JP2001100486A - Image forming device - Google Patents

Abstract

(57) [Problem] To improve a transfer efficiency by increasing a first printing speed in an intermediate transfer type color image forming apparatus, reducing image deterioration. When an image is formed using only black toner, a photosensitive body is uniformly charged by a charger of a monochrome image forming section, and an exposure corresponding to the image is performed by an exposure device. And an electrostatic latent image is formed on the photosensitive member 1.
2, a sheet fed from the cassette 20 or 21 is conveyed between the photoreceptor 12 and the transfer roller 15 in synchronization with the movement of the toner image on the photoreceptor 12, and black on the sheet. When the toner image is transferred, the toner image is fixed on the paper by the fixing device 16, and when a color image is printed,
After the yellow, magenta, and cyan are transferred to the intermediate transfer member 45 and transferred to the paper in the color image forming section 2, the black toner is transferred and fixed as described above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image forming apparatus for forming a color image or a monochrome image based on image data transmitted from a scanner or an external device.

[0002]

2. Description of the Related Art In recent years, the number of opportunities for printing color images in offices has increased, and the number of electrophotographic color image forming apparatuses has increased. Electrophotographic color image forming apparatuses include a quadruple tandem system, a transfer drum system, and an intermediate transfer system. Among them, the intermediate transfer method is recently used in many color image forming apparatuses because of its small size and low cost.

FIG. 5 shows a conventional intermediate transfer type color image forming apparatus. This method is a method in which four color toner images are formed on the intermediate transfer member 200 in a superimposed manner, and thereafter, are collectively transferred to paper.

[0004] However, the printing speed of the color is reduced to 1/4 of that of the single black color, and the printing speed of the intermediate transfer member 20 is not limited to the printing of the single black color.
Since 0 is used, the distance over which the toner image is conveyed in the apparatus becomes longer as shown by the bold line in FIG. 5 as compared with an image forming apparatus dedicated to black images, and the first printing speed becomes slower. There are two transfers, primary transfer to the intermediate transfer member 200 and secondary transfer from the intermediate transfer member 200 to the paper, which deteriorates the image and reduces the efficiency of toner transfer from the photoreceptor to the paper. Running costs are increasing due to increased consumption.

Although the number of color images in the office is increasing, the number of monochrome images is not decreasing. As described above, in the intermediate transfer type image forming apparatus, the productivity of the monochrome images is reduced. In particular, the first printing speed is reduced, and a monochrome image forming machine is often used separately for monochrome image printing.

[0006]

As described above, in the color image forming apparatus of the intermediate transfer system, the printing speed of the color is reduced to 1/4 of that of the black single color, and the intermediate transfer body 200 can be printed even in the black single color printing. As compared to an image forming apparatus dedicated to black images, the distance over which the toner image is transported in the apparatus is longer, the first printing speed is slower, and the primary transfer from the photoconductor to the intermediate transfer body and the intermediate transfer body are used. There is a secondary transfer from the paper to the paper and a two-time transfer.
There is a problem that the toner consumption increases due to a decrease in transfer efficiency.

In view of the above, the present invention provides a method for increasing a first printing speed in an intermediate transfer type color image forming apparatus,
An object of the present invention is to provide an image forming apparatus capable of improving transfer efficiency by reducing image deterioration.

[0008]

An image forming apparatus according to the present invention comprises at least a first photosensitive member, first charging means for charging the first photosensitive member, and charging by the first charging means. First exposing means for exposing the first photoconductor thus formed to form an electrostatic latent image, and forming an electrostatic latent image formed on the first photoconductor by the first exposing means. First developing means for visualizing an image with toner of one color, first transferring means for transferring the toner image visualized on the first photoconductor by the first developing means to paper, A first image forming unit having a fixing unit for fixing the toner image transferred onto the sheet by the first transfer unit to the sheet; at least a second photosensitive member; and charging the second photosensitive member A second charging unit, and the second sensor charged by the second charging unit. A second exposing unit for exposing the body to form an electrostatic latent image, and a plurality of electrostatic latent images formed on the second photoreceptor by the second exposing unit, the plurality of electrostatic latent images being different from the first color. A plurality of second developing means for visualizing the image with the color toner, and a toner image of at least one color sequentially visualized on the second photoconductor by the plurality of second developing means. A second image forming unit including an intermediate transfer body that is once held, a second transfer unit that transfers a toner image from the intermediate transfer body to a sheet, and a toner image transferred by the second image forming unit. Transport means for transporting the sheet to the first transfer means of the first image forming section.

