JPH0553404A - Color image forming device - Google Patents

Abstract

PURPOSE:To perform economical exchange of a developing machine color cartridge, mounted on a process unit, and reliable formation of an image. CONSTITUTION:Developing machines 8-11 containing a color developer are located below a photosensitive substance belt 1 run around rotation rollers 2 and 3 and form a cartridge type. An electrifier 6 and a transfer device 12 are located facing the curved part of the photosensitive substance belt 1 run around the rotation roller 3. A cleaning device 13 is located adjacently to the developing machine 8 and situated facing and separately away from the curved surface of the photosensitive substance belt on the rotation roller 2 side on the opposite side. The stretched photosensitive substance belt 1, the cleaning device 13, and the developing machines 8-11 respectively form a cartridge type and are removably mounted on a color image forming device 25. Sensors 8-11B to detect amounts of remaining toner are arranged to the developing machines 8-11, respectively, and feedback to a CPU in the image forming device 25 is effected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms a toner image on a belt-shaped or drum-shaped image forming body by an electrophotographic method,
The present invention relates to a color image forming apparatus which transfers an image onto a transfer material to obtain an image.

[0002]

2. Description of the Related Art Conventionally, for example, a color image forming apparatus in which an image carrier belt is suspended substantially horizontally and a plurality of developing devices are arranged in parallel on the lower surface of the belt is disclosed in, for example, JP-A-61-15156.
It is described in Japanese Patent Publication No. 0, etc. and is publicly known. According to the color image forming apparatus described in the above publication, the image carrier belt is arranged substantially horizontally and horizontally, and a plurality of developing devices are arranged in parallel on the lower surface of the belt with the development openings thereof facing upward. ..
Then, around the image carrier belt stretched between the two rotating rollers provided opposite to each other, the charger, the exposure unit by the laser writing system, and the yellow disposed at the above-described position in the order of forming an image. , A magenta, cyan, and black developer respectively, and a transfer provided at a predetermined interval so as to face the curved surface of the image carrier belt wound around one rotating roller and each developing device. A fixing device and a fixing device are provided above the transfer device and the transfer device, respectively. A cleaning device is provided adjacent to the charging device, facing the curved surface of the image carrier belt wound around the other rotating roller and having a predetermined distance.

The color image forming apparatus having the above-described structure records color images one after another on recording paper that is intermittently conveyed.

[0004]

For example, in a color image forming apparatus equipped with a process cartridge in which toners of yellow, magenta, cyan, and black are hermetically sealed, the type of color forming a color image and Depending on the number of times, the consumption amount of each of the toners inevitably varies, and eventually, any one of the four colors is consumed and disappears. In such a state, naturally, a color image faithful to the original image cannot be formed.

Therefore, it is necessary to constantly monitor the consumption state of each toner and to supply accurate information and replenishment and replacement based on this.

Conventionally, if one of four color toners is consumed and consumed, even if black toner remains, it is very uneconomical to replace the cartridge containing the four colors.

Further, there are many demands from users for recording an image in black monochromatic color, and it is necessary to form an image in a monochromatic black mode by a color image forming apparatus.

The present invention solves such a problem, constantly monitors the consumption state of each toner and records a color image accurately, and it is also possible to switch to image formation with a single black color image. An object is to provide a forming apparatus.

[0009]

[Means for Solving the Problems]
b is achieved by any means.

(A) In a color image forming apparatus equipped with a process cartridge in which a plurality of color toners of a specific color and a black toner are sealed, when one of the color toner of the specific color and a black toner is consumed Is a color image forming apparatus, which prohibits image formation in the color mode and forms an image in the black single color mode when only black toner remains.

(B) In (a), when the image formation in the color mode is prohibited, the image formation in the single color mode other than the black toner is prohibited.

[0012]

1 is a side sectional view showing the structure of a color image forming apparatus of FIG. 1, a block diagram showing an image forming system of FIG. 2, and a block diagram showing an image mode system of FIG. And a chart showing the relationship between the remaining toner amount and the image mode in FIG.

However, the present invention is not limited to this embodiment.

In FIG. 1, reference numeral 1 denotes a flexible photosensitive belt which is a belt-shaped image forming body. The photosensitive belt 1 is provided between rotating rollers 2 and 3 and is driven by the rotating roller 2. It is conveyed counterclockwise as indicated by the arrow.

