JPH09190102A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent soiling caused by a mixed foreign matter as far as possible when used releasing agent is recovered and recycled. SOLUTION: A first holding part 12a for recovering and holding the used releasing agent 15a recovered by a recovering means 8, and a second holding part 12b for holding unused releasing agent 15b newly supplied are separately provided on a holding means 12. A mixing means 13 mixing the releasing agent 15a held by the part 12a and the unused releasing agent 15b held by the part 12b is provided. Thus, the mixing ratio of the foreign matter is reduced, thus the soiling in the releasing agent is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a laser beam printer, an electrostatic printer or a facsimile, and more particularly to a release agent applying mechanism applied to a heat roller.

[0002]

2. Description of the Related Art In a conventional image forming apparatus using an electrophotographic method, a releasing agent such as silicone oil (hereinafter referred to as oil) is formed on a surface of a heat roller when a toner image is fixed on a recording material.
In many cases, the color image forming apparatus uses a large amount. Therefore, most of the types have a tank for holding oil in the apparatus and supply the oil from the tank in the fixing apparatus.

Further, the oil applied to the surface of the heat roller, which has not adhered to the recording material, is scraped off by a cleaning member such as a blade, and is collected as excess oil in the apparatus and returned to the tank for reuse. Many models are used.

[0004]

However, the above-mentioned prior art has the following drawbacks.

Toner and paper powder are gradually mixed into the oil that has passed through the heat roller. When such oil is circulated and used, the ratio of the contaminant to the oil in the tank gradually increases. That is,
The oil becomes dirty. Then, the releasing ability of the oil is deteriorated, the heat roller is easily scratched, and the deterioration is accelerated, which results in a remarkable deterioration in image quality.

[0006] Therefore, it is conceivable to install a filter in the oil circulation path to remove contaminants from the oil.

However, in order to remove paper dust and toner, it is necessary to use a fine filter having a mesh of several [μm].

As a result, there are many problems such as immediate clogging, and it takes a long time to collect the oil due to its high viscosity, and a dedicated pump for suction is required for practical use.

The present invention has been made in order to solve the above-mentioned prior art, and an object thereof is to prevent contamination by foreign matters when a used release agent is recovered and reused. An object is to provide an image forming apparatus capable of preventing the above.

[0010]

In order to achieve the above object, in the present invention, a heat roller for pressing and heating a recording material to fix an unfixed image transferred to the recording material, Coating means for applying a release agent to the heat roller, holding means for holding the release agent, and collection means for collecting an excess release agent of the release agent applied to the heat roller in the holding means. An image forming apparatus comprising: a supply unit that supplies the release agent held by the holding unit to the coating unit. The holding unit collects and holds the excess release agent collected by the collecting unit. A first holding part and a second holding part for holding a freshly supplied unused release agent are separately provided, and the surplus release agent held by the first holding part and the second release agent are provided. Mixing means for mixing the unused release agent held in the holding part of

With the above structure, the release agent collected and held in the first holding section and the unused release agent held in the second holding section are mixed by the mixing means, and the released release agent is mixed. Is supplied to the coating means by the supply means.

Therefore, even if foreign matter is mixed in the used release agent to be collected, the mixing ratio of the foreign matter is diluted by mixing the unused release agent, and the supplied release agent is fixed by the mixed foreign matter. There is no risk of contamination as described above, and as a result, it is possible to prevent the release ability of the release agent from deteriorating, the deterioration of the heat roller from accelerating, and the like, and it is possible to maintain a stable high-quality image level.

The mixing means is provided with two pump means for independently sucking and mixing the release agent held in the first and second holding portions through the first and second suction flow paths. Characterize.

In this case, the used release agent in the first holding portion and the unused release agent in the second holding portion are independently sucked and mixed by the pump means and mixed by the supply means. Is supplied to.

It is characterized in that the mixing ratio of the release agent supplied from the first and second holding portions is changed by changing the suction amounts of the two pump means independently.

By doing so, the ratio of the contaminants in the release agent can be adjusted.

Further, the mixing means includes first and second suction passages communicating with the first and second holding portions, and one supply communicating with the first and second suction passages and the coating means. The flow path switching valve means for selectively communicating with the passage may be provided.

In this case, by appropriately switching the flow path switching valve means, the first and second suction flow paths and the supply flow path are selectively communicated with each other, and the used release agent and the unused release agent are connected. Is supplied to the coating means at a predetermined ratio to mix the release agent.

Further, it is characterized in that a filter member provided on a partition wall separating the first and second holding portions is used as the mixing means.

In this case, the release agent collected in the first holding portion penetrates into the second holding portion through the filter member, but the foreign matter in the release agent which enters the second holding portion is filtered. Since it is removed by the member, the foreign matter mixing rate in the release agent mixed in the first holding portion does not exceed a certain level.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiment.

