JPH01972A - developing device - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION (Al Industrial Field of Application) This invention relates to an image forming apparatus, such as a color copying machine, having a plurality of developer tanks, which is equipped with a means for determining when to replace the developer in each developer tank. (b) Conventional technology Some image forming apparatuses, such as copying machines, include a plurality of developer tanks, each of which is filled with a different developer, and an image is formed using a plurality of or a single developer. For example, it is equipped with three developing tanks filled with developers of blue, red, and yellow colors, so that a full-color image or a single-color image using all three colors can be formed.The developers include: For example, a two-component developer is used.A two-component developer has two main components: a toner made of a resin mixed with a colorant, and a carrier made of iron powder, etc. As a result of stirring, each is triboelectrically charged to opposite polarity.

The toner is attached to the photoreceptor due to its electrical charge to form a developed image.

When using a two-component developer, the toner is replenished as it is consumed, so it does not deteriorate, but the carrier continues to be rubbed against the toner in the developer tank, so it deteriorates with use and its charging properties deteriorate. Sometimes I put it away. Therefore,
I try to replace carriers that have been used for a certain period of time.

Usually, the number of times image formation is performed using the same carrier (hereinafter referred to as the number of times of use) is counted, and the number of times the chargeability starts to deteriorate is set as the number of times of replacement, and when the number of times of use reaches the number of times of replacement, the carrier is We are trying to do the exchange. In reality, it is not possible to replace only the carrier.
The entire developer is replaced.

(C) Problems to be Solved by the Invention As described above, in a developer tank having a two-component developer, the developer is replaced when the number of times of use reaches the number of replacements. In an image forming apparatus equipped with multiple developer tanks, each developer tank is used singly or in combination, so the number of times each developer tank is used is different, and each developer tank is replaced every time the number of times each developer tank is used reaches the number of replacements. However, it has the disadvantage of being time consuming. In addition, for example, if the number of times of replacement is 10,000 sheets, and when the developer in one developer tank is replaced (the number of times of use is 0) and the number of times of use of the other developer tank is about 9,000 sheets, it is possible to If there is too much difference in the number of times the tanks are used, the charging properties of the toner in each developer tank will be unbalanced, resulting in an unbalanced toner density when forming an image using both developer tanks. . However, if the developer in all the developer tanks is replaced at the same time when the number of times one developer tank is used reaches the number of sheets to be replaced, there is a drawback that the developer in the developer tank that is used less often is wasted.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a developing device that is equipped with a means for determining whether or not the developer in all developing tanks needs to be replaced at the same time, and that can prevent image quality from becoming unstable and reduce waste of carrier. With the goal.

Means for Solving the FD1 Problem The developing device of the present invention includes a plurality of developing tanks, each of which is filled with developer, and forms an image using all or a selection of the developing tanks. In the forming apparatus, an image forming number detecting means for detecting the number of times of image forming using the same developer is provided for each developing tank, and it is also possible to determine whether or not all the developers need to be replaced according to the number of times image forming is performed for each developing tank. and a means for displaying whether or not the developer needs to be replaced.
It is characterized by having the following.

(e) Effect If an image is formed using all or one of the developers in a plurality of developer tanks, the number of times the image is formed (number of times of use) of the developer in each developer tank is the number of times the image is formed. Detected by a detection means. The number of times the developer is used differs depending on the developer tank, but based on the number of times at least one developer is used, it is necessary to ensure that at least one developer does not significantly exceed the number of times it is replaced and the toner's chargeability deteriorates. In order to avoid the waste of developer being discarded while the number of times it has been replaced is significantly less than the number of times it has been replaced, it is necessary to determine whether or not the developer in all developer tanks needs to be replaced at that time. Since the necessity of replacing the developer is displayed on the display section, the developer can be replaced based on the display.

(f) Embodiment FIG. 4 is a schematic diagram of a copying machine to which a developing device according to an embodiment of the present invention is applied.