[0009] The image forming apparatus of the present invention comprises:
A first photoconductor, first charging means for charging the first photoconductor, and exposing the first photoconductor charged by the first charging means to form an electrostatic latent image A first exposure unit, a first development unit that visualizes the electrostatic latent image formed on the first photoconductor by the first exposure unit with a first color toner, First transfer means for transferring the toner image visualized on the first photoconductor by the first developing means onto a sheet, and fixing the toner image transferred onto the sheet by the first transfer means onto the sheet; A first paper feeder having a fixing unit and a first paper supply unit for feeding paper from the first paper storage unit provided in advance to the first transfer unit;
, At least a second photoconductor, a second charging unit for charging the second photoconductor, and exposing the second photoconductor charged by the second charging unit. A second exposing means for forming an electrostatic latent image on the second photoreceptor by the second exposing means using toner of a plurality of colors other than the first color. A plurality of second developing means for visualizing, and an intermediate transfer for temporarily holding at least one toner image of at least one color sequentially visualized on the second photoconductor by the plurality of second developing means; Body, a second transfer unit for transferring the toner image from the intermediate transfer body to a sheet, and a second sheet feeding unit for feeding a sheet from the second sheet storage unit provided in advance to the second transfer unit. A second image forming section having a means, and a toner image being transferred by the second image forming section. It has been the paper, and a conveying means for conveying the first transfer means of the first image forming unit.

[0010] The image forming apparatus of the present invention comprises:
A first photoconductor, first charging means for charging the first photoconductor, and exposing the first photoconductor charged by the first charging means to form an electrostatic latent image A first exposure unit, a first development unit that visualizes the electrostatic latent image formed on the first photoconductor by the first exposure unit with a first color toner, First transfer means for transferring the toner image visualized on the first photoconductor by the first developing means onto a sheet, and fixing the toner image transferred onto the sheet by the first transfer means onto the sheet; A first image forming unit having a fixing unit, a first sheet feeding unit for feeding a sheet from a previously provided sheet storage unit to the first transfer unit, at least a second photoconductor, A second charging unit for charging the second photoconductor, and a second charging unit for charging the second photoconductor. A second exposing means for exposing the second photoconductor to form an electrostatic latent image, and a first exposing means for converting the electrostatic latent image formed on the second photoconductor by the second exposing means into a first A plurality of second images to be visualized with toners of a plurality of colors other than the colors
And an intermediate transfer member that temporarily holds at least one toner image of at least one color sequentially visualized on the second photoconductor by the plurality of second developing devices, and
A second image forming apparatus including: a second transfer unit that transfers a toner image from the intermediate transfer body to a sheet; and a second sheet feeding unit that feeds a sheet from the sheet storage unit to the second transfer unit. And a transport unit that transports the sheet on which the toner image has been transferred by the second image forming unit to the first transfer unit of the first image forming unit.

[0011] The image forming apparatus of the present invention comprises:
A first photoconductor, first charging means for charging the first photoconductor, and exposing the first photoconductor charged by the first charging means to form an electrostatic latent image A first exposure unit, and the first exposure unit exposed by the first exposure unit.
Developing means for visualizing the electrostatic latent image formed on the photoreceptor by a first color toner, and toner visualized on the first photoreceptor by the first developing means A first image forming unit including a first transfer unit that transfers an image to a sheet, and a fixing unit that fixes the toner image transferred to the sheet by the first transfer unit to the sheet;
A second photoconductor, a second charging unit for charging the second photoconductor, and the second charging unit charged by the second charging unit.
A second exposing means for exposing the photoreceptor to form an electrostatic latent image, and forming the electrostatic latent image formed on the second photoreceptor exposed by the second exposing means into a first A plurality of second developing means for visualizing with a plurality of color toners other than the color, and a toner image of at least one color sequentially visualized on the second photoconductor by the second developing means; A second transfer unit that temporarily holds the intermediate transfer member and a second transfer unit that transfers a toner image from the intermediate transfer member to a sheet.
An image forming apparatus comprising: an image forming unit; and a conveying unit that conveys the sheet on which the toner image has been transferred by the second image forming unit to a first transfer unit of the first image forming unit. When the image to be formed is formed only in the first color, the second image forming section does not operate.

