JPH01271258A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To always obtain a constant recording image without decreasing a recording speed, by providing a voltage variable device for changing the voltage to be applied to a recording electrode corresponding to a toner arranging state. CONSTITUTION:Toner 1 is drawn in by a rotary magnet 2 and an electronic conductive passage is formed between a recording electrode 4 and an image carrying means 5 and voltage is applied to the recording electrode 4 to bond the toner 1 to the image carrying means 5 to form an image. At this time, the arranging state of the toner 1 is detected by a toner arrangement detector 12. The voltage to be applied to the recording electrode 4 is changed corresponding to the detected arranging state of the toner 1 by a voltage variable device 4 to always form a constant recording image.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image forming apparatus, in particular, to applying a voltage between a recording electrode and an image bearing means, during which image forming particles (toner) are attached to the image bearing means. The present invention relates to an image forming apparatus.

[Prior art] Such an image forming power method is disclosed in Japanese Patent Application No. 49-4433.
There is a method known from Publication No. 6. As shown in FIG. 2, this method involves transporting a conductive magnetic l-toner 1 (hereinafter referred to as toner) by a rotating magnet 2 over a non-magnetic cylinder 3 onto a recording electrode 4 composed of a magnetic material C. When the conductive magnetic toner i is in physical contact with the image holding layer 5 having an insulating layer on its surface, the conductive magnetic toner i passes between the conductive layer 7 of the image holding layer 5 and the recording electrode 4. A voltage is applied to the image carrying means 5, and
It is configured to attach a toner (1) and form an image (C).

[Problem to be Solved by the Invention] However, the prior art described above has the disadvantage that the amount of toner and the alignment of the toner vary between maximum and minimum levels due to cyclic magnetic forces.

Fluctuations in the toner during recording cause changes in the alignment of the I-toner as well as changes in the gate of the I-toner sent to the image bearing means during recording, resulting in uneven recording density as shown in FIG.

In other words, in areas with high density, excessive toner is supplied, causing blurring and trailing in the recorded image, and in areas with low temperature, too little 1-toner is supplied, causing blurring in the recorded image. Therefore, a 1-ner image cannot be recorded with uniform and high performance recording quality and resolution.

In addition, a patent application was filed in 1973 as an invention to eliminate the above-mentioned drawbacks.
130894, and this method uses l.
Printing is performed when the amount of toner and the alignment of the toner are optimal for forming a high concentration deposit of toner between the image bearing means, and the printing is carried out at a temperature of -e degrees This is for recording images.

In other words, in Figure 3, is there any proposal for recording at point a, where the recording density is high, to ensure a constant density?1 If such a recording method is used, the timing of recording. Or, due to the magnetic force mentioned above, the toner alignment is improved.
The disadvantage is that the recording speed is very low, and only at maximum speed.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of forming high-quality images in which the Q density is always kept constant without slowing down the recording speed.

[First step (and operation) to solve the problem] According to the present invention, a rotating magnet, a non-magnetic cylindrical member covering it, and a recording electrode provided on the surface of the cylindrical member, and a recording electrode located close to the recording electrode. An image bearing-r stage is provided facing each other so as to be movable relative to each other, and further there is electronic conduction between the recording electrode and the image bearing means,
The magnetically attractable toner is drawn in by the rotating magnet to form an electronic conduction path between the recording electrode and the image bearing means, and a voltage is applied to the recording electrode to form the image 11:! In an image forming apparatus that forms an image by depositing the toner on a holding means, a means for detecting the alignment state of the toners 1 to 2 and changing a voltage applied to the recording electrode according to the detected alignment state. 41F sign.
image forming device.

