JPH03219267A - Electrostatic recording device - Google Patents

Abstract

PURPOSE:To eliminate the inclined printing of an image and to improve the print quality by composing a control electrode, arranged between the toner conveyance surface of a toner conveyance body and a spiral electrode body, of plural split electrodes which slant at a specific angle to the axial direction of a cylindrical elec trode arranged opposite the toner conveyance surface side of the toner conveyance body. CONSTITUTION:An intermediate transfer medium 3 is the cylindrical electrode and rotates around a shaft 3a at a specific speed. A transfer device 4 which is arranged opposite the intermediate transfer medium 3 is applied with a specific high voltage from a high voltage power source 4a. A linear electrode 17 embedded in the peripheral surface of a sleeve 13c is applied with a specific high voltage V1 and the intermediate transfer medium 3 is applied with a specific voltage V2 from a power source 3b con nected to the shaft 3a. The control electrode formed in a film 15 consists of the split electrodes slanting at the angle thetaw to the axial direction of the cylindrical electrode and then tanthetaw = (K-cotthetasp)<-1> (K: optional integer), where thetasp is the angle between the axial directions of the spiral electrode and cylindrical electrode. Consequently, no inclined print is made on a form and an image of superior print quality is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a recording device, and particularly to an electrostatic recording device that records images on plain paper without using a photoreceptor.

[Conventional technology]

As one type of recording device that does not use a photoreceptor, a spirally formed linear electrode is provided on the surface of a sleeve that rotates at high speed, and an intermediate transfer medium, which is a rotatable cylindrical electrode, is provided at a position opposite to this linear electrode. , a control electrode is disposed between them, and by applying a pulsed high voltage to the control electrode, for example, toner adhering to the film surface is transferred to an intermediate transfer medium, and furthermore, the toner on this intermediate transfer medium is transferred. An electrostatic recording device has been devised that records an image by transferring it onto paper using a device.

In such an electrostatic recording device, the control electrode is arranged parallel to the axial direction (main scanning direction, which will be described in detail later) of the intermediate transfer medium. The electric field formed between the linear electrode and the intermediate transfer medium is formed through a gap provided at the control t-pole, and transfers the toner on the film to the intermediate transfer medium.

[Problems with the Prior Art] In the electrostatic recording device configured as described above, the control electrode is arranged parallel to the axial direction of the intermediate transfer medium as described above.

However, printing one line on paper involves sequentially printing a plurality of dots, and during this time the paper moves in the sub-scanning direction orthogonal to the main scanning direction. Therefore, the state of toner transfer to the intermediate transfer medium is inclined at a predetermined angle with respect to the main scanning direction. Therefore, the recorded image formed on the paper by receiving the toner image transferred from this intermediate transfer medium also becomes an image shifted by a predetermined angle with respect to the main scanning direction. This becomes especially noticeable when printing in a line, and the print quality is extremely degraded.

[Object of the Invention] In view of the above-mentioned drawbacks of the conventional art, the present invention has been developed to eliminate the slanted printing of images (
The purpose of the present invention is to provide an electrostatic recording device with excellent printing quality.

(Summary of the Invention) In order to achieve the above object, the present invention includes a toner conveying body that carries toner on its surface, and a spiral shape on the circumferential surface of the toner conveying body that is rotatably disposed on the opposite side to the toner conveying surface of the toner conveying body. a spiral electrode body provided with a shaped electrode; a control electrode disposed between the toner conveying surface of the toner conveying body and the spiral electrode body; and a control electrode disposed facing the toner conveying surface side of the toner conveying body. The toner on the toner transport body is transferred to the cylindrical electrode by applying a signal voltage according to print information to the control electrode, and the toner transferred to the cylindrical electrode is transferred to the paper. In an electrostatic recording device for transferring, the control electrode is composed of a plurality of divided electrodes inclined at an angle θ8 with respect to the axial direction of the cylindrical electrode, and the θw is the angle between the helical electrode and the axial direction of the cylindrical electrode. θ5. When tanθ
It is characterized in that w= (K cotθ=p) −' (where K is an arbitrary integer).