[0012]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of an image forming apparatus according to the present invention. The image forming apparatus includes a monochrome image forming section 1, a color image forming section 2, and a paper transport section 3 for double-sided printing.

First, the operation of printing a monochrome image, that is, forming an image using only black toner, will be described.
The rotating drum-shaped photoconductor 12 is uniformly charged by the charger 11 of the monochrome image forming unit 1, and subsequently,
The exposure device 13 that scans the laser beam in the main scanning direction using a polygon mirror performs exposure corresponding to the image on the photoconductor 12 to form an electrostatic latent image. Photoconductor 1
The electrostatic latent image formed on 2 is developed by black toner developing device 14, and a toner image is formed on photoconductor 12.
The paper fed from the cassette 20 or 21 is conveyed between the photoconductor 12 and the transfer roller 15 in synchronization with the movement of the toner image on the photoconductor 12, and the black toner image is transferred to the paper.

Since the diameter of the photosensitive member 12 is about 30 mm,
The paper on which the black toner has been transferred is separated from the photoreceptor 12 by the stiffness of the paper (hardness of the paper), the toner image is fixed on the paper by the fixing device 16, and the paper discharge tray 19 is driven by the paper discharge roller pair 17. And a monochrome image is formed. Toner remaining without being transferred from the photoconductor 12 to the sheet is removed from the photoconductor 12 by a rubber blade cleaner 18. A plurality of paper cassettes for storing the paper used for printing and feeding the paper to the image forming unit are provided according to the size of the paper. In this embodiment, an A4-size cassette 20 and an A3-size cassette 21 are provided. .

The paper to be fed is taken out of the cassettes 20 and 21 by the feed rollers 22 and 23, and then, when a plurality of sheets are taken out, the separation roller pair 2 separates and conveys only one sheet.
The rollers 4 and 25 convey the roller to the aligning roller pair 26. Further, the sheet is transported by the aligning roller pair 26 to a transfer position where the leading end position of the sheet matches the leading end position of the toner image on the photoconductor 12.

Next, a color image printing operation will be described. The charging device 41 of the color image forming section 2 uniformly charges the photosensitive member 42 of the endless belt conveyed on the same track, and then scans the laser beam in the main scanning direction using a polygon mirror. The exposure corresponding to the yellow image is performed on the photoconductor 42 by the device 43, and an electrostatic latent image is formed. The electrostatic latent image formed on the photoconductor 42 is developed by the yellow toner developing device 44Y, a yellow toner image is formed on the photoconductor 42, and is further electrostatically transferred to the intermediate transfer body 45. After the transfer, the photoconductor 42
Is removed by a light remover 46, and the toner remaining on the photosensitive member 42 without being transferred to the intermediate transfer member 45 is removed by a photosensitive member cleaner 47.
Cleaning. The cleaned toner is collected in the waste toner box 54.

Subsequently, a magenta electrostatic latent image is formed on the photoconductor 42 in the same manner as yellow, and is developed by a magenta toner developing unit 44M to form a magenta toner image on the photoconductor 42. The toner image is transferred so as to be superimposed on the upper yellow toner image, and is electrostatically transferred onto the intermediate transfer body 45. After the transfer, the photosensitive member 42 is removed and cleaned in the same process.