A drum-shaped photoreceptor 1 is arranged in the center of the main body of the copying machine. Around the photoreceptor 1, there are a charger 2, a developer tank 3. A transfer drum 4 and the like are arranged. The photoreceptor 1 is rotatable clockwise in the figure, and after being charged by a charger 2, is exposed to light reflected from an original at an exposure point P to form a latent image. The original is placed on an original table 5 on the top of the copying machine main body. A document is scanned by a light source 61, and the reflected light is reflected from mirrors 62 to 62.
65, a lens 66, and a color separation filter 67 to irradiate the photoreceptor 1 at an exposure point P. The color separation filter 67 is composed of four filters, one for transmitting blue, one for transmitting red, one for transmitting yellow, and one for transmitting gold.By interposing any of the filters in the light reflected from the original, the color separation filter 67 can separate the single color or all colors of the original. can be reproduced.

The developer tank 3 consists of three developer tanks 3V and +3C, and the difference between each developer tank is that 3V carries yellow toner, 3
14 has a red (magenta) toner, and 3c has a blue (cyan) toner. The developing tank 3 is equipped with a developing roller, an agitation roller, a toner concentration sensor, etc., and is filled with a two-component developer whose main components are toner and carrier (about 10% of which is toner).

The developer is stirred by a stirring funnel, and the toner and carrier are triboelectrically charged to opposite polarities. The developing roller attaches charged toner to the latent image on the photoreceptor 1 to form a developed image. The toner concentration sensor detects the toner concentration by, for example, measuring the magnetic permeability of the carrier.

A transfer charger 41 and a charger 42 are wound around the transfer drum 4. Peeling charger 43. Peeling claws 44 and the like are arranged. Paper is fed to the transfer drum 4 from a paper feed section 7. A sheet of paper is wound around the transfer drum 4 by a winding charger 42, and the toner on the photoreceptor 1 is transferred to the sheet by the transfer charger 41. The paper on which the toner has been transferred is transferred to a peeling charger 43. The sheet is peeled off from the transfer drum 4 by the peeling claw 44, the toner on the surface is fixed, and the sheet is discharged to the sheet discharge section 8.

A latent image is formed using a gold transmission filter, developed in one of the developer tanks (<3v, -3g, 3c), and exposed to light on the paper wrapped around the transfer drum 4. A single color image can be formed by transferring the toner on the body 1 and ejecting the paper.

In addition, formation of a latent image using a filter for transmitting a single color.
Development using a developer tank containing toner of the same color as the single color.
By performing the operation of transferring the toner on the photoconductor 1 to the paper wrapped around the transfer drum 4 for each color of yellow, red, and blue, and discharging the paper to which the three colors of toner have been transferred. , full-color images such as photographs can be copied.
.

FIG. 5 is a partial plan view of the operation section of the copying machine. The operation unit 9 includes display units 91 and 92, a numeric keypad 93, and a clear key 9.
4, a print switch 95, a color selection section 96, etc. are provided. The display section 91 is a section where error messages and the like are displayed, including a developer replacement lamp 91a, a replenishment lamp 91b, a yellow lamp 91C, a red lamp 91d, a blue lamp 91e, a lamp that lights up when a paper jam occurs, and a waste lamp. A lamp or the like is provided that is turned on when the toner is full. The display section 92 is a numerical display section, and displays the number of copies to be made and an error message number. Numeric keypad 9
3 is a key for inputting the number of copies, a clear key 94 is a key for interrupting the copying process, and a print switch 95 is a key for starting the copying process. Further, when an image is to be formed using one of the three colors, the color selection unit 96 designates that color.

