JPS61174566A - Polychromatic recorder - Google Patents

Abstract

PURPOSE:To eliminate the complexity of constitution and to facilitate manufacture, adjustment, and maintenance by forming a two-color toner visible image on each photosensitive drum of tandem constitution by one exposing part and two developing parts continuously and transferring images to one recording form continuously. CONSTITUTION:The exposing part 74 forms a latent image corresponding to information of the 1st color on a photosensitive drum 71 in its one turn after uniform electrostatic charging is performed by an initial electrostatic charger 73 and the image is developed 75 to form the 1st toner visible image. This part is recharged by the charger 73 to the same potential as the background potential of the drum 71, and a latent image corresponding to information of the 2nd color is formed on the drum 71 in its one turn from said recharging by the exposing part 74 and developed 76 to form the 2nd toner visible image; and those visible images of the two colors are transferred to the recording form by a transfer part 77 at a time. Then, the 3rd and the 4th toner visible images are formed on a drum 72 similarly to the images on the drum 71 while image formation timing is shifted. Then, the two-color visible images are transferred by a transfer part 85 to the same form 90 where the 1st and the 2nd toner visible images are transferred.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a multicolor recording device using an electrophotographic recording method.
In particular, the present invention relates to an apparatus structure that can perform clear multicolor recording without color mixture over a long period of time at high speed.

In recent years, with the diversification of information, the color of recorded information such as characters, symbols, images, etc. can be changed as necessary, and color recording can be performed in which characters, symbols, images, etc. of different colors are mixed on the same recording paper. is required, and various devices or methods related to multicolor recording have been proposed.

Generally, in electrophotographic recording, a photosensitive drum is uniformly charged, an electrostatic latent image is formed by exposing the photosensitive drum to light corresponding to the information image to be recorded, and then the latent image is transferred to a developing device. The toner is developed to form a visible image using toner, and this visible image is transferred onto recording paper for recording.

Therefore, image forming sections each including a latent image forming means and a developing device are provided in multiple stages around the photosensitive drum, and each image forming section sequentially forms a visible image using toners of different colors on the surface of the photosensitive drum. By transferring the visible image to recording paper,
A multicolor record can be obtained.

In devices that perform multicolor recording using toners of different colors, the toner in the developer used in the previous development process is mixed into the developer in the next development process, and this mixing There is a problem in that as the amount of accumulated toner increases, color mixture tends to occur in the toner visible image, and there is a demand for solving this problem.

[Conventional technology]

As a conventional device that performs multicolor recording at high speed using an electrophotographic recording method, a device or method that performs multicolor recording during one rotation of a photosensitive drum has already been proposed by the applicant in JP-A-52
-108743. This is proposed by Japanese Patent Application Laid-Open No. 58-118553.

The conventional multi-color recording device using the electrophotographic recording method described above is shown in FIG. 4, which is a schematic diagram of a two-color recording device, and in FIGS. As shown in the potential level diagram, first, the entire surface of the photosensitive drum made of a photosensitive layer of selenium (Se) is uniformly charged to the initial charging potential level Vs by the initial charger 2 as shown in FIG. Performs charging.

Next, negative exposure corresponding to the first color information was performed on the surface of the photosensitive drum 1 by the first exposure section 3, and as shown in FIG. 6, the charged potential of the exposed portion was attenuated to approximately Qv. A first latent image 21 is formed. After that, the first latent image 21 is
Magnetic brush reversal development is performed by the first developing device 4 using a two-component magnetic developer containing a mixture of toner of color and carrier to form a first toner visible image 22 as shown in FIG.

Next, the recharger 5 recharges the first toner visible image 22 so that the potential Vt of the first toner visible image 22 becomes approximately the same potential as the background potential Vs on the photosensitive drum 1, as shown in FIG. This process is to prevent toner from subsequent development from adhering to the first toner visible image 22 that has already been formed.