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a schematic cross-sectional view of an electrostatic recording device according to an embodiment. In the figure, an electrostatic recording device 1 includes a developing device 2, an intermediate transfer medium 3, a transfer device 4 for recording an image on paper, a paper feed cassette 5 for feeding/transporting paper, and a paper feed roller 6. , transport guide plates 7 and 8, a transport roll 9, a fixing roll 10, and the like. A claw 19 for separating paper from the intermediate transfer medium 3 and a cleaner 12 for removing toner remaining on the intermediate transfer medium 3 are provided near the circumferential surface of the intermediate transfer medium 30. Further, a recycling pipe 20 is provided from the cleaner 12 to a developing container 2', which will be described later, in order to reuse the toner collected by the cleaner 12. Further, the fixing roll 10 is composed of a heating roll lOa having a built-in heater 10a' and a pressure roll 10b, and is a roll that fixes the unfixed toner image to the paper while conveying the paper. Further, the sheet of paper on which the toner image has been fixed by the fixing roll 10 is discharged to the tray 11.

The developing device 2 is constructed by disposing a developing roll 13 in a developing container 2', and a one-component highly magnetic toner T of negative polarity is stored in the developing container 2'. Further, a blade 2a is formed at one end of the developer container 2' to regulate the thickness of the toner layer adhering to a film (insulating film) to be described later.

The developing roll 13 is composed of a magnet roll 13b fixed to a rotating shaft 13a, and a sleeve 13c fixed to the outer periphery of the magnet roll 13b.A fixed sleeve is provided at a predetermined distance from the sleeve 13c. 14 and a film 15 stretched over both ends of the fixing sleeve 140.

The rotating shaft 13a is rotated at high speed in the direction of arrow C shown in the drawing by a drive mechanism (not shown), and the toner is conveyed in the opposite direction of arrow a. Furthermore, a spiral linear electrode 17 is embedded in the circumferential surface of the sleeve 13C, as will be described later. still,
The magnet roll 13b functions to attract and convey the toner T in the developer container 2' to the circumferential surface of the fixed sleeve 15.

The intermediate transfer medium 3 is disposed directly above the developing roll 13, and is disposed at a position facing the film 15 with a predetermined interval therebetween. This intermediate transfer medium 3 is a cylindrical electrode made of a metal tube, and rotates at a predetermined speed in the direction indicated by the arrow around an axis 3a. The above-mentioned cleaner 1 is applied to the circumferential surface of the intermediate transfer medium 3.
A blade 12a disposed inside the intermediate transfer medium 2 is in contact with the intermediate transfer medium 3 to remove toner remaining on the circumferential surface of the intermediate transfer medium 3. Further, the above-mentioned transfer device 4 is disposed facing the intermediate transfer medium 3 across the paper conveyance path, and this transfer device 4 is equipped with a high-voltage power source 4.
A predetermined high voltage is applied from a.

FIG. 3 is a perspective view showing the arrangement of the intermediate transfer medium 3, the developing roll 13, and the film 15, and FIG. 4 is a schematic circuit diagram thereof. A power source 18 is connected to the linear electrode 17 embedded in the circumferential surface of the sleeve 13c.
A predetermined voltage (1) is applied from. In addition, the intermediate transfer medium 3
A predetermined voltage ■2 is applied from the power source 3b connected to the rotating shaft 3a.
is applied. As the toner T on the film 15 shown in FIG. 4 rotates in the direction of arrow C of the magnet roll 13b, the toner T in the developer container 2' adheres to the fixed sleeve 14 due to the magnetic force of the magnet roll 13b.
Further, the fixing sleeve 14 → the upper surface of the film 15 is conveyed. Further, the layer thickness of the toner on the film 15 is regulated to a constant layer thickness by the aforementioned blade 2a, so that the upper surface of this toner layer and the circumferential surface of the intermediate transfer medium 3 are at a constant distance (air gap). is formed.