[First Embodiment] FIG. 1 is a schematic sectional view showing an image forming apparatus according to a first embodiment of the present invention.

Recording material P separated from the transfer portion (not shown)
Passes through the conveyance path 60 and is guided to the entrance guide 6 of the fixing device. Then, the transfer image is fixed on the recording material by heat and pressure in the nip portion between the fixing roller 1 as a heat roller and the pressure roller 2. After that, the recording material P is guided to the paper ejection guides 9a and 9b and ejected to the outside of the machine by the paper ejection roller 10.

A release agent applying device 3, a cleaning device 4, a roller surface temperature detector 5 (hereinafter referred to as a thermistor), etc., as application means are in contact with the circumference of the fixing roller. The heater 1a is arranged at the center.

In the release agent coating device 3, an oil such as silicone oil is used as a release agent, and the oil pumped from the oil pan 3d through the pumping roller 3c is regulated to a specified amount by the coating roller 3a and the coating blade 3b. After that, it is applied to the surface of the fixing roller 1.

In the cleaning device 4, the surface of the fixing roller 1 is cleaned at the contact portion between the cleaning roller 4b and the fixing roller 1 while winding the strip-shaped cleaning member 4a little by little.

On the circumference of the pressure roller 2, a cleaning blade 8 as a collecting means, a roller surface temperature detector 7 and the like are in contact, and a heater 2a is arranged at the center.
The cleaning blade 8 scrapes off foreign matter such as toner and paper dust remaining on the pressure roller 2 and excess oil. The used oil 15a scraped off is collected by the oil receiver 11 and returned to the oil tank 12.

Next, the oil tank 12 as a holding means for holding the oil, the supply device as the supply means for supplying the oil, and the mixing section 13 as the mixing means will be described.

The used oil 15a collected by the oil receiver 11 enters the first holding portion 12a of the oil tank 12. On the other hand, the second holding portion 12b has an unused oil 15b.
Is held.

Sensors 13a and 13b for detecting the remaining amounts of the used oil 15a and the unused oil 15b are provided on the respective holding portions 12a and 12b. Also,
Each holding portion 12 is provided with first and second suction pipes 14a and 14b forming first and second suction passages, and is provided to the first and second pumps P1 and P2 in the mixing portion 13. It is in communication.

The two flow paths formed by the first and second suction pipes 14a and 14b are the first and second pumps P1 and P2.
Combined on the downstream side of P2, used oil 15a and unused oil 15b to the oil pan 3d through the supply pipe 14.
The mixed oil 15c is supplied. In addition, when the oil runs out, a new oil 15b is supplied from the replenishment port 12c to the second
Supply to the holding portion 12b. The first and second suction pipes 14a and 14b and the supply pipe 14 constitute a supply means.

Next, a series of operations will be described.

When starting to use the device, the first holding part 1
2a is empty, and unused oil 15b is contained in the second holding portion 12b. When it is detected by the sensors 13a and 13b, only the second pump P2 operates to supply the unused oil 15b to the oil pan 3d. After being used for a while, the used oil 15b scraped off by the cleaning blade 8 collects in the first holding portion 12a via the oil receiver 11. When the sensor 13a detects this, the first pump P1 starts operating and starts supplying the used oil 15b.

At that time, an unused oil 1 determined in advance
The mixing ratio of 5b and the used oil 15a (for example, 5:
1) to make the supply capacities of the first and second pumps P1 and P2 different. Ii) Make the supply times of the first and second pumps P1 and P2 different.

The used oil 15a and the unused oil 15b are supplied so as to have a predetermined mixing ratio by any of the above methods or a combined method.

In this way, the mixed oil 15c supplied to the oil pan 3d will not be contaminated beyond a certain level even if it is circulated and repeatedly used, and as a result, the oil releasing ability is improved. It is possible to prevent deterioration, acceleration of deterioration of the fixing roller 1, and the like, and it is possible to maintain a high-quality image level in the end.

Further, the following method may be adopted.

Each of the sensors 13a and 13b is a reflection type sensor so that the transparency of the oil can be detected.

When the oil is circulated and used many times, the amount of foreign matter such as toner and paper powder mixed in increases, so that the transparency of the used oil 15a gradually decreases. That is, it indicates the degree of pollution of the oil 15a. Therefore, the degree of pollution is detected by the sensor 13a, and while the degree of pollution is low, the operating time of the first pump P1 is increased and the total supply amount is kept constant. Therefore, the operating time of the second pump P2 is reduced.

As the pollution degree increases, the operating time of the pump P1 is shortened and the operating time of the second pump P2 is increased.

By doing so, it becomes possible to more stably supply the oil having the degree of pollution below a certain level to the oil pan 3d.