Next, the second exposure unit 6 performs negative exposure corresponding to the second color information on the recharged photosensitive drum surface, and the ninth
As shown in the figure, a second potential @23 is formed in which the charged potential of the exposed portion is attenuated to approximately Qv. Thereafter, the second latent image 23 is subjected to magnetic brush reversal development using a second developing device 7 using a two-component magnetic developer containing a second color toner and a carrier, as shown in FIG. A second toner visible image 24 is formed.

The first image formed on the surface of the photosensitive drum in this manner. The second toner visible images 22 and 24 are transferred all at once onto the recording paper 13 by the transfer device 8, and further fixed by the fixing section 9 to record two-color information.

On the other hand, the toner remaining on the surface of the photosensitive drum is
The static electricity is removed by a static eliminator 10, the photosensitive drum 1 is cleaned and removed by a cleaner 11, and then all charges on the surface of the photosensitive drum 1 are removed and erased by an optical static eliminator 12, and the next recording cycle begins.

In addition, in the above-mentioned recording apparatus, in order to prevent the first toner visible image 22 formed in the previous GSL development process from being destroyed in the next second development process, in the second developing device 7, the second color is The particle size of the carrier mixed with the toner is 5 to 100μ.
Non-contact development in which a two-component magnetic developer using a flying microcarrier is used, or an AC bias voltage is applied to the developing device 7 to cause the second color toner to fly away from the developer. A soft-touch developing method is used.

Further, in order to prevent color mixing of the second toner visible image 24 caused by the toner of the first color mixed in and accumulated in the second developing device 7, the mixed toner of the first color is removed from the second developing device 7. 2
The method of separation from the developer was also developed by the applicant in Japanese Patent Application Laid-Open No. 58-10
It has already been proposed by No. 57134.

That is, in the above separation method, the first developer and the second developer are separated from each other. Toner 31, 32 of a second color and a first carrier 33 and a second carrier 3 mixed therewith, respectively.
This is done by selecting 4 triboelectrification series as shown in FIG.

Part 1. The second color toners 31 and 32 are respectively
Career 33. It is charged to a positive polarity by frictional charging with the second carrier 34. Further, the first color toner 31 is
When mixed into the developing device 7, the polarity is reversed to negative polarity or becomes approximately O due to frictional charging with the second developer.

Further, the first color toner 31 of negative polarity is mixed with the second color toner 31 of positive polarity.
It electrostatically combines with the toner 32 of the color , the apparent amount of charge becomes approximately O, and as a result, the bonding force with the second carrier 34 weakens and becomes the same as the toner 32 of the first color. The toners 31 and 32 of the second color remain electrostatically combined, or the toner 31 of the first color with a charge amount of approximately O is applied by centrifugal force from above the developing roller in the second developing device 7. Since the toner 31 of the first color that has been scattered and separated and mixed in is not accumulated in the second developing device 7, good two-color information recording without color mixing can be stably performed even if the above recording operation is repeated over a long period of time. It is possible to do so.

As a configuration for recording more color information in accordance with such a two-color recording configuration, for example, as shown in FIG.
3, a developing section 44, a recharging device 45, a second exposing section 46, a developing section 47, a recharging device 48, a third exposing section 49, and a developing section 50, and a transfer device 54, a fixing device 55, and an AC remover. The electric device 56, the cleaner 57, and the optical static eliminator 58 are arranged in this order, and the toner colors of the developer used in the respective developing devices 44, 47, and 50 are changed to cyan, magenta, and yellow, according to the two-color recording process. By performing the recording operation,
Good multicolor recording without color mixture can be realized.

[Problem that the invention seeks to solve]

Incidentally, in the multicolor recording apparatus as described above, black character information is generally recorded in many cases, but in this case, recording is performed by mixing visible toner images of the three colors.

However, even if three color toners are mixed, complete black is not obtained, so a recharging device 51, a fourth exposure section 52, and a black toner are further included after the third developing section 50 in the recording device. Attempts have been made to arrange a developing section 53 using a developer.