FIG. 3 is a block diagram of the control section of the copying machine. Overall control is performed by the CPU II, and its processing program is stored in the ROM 12 in advance. When this program is executed, the RAM 13 is used as a working area. CPUl1 is connected to developer exchange lamp 91a of operation unit 9 via l1014,) Qi replenishment lamp 91b,
Yellow, red, and blue lamps 91c to 91e, photoreceptor 1. Data is exchanged with the developing roller, stirring roller, transfer drum 4, etc. of the developing tank 3. CPUII has each developer tank 3V, 3N
, 3C are counted and stored in Mt, Mz, and M3 of the RAM 13, respectively. For example, when a monochromatic red image is formed, 1 is added to the red count value, and when a full color image is formed, 1 is added to each of the yellow, red, and blue count values. This count value can be reset by operating an operation switch within the main body of the copying machine. In addition, in this embodiment, the number of times of use is
Although the counter is counted at I 1, a mechanical counter may be provided.

FIG. 1 is a flowchart of a program stored in the ROM 12. The carrier of this embodiment has a replacement number of 10,000 sheets at which the chargeability starts to deteriorate, and can be used up to about 11,000 sheets without degrading the image quality. Therefore, at least one usage count is 1.
If the number of sheets exceeds 11,000, or the difference between the number of times each developer is used and the number of times it is replaced is calculated and the sum becomes 0 or more (the average is 10,000 or more sheets), the developer must be replaced. It is considered necessary.

In the figure, MI, Mz, and Mz are each yellow.

The number of times red and blue are used is MI '+ Mz '+
Ml' stores the difference between the number of uses of yellow, red, and blue and the 1B sheet, and M4 stores the total sum of Ml' to M3'. Further, F4 is a flag that is set when the number of times at least one developer tank has been used is 1B1,000 times or more, and Fs is a flag that is set when the number of times at least one developer tank has been used is 1B1,000 times or more.
This is a flag that is sent when the number of coins is B or more and less than 11,000.

First, when the main body of the copying machine is turned on, warm-up is performed in nl and the memory is initialized. Note that M1 to M3 are areas that will not be cleared unless a special operation, which will be described later, is performed. When the warm-up is completed and the operation of the print switch 95 is determined at n2, copy processing is performed at n3. This copying process is performed in a single color or in a plurality of colors, and when the copying process is completed, the number of used developer tanks is counted up in step n4.

Set m to 1 at n5. m is memory M, ~M3
and M, is a numerical value representing a permutation of ′ to M3 ′, and ni
It is designed to be repeated until it reaches 3 at l→n12. At n6, the difference between the number of times each developer tank is used and the number of replacements, ie, 1B sheets, is determined and stored in MH' to M3'.

If the value exceeds O, that is, the number of uses is 1B
If the number is less than 1B, proceed directly to nil; if it is 1B or more, proceed to n8 to determine whether the difference between the number of exchanged sheets is 1,000 or more (whether the number of times used is 1,000 or more 1B). . When the number of sheets is 1,000 or more, F4 is set at n9, and when the number is less than 1,000, F is set at nto.

Developer tank 3V, 3. ．． Number of uses of 3c: M,,M.

, if the difference between Ms and the number of exchanges (1B pieces) is found, n
At step 13, the set state of F4 is determined. As mentioned above, in F4, the number of times of use of at least one developer tank is 175i1.
This is a flag that is set when the number of sheets reaches 1,000 or more. If this flag is set, it is necessary to replace the developer, so a replacement display signal is output at n14. and n18
Go to memory M l' + M z ' r M 3
Clear ' and return to n2.

When F4 is in the reset state, eFs proceeds to n15 and determines the set state of F5.As mentioned above, the eFs is small (both 1
This flag is set when the number of times a developer tank is used is 1B or more and less than 11,000 sheets. When this flag is set, proceed to n16 and read Ml ′ to M3 ′
The difference between the number of uses and the number of replacements for each developer tank stored in is added and stored in M4. When this value becomes 0 or more, that is, the average number of times each developer tank is used is 1B.
When the number of sheets exceeds that number, the developer needs to be replaced.
At step 14, an exchange display signal is output. And in n18 M
Clear 1', Mz', Mz' and n2
Return to

Also, when both F4 * F and S are in the reset state, and when M4 exceeds O, it remains as 018.
, clear M and t 4 r at n1B, and return to n2.