Subsequently, a cyan electrostatic latent image is formed on the photoreceptor 42 and is developed by a cyan toner developing unit 44C to form a cyan toner image on the photoreceptor 42, and a yellow toner on the intermediate transfer member 42. The image is superimposed on the image and the magenta toner image and is transferred onto the intermediate transfer member 45 electrostatically. After the transfer, the photosensitive member 42 is removed and cleaned in the same process.

Thus, toner images of three colors (yellow: Y, magenta: M, and cyan: C) are formed on the intermediate transfer member 45. Thereafter, the aligning roller pair 5 is fed from the cassette 50 by the paper feed roller 51 and the separation roller pair 52.
3 is conveyed between the intermediate transfer member 45 and the transfer roller 48 in synchronization with the movement of the toner image on the intermediate transfer member 45, and the Y, M, and C toner images are superimposed on the sheet. The combined toner image is transferred. The sheet holding the three color toner images is separated from the intermediate transfer body 45 by the separation charger 49. On the other hand, since the toner that has not been completely transferred to the sheet remains on the intermediate transfer member 45, the intermediate transfer member cleaner 5 is closed after the completion of the secondary transfer (transfer from the intermediate transfer member to the sheet).
0, and the intermediate transfer member 45 is cleaned. Of course, the intermediate transfer member cleaner 50 is separated from the intermediate transfer member 45 during the above-described operation of superimposing the three color toner images.

The intermediate transfer member 4 holding the three color toner images
The sheet peeled from the sheet 5 is conveyed between the photoconductor 12 and the transfer roller 15 of the monochrome image forming unit 1 by a sheet conveying belt 60 that conveys the sheet from the color image forming unit 2 to the monochrome image forming unit 1. Here, a black toner image is formed on the photoconductor 12 in the process described above in the monochrome image printing operation.
The sheet is formed so as to be aligned with the sheet to be conveyed, and the black toner is transferred to the sheet so that the four color toners overlap on the sheet. Further, the sheet passes through a fixing device 16 and four color toners are fixed on the sheet, and the sheet is discharged to a discharge tray 19 by a pair of discharge rollers 17 to form a color image.

The paper transport belt 60 is formed by processing a resin, which is a dielectric material, into an endless shape and holding it under tension by a plurality of rollers 61a to 61c.
The same orbit can be moved by the rotation of 61c.
The charger 62 provided upstream of the sheet conveyance start position includes:
The surface of the paper transport belt 60 is charged to a polarity opposite to that of the toner. As a result, the paper is attracted to the paper transport belt, so that the paper does not move during transport, and the three-color toner image on the paper and the black toner image on the photoconductor 12 are accurately overlapped. Can be. In addition, since the paper can be transported upward from below, the monochrome image forming section 1 and the color image forming section 2 can be arranged side by side in the vertical direction as shown in the figure, and the installation area of the apparatus can be reduced. Is possible.

The separation of the paper from the paper transport belt 60 is performed by using the stiffness (hardness of the paper) of the paper by reducing the diameter of the roller 61a at the transport end position. Also,
Since the pair of aligning rollers 26 of the monochrome image forming section 1 is kept apart when forming a color image, the surface of the sheet holding the unfixed three-color toner is aligned with the aligning roller 26.
Is transferred to the transfer position of the monochrome image forming section 1 (between the photosensitive member 12 and the transfer roller 15) without contacting the transfer member.

Incidentally, the first copy (print) time of the electrophotographic image forming apparatus depends on the process speed,
In other words, if the moving speed of the photoconductor is the same, the longer time is required until the paper is fed from the cassette and reaches the transfer position, or the time until the photoconductor starts to move and the tip of the toner image reaches the transfer position is longer. Is determined. Therefore, in order to shorten the first copy time, the transfer position from the cassette,
In particular, it is necessary to shorten the paper conveyance path from the aligning roller to the transfer position and the toner image conveyance path from the charging position to the transfer position.

In a conventional intermediate transfer type color image forming apparatus, when a monochrome image is printed, the toner image visualized by the photosensitive member 201 is temporarily transferred to the intermediate transfer member 200 as shown by a thick line in FIG. Since the toner image is transferred to the paper, the transport path from the development to the transfer of the toner image (from the developing roller position to the photosensitive member → intermediate transfer member → paper transfer position) becomes long. On the other hand, in the image forming apparatus of the present invention, the paper and toner transport path during monochrome image formation can be made shorter than in the conventional intermediate transfer method, so that the first copy time of a monochrome image can be shortened.