The film 15 is made of polyethylene terephthalate (PET) with a thickness of several μm, and control electrodes 15a and 15b are formed within the film 15. This control electrode 1
5a and 15b are shafts 3a of the intermediate transfer medium 3, as described later.
It is formed to be inclined at a predetermined angle with respect to the arrangement direction (main scanning direction).

Therefore, the gap 15' is also connected to the axis 3a of the cylindrical electrode body 3.
It is formed to be inclined at a predetermined interval with respect to the main body.

Note that although the control electrodes 15a and 15b are shown filled in with black in FIG. 3, a plurality of control electrodes 15a and 15b are formed in the main scanning direction. A high voltage pulse signal is supplied to each of the control electrodes 15a and 15b from a control signal output section 15''.The pulse signal output from this control signal output section 15 is based on image (print) data. It is.

FIG. 5 is a diagram showing a state in which a gap 15' is formed where the control electrodes 15a and 15b are not formed, and shows the linear electrode 1 with the gap 15' and sleeve 13c expanded.
The arrangement relationship with 7 is shown.

In addition, FIG. 1 further shows a gap 15' (15a15
b' 15 c',...) is a diagram showing the formation state in detail. That is, the linear electrodes 17 (17a, 17b
, 17c, =l assume that the sleeve 13c rotates in the direction of arrow C and moves upward in the drawing.

With respect to this direction, the moving direction (sub-scanning direction) of the intermediate transfer medium 3 is the direction indicated by the arrow A shown in the figure, and the axial direction (main scanning direction) of the intermediate transfer medium 3 is the direction indicated by the arrow a in the figure. Further, LSP shown in the figure indicates the width of the linear electrode 17 in the main scanning direction, and in the case of this embodiment, one control electrode 15a, 15
If it is configured to process dot printing in b, then L and sp are -Ds (where Ds indicates the size of one dot). Further, as shown in the same figure, the linear electrodes 17a, 17b, 17C, . . .
, 15b'15c' . During this time, the intermediate transfer medium 3 moves in the direction indicated by the arrow, so that the first printing position (for example, ) and the last printing position (DI') are shifted by one dot (Ds). therefore,
In order to compensate for this printing position deviation in advance, in this embodiment, the control electrodes 15a, 15b (gap portions 15a', 15b'
15C') is arranged at an angle θ1 counterclockwise with respect to the main scanning direction, as shown in the figure.

This angle θ. are the linear electrodes 17a, 1 in the main scanning direction.
If the clockwise inclination angle of 7b, 17c, etc. is θSF, the LSE shown in the figure is L sp D 5cotθ.

It is expressed as Therefore, tanθ is DS/LSE, and Ds/Lsp DscotθSP.

Here, by substituting -Ds into the above equation for Lsp=, ts
nθ0 becomes (K-cotθ5p)-', therefore, by tilting this angle by 88 minutes, the gap portions 15a'15b'
15c' is formed.

When printing is performed by the electrostatic recording device configured as described above, the toner T is transferred to the transfer area F (the above-mentioned intermediate transfer medium 3 via the gap 15') as the magnet roll 13b rotates. and the space between the linear electrode 17). At this time, the electric field for attracting the toner T on the film 15 toward the intermediate transfer medium 3 is the voltage (1) applied to the linear electrode 17 and the voltage (2) applied to the intermediate transfer medium 3.
It cannot be formed only by the voltage generated between the control voltage output section 15'', but is formed via the gap section 15' at the timing when a high voltage pulse signal output from the control voltage output section 15'' is applied to the control electrodes 15a and 15b. Ru.