FIGS. 2(A) and 2(B) show the display lamp 91 of the operation unit 9.
It is a flowchart showing the control program of a to 91e.

When the replacement display signal is output in step n18 in FIG.
Turn on c, 91 d, and 91 e. By lighting these lamps, the user can know that the developer needs to be replaced. Further, in this embodiment, yellow, red, and blue lamps 91c, 91d,
91e also serves as a lamp to notify you of toner replenishment.
n23. n25. If it is detected that the yellow, red, and blue toner densities are low in n27, r1
24. In n25.28, toner supply lamp 91b and yellow, red, and blue lamps 91c, 91d, and 91, respectively.
Turn on e.

If all the developers are replaced according to the display prompting developer replacement, and the switch indicating that the developer has been replaced, which is provided in the copying machine body, is operated, this is determined at n31, and the developer replacement lamp 91a is turned on at n32. and yellow, red, and blue lamps 9
1C, 91d, and 91e go out. Also, in n33, flag F4. As F5 is reset, memory M.

~M3 is cleared. In this way, it is determined whether or not the developer needs to be replaced. When replacement is necessary, an indicator lamp is turned on, and when replacement is completed, the indicator lamp is turned off.

Note that if you replenish toner when the toner density is low and the toner replenishment lamp is lit, n34, n36. n3
At n35.8, the toner concentration sensors of the respective developer tanks 3V and 37.3c detect an increase in toner concentration. n37.
n39, toner replenishment lamp 91b and yellow, red,
The blue lamps 91c, 91d, and 91e are turned off.

Further, FIG. 6 is a flowchart showing another embodiment,
In this example, when at least two developer tanks have been used for 10,000 sheets or more, it is determined that replacement is necessary, and a replacement display signal is output.
The indicator lamps are turned on and off as shown in Figures (A) and (B). In addition, in the figure, M I"' M
3 and Ml' to M3' represent the number of times each developer tank is used and the difference between the number of times each developer tank is used and the number of replacements, as in the previous embodiment. FI-F3 is a flag that is set when the number of times each developer tank has been used reaches 10,000 or more.

(a) Effects of the Invention According to the developing device of the present invention, for example, when the number of uses of at least one developer tank reaches the limit number of uses, which is slightly higher than the number of uses, the average number of times of use of all the developer tanks is 10,000. When the number of sheets is exceeded, a display prompting you to replace the developer is displayed at the perfect time to compare it with the developer that has not yet reached the number of replacements and before the charging performance of the developer deteriorates. As a result, variations in chargeability, waste of developer, waste of maintenance, etc. can be avoided.

[Brief explanation of drawings]

1 and 2 (A) and (I3) are flowcharts of a processing program of a copying machine to which a developing device according to an embodiment of the present invention is applied, and FIG. 3 is a block diagram of the same copying machine.
FIG. 4 is a schematic configuration diagram of the copying machine, and FIG. 5 is a plan view of the operation section of the copying machine. FIG. 6 is a flowchart showing a processing program according to another embodiment. 3V, 3. ．． 3. - Developer tank 91a - Developer replacement lamp, 91C - Yellow lamp, 91d - Red lamp, 91e - Blue lamp.

Claims (1)

[Claims] (1) Image formation using the same developer in an image forming apparatus that is equipped with a plurality of developer tanks, each of which is filled with developer, and forms an image using all or a selection of the developer tanks. A means for detecting the number of times of image formation is provided for each developer tank, and a means for determining the necessity of replacing all the developers according to the number of times of image formation for each developer tank, and a means for determining the necessity of replacing the developer. a means for displaying;
A developing device characterized by being provided with.