Reference numeral 4 denotes a guide member fixed to the main body of the apparatus so as to be inscribed in the photoconductor belt 1. The photoconductor belt 1 is stretched by the action of the tension roller 5 so that its inner peripheral surface is The guide member 4 is rubbed. The guide member 4 is provided with a concave portion in an area unnecessary for image formation to reduce resistance due to rubbing. Of course, this recess may be omitted if the rubbing resistance is low. Further, a low friction member such as a Teflon coating is provided on either surface of the photoconductor belt 1 or the guide member 4 for the purpose of reducing the sliding resistance between the photoconductor belt 1 or the guide member 4, or is constituted by the above low friction member. Preferably.

Therefore, the photoconductor on the outer peripheral surface of the photoconductor belt 1 is always kept in a constant relation position with respect to the surface of the guide member 4 even during conveyance, so that a stable image forming surface can be formed. ..

Further, by disposing the developing device and the cleaning device below the photosensitive belt, it is possible to prevent the developer from scattering and spilling.

6 is a scorotron charger as a charging means, and 7
Is a laser writing system unit as an image exposing means, 8 to 11
Is a developing device that is a plurality of developing means that contains a developer of a specific color, and these image forming means are arranged at positions facing the guide member 4 of the photosensitive belt 1. Then, in order to hold the gap without hindering the movement of the photoconductor belt 1, the guide member 4 is brought into contact with the gap holding means on the outer side of the photoconductor belt 1.

In addition to the illustrated optical system, the laser writing system unit 7 may also be an optical system in which a light emitting portion and a converging optical transmission body are integrated.

The developing units 8, 9, 10, and 11 contain, for example, yellow, magenta, cyan, and black developers, respectively, and the developing sleeves 8A and 9A that maintain a predetermined gap from the photosensitive belt 1. , 10A, 11A, and has a function of visualizing the latent image on the photoconductor belt 1 by a non-contact developing method. Unlike the contact development, the non-contact development has an advantage that the movement of the photosensitive belt 1 is not hindered.

A transfer device 12 is provided above the charging device 6 and slides up and down integrally with the charging device 6 to switch the position. 12A is a static eliminator, 13 is a cleaning device, and 13A is a blade of the cleaning device and 13 is a toner conveying roller.
B is kept at a position separated from the surface of the photosensitive belt 1 during image formation and is pressed against the surface of the photosensitive belt 1 as shown in the figure only during cleaning after image transfer.

A color image forming process by the color image forming apparatus 25 is performed as follows.

First, the formation of a multicolor image according to the present embodiment is shown in FIG.
Image forming system. That is, the data obtained by the color image data input unit (FIG. 2A) in which the image sensor scans the original image is processed by the image data processing unit (FIG. 2B) to create image data, This is once stored in the image memory (FIG. 2C). Then, the image memory is taken out at the time of recording and is recorded (see FIG. 2).
(D)), for example, is input to the color image forming apparatus 25 shown in the embodiment of FIG.

That is, the color signal output from the image reading device separate from the printer is the laser writing system unit 7.
Is input to the laser writing system unit 7, the laser beam generated by the semiconductor laser (not shown) is rotationally scanned by the polygon mirror 7B rotated by the drive motor 7A, and passes through the fθ lens 7C and the mirror 7D. The optical path is bent by 7E, and a bright line is formed by being projected onto the peripheral surface of the photosensitive belt 1 to which electric charges have been previously given by the charger 6 as a charging means.

On the other hand, when the scanning is started, the beam is detected by the index sensor, the modulation of the beam by the first color signal is started, and the modulated beam scans the peripheral surface of the photosensitive belt 1. Therefore, a latent image corresponding to the first color is formed on the peripheral surface of the photosensitive belt 1 by the main scanning by the laser beam and the sub-scanning by the conveyance of the photosensitive belt 1. This latent image is subjected to reversal development in a non-contact state by the developing device 8 loaded with yellow (Y) toner (visual medium) in the developing means, and a toner image is formed on the belt surface. The obtained toner image passes under the cleaning device 13, which is a cleaning means separated from the peripheral surface of the photosensitive belt 1 while being held on the belt surface, and enters the next copy cycle.

That is, the photoconductor belt 1 has the charger 6
Then, the second color signal output from the signal processing unit is input to the writing system unit 7, and writing on the belt surface is performed in the same manner as in the case of the first color signal described above. The image is formed. The latent image is subjected to reversal development in a non-contact state by the developing device 9 loaded with magenta (M) toner as the second color.

The magenta (M) toner image is formed in the presence of the previously formed yellow (Y) toner image.

Reference numeral 10 denotes a developing device having cyan (C) toner, which forms a cyan (C) toner image on the surface of the belt based on a control signal generated by a signal processing section.

Further, 11 is a developing device having a black toner, which is formed by superposing a black toner image on the belt surface by the same process. These developing devices 8, 9, 10 and
A direct current or an alternating current bias is applied to each sleeve of 11, and jumping development is performed by a one-component or two-component developer that is a developing device, and the development is performed in a non-contact manner on the photoreceptor belt 1 whose base is grounded. It is supposed to be done.

Thus, the color toner image formed on the peripheral surface of the photoconductor belt 1 is slid downward and switched to the position of the charger 6, and the transfer unit 12 and the neutralizing plate are removed.
At 12A, the image is transferred onto the transfer material sent from the paper feed cassette 14 through the paper feed guide 15.

That is, the transfer material contained in the paper feed cassette 14 is carried out by the rotation of the paper feed roller 16 and one of the uppermost layers is carried out, and the timing is adjusted with the image formation on the photosensitive belt 1 via the timing roller 17. And is supplied to the transfer device 12.

The transfer material subjected to image transfer and charge removal is more reliable than the photosensitive belt 1 which suddenly changes its direction along the rotating roller 2 without being affected by the charge removal effect on the image quality such as toner scattering. And then move it upwards to the fixing roller.
The image is fused by 18 and then discharged onto a tray 20 via a discharge roller 19.

On the other hand, in the cleaning device 13, the photosensitive belt 1 which has been transferred to the transfer material is further conveyed and the blade 13A facing the rotating roller 3 and the rotating toner conveying roller 13B are brought into pressure contact with each other. After the residual toner is removed and after the completion of the removal, the blade 13A is separated again, and a little later, the toner carrying roller 13B is separated, and a new image forming process is started.

Although not shown, the charging device 6 and the transfer device 12 are also provided.
It is also possible to switch the output from the same power source so as to output 4 kv and 0.25 mA when the scorotron charging is charged to the photosensitive belt 1 and output 5 kv and 2-3 mA during the transfer. The space is reduced and the color image forming apparatus 25 can be made compact. The cleaning device 13 is disposed to face the curved surface at the left end of the photoconductor belt 1 wound around the rotating roller 2 with a predetermined interval, and the waste toner box 13C.
Is connected below the cleaning device 13.

Then, the cleaning device 13 and the waste toner box 13C are formed into a cartridge together with the developing devices 8, 9, 10, 11 and the stretched photoreceptor belt 1 as shown by a chain line, and the color image forming device 25 is formed. It is designed to be detachably attached.

Further, at least the process of the photosensitive belt 1 and the cleaning device 13 and / or the waste toner box 13C is made into a cartridge, and each developing device 8, 9, 10, 11 is made into a cartridge, and each of them is placed in the process cartridge. It may be attached.

Therefore, the charging device 6, the transfer device 12, the static eliminator 12A and the cleaning device 13 are provisionally provided as a cleaning device by a cartridge which is disposed separately on both longitudinal ends of the photosensitive belt 1 and whose outer circumference is hermetically sealed. Even if the toner is scattered from the color image forming apparatus 25, it hardly diffuses into the color image forming apparatus 25. Therefore, each optical system 7A, 7B, 7C, 7D, 7E of the charger 6, the transfer unit 12 and the laser writing system unit is
A stable color image is formed even when the color image forming apparatus 25 is operated for a long time without being contaminated by toner such as.

Then, as shown in FIG. 3, the developing devices 8 for accommodating the yellow, magenta, cyan and black toners,
9, 10 and 11 are respectively provided with toner remaining amount detecting sensors 8B, 9B, 10B and 11B for detecting the remaining amount of toner, which are stored in advance based on the information of the sensors 8B, 9B, 10B and 11B. Under the control of the CPU controller, image formation in the color mode, image formation in the mono-black mode, or stop of image formation is performed.