However, adding an image forming function unit that records black text information not only makes the already complicated device configuration even more complicated, but also makes it possible to increase the complexity of each of the developing units 50 and 52 after the second developing unit 47. Toners 61, 62, 63 and 64 of the first to fourth colors in the so-called first to fourth developers are used to separate and remove different color toners mixed in the toner and prevent color mixture. 1st to 4th carriers 65
．． 66, 67 and 6 days had to be selected to have the triboelectric charging series shown in Figure 13, and it was extremely difficult to procure and manufacture toners and carriers with such triboelectric charging series. .

[Means for solving problems]

The above-mentioned problem is that the first photosensitive drum has one charger, one latent image forming section, two developing sections using toner of different colors, a transfer section and a cleaning section disposed around each of the first photosensitive drums; A second photosensitive drum is arranged in parallel in the recording paper traveling direction, and the latent image forming section and the other developing section are placed on the photosensitive drum while the first photosensitive drum rotates twice. , the first . A visible image is sequentially formed with toner of a second color, and the visible image is transferred all at once onto a recording paper in a transfer section, and the second photosensitive The third and fourth colors of information images to be recorded are formed on the photosensitive drum during two rotations of the drum by the latent image forming section and one developing section, and by the same latent image forming section and the other developing section. The third. This problem is solved by the multi-color recording apparatus according to the present invention, which is configured to perform multi-color recording by transferring a visible image of the fourth color toner all at once at the selvage portion.

[Effect]

In other words, two photosensitive drums are used, and four developing sections using developers containing toners of cyan, magenta, zenta, yellow, and black colors are used to form one latent image around each of the two photosensitive drums. One latent image forming part and two latent image forming parts are arranged while one photosensitive drum rotates twice.
Two developing units collectively transfer visible images of two colors of toner formed sequentially onto recording paper, and then
Subsequently, while the other photosensitive drum rotates twice, one latent image forming section and two developing sections sequentially form a visible image of two colors of toner on the photosensitive drum and transfer them all at once, thereby producing multicolor recording. Furthermore, each color of toner and carrier used in the two developing sections arranged on each photosensitive drum has a triboelectrification series, so that the toner of the subsequent stage mixed in the developing section of the previous stage is charged by friction. By reversing the polarity or attenuating the amount of charge and separating and removing it due to the difference in the order in the charging series, color mixing is prevented, and the device configuration is not complicated and good multicolor recording without color mixing is achieved. This enables stable operation.

[Examples] Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of a multicolor recording apparatus according to the present invention.

In order to avoid complication of the structure, the device configuration of the present invention includes two photosensitive drums made of a photosensitive layer of selenium (Se), 5eTe, etc. as shown in the figure, that is, first and second photosensitive drums 71. .72 are arranged in parallel in the running direction of the recording paper 90.

Further, an initial charger 7 is provided around the first photosensitive drum 71.
3, He-Ne gas laser, semiconductor laser, or L
A first latent image forming exposure section 74, a first developing section 75, and a second developing section 76 each including an ED array or the like, and a transfer section 77,
An AC static eliminator 78, a cleaner 79, and an optical static eliminator 80 are arranged in this order, and around the second photosensitive drum 72,
An initial charger 81, a second latent image forming exposure section 82 consisting of a He-Ne gas laser, a semiconductor laser, an LED array, etc., a third developing section 83, a fourth developing section 84, and a transfer section 85, an AC A static eliminator 86, a cleaner 87, and an optical static eliminator 88 are arranged in this order.