[Second Embodiment] A second embodiment of the present invention will be described below with reference to FIG.

The same parts as in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

Mixing unit 2 as the mixing means of the present embodiment
Reference numeral 1 denotes a first and a second suction pipe 14 that form a suction passage communicating with each of the first and second holding portions 12a and 12b.
a valve portion 22 provided with a port for connecting a and 14b,
It comprises an operating valve 23 and a supply pump P1. The home position of the operating valve 23 is position A, and the unused oil 15
Second suction pipe 14b for supplying b and supply pipe 14
To communicate. The valve portion 22 and the actuating valve 23 constitute a switching valve means.

Used oil 15a in the first holding portion 12a
When is accumulated, the sensor 13a detects it. Then, the operation valve 23 moves to the position B, the first suction pipe 14a for supplying the used oil 15a and the supply pipe 14 are communicated with each other, and the used oil 15a is supplied by the first pump P1. After a certain time, the operating valve 23
Returns to position A and supplies unused oil 15b.

As a result, the unused oil 15b and the used oil 15a have a degree of contamination below a certain level, and it is possible to stably supply a high-quality image.

At this time, it is preferable that the ratio of the time when the operating valve 23 is fixed to the positions A and B is about 5: 1.

[Third Embodiment] The third embodiment will be described below with reference to FIG.

The same parts as those in the first and second embodiments are designated by the same reference numerals, and the description thereof will be omitted.

In this embodiment, the used oil 15a is used.
The mixing means for mixing the oil and the unused oil 15b is constituted by the filter 25 provided on the partition wall that partitions the first holding portion 12a and the second holding portion 12b.

When starting the use of the apparatus, the unused oil 15b is replenished from the replenishing port 12c. Then, the unused oil 15b passes through the filter 25 and the unused oil 15b passes through the first holding portion 12a.
And the oil in the first holding portion 12a and the second holding portion 12b has the same liquid level with only unused oil.

When the apparatus starts operating, the pump P1 sucks the unused oil 15b from the second holding portion 12b and supplies it to the oil pan 3d. After that, used oil 15
b is collected in the second holding unit 12a. In such a series of cycles, the used oil 15a and the unused oil 15b are always kept at the same liquid level through the filter 25. However, since foreign matter such as toner and paper dust contained in the used oil 15a cannot pass through the filter 25,
It remains in the first holding portion 12a.

While the above operation is repeated, the total amount of oil decreases, and the sensor 13 detects no oil. In that case, a message is sent to the user from the operation unit of the apparatus.

New unused oil is replenished through the replenishing port 12c and evenly replenished to the first and second holding portions 12a and 12b.

With the above arrangement, the pump P1 can always mix the used oil and the unused oil that have been filtered, and can supply the mixed oil to the oil pan 3d.

Further, unlike the filter shown in the conventional example, the filter 25 is installed in the vertical direction, and the force to force the oil to pass through the filter 25 does not work (natural convection of oil). It is hard to be clogged and can exert its ability for a long time.

As described above, according to the present embodiment, it is possible to suppress oil contamination with a simple device configuration.

[0058]

As described above, according to the present invention,
Since the used releasing agent and the unused releasing agent are mixed by the mixing means and supplied to the applying means, there is no possibility that the releasing agent is contaminated more than a certain amount, and as a result, the releasing agent is released. It is possible to prevent deterioration of the mold ability, acceleration of deterioration of the fixing roller, and the like, and in the end, it is possible to stably maintain a high-quality image level.

In addition, the used release agent and the unused release agent are 2
If the two pump means are used to independently perform suction mixing, the mixing ratio of the release agent is changed.

Further, if the used release agent and the unused release agent are selectively supplied to the coating means by the flow path switching valve and mixed, only one supply pump means is required.

If a filter member provided on the partition wall separating the first and second holding portions is used as the mixing means, the structure of the apparatus can be extremely simplified.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view according to a second embodiment of the present invention.

FIG. 3 is a schematic sectional view according to a third embodiment of the present invention.

[Explanation of reference symbols] S recording material 1 fixing roller (heat roller) 2 pressure roller (heat roller) 3 release agent applying device (application means) 8 cleaning blade (collection means) 11 oil receiver (collection means) 12 oil tank (Holding means) 12a 1st holding part 12b 2nd holding part 13 Mixing part (mixing means) 13a, 13b Sensor 14 Supply pipe 14a, 14b 1st, 2nd suction pipe (1st, 2nd)
Suction flow path) P1, P2 First and second pumps 15a Used oil (used release agent) 15b Unused oil (unused release agent) 15c Mixed oil 21 Mixing section 22 Valve section 23 Actuating valve 25 Filter ( Mixing means)

Claims (5)

[Claims] 1. A heating roller for pressing and heