JPS58159551A - Multicolor recording device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Al) Technical Field of the Invention The present invention relates to a multicolor recording device such as an electrostatic recording device or an electrophotographic device. The present invention relates to a multicolor recording device that can perform good multicolor recording even when developing methods with different safe latent image intensities are used by variable control of the surface potential.

(BL Technology Background) In recent years, as electronic computers have become faster, output devices such as line printers are required to meet the following requirements.

tl) High-speed dango (2) Miniaturization of the device (3) Easy maintenance (41 Noise-free In order to meet these demands) / Research on an innocuous type line printer is progressing.

In addition to simply checking the results of information processing as in the past, there is a tendency for printed materials to be treated as official documents, such as editing, tabling, etc.
Color of characters, symbols, figures, etc. on printed matter? It is required that it can be changed as necessary.

IcI Conventional technology and problems Disadvantages of the prior art will be explained using two-color recording [1i'i].

FIG. 1 shows a schematic diagram 7 of a conventional two-color recording device.

In addition, Fig. 2 shows a two-color recording session and each process = 11 (
Shows Asahi gamma level.

In FIG. 1, a photoreceptor 1 is uniformly charged over its entire surface by an initial charger 2. As shown in FIG. The potential T at this time is set to the initial band potential level VB as shown in FIG. 2(1).

At this time, the potential level of the photoreceptor l exposed by the exposure unit 3,
Fig. 2+21 The strike shown at K is attenuated to O[V]. After that, when the toner is red and has a positive charge, the current 1ψ bias voltage setting section 5 VC and Q developing bias voltage V61 are applied.
As shown in FIG. 2 (3), the initial charging potential is set to a value slightly lower than Novel J6, and development is performed using the two-component magnetic plan developer 4.

After the entire development is completed, the toner adheres to the photoreceptor in the area where the charge has been removed, as shown in Figure 2 (131K). This is done using the salmon ft, +r dew base part 6. At this time, the potential of the photoreceptor l that has been reduced by the exposure section 6 is shown in Figure 2 (
As shown in 4), the voltage is attenuated to approximately 0 (V).

Next, if the black charge is positive, use the center toner and apply the developing bias pressure foot 8 to the developing bias voltage VBJr (Fig. 2).
As shown in 5), the initial charging potential is set to a value slightly lower than No. 8, and development is carried out using the two-component magnetic brush developer 7. By performing development, black toner adheres to the portions from which the electric charge has been removed, as shown in FIG. 2 (5). Therefore, almost two colors of toner adhere to the photoreceptor 1, and the photoreceptor 1
A two-color toner image is formed thereon. Next, the toner image τ is transferred onto the recording paper 10 by the transfer means 9. Next, as in the printing process of a normal electrophotographic apparatus, the toner image is heated and fixed on the recording paper 10, a cleaning process 11, and a static elimination process 1.
After two meetings, the l process is completed.

Two-color recording can be performed by repeating the steps described above in sequence.

However, the conventional method has all the problems described below.

First, in the two-component magnetic brush development method, the particle size is 10
It is used as an iron powder carrier of about 0 to 300 [μm]. This developer, in which the carrier and toner are completely mixed, forms spikes 14 with a height of about d, -= 5 LJ, 3 on the sleeve 13 as shown in FIG. 3 due to the magnetic force of a mag roll (not shown). , 14 photoreceptors during development],
The contact depth is about δ-d-q=3 [Liao].

In this manner, in the two-component magnetic brush development method, the entire development is carried out by pressing and rubbing the brush 14i made of developer against the photoreceptor l.

Therefore, if the contact depth δ of the ears 14 of the second developing device 7 is not set appropriately, the red image formed on the photoreceptor 1 by the first developing device 4 will be lost when passing through the second developing device 7. It is mechanically scraped off, resulting in a red image ti1 destruction. Further, after the red image is rubbed off, black toner may adhere to the red image, causing an image that is originally red to become a mixture of red and black.

FIG. 4 shows the relationship between the contact depth δ of the second developing device 7 and the developer density when red developer is used as the first developer and black developer is used as the second developer.

As the contact depth δ of the second developing device 7 increases, the density of the black image increases, but decreases to the density of the red image.

This is because the red image is mechanically scraped off by the second developing device 7, and after being removed, the black toner of the second developing device 7 adheres, causing color mixing.

For this reason, it is possible to mix colors by making the contact depth of the second developer shallower than in the past. However, by making the contact depth of the second developer shallower, sufficient developer density could not be obtained.
It has the disadvantage that density unevenness occurs. As a method for eliminating the above-mentioned drawbacks, the present inventors have proposed a system in which a one-component magnetic toner development method, which is a soft development method, is used for the second development.

With this one-component magnetic toner development method, a diameter of 10 [μm:
Using the toner dispersed inside the magnetic head, an ear of about αl to α3IJIIm] is formed on the sleeve of the developing device.

This toner originally has no charge, but during development, toner KlK and charge are injected by electrostatic induction of the latent image, and development is performed. This 1g magnetic toner development method does not use carriers with large particle sizes like the two-component development magnetic brush method, and development is performed near the point where the toner tip contacts the photoreceptor, resulting in extremely soft development. It can be said that it is a law.

Figure 5 is a diagram showing the relationship between the contact depth δ of the second developer and the developer density when a one-component magnetic toner development method is used for the second developer. Contact depth δ to black image is 0 [Kaku]
A development degree of about i12 was obtained in the vicinity. At this time, the density of the red image does not change even if the contact depth δ of the second developing device increases, unlike in the conventional method.

This is because a soft developing method was used for the second development, and the red image was mechanically rubbed off during the second development, and black toner was then deposited on it, resulting in color mixing. This is because they do not do so.

Therefore, if a one-component magnetic toner development method is used for the second development, good recording can be obtained without destruction of black and red images, color mixing, etc.

However, are there any drawbacks to this method as well? have. That is, in the l-component magnetic toner development method, when the toner is formed on the photoreceptor and then completely transferred to plain paper, a high-resistance toner τ must be used as the developer. Therefore, if the latent image strength (difference between the potential of the developing device and the surface potential of the photoreceptor) required for the toner image obtained by the l-component magnetic toner development method to have sufficient development density and smoothness is obtained by the two-component magnetic brush development method, must be larger than that of .

In other words, Figure 1, Figure 2? The developed density with respect to the initial band potential level vB explained using the l-component magnetic toner development method is lower than that of the two-color image obtained with the two-component magnetic brush development method and the l-component magnetic toner development method. It has a shortcoming that there is some unevenness in the thickness.

tD) Purpose of the Invention What is the purpose of the present invention? Is it possible to obtain a good multicolor recording material even when developing methods with different latent image intensities are used? It is possible to achieve a multi-color recording device that is beautiful.

According to the present invention, a plurality of latent image forming means are provided corresponding to the latent image forming means, and the latent image forming medium is provided with a plurality of latent image forming means. The latent image forming means is equipped with an imaginary number representation means for making the upper image a visible (acclimated) by a developer, and the latent image forming means is arranged so that the developing density of each of the developing means is approximately the same. 4FJ51 can be obtained by making the multi-color recording device with the characteristics of Table 1'fi, which is equipped with a means for varying the electric potential.

1’Fl　Embodiment of the invention Hereinafter, an actual example of the present invention will be explained in detail with reference to the drawings.

For the sake of brevity, let us explain a two-color recording device in this example.

FIG. 6 is a diagram showing the relationship τ between the exposure amount of the exposed portion and the surface potential of the photoreceptor surface. In the figure, the initial image 4 on the photoreceptor 1 is
The potential Vs is set to approximately 800 (V). As shown in Figure 6, as the exposure is gradually increased, the surface potential on the photoreceptor 1 gradually decreases.

The present invention utilizes this characteristic.

FIG. 7 is a schematic diagram of a two-color recording device d for explaining the hook multicolor recording device according to the present invention.

In the figure, the exposure at the base part 3 is different from that in Figure 1.
ke control 1 f/) 11 light amount control means 15? I'm glad you have it.

Further, FIG. 8 is a diagram showing all the potential levels in the printing process of the two-color recording apparatus for explaining the embodiment.

In this embodiment, a developing method with a small latent image strength required for the first development, for example, 21'jy, magnetic brush developing method is used. For the case where a component magnetic toner development method with a large latent image strength required for the second development is used, the strength is rL. At this time, as shown in Figure 8 (1), the initial fi electric potential level Ve7800 (η) is the initial fluorescent potential level V8. The potential is set to obtain the recording density.

Next, the photoreceptor 1rfX is exposed to an image corresponding to red by the exposure section 3.

At this time, as shown in FIG. 8 (2), the exposure amount of the exposure section 3 is set to (1) a potential at which sufficient recording lateral variation can be obtained in the iron where the potential VL on the photoreceptor is 3001 J). )O After that, a developing bias voltage of approximately 2700 [Bl] is applied, and development is carried out by a two-component magnetic bluff development method using red and positively charged purple toner. Therefore, the latent image intensity at this time is 400 cV. ], and the number is determined.

Next, the exposure of the image on the photoreceptor 1 is black, and the exposure part 6 is
At this time, the potential of the photoreceptor 1 exposed by the exposure unit 6 is as shown in FIG. 8 (4).
attenuates up to OCV).

Next, as shown in FIG. 8 (51), the developing bias voltage was increased to 80
Apply approximately 0 force and use black high-resistance magnetic toner.
All development is done by extra-divisional magnetic toner development.

Therefore, the faflJ strength at this time is s o OL:V
], and as shown in FIG. 8 (5), even when the second development uses a high-resistance magnetic toner sound 11iy and the external magnetic toner development method, the recording #! is as sufficient as the eleventh development. i can get it.

As explained above, according to this embodiment, the first development uses a development method with a required latent image strength of 400 (V), and the second development uses a development method with a required latent image strength of s o o (v). Even so, by fully controlling the exposure amount in the exposed area, it is possible to obtain the optimum latent image strength for each developing method, and to obtain a good two-color recorded material without density unevenness. Similarly, in this embodiment, a case will be explained in which a developing method with a small required latent image strength is used for the first development, a developing method with a large required latent image strength is used for the second development, and a case where the exposure amount in the first exposure is fully controlled. However, the present invention is not limited to this.

For example, the first development method requires a large latent image strength, the second development method requires a large latent image strength,
A similar effect can be obtained by using all developing methods requiring low latent image strength for development and by controlling all exposure amounts in the second exposure.

Further, although this embodiment has been described only with respect to a two-color recording apparatus, it goes without saying that the present invention is not limited thereto and can also be applied to a multi-color recording apparatus.

However, even if the latent image produced by the developing method used is the same, the developed density may differ due to various conditions, such as the contact depth of the magnetic brush, toner in the developer, and changes in temperature. Even in such cases, by following the entire description of the present invention, it is possible to fully open the development density, and it is possible to write a good recorded material without density unevenness f).

+Gl As described in detail, according to the present invention, it is possible to obtain a good multicolor recorded material without unevenness in density even when developing methods with different required latent image hardnesses are used.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a conventional two-color recording device for fully explaining the present invention, Fig. 2 is a diagram showing potential levels of the two-color recording process of the two-color recording device shown in Fig. 1, and Fig. 3 4 is a diagram to explain the two-component magnetic brush development method, FIG. 4 is a diagram showing the relationship between the contact depth of water in the second developer and the developer density in the two-component development method, and FIG. 5 is a diagram for explaining the two-component magnetic toner. The second development method used
Figure 6 shows the relationship between the exposure amount of the exposed area and the surface potential of the photoreceptor surface. 7 is a schematic diagram of a two-color recording device for explaining the multicolor recording device according to the present invention, and FIG. 8 is a diagram showing potential levels of the printing process of the two-color recording device shown in FIG. be. In the figure, 1 is a photoreceptor, 2 is an initial charger, 3°6 is an exposure section, 4.7 is a developer, 5.8 is a development bias setting section,
9 is a transfer means, 10 is a recording paper, 11 is a cleaning process, 12 is a static electricity removal process, 13 is a mushroom 3 a broom 1 figure (red n (51 ears 2 □, I drama dice 2 η (cumulative, color) 419- θ l ? 3 4 strokes S
(Shoulder Wie 4 Figure

Claims (1)

[Claims] @Latent image forming means of the number of films to form a latent image on the image forming medium,
A plurality of developing means are provided corresponding to the latent image fix+ stage and are provided to visualize the latent image on the latent image forming medium with a developer, and the latent image forming means is provided with a Means for varying the surface potential on the latent image forming medium so that the current yield is approximately the same? Equipped with all features and a multi-color recording device.