Further, each of the developers used in the first to fourth developing units 75 to 84 contains toner in the order of cyan, magenta, yellow, and blank, and in addition, the carrier and toner of each developer is each of the photosensitive drums 71 and 72.
The first developing section 75 and the second developing section 76 and the third developing section 83 and the fourth developing section 84 are arranged in two developing sections, namely, a first developing section 75 and a second developing section 76 and a third developing section 83 and a fourth developing section 84, respectively. The second color toner 101.102 and the first color toner 101.102. The second carrier 103.104, and the third carrier. A fourth color toner 105, 106 and a third and fourth carrier 107.
108 are separately selected to form independent triboelectrification series as shown in FIG. Fourth developing section 76, 8
1st mixed into 4. The third color toner 101, 105 is triboelectrified with a second developer or a fourth developer having a different rank on the triboelectrification series to reverse the polarity or attenuate the amount of charge and separate and remove it. ing.

Now, in order to perform multicolor recording using the recording apparatus having such a configuration, first, the first photosensitive drum 71 is uniformly charged to an initial charging potential level by the initial charger 73, and then the first photosensitive drum 71 is rotated once. A latent image corresponding to the first color information is formed by the first exposing section 74 on the first photosensitive drum 71 in between, and the latent image is subsequently developed by the first developing section 75 to form a first toner. Forms a visual image (cyan).

Next, the potential of the first toner visible image (cyan) portion formed on the first photosensitive drum 71 is reset by the initial charger 73 so that it becomes approximately the same potential as the background potential of the first photosensitive drum 71. Apply electrical charge.

Subsequently, the first exposure section 74 forms a latent image corresponding to the second color information on the first photosensitive drum 71 during the next rotation, and the latent image is subsequently transferred to the second developing section 76. After developing to form a second toner visible image (magenta),
These two-color visible images are transferred to the recording paper 90 in the transfer section 77.
Transfer them all at once.

On the other hand, the image forming timing on the second photosensitive drum 72 is shifted from that on the first photosensitive drum 71 side, and the initial charger 81 first charges the second photosensitive drum 72 uniformly to the initial charging potential level. A latent image corresponding to the third color information is formed by the exposing section 82, and the latent image is subsequently developed by the third developing section 83 to form a third visible toner image (yellow).

Next, the potential of the third toner visible image (yellow) portion formed on the second photosensitive drum 72 is reactivated by the initial charger 81 so that it becomes approximately the same potential as the background potential of the second photosensitive drum 72. Apply electrical charge.

Subsequently, the second exposure section 82 forms a latent image corresponding to the fourth color information on the second photosensitive drum 72 during the next rotation, and the latent image is subsequently transferred to the fourth developing section 84. After developing to form a fourth toner visible image (blank),
These two color visible images are collectively transferred in the transfer unit 85 onto the same recording paper 90 onto which the first toner visible image (cyan) and the second toner visible image (magenta) have already been transferred.

After that, the multicolor toner image transferred onto the recording paper 90 is
By thermally fixing, for example, in the fixing section 89, permanent multicolor recording without color mixture can be obtained.

Note that the toner remaining on the surfaces of the first and second photosensitive drums 71 and 72 is neutralized by AC static eliminators 78 and 86, and cleaned and removed by cleaners 79 and 87, respectively.
Furthermore, all charges on the surfaces of the photosensitive drums 71 and 72 are eliminated by optical charge removers 80 and 88, and the next recording cycle begins.

In addition, the second development and the fourth development during the recording process in this device
For development, first. The already formed first photoconductor on the second photosensitive drum 71,72. To prevent destruction of the third toner visible image, the second. The particle size of the fourth carrier 103.108 is 5 to 1
Soft-touch development methods are commonly used, such as micro-development with a size as small as 00 μl, or non-contact development in which an AC bias voltage is applied to each development section to cause the toner to fly out of the developer.

Further, FIG. 3 shows an example of a second developing device and a fourth developing device that perform the second developing and fourth developing described above.

The developing roller 111 consists of a magnetic roller 112 and a non-magnetic cylindrical sleeve 113, and the rotation of the magnetic roller 111,
Alternatively, the developer is conveyed to the photosensitive drum 71 (72) side by also using the rotation of the sleeve 113.

