JPS58108557A - Two-color recording device - Google Patents

Abstract

PURPOSE:To prevent the generation of image destruction and color mixture due to the 2nd development and to make it possible to separate a two-component toner used in the 1st development and mixed into the 2nd development, by using a soft one-component developing method as the 2nd development. CONSTITUTION:The one-component developing method is an extremely soft means unlike a two-component developing method because a carrier is not used. When the contact depth delta of the 2nd developing device is about 0mm. in case of using the one-component developing method, the development density of a black image is about 1.2. The density of a red image is not changed even if the contact depth delta of the 2nd developing device is increased. The reason is caused by the utilization of the 2nd soft developing method, removing phenomena that the toner of the red image is mechanically rubbed off by the 2nd development and then color mixture is generated by adhering black toner to the red toner.

Description

Detailed Description of the Invention (A) - Technical Field of the Invention The present invention relates to a two-color recording device such as an electrostatic recording device or an electrophotographic device, and particularly relates to a two-color recording device such as an electrostatic recording device, an electrophotographic device, etc. The present invention relates to a two-color recording device equipped with a second fA imager having a separation device for removing developer.

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

(1) High-speed printing (2) Miniaturization of the device (3) Easy maintenance (4) No noise In order to meet these demands, research is underway on non-incursion (II) line printers.

In addition, the printed matter from the output device is not only used to confirm information processing results as in the past, but also processed, edited, tabulated, etc., and there is a tendency for the printed matter to be treated as an official document. It is required to be able to change the color of Figure 1, etc., as necessary.

C. Prior Art and Problems FIG. 1 shows a schematic diagram of a conventional two-color recording apparatus. Further, FIG. 2 shows the potential levels of each process for two-color recording. In FIG. 1, a photoreceptor 1 is charged by an initial charger 2.
The entire surface is charged uniformly. The potential at this time is shown in Figure 2 (1).
The initial charging potential level is set to Va as shown in FIG. Next, the photoreceptor 1 is exposed to an image corresponding to the color Jll (hereinafter referred to as red) by the exposure section 3. At this time, the potential on the photoreceptor l exposed by the exposure section 3 is as shown in FIG.
) As shown in FIG. 2(3), the developing bias voltage V1 is set using the developing bias voltage setting section 5 using toner with a positive red charge. Developing is carried out by the secondary developer 4 with the setting set to a value slightly lower than the initial charging potential level Vs.
As shown in FIG. 2, toner adheres to the photoreceptor 1 at the portion where the charge has been removed. Next, the exposure unit 6 exposes an image corresponding to a second color (hereinafter referred to as black). At this time, the potential on the photoreceptor 1 exposed by the exposure section 6 is shown in Fig. 2 (4).
As shown in , it attenuates approximately at Ovi. Next, using toner with a positive black charge, the developing bias voltage vl is set to a value slightly lower than the initial charge level Vss by the developing bias voltage setting section 8, as shown in FIG. Developing is performed by the partial developing unit 7. By performing development, black toner adheres to the portion from which the charge has been removed, as shown in FIG. 2 (5), and a two-color visible image is formed on the photoreceptor l. Next, the visible image is transferred onto the recording paper 10 by the transfer unit 9.
Next, as in a normal electrophotographic process, a visible image on the recording line is heated and fixed, a cleaning step 11, and a static elimination step 1.
1 process is completed after 2 steps. Two-color recording can be performed by sequentially repeating the above steps.

However, the above conventional method has the following problems. First, in the secondary development method, the particle size is 100 to 30
Iron powder of about 0 [μm] is used as a carrier. This developer mixed with carrier and toner is used to form spikes 14 of approximately d=s(sa+) on the sleeve 13 of the developing device 4, as shown in FIG.
! &The touching depth is about δ=3 (all).