FIG. 6 is a diagram showing how the electric field E is formed at this time, and the electric field E is formed between the intermediate transfer medium 3 and the linear electrode 17 via the gap 15'. Also, at this time, the gap 15
The electric field E formed through ' has a dot-shaped cross section as shown in FIG.

Therefore, as shown in FIG. 4, the toner T on the film 15 of the intermediate transfer medium 3 moves along the electric field path and is attracted to the circumferential surface of the film 15 in the form of dots.

The toner image formed by the toner transferred to the circumferential surface of the intermediate transfer medium 3 is sequentially transferred onto the paper P by the electric field E during the transfer operation, but the gap 15' is formed at an angle θw as described above. Since the toner is formed at an angle and the angle corresponds to the moving speed of the intermediate transfer medium 3 in the direction indicated by the arrow, the toner transfer position on the intermediate transfer medium 3 is attached parallel to the main scanning direction for each line. do.

The toner image attracted to the circumferential surface of the intermediate transfer medium 3 as described above reaches the vicinity of the transfer device 4 as the intermediate transfer medium 3 rotates, and the voltage applied to the transfer device 4 at this time is from the high voltage power source 4a. Voltage ■2 which is high voltage and is applied to the intermediate transfer medium 3
Since the transfer rate is higher, the toner adsorbed on the intermediate transfer medium 3 is sucked toward the transfer device 4 side. Therefore, at this time, the toner image is transferred onto the paper P by feeding the paper P between the intermediate transfer medium 3 and the transfer device 4 by the above-mentioned paper transport mechanism. The paper P onto which the toner image has been transferred in this manner is subjected to the fixing process by the fixing roll 10 as described above, and then discharged onto the tray 11.

Therefore, by sequentially performing the above printing process for each line using the electrostatic recording device configured as in this embodiment, it is possible to accurately transfer toner parallel to the main scanning direction onto the intermediate transfer medium 3, and furthermore, A high quality image is formed by transferring the toner image transferred to the intermediate transfer medium 3 onto the paper P as described above.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to obtain an image of extremely excellent print quality without performing slanted printing on paper as in the conventional method.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the main parts of an electrostatic recording device according to an embodiment, FIG. 2 is a diagram showing the overall configuration of an electrostatic recording device according to an embodiment, FIG. 3 is a perspective view of a cylindrical electrode body and a developing roll, and FIG. Figure 4 is a power supply connection diagram for the cylindrical electrode body, linear electrode, and control electrode. Figure 5 is a diagram showing the arrangement relationship between the gap and the linear electrode. Figure 6 is an explanatory diagram of the formation of the electric field E. FIG. 7 is a diagram explaining that the electric field E is formed in a dot shape. DESCRIPTION OF SYMBOLS 1... Electrostatic recording device, 2... Developing device, 3... Intermediate transfer medium, 5... Paper feed cassette, 9... Conveyance roll, 13... Developing roll, 13b... Magnet roll, 13c... Sleeve, 14... Fixed sleeve, 15... Film, 16... Control signal output section, 17... Linear electrode.

Claims (1)

[Scope of Claims] A toner conveying body that carries toner on its surface, and a helical electrode body that is rotatably disposed on the opposite side to the toner conveying surface of the toner conveying body and has a helical electrode on its peripheral surface. a control electrode disposed between the toner conveying surface of the toner conveying body and the spiral electrode body; and a cylindrical electrode disposed opposite to the toner conveying surface side of the toner conveying body; In the electrostatic recording device, the toner on the toner transport body is transferred to the cylindrical electrode by applying a signal voltage according to print information to the control electrode, and the toner transferred to the cylindrical electrode is transferred to paper. The control electrode has an angle θ_ with respect to the axial direction of the cylindrical electrode.
w Consists of a plurality of tilted divided electrodes, and the θ_w is the angle between the helical electrode and the axial direction of the cylindrical electrode. θ_s_p
When t_a_nθ_w=(K-cotθ_s_p)
An electrostatic recording device characterized in that ^-^1 (where K is any integer).