The ``first'' mixed into each opening 114 and 115 of these developing devices When the third color toner is separated, by providing an air suction collection device or the like for collecting the third color toner, it becomes possible to efficiently collect the separated color toner.

〔Effect of the invention〕

As is clear from the above description, according to the multicolor recording device according to the present invention, the main photosensitive drum is configured in two sets,
One latent image forming exposure section and two
Since a configuration is adopted in which visible toner images of two colors are continuously formed by two developing sections, and these two visible toner images are successively transferred onto one sheet of recording paper in a superimposed manner, The number of image forming functions placed around each photosensitive drum is reduced,
Eliminates the complexity of device configurations, making it easier to manufacture devices,
The advantage is that adjustment, maintenance, etc. are easy.

In addition, in order to prevent color mixing, the triboelectric charging series of the toner and carrier of each developer should be selected in consideration of the triboelectric charging series for each developer used in the two developing devices of each photosensitive drum unit. (This method has many excellent practical effects, such as facilitating the procurement and production of toner and carrier for each of these developers.)

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of a multicolor recording device according to the present invention, and FIG. 2 is a schematic diagram showing an embodiment of a triboelectric charging system of toner and carrier used in each developing section of the recording device of the present invention. Figure 3 is a vertical sectional view of essential parts showing an embodiment of the developing section of the recording device of the present invention, and Figure 4 is a two-color recording device commonly used to simplify the explanation of the conventional multicolor recording device. Figures 5 to 10 are diagrams showing the potential levels on the photosensitive drum in each process for two-color recording, and Figure 11 is a diagram showing the toner and carrier levels used in each developing section for two-color recording. Figure 12 is a schematic configuration diagram showing an example of a conventional multicolor recording device; Figure 13 is a diagram showing the frictional charging system of toner and carrier used in each developing section in the multicolor recording device shown in Figure 12. It is a diagram showing a series. In the figure, 71.72 is the 1st. Second photosensitive drum, 73.81
74.82 is the initial charger, 74.82 is the first and second exposure section, and 75.
76, 83, and 84 are the first to fourth developing sections, 77 and 85 are transfer sections, 78.86 is an AC static eliminator, 79.87 is a cleaner, 80.88 is an optical static eliminator, 89 is a fixing section, and 90 is a Recording paper, 101.102.105.106 are toners of the first to fourth colors, 103.104.107.108 are first to fourth carriers, 111 is a developing roller, 112 is a magnetic roller, 113 is a sleeve, 114 and 115 indicate openings, respectively. Fig. 2 1m) Fig. 4

Claims (2)

[Claims] (1) A first photosensitive drum around which one charger, one latent image forming section, two developing sections using toner of different colors, a transfer section and a cleaning section are arranged; and a photosensitive drum are arranged in parallel in the recording paper running direction, and on the photosensitive drum while the first photosensitive drum rotates twice,
The latent image forming section and one developing section, and the same latent image forming section and the other developing section, produce first and second color toners corresponding to the first and second color portions of the information image to be recorded. A visible image is sequentially formed, and the visible image is transferred all at once onto a recording paper by a transfer section, and the latent image forming section and one developer are placed on the photosensitive drum while the second photosensitive drum rotates twice. Visible images formed by the third and fourth color toners corresponding to the third and fourth color portions of the information image to be recorded are formed sequentially by the same latent image forming portion and the other developing portion. A multi-color recording device characterized in that the transfer section performs multi-color recording by collectively transferring toner visible images of first and second colors onto a recording sheet. (2) Toner of each color in the first and second developers used in the two developing sections on the first photosensitive drum side and the third and fourth developers used in the two developing sections on the second photosensitive drum side. and the carrier are selected in independent triboelectrification series, and the polarity of the first and third color toners mixed in the second and fourth developing sections, respectively, is reversed due to the difference in the order on the triboelectrification series. The multicolor recording apparatus according to claim 1, wherein the amount of charge is attenuated and separated and removed from the second and fourth developing devices.