In this manner, development is carried out by pressing the L1 developing agent against the photoreceptor 1 and rubbing it by the second-stage development method. Therefore, if the setting of the contact height a of the ears 14 of the second developing device 7 is not appropriate, the red image formed by the first it developing device 4 will be mechanically scraped off when passing through the second developing device 7. , resulting in destruction of the red image.

Additionally, after the red image is removed, black toner may adhere to the red image, causing the originally red image to become a mixture of red and black. Fig. 4 Co., Ltd. No. 1gA image agent, red color, No. 21
Second developing device 7 when black is used as the first developer
This shows the relationship between contact depth δ41+development density. As the contact depth δ of the second developing device 7 increases, the density of the black image increases, but the density of the red image decreases. This is because the black toner in the second developing device 7 adheres after being removed and color mixing occurs.

Further, the red toner is mixed little by little into the second developing device 7 as well. Therefore, when recording is performed for a long time, the originally black second developer appears as a mixed @* agent of red and black.

(f) Purpose of the Invention An object of the present invention is to provide a system for preventing the destruction of toner images and color mixing caused by the second development, and for reducing the mixing of toner from the first development into the second development device. It is in.

Furthermore, the second object of the present invention is to provide a second developing device having a function of separating the developer from the first developing device mixed into the second developing device.

(Translated) Structure of the Invention The object of the present invention is to develop a two-color recording medium that performs 92-color recording by developing a latent image formed on a latent image forming medium using a first developing device and a second developing device. In the apparatus, the first developing device performs development using a two-component developer, and the second developing device performs development using a one-component developer, and further, the 21!1m device performs development using a one-component developer. This is achieved by providing a two-color recording device characterized by having a separation device for removing the second two-component developer used in the developing device mixed into the developing device. Embodiments of the Invention The present invention is characterized in that a one-component developing method is used in the second developing device. That is, the one-component developing method uses toner in which magnetic powder is dispersed. The diameter of the grain toner is about 10 [μm], and it forms ears of about 0.1 to 0.3 (m) on the sleeve of the developing device. This toner does not originally have an electric charge, but during development, an electric charge is injected into the toner (due to electrostatic induction of the latent image) and development is performed. This l-component development method does not use carriers with large particle sizes like the two-component development method, and it is an extremely soft development method because development is carried out near the point where the toner tip contacts the photoreceptor. I can say that.

Figure 5 shows the second developing device when the one-component development method is used.
FIG. 6 is a diagram showing the relationship between the contact depth δ of the developing device and the current angle [11 degrees]. For a black image, the contact depth δ is around 0 and the development density is 1.
You can get about 2. At this time, the density of the red image is the second Mm
Even if the contact depth δ of the container increases, there is no difference from the conventional method. This is because a one-component development method, which is a soft development method, was used as the second development, and the red image toner was mechanically scraped off during the second development, and after that, This is because phenomena such as black toner adhesion and color mixing do not occur.

As described above, if the one-component development method is used as the second developing device, good recording of both red and black images can be obtained.

According to the present invention, since the second development uses a soft development method, the proportion of red toner mixed into the second developing device can be significantly reduced. However, when recording for a long time, red toner may get mixed into the second printer. In this case, it is necessary to remove the red toner from the second developer. FIG. 6 is a diagram showing a developing device equipped with the toner separation device of the present invention. The principle of toner separation will be described below.

! The toner used in the component development method has magnetic powder dispersed inside it, so the magnetic roller 17! It is attracted by the magnetic force of the magnet 15. However, the toner used in the two-component development method does not contain magnetic powder and is not attracted by magnetic force. Therefore, the toner used in the one-component development method is attracted to the magnetic row 217 by the magnetic force of the magnet 15 and the electrostatic force of the sleeve 13. Further, the toner used in the two-component printing method is transferred to the magnetic roller 1 by the electrostatic force of the sleeve 13.
It is adsorbed to 7. In this state, by blowing air (arrow indicated by symbol A in the figure) from an air supply source (not shown), only the toner used in the two-component developing method, which has a weak adsorption force, is blown away. By blowing air onto a portion of the magnetic roller 17, the toner can be easily separated.

