JPH0880633A - Image forming device - Google Patents

Abstract

PURPOSE: To provide a small-sized, low cost and silent image forming device instead of a valuable and large-sized electrophotographic process or a low cost but noisy impact system. CONSTITUTION: This image forming device has a rotatable sleeve 2 having a spiral groove on its surface, a plurality of signal electrodes 10, which are arranged toward the direction of the rotation axis of the sleeve 2 and parallel to one another, and a pair of carrying rolls for carrying recording paper 9 to the gap between the sleeve 2 and the signal electrodes 10. By respectively applying high voltage between the sleeve 2 and the signal electrode 10, the toner 4 in the spiral groove at the position of an intersection of the signal electrode 10 and the spiral groove is selectively transferred onto the recording paper to obtain an image. In addition, no more than two intersections are set to develop when the signal electrodes 10 are projected onto the surface of the sleeve 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus which directly visualizes toner on recording paper without using a photoreceptor.

[0002]

2. Description of the Related Art At present, two types of printers widely used as impact printers are an impact dot printer and a non-impact laser printer. The features of dot printers are that they are small and low-priced, but they have the drawbacks of poor resolution and high noise. Therefore, a printer with good resolution and quietness is required. Laser printers have met that demand. A laser printer charges a photoconductor called an optical semiconductor and exposes it with a laser to form an electrostatic latent image according to the recorded information on the photoconductor, and develops toner particles on the electrostatic latent image to visualize it. The output is performed by transferring the toner onto the conveyed recording paper and fixing the toner on the recording paper by heat and pressure. The surface of the photoconductor after transfer is cleaned by a cleaner so that it can be used repeatedly. In this way, the laser printer can print out by repeating the electrophotographic process of charging, exposing, developing, transferring, and cleaning, and fixing the toner on the recording paper.

[0003]

However, in the laser printer, there are problems that the optical means for exposure and the scanning means are expensive, and that the size of the apparatus becomes large by using an intermediate medium called a photoconductor. Had.

[0004]

Therefore, an image forming apparatus according to the present invention does not use a laser scanning unit of a laser printer and a photosensitive member for holding an electrostatic latent image, and a rotatably provided sleeve. At least one groove formed on the surface of the sleeve, parallel to each other, and at least one groove formed on the surface of the sleeve, and signal electrodes arranged opposite to the groove and parallel to each other in the rotation axis direction of the sleeve. And a belt-shaped electric field control electrode having a linear through hole facing the signal electrode provided between the sleeve and the signal electrode, and the recording paper is conveyed to a gap between the electric field control electrode and the signal electrode. A conveying means and a means for supplying toner into the groove formed on the sleeve are provided, and a high voltage is selectively applied between the sleeve and the signal electrode according to recording information, and the high voltage is applied on the groove. Tona In an image forming apparatus for selectively transferring a sheet onto a recording sheet to form an image, when the signal electrodes are projected onto the sleeve, there are no more than two intersections with the grooves and the signal electrodes face the signal electrodes. The groove and the signal electrode are arranged so that only the toner in the groove is affected by the high voltage applied to the signal electrode.

[0005]

According to this structure, an image can be formed without using the optical means, the scanning means, and the photoconductor, and the apparatus can be made compact and inexpensive.

[0006]

Embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 is a toner feeder,
2 is a sleeve which is rotatably supported by the toner feeder 1 and is made of a conductive material and grounded; 3 is a blade which is parallel to the rotation axis direction of the sleeve 2 and is in contact with the sleeve 2; Toner filled in the container 1,
5 is a pair of conveyance rolls, 6a and 6b are paper feed side guides, 7a,
7b is a paper discharge side guide, 8 is a fixing device, 9 is recording paper, and 10
Is a signal electrode, 11 is a switch, 12 is a signal power source for applying a constant high voltage having a polarity opposite to that of the toner 4 to the signal electrode 10, 13 is an electrode support base made of an insulating material for supporting the signal electrode 10, 14 is a grounded electric field control electrode made of a conductive material for controlling the distribution of the electric field generated between the sleeve 2 and the signal electrode 10, and 15 is provided on the downstream side of the paper feed side guide 6b to connect the recording paper 9 to the signal electrode. A pressing plate for pressing 10 and a roll brush 16 for contacting the sleeve 2 and rotatably supported to sweep out the toner 4 in the spiral grooves 2a and 2b formed on the surface of the sleeve 2.

FIG. 2 is a perspective view of the sleeve 2, and 2a and 2b are spiral grooves formed on the surface of the sleeve 2 parallel to each other and inclined with respect to the rotation axis of the sleeve 2. FIG. 3 is a perspective view showing the periphery of the signal electrode.
sleeve 2 like a, 10b, 10c, 10d ...
It is divided into shorter pitches than the upper spiral grooves 2a and 2b, and is arranged by the electrode support 13 so as to be inclined with respect to the rotation axis of the sleeve 2. Each electrode is a switch 11
signal power source 12 via a, 11b, 11c, 11d ...
It is connected to the. On the other hand, the electric field control electrode 14 is the signal electrode 1
0 A strip-shaped electrode arranged at a fixed distance from the upper surface,
Linear through holes 14a, 14b, 14 at positions corresponding to the signal electrodes 10a, 10b, 10c, 10d, ...
c, 14d ... Are provided. These signal electrodes 1
0 and the electric field control electrode 14 are arranged so that the tip of the pressing plate 15 presses the signal electrodes 10a, 10b, 10c, 10d, ... In the direction of the signal electrode 10 without covering them.