Further, cassettes 20 and 21 for supplying sheets to a monochrome image forming section 1 for forming a monochrome image,
By separately providing a cassette 50 for supplying paper to the color image forming unit 2 for forming Y, M, and C images for forming a color image, the monochrome image forming unit 1 and the color image forming unit 2 You can place cassettes in between,
The paper transport path from the cassettes 20 and 21 to the transfer position of the monochrome image forming unit 1 is shortened, and the first copy time of the monochrome image can be shortened.

FIG. 2 shows a schematic configuration of a control system of the image forming apparatus. This image forming apparatus includes two CPUs, a main CPU 31 in a main control unit 30 and a printer CPU 80.

The main CPU 31 is a printer CPU 80
The main CPU 31 issues an operation instruction to the printer CP through the shared RAM 35.
U80 returns a status status.

The operation panel 70 is connected to the main CPU 31 and controls the entire panel CPU 71 and the liquid crystal display 7.
2 and a print key 73.

The main control unit 30 includes a main CPU 31, an RO
M32, RAM 33, NVM 34, shared RAM 35, image processing device 36, page memory control unit 37, page memory 38, printer controller 39, and printer font ROM 93.

The main CPU 31 controls the entire main controller 30. The ROM 32 stores a control program. The RAM 33 temporarily stores data.

NVM (lasting random access memory: no
The nVM 34 is a non-volatile memory backed up by a battery (not shown), and retains data on the NVM 34 when the power is turned off.

The shared RAM 35 is used for performing bidirectional communication between the main CPU 31 and the printer CPU 80.

The page memory controller 37 stores and reads out image data in the page memory 38. The page memory 38 has an area capable of storing image data for a plurality of pages, and is formed so as to be able to store data obtained by compressing image data from an external device such as a scanner or a personal computer for each page.

The printer font ROM 93 stores font data corresponding to print data.

The printer controller 39 includes a scanner,
This is for developing print data from an external device or the like into image data at a resolution corresponding to data indicating the resolution given to the print data, using font data stored in the printer font ROM 93.

The printer CPU 80 has a ROM 81 in which a control program and the like are stored, a RAM 82 for storing data, a laser driver 83 for turning on / off a semiconductor laser (not shown) of the exposure device 13, and a laser of the exposure device 43. A driver 84, a polygon motor driver 85 for controlling the rotation of a polygon motor (not shown) of the exposure device 13, and a polygon motor driver 8 for the exposure device 43
6, a paper transport unit 89 for controlling the transport of the paper by the paper transport unit 3, a charger 11, a photoconductor 12, a black toner developing device 14,
A developing process unit 87 that performs charging, development, and transfer using the transfer roller 15; a developing unit that performs charging, development, and transfer using the charger 41, the photoconductor 42, the toner developing units 44Y, 44M, 44C, and the intermediate transfer body 45 Process unit 88, fixing unit 16
, And an option unit 90 are connected.

The image processing device 36 and the page memory 3
8, printer controller 39, laser driver 83,
84 is connected by an image data bus 92.

Next, the image forming operation in the image forming apparatus of the present invention will be described with reference to the flowchart of FIG.

First, the main CPU 31 determines whether image data read by a scanner (not shown) or image data transferred from an external device such as a personal computer is monochrome or color (ST1).

If it is determined that the printing is color printing, the main CPU
31 is charging by the charger 41 of the color image forming unit 2;
Laser scanning by the exposure device 43, driving of the photoconductor 42, transfer to the intermediate transfer body 45, and feeding operation from the cassette 50 are started, charging, laser scanning, photoconductor drive, and transfer to the intermediate transfer body. Are performed three times for yellow, magenta, and cyan (ST2). After a lapse of a predetermined time from the start of the laser scanning (ST3), the main CPU 31 starts conveying the sheet by the aligning roller pair 53 (ST4), and transfers the sheet by aligning the position of the sheet with the toner image on the intermediate transfer member 45. I do. Further, after a lapse of a predetermined time from the start of laser scanning, the main CPU 31 starts charging of the monochrome image forming section 1 by the charger 11, laser scanning by the exposure device 13, driving of the photoconductor 12, and the like (ST 5). Photoconductor 12
The image is transferred by the transfer roller 15 in alignment with the upper toner image (ST6), fixed by the fixing device 16 (ST7), and discharged to the discharge tray 19 to form a color image.

If it is determined in step ST1 that the monochrome printing is to be performed, the main CPU 31 charges the monochrome image forming section 1 by the charger 11, laser scans by the exposure device 13,
Driving of the photoreceptor 12 and feeding operation from the cassette 20 or 21 are started (ST11), and after a lapse of a predetermined time from the start of laser scanning (ST12), the aligning roller pair 26
Is started (ST13), the position of the sheet and the toner image on the photoreceptor 12 are aligned, transferred by the transfer roller 15 (ST14), and fixed by the fixing device 16 (ST1).
5) The paper is discharged to the paper discharge tray 19 to form a monochrome image.

FIG. 4 shows the configuration of another embodiment of the image forming apparatus of the present invention. The same parts as those of the image forming apparatus shown in FIG. This image forming apparatus includes a monochrome image forming unit 1, a color image forming unit 2, and a paper transport unit 3 for double-sided printing, as in FIG. In this embodiment, a cassette 1 for storing paper used for printing and feeding the paper to an image forming unit
Reference numerals 00 and 101 are provided between the monochrome image forming unit 1 and the color image forming unit 2. When a color image is formed, the paper fed from the cassettes 100 and 101 is transported in the direction of the arrow through the paper transport unit 3 for double-sided printing by gates 102, 102b, 103a and 103b, and reaches the aligning roller 104. The sheet is conveyed between the intermediate transfer member 45 and the transfer roller 48 in synchronization with the position of the toner image on the intermediate transfer member 45. Thereafter, the transferred sheet is conveyed to the monochrome image forming unit 1 by the sheet conveying belt 60, and a color image is formed.

Here, since the cassettes 100 and 101 are arranged near the monochrome image forming section 1, the first copy time of a monochrome image can be shortened. Next, in the case of a color image, it takes about three times as long as a monochrome image to form a Y (yellow), M (magenta), and C (cyan) image on the intermediate transfer member 45 in a superimposed manner. Even if the paper transport path from the cassette 100 or 101 to the transfer position is long, the leading edge of the paper can reach the transfer position, and the first copy time does not become long. Further, since it is not necessary to separately provide the cassette in the monochrome image forming section 1 and the color image forming section 2, the apparatus can be downsized.

As described above, according to the embodiment of the present invention, in a monochrome image printing operation, the intermediate transfer member of the color image forming section for forming a color image does not rotate, so that there is no deterioration due to abrasion and a long life. Can be achieved.

In the case of monochrome printing, the conventional intermediate transfer method involves two transfers, a primary transfer from the photosensitive member to the intermediate transfer member and a secondary transfer from the intermediate transfer member to the paper, resulting in image deterioration. And the transfer efficiency is reduced, the toner consumption is increased due to a decrease in the transfer efficiency, and the running cost is increased.However, in the case of a monochrome image, since the toner image is directly transferred from the photoconductor to the paper, the deterioration of the image quality is small, The toner consumption can also be reduced.

[0047]

As described in detail above, according to the present invention,
It is possible to provide an image forming apparatus capable of increasing a first printing speed in an intermediate transfer type color image forming apparatus, reducing image deterioration, and improving transfer efficiency.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an image forming apparatus according to the present invention.

FIG. 2 is a block diagram illustrating a schematic configuration of a control system of the image forming apparatus.

FIG. 3 is a flowchart for explaining an image forming operation in the image forming apparatus of the present invention.

FIG. 4 is a diagram showing a schematic configuration of another embodiment of the image forming apparatus of the present invention.

FIG. 5 is a diagram showing a configuration of a conventional intermediate transfer type image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Monochrome image formation part (1st image formation part) 2 ... Color image formation part (2nd image formation part) 3 ... Paper conveyance part 11, 41 ... Charging device (charging means) 12, 42 ... Photoconductor 43 Exposure device (exposure device) 14 Black toner developing device (first developing device) 15, 48 Transfer roller (transfer device) 16 Fixing device (fixing device) 19 Discharge tray 21, 50, 100, 101 ... Cassette (paper storage unit) 44Y ... Yellow toner developing unit (second developing unit) 44M ... Magenta toner developing unit (second developing unit) 44C ... Cyan toner developing unit (second developing unit) 45 ... Intermediate transfer Body 60: paper transport belt (transport means)

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Koji Tanimoto, Inventor F-term (reference) 2H027 DA32 DA36 DB02 ED06 ED08 ED16 ED25 EE07 EE08 FA11 FA28 FB08 FD08 in Yanagimachi Office, Kochi-ku, Kawasaki City, Kanagawa Prefecture GA01 ZA10 2H030 AD01 AD02 AD04 AD05 AD11 AD17 BB02 BB23 BB42 BB44 BB46 BB52 2H032 AA05 AA15 BA02 BA05 BA08 BA18 BA21 BA23 CA02 CA13

Claims (9)

[Claims] At least a first photoconductor and a first photoconductor are provided.
A first charging unit for charging the photoconductor, a first exposing unit for exposing the first photoconductor charged by the first charging unit to form an electrostatic latent image, A first developing means for visualizing the electrostatic latent image formed on the first photoconductor by the first color toner by the first color toner;
First transfer means for transferring the toner image visualized on the first photoconductor by the first developing means to a sheet,
A first image forming unit having a fixing unit for fixing the toner image transferred onto the sheet by the first transfer unit to the sheet; at least a second photosensitive member; and charging the second photosensitive member A second charging unit, a second exposing unit that exposes the second photoconductor charged by the second charging unit to form an electrostatic latent image, and a second exposing unit that forms the electrostatic latent image. A plurality of second developing means for visualizing the electrostatic latent image formed on the second photoreceptor with toners of a plurality of colors other than the first color, and the plurality of second developing means An intermediate transfer member for temporarily holding a toner image of at least one color visualized on the second photoconductor in a superimposed state; and a second transfer unit for transferring the toner image from the intermediate transfer member to a sheet. A second image forming unit, and a toner in the second image forming unit. An image forming apparatus comprising: a conveying unit configured to convey a sheet on which the image is transferred to a first transfer unit of the first image forming unit. 2. A toner image formed in a first image forming unit by a first transfer unit of the first image forming unit, on a toner image transferred to a sheet in the second image forming unit. The image forming apparatus according to claim 1, wherein the image forming apparatus is combined. 3. A black color is formed in the first image forming section,
2. The image forming apparatus according to claim 1, wherein the second image forming section forms an image in which yellow, cyan, and magenta colors are superimposed. 4. At least a first photoconductor and the first photoconductor
A first charging unit for charging the photoconductor, a first exposing unit for exposing the first photoconductor charged by the first charging unit to form an electrostatic latent image, A first developing means for visualizing the electrostatic latent image formed on the first photoconductor by the first color toner by the first color toner;
First transfer means for transferring the toner image visualized on the first photoconductor by the first developing means to a sheet,
Fixing means for fixing the toner image transferred to the sheet by the first transfer means to the sheet; and first supply means for feeding the sheet from the first sheet storage unit provided in advance to the first transfer means. A first image forming unit having a paper unit, at least a second photoconductor, a second charging unit for charging the second photoconductor, and the second charging unit charged by the second charging unit. A second exposing means for exposing the second photoreceptor to form an electrostatic latent image, and exposing the electrostatic latent image formed on the second photoreceptor by the second exposing means to colors other than the first color. A plurality of second developing means for visualizing with a plurality of color toners and a toner image of at least one color sequentially visualized on the second photoconductor by the plurality of second developing means. An intermediate transfer member that is temporarily held together, and a toner image is A second image forming unit having a second transfer unit for transferring, and a second paper feeding unit for feeding paper from a second paper storage unit provided in advance to the second transfer unit; An image forming apparatus, comprising: a transport unit configured to transport a sheet on which a toner image has been transferred by a second image forming unit to a first transfer unit of the first image forming unit. 5. A first paper storage unit for supplying paper to a first transfer unit of the first image forming unit, the first paper storage unit comprising a first transfer unit of the first image forming unit and the second image storage unit. Second of forming part
The image forming apparatus according to claim 4, wherein the image forming apparatus is disposed between the image forming apparatus and a transfer unit. 6. At least a first photoconductor and the first photoconductor
A first charging unit for charging the photoconductor, a first exposing unit for exposing the first photoconductor charged by the first charging unit to form an electrostatic latent image, A first developing means for visualizing the electrostatic latent image formed on the first photoconductor by the first color toner by the first color toner;
First transfer means for transferring the toner image visualized on the first photoconductor by the first developing means to a sheet,
Fixing means for fixing the toner image transferred to the sheet by the first transfer means to the sheet; first sheet feeding means for feeding the sheet from the sheet storage provided in advance to the first transfer means; A first image forming unit having at least a second photoconductor, a second charging unit for charging the second photoconductor, and the second photoconductor charged by the second charging unit. A second exposure means for exposing the body to form an electrostatic latent image, and a plurality of colors other than the first color for the electrostatic latent image formed on the second photoconductor by the second exposure means. A plurality of second developing means for visualizing the image with the toner, and a toner image of at least one color sequentially visualized on the second photoreceptor by the plurality of second developing means. Holds the intermediate transfer body and transfers the toner image from this intermediate transfer body to paper A second image forming unit having a second transfer unit, a second sheet feeding unit for feeding a sheet from the sheet storage unit to the second transfer unit, and a second image forming unit. An image forming apparatus comprising: a conveying unit configured to convey a sheet on which the toner image is transferred to a first transfer unit of the first image forming unit. 7. The paper storage section is configured to be configured such that the second paper supply means feeds the paper from the paper storage section to the second transfer means through a paper transport path, and the first paper supply means feeds the paper. 7. The image forming apparatus according to claim 6, wherein the paper transport path for feeding paper from the storage unit to the first transfer unit is located at a position where the paper transport path is shorter. 8. At least a first photosensitive member and the first photosensitive member
A first charging unit for charging the photoconductor, a first exposing unit for exposing the first photoconductor charged by the first charging unit to form an electrostatic latent image, A first developing means for visualizing the electrostatic latent image formed on the first photoconductor exposed by the exposure means with a first color toner; and A first transfer unit that transfers the toner image visualized on the first photoconductor to a sheet, and a fixing unit that fixes the toner image transferred to the sheet by the first transfer unit to the sheet. An image forming unit, at least a second photoconductor, and a second photoconductor;
A second charging unit for charging the photosensitive member, a second exposing unit for exposing the second photosensitive member charged by the second charging unit to form an electrostatic latent image, A plurality of second developing means for visualizing an electrostatic latent image formed on the second photoconductor exposed by the exposing means with a plurality of color toners other than the first color; An intermediate transfer member for superimposing and temporarily holding a toner image of at least one color sequentially visualized on the second photoconductor by the second developing means; and a second image transfer device for transferring the toner image from the intermediate transfer member to a sheet. A second image forming unit having transfer means
And a transport unit for transporting the sheet on which the toner image has been transferred by the image forming unit to the first transfer unit of the first image forming unit, wherein the image to be formed is the first color The image forming apparatus according to claim 1, wherein the second image forming unit does not operate when the image forming apparatus is formed only by the image forming apparatus. 9. When the image to be formed is formed only with a first color, at least a second photoconductor, a second charging unit, a second exposing unit, and a second exposing unit of the second image forming unit. 9. The image forming apparatus according to claim 8, wherein the developing unit and the intermediate transfer member do not operate.