponding to a relatively bright portion of the image light is transferred to the recording medium 312, and a toner image corresponding to the signal input to the exposure section 302 or the image light is formed on the recording medium 312. The toner 316 transferred to the recording medium 312 is
It is fixed semi-permanently by a conventional fixing section (not shown). In addition, the surface layer 1 of the toner transport body 100
The toner 318 remaining on the toner 318 is further conveyed by the toner conveying body 100, returned to the position of the toner adhesion section 200, collected, and reused.

In this way, in this embodiment, a high voltage drive circuit that drives the needle electrode of each pixel of the contrograph,
It is not necessary to provide a circuit for such switching. Furthermore, there is no need for a toner cleaning device as in conventional photoreceptor systems. Therefore, the configuration of the device is simplified, it does not require a large space, and the cost is reduced. Furthermore, there is no generation of ozone due to discharge, and no deterioration of the photoconductive layer due to this.

Effects As described above, according to the present invention, there is no high-voltage drive circuit for driving the needle electrode of each pixel of the contrograph, and there is no circuit for switching them.
Also, there is no conventional toner cleaning device.
Therefore, the configuration of the device is simplified, it does not require a large space, and the cost is reduced.

[Brief explanation of drawings]

1 is a schematic configuration diagram showing an embodiment of a recording apparatus according to the present invention, FIG. 2 is a sectional view showing an example of the configuration of a toner conveying body included in the embodiment shown in FIG.
The figure shows an example of the structure of the toner adhesion section included in the embodiment shown in FIG. 1, FIG. 4 shows an example of the structure of the recording section included in the embodiment shown in FIG. 1, and FIG. Fourth
FIG. 2 is a circuit diagram showing an electrical equivalent circuit of the recording section shown in the figure. Explanation of symbols of main parts, 14, 18...power supply,
100... Toner transport body, 102... Photoconductive layer, 1
04,106...Conductive layer, 108...Surface layer, 1
10...Transparent surface layer, 200...Toner adhesion part,
202...Roller, 300...Recording section, 302...
...Exposure section, 310...Opposing roller, 312...Recording medium, 314...Gap.

Claims (1)

[Scope of Claims] 1. A photoconductive layer containing a photoconductive material, a first conductive layer containing a conductive material formed on one main surface of the photoconductive layer, and a first conductive layer containing a conductive material formed on the other main surface of the photoconductive layer. a second conductive layer comprising a conductive material capable of transmitting light; and a first conductive layer.
a toner conveying means comprising a surface layer formed on the conductive layer and containing an insulating material, for conveying a one-component toner having a relatively high resistance while being placed on the surface layer; a first power supply means for applying a potential of a polarity to the second conductive layer; a second power supply means for applying a potential of a second polarity opposite to the first polarity to the second conductive layer; charged to the polarity of
a charged adhering means for substantially uniformly depositing the toner on the surface layer; an exposing means for exposing the toner to the toner-adhered portion of the toner transporting means from the second conductive layer side; an electric field forming means, which is disposed on the surface layer side of the toner conveying means, facing the exposure means, and forms an electric field between the second conductive layer and the second conductive layer in a direction to attract the toner charged to the second polarity; A recording medium is transferred between the electric field forming means and the toner conveying means, and the electric field formed by the electric field forming means causes the toner on the surface layer to be transferred to the recording medium according to the exposure state by the exposing means. 1. A recording device that forms a toner image on the recording medium by transferring the toner image to the recording medium.