FIG. 4 is a schematic view showing the relationship between the signal electrode 10 and the spiral grooves 2a and 2b when the signal electrode 10 is projected on the surface of the sleeve 2, and the spiral grooves 2a and 2b on the sleeve 2 are shown.
Are signal electrodes 10a, 10b, 10c, 10d ...
・ They are arranged so that each crosses only at one place,
For example, when the spiral groove 2a intersects the signal electrode 10a, the toner in the adjacent spiral groove 2b flies in the electric field generated between the sleeve 2 and the signal electrode 10a when a high voltage is applied to the signal electrode 10a. It is arranged in a position not to.

In the image forming apparatus constructed as described above, the toner 4 moves on the sleeve 2 as indicated by an arrow a as the sleeve 2 is rotated by a driving device (not shown).
Move in the direction. However, the blade 3 causes the spiral groove 2
The toner attached to other than a and 2b is retained in the toner supply device 1 and is moved to a position facing the signal electrode 10 while leaving the toner only in the spiral grooves 2a and 2b.

Next, the recording paper 9 is transported by the transport roll pair 5 along the transport guide 6a and reaches the lower signal electrode 10 of the electric field control electrode 14 while being pressed by the electrode support 13 by the pressing plate 15. At this time, the switches 11a, 11b, 1
1c, 11d, ... Are brought into conduction in accordance with an image signal to be recorded, and the sleeve 2 and the signal electrodes 10a, 10
An electric field is generated only in the signal electrodes corresponding to the switches in the conductive state among b, 10c, 10d, ... And the recording paper 9 is pressed against the signal electrodes 10 by the pressing plate 15, so The electric charges are injected from the signal electrode 10, and the toner in the spiral grooves 2a and 2b is in the conductive state. The through holes 14a and 14b of the electric field control electrode 14 are formed on the recording paper 9 in a portion facing the signal electrode 10. 14c, 14
Transfers through d. For example, as shown in FIG. 4, when the switch 11b is turned on until the spiral grooves 2a, 2b with the rotation of the sleeve reach the position of the broken line from the position of the solid line, the toner is transferred only to the range of c. At this time, only the electric field generated between the sleeve 2 and the signal electrode 10 disperses the toner in a wide range, but the electric field control electrode 14 prevents the toner from transferring from the sleeve 2 to the recording paper 9. In addition, the transfer range of the toner is restricted only to the through holes 14a, 14b, 14c, 14d, ..., It is possible to obtain a sharp image quality.

Next, the recording paper to which the toner has been transferred is fixed by the fixing device 8 by a conventionally known means through the paper discharge side guides 7a and 7b, and the spiral grooves 2a and 2b which have not been transferred.
The toner inside the brush 16 is rotated at a peripheral speed exceeding the peripheral speed of the sleeve 2 in the direction of b by a driving device (not shown).
The toner is swept out of the spiral grooves 2a, 2b by means of and prevents deterioration of the toner to be transferred next time.

Although the groove on the sleeve 2 is a spiral groove in the embodiment, it may be a groove parallel to the rotation axis of the sleeve 2. In the embodiment, the spiral grooves 2a and 2b on the sleeve 2 are also formed. Although the signal electrode 10 is divided into two, the spiral groove 2 may be set to one and the signal electrode 10 may be set to one.

[0014]

As described above, according to the present invention,
Printing can be performed directly on plain paper without using optical means, scanning means, and a photoconductor, and the apparatus can be made small and inexpensive.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a sleeve in the embodiment.

FIG. 3 is a perspective view showing the vicinity of a signal electrode in the same embodiment.

FIG. 4 is a plan view of a main part for explaining a recording operation of the embodiment.

[Explanation of symbols]

 2 Sleeve 4 Toner 5 Conveying Roll Pair 8 Fixing Device 9 Recording Paper 10 Signal Electrode 11 Switch 12 Signal Power Supply 13 Electrode Support 14 Electric Field Control Electrode

Claims (1)

[Claims] 1. A rotatably provided sleeve made of a conductive material, a groove formed in parallel with each other on the sleeve surface, and opposed to the groove and parallel to each other in the rotational axis direction of the sleeve. And a plurality of signal electrodes arranged in
A belt-shaped electric field control electrode having a linear through hole corresponding to the signal electrode provided between the sleeve and the signal electrode, and a conveying unit for conveying the recording paper to a gap between the electric field control electrode and the signal electrode. And a means for supplying toner into a groove formed on the sleeve, wherein the sleeve and the electric field control electrode are grounded, and are recorded between the sleeve and the signal electrode in accordance with recording information. In an image forming apparatus that selectively applies a high voltage having a polarity opposite to that of the toner to selectively transfer the toner to the recording paper through the through hole to form an image, when the signal electrode is projected onto the sleeve surface. , So that there are no more than two intersections with the groove,
Further, the groove and the signal electrode are arranged so that the high voltage applied to the signal electrode affects only the toner in the groove facing the signal electrode.