A rotating magnet, a non-magnetic cylindrical member covering the rotating magnet, a recording electrode provided on the surface of the cylindrical member, an image carrying means disposed close to and opposite to the recording electrode so as to be movable relative to each other; There is electronic conduction between the recording electrode and the image bearing means, and an electronic conduction path is formed between the recording electrode and the image bearing means by drawing in toner that can be magnetically attracted to the recording electrode by the rotating magnet. An image-forming J& device that forms an image by causing the toner to adhere to the image bearing means by applying a voltage, characterized in that the voltage applied to the recording electrode is changed in accordance with the magnetic field distribution of the rotating magnet. The above problems are solved by the image forming apparatus. , [
Embodiment] The present invention will be described in detail below based on an embodiment shown in the drawings. For the same parts between the structure in this embodiment and the structure shown in the conventional example, the reference numerals cited in the conventional example will be used in the present embodiment. Due to the structure, a description of the structure will be omitted.

FIG. 1a is an operational principle diagram showing an embodiment to which the present invention is applied. A power source 8 is connected to the recording electrode 4 and a voltage variable device 11, which will be described later.

Reference numeral 12 denotes a toner alignment detector, which is composed of a Hall element whose output voltage changes depending on the alternating magnetic field in the toner generated by the rotating magnet 2, or an LED and a photodetector. The toner alignment detector 12.11 constituted by a photoelectric converter whose output voltage varies is a voltage variable device configured to vary the voltage applied to the recording electrode 4 according to the output voltage of the aforementioned toner alignment detector 12. It is 11.

FIG. 1b is a diagram explaining in detail the portion of the recording electrode 4 in FIG. 1a.
A recording section 4-1, which performs recording using the recording electrode 4, is arranged above. The opening 4-2 is provided on a substrate 4-4, which will be described later, and is a portion through which the toner 1 that is aligned and rotated by the two-rotation magnet 2 passes through. The board 4-4 is often composed of a flexible printed circuit board. In this embodiment, the drive element 4-3 is MSG116 manufactured by Oki Electric.
A VFD driver called 3 is used.

The mlc diagram is a flock diagram of the rlSla diagram and Figure 1b. In FIG. 1C, an external controller 10 (not shown in FIGS. 1a and 1b) generates an image to be printed by the recording electrodes 4, and generates recording timing signals (1), 2 image signals (2), 9 Generates an image transfer clock (3).

The driving element 4-3 will be explained in detail in FIG. 1b, including its operation in FIG. 1c. 4-3a.

4-3b and 4-3c show the internal structure of the driving element 4-3, and 4-3a is a shift register which receives the image signal (2
) and the image transfer clock (3) to latch the image signal.

A latch 4-3b is provided to output the image signal (2) latched at 4-3a into the drive element 4-3 in parallel. 4-3C is a driver for converting the latch output of 4-3b into a voltage sufficient for recording.

FIG. 1d shows the relationship between the toner alignment state for keeping the recording device constant and the recording voltage, which is the technical background for implementing the present invention. As is clear from this figure, when the toner alignment is small, that is, the amount of toner between the recording electrode 4 and the image bearing means 5 is small, and the area where the toner 1 is in contact with the image bearing means 5 is small, the recording voltage is increased. , Also, the toner alignment state is large.

That is, when the amount of toner between the recording electrode 4 and the image bearing means 5 is large, and the area in which the toner 1 is in contact with the image bearing means 5 is large, recording is formed with a low voltage, so that the recording density becomes constant. I understand that.

In this embodiment, when the toner alignment state in the toner alignment detector 2 is minimum, that is, when the toner alignment state between the recording electrode 4 and the image bearing means 5 is maximum, the recording voltage is set to 2.
The voltage variable device 11 is controlled so that the recording voltage becomes 27 V when the toner alignment state is the maximum at the toner alignment detector 2 and the minimum between the recording electrode 4 and the image holding means 5. This makes it possible to record images with uniform density without reducing the recording speed.

[Other Embodiments] A second embodiment is shown in FIG. 4. In FIG. 4, 13 is an electric terminal A, 14 is an electric terminal B, these two are arranged in the conductive toner l, and the recording electrode 4
When the toner alignment is maximum, the electrical terminals A and B are placed at the position where the toner alignment is the minimum. As a result, electrical terminal A.

When the electrode 4 has the maximum toner alignment, the impedance between the electrodes 8 and 8 becomes the maximum because the toner alignment between the electrical terminals A and B is the minimum, that is, the amount of toner is small, and the voltage applied to the recording electrode 4 is lowered. When the toner alignment is at its minimum, the impedance between the electrical terminals A and B is at its minimum, which increases the voltage applied to the recording electrode 4.

According to this embodiment, the voltage variable device 11. Toner alignment detector 1
2 is unnecessary, and the gist of the present invention can be implemented while reducing costs.

In carrying out the third embodiment, the magnetism and magnetic field distribution by the rotating magnet 2 are shown in FIG.

In the first embodiment, as already mentioned, toner alignment is proportional to magnetic field strength. Therefore, by controlling the electrode voltage in inverse proportion to the magnetic field distribution, an image with constant recording density can be obtained.

That is, in FIG. 1, a magnetic field distribution detector 15 made of a Hall element is fixedly installed near the rotating magnet 2 inside the nonmagnetic cylinder 3, and a change in the magnetic field distribution becomes a change in the output voltage due to the Hall effect of the Hall element. The voltage applied to the recording electrode 4 in the voltage variable device 11' is changed in accordance with the change in the output voltage from the magnetic field distribution detector 15. Therefore, this embodiment also has the same effect as the first embodiment. You can get it.

[Effects of the Invention] As described above, according to the present invention, since the voltage applied to the recording electrode is changed according to the alignment state of the toner, a constant recorded image can be obtained at all times without reducing the recording speed. It will be done.

[Brief explanation of the drawing]

Fig. 1a is a diagram showing the operating principle of an embodiment of the image forming apparatus according to the present invention, and Fig. ib is 'i1! Polar polarization network diagram, 1st
Figure c is a block diagram of the present invention, Figure 1d is a toner alignment state versus recording voltage characteristic, Figure 2 is a diagram explaining a toner image using a conventional recording electrode, Figure 3 is a conventional printed image, and Figure 4 is a diagram illustrating a toner image using a conventional recording electrode. The figure shows another embodiment using the present invention, and FIG. 5 is a magnetic pole and magnetic field distribution diagram. 1 is a conductive magnetic toner, 2 is a rotating magnet, 3 is a non-magnetic cylinder, 4 is a recording electrode, 5 is an image bearing-f stage, 6 is an insulating layer, 7
1 is a conductive layer, 8 is a power source, 9 is a convex portion, 10 is an external controller 1-roller, 11 is a voltage j1f transformer, 12 is a 1-ner alignment detector, and i3 and 14 are electrical terminals. I-? Figure 1d comparison J missing 2 times Jinkan-15 ;; S! 4th/2 rotation Sohi 6

Claims (2)

[Claims] (1) A rotating magnet, a non-magnetic cylindrical member covering the rotating magnet, a recording electrode provided on the surface of the cylindrical member, an image bearing means provided so as to be relatively movable in close opposition to the recording electrode, and furthermore, the recording electrode and the image bearing means are provided so as to be relatively movable. Toner that is electrically conductive and magnetically attracted between the supporting means is drawn in by the rotating magnet to form an electronic conductive path between the recording electrode and the image supporting means, and a voltage is applied to the recording electrode. In an image forming apparatus that forms an image by causing the toner to adhere to the image bearing means by applying a voltage to the toner, the image forming apparatus includes a means for detecting an alignment state of the toner, and a voltage applied to the recording electrode according to the detected alignment state. An image forming apparatus characterized by changing the image forming apparatus. (2) A rotating magnet, a non-magnetic cylindrical member covering the rotating magnet, a recording electrode provided on the surface of the cylindrical member, an image bearing means provided so as to be relatively movable close to and facing the recording electrode, and furthermore, the recording electrode and the image bearing means are provided so as to be relatively movable. There is electronic conduction between the supporting means, and toner that can be magnetically attracted is drawn in by the rotating magnet to form an electronic conductive path between the recording electrode and the image supporting means, and a voltage is applied to the recording electrode. An image forming apparatus that forms an image by causing the toner to adhere to the image bearing means by applying voltage, the image forming apparatus comprising: changing the voltage applied to the recording electrode according to the magnetic field distribution of the rotating magnet. Device.