Next, another embodiment of a developing device equipped with the toner separation device of the present invention will be described.

FIG. 7 shows the current g
It is a schematic diagram showing another example of R device.

FIG. 8 is a schematic diagram for explaining the toner separation device in FIG. 7.

In this embodiment, a separating roller 18 and a magnetic blade are provided in order to separate the two-component developer used in the first developing device mixed into the developing device using the -component developer, that is, the second developing device. It is characterized by: This separation row 218 uses a non-magnetic conductive sleeve 21 that encloses a magnetic row 220.

Next, the operation of this embodiment will be explained.

First, the magnetic row 220 in the separation roller 18 and the non-magnetic conductive sleeve 21 are rotated (
In the direction of the arrow shown by symbol B in the figure), the l-component magnetic toner 22 and the two-component toner 23 are conveyed in a mixed state over the separation roller 18 (in the direction of the arrow shown by symbol C in the figure).

Among these toners 22.23, l component magnetic toner 2
2 is attracted by the magnetic blade 19 if the magnetic force of the magnetic blade 19 is made strong enough, and the non-magnetic conductive sleeve 2
1 and the gap 24 between the magnetic blade 19. However, since the two-component toner 23 does not contain a magnetic material, it is not attracted to the magnetic blade 19, and since it retains an electric charge (in this case, a positive charge), it is not a non-magnetic conductive material due to image force. It adheres to the sleeve 21 and is conveyed through the gap 24 with the magnetic blade 19. Therefore, as shown in FIG. 8, the magnetic blade 19 and the non-magnetic conductive sleeve 21
The two-component toner 23 can be separated by collecting it from the non-magnetic conductive sleeve 21 using a means such as a vacuum cleaner.

Therefore, if a one-component developer is used in the second developer of a developing device equipped with the above-mentioned toner separation device, color mixing will not occur even if two-color recording is performed for a long time, and good two-color recording will be performed. be able to.

(F) Effects of the Invention According to the present invention, since a one-component development method, which is a soft development method, is used as the second development, destruction of the image or color mixing due to the second development does not occur, and a good two-component development method is used. A color record is obtained. Further, even if the two-component toner used for the first development gets mixed into the second developing device, good recording can be maintained even if recording is performed for a long time because a toner separation device is provided.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a conventional two-color recording device, published by Fig. 2.
A diagram showing the potential levels of each process for color recording, Figure 3, and a schematic diagram showing the developing method, Figure 4 are as shown in Figure 1. Figure 5 is a diagram showing the development characteristics when the two-component development method is used for the second development. Figure 5 is a diagram showing the development characteristics when the one-component development method is used for the second development. 3.6 is an exposure section, 4 and 7 are '1A' parts, 5.8 is a development bias voltage setting part, a Qti transfer part, 10L-written sickle paper, and 11 is a clear plate, which is equipped with a toner separation device. 12 is the static elimination process, 13 is the welfare sleeve, 14 is the wire,
15 is a magnet, 16 is a blade, 17 is a magnetic row 2
, A indicates air.

Claims (1)

[Claims] 1. A two-color recording device that performs 3° two-color recording by developing a latent image formed on a latent forming medium using a first developing device and a second developing device. A two-color recording device, wherein the first developing device performs development using a two-component developer, and the second developing device performs development using a one-component developer. 2. In the two-color recording device according to claim 1, the second developing device includes a separation device for removing the two-component developer used in the first developing device mixed in the developing device. A two-color recording device characterized by: 3.4I The two-color recording device according to claim 2, comprising means for blowing air onto the sleeve. In the two-color recording device, the 28th! A two-color recording device comprising a non-magnetic conductive sleeve containing a magnetic polarizer and a magnetic blade disposed between the non-magnetic conductive sleeve and a gap.