FIG. 4 is a diagram showing the relationship between the specific toner erasing state, the detection signal thereof, the copy control signal (copy signal) controlled by the toner remaining amount detection signal, and the image mode control. is there. That is, the vertical axis is a copy signal controlled by the toner remaining amount detection signals of yellow (Y), magenta (M), cyan (C) color toner and black (B) toner, and the color copy, mono copy, and It shows a state of image mode control such as black copy and copy stop.

The abscissa indicates the presence / absence of the remaining amount by each toner remaining amount detection signal, the availability of image formation in each image mode control by the corresponding copy signal, and whether the copying is stopped.

However, the display of 1 in the toner remaining amount signal indicates that there is a remaining amount, 0 indicates that there is no remaining amount, and the display of 1 in the copy signal indicates the control (or control status) of image formation availability by each image mode control signal. Indicated at 0 is control of image formation failure. Further, when the copy is stopped, 0 is a signal indicating that the copy is not stopped, that is, copy is possible, and 1 is a signal indicating that the copy is stopped (copy prohibited or copy prohibited). And each developing device 8,
The relationship between the designated state of the image mode and whether the copying is stopped or not is described below for some cases of whether or not the toner remains in 9, 10, and 11.

In FIG. 4, the remaining amount detection of the yellow, magenta, and cyan color toners and the black toner is all 1, and the respective toners still remain in the developing devices 8, 9, 10, and 11. In this case, naturally, the corresponding color mode or mono-black mode shows 1 and image formation is possible. Therefore, copying is not stopped and therefore 0 is displayed. If it is detected that any one of the color toners of yellow, magenta, and cyan is out of toner, as shown in the four-color middle diagram, the image formation of the color copy is prohibited as indicated by 0, and is prohibited. In addition, image formation with mono-color toner other than black toner is prohibited. Then, as shown by 1, the mono black copy can form an image with the remaining black toner. Therefore, copying is not stopped. On the other hand, when it is detected that the black toner has no remaining amount, even if the yellow, magenta, and cyan color toners remain, a color copy (a full-color copy of three colors of Y, M, and C toners or Y, M, and Image formation of C and B four-color full color copy) and monochrome copy (copy with B toner) is disabled, and the copy function is stopped. Although the above-mentioned examples are only some cases that can occur, in other similar cases, color copying, mono-black copying, and whether or not copying can be stopped are performed based on the same purpose.

Then, each information such as the above-mentioned toner remaining amount status and copy permission / prohibition based on the image mode status is displayed on the operation panel (not shown) of the color image forming apparatus 25, and the user appropriately responds to each case. Is ready for you.

[0044]

According to the toner remaining amount detection information of the present invention, for example, it is possible to accurately prohibit the image formation in the color mode or switch the image formation to the mono-black mode so that a good image is always formed. Along with this, it became possible to replace the toner cartridge economically.

[Brief description of drawings]

FIG. 1 is a side sectional view showing the configuration of a color image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the image forming system of the above.

FIG. 3 is a block diagram showing an image mode system according to an embodiment of the present invention.

FIG. 4 is a chart showing a relationship between remaining toner amount detection and an image mode according to an embodiment of the present invention.

[Explanation of symbols]

 1 Photoreceptor Belt (Image Forming Belt) 2 Rotating Roller 3 Rotating Roller 6 Charging Device 7 Laser Writing System Unit 8 Developing Device (Yellow) 8B Toner Remaining Detection Sensor 9 Developing Device (Magenta) 9B Toner Remaining Detection Sensor 10 Developing device (cyan) 10B Toner remaining amount detection sensor 11 Developing device (black) 11B Toner remaining amount detection sensor 12 Transfer device 12A Electrification plate 13 Cleaning device 13C Waste toner box 18 Fixing roller 25 Color image forming device

Claims (2)

[Claims] 1. In a color image forming apparatus equipped with a process cartridge in which a plurality of color toners of a specific color and a black toner are sealed, when one of the color toner of the specific color and the black toner is consumed, A color image forming apparatus, wherein image formation in a color mode is prohibited and an image is formed in a black single color mode when only black toner remains. 2. The color image forming apparatus according to claim 1, wherein when the image formation in the color mode is prohibited, the image formation in the single color mode other than the black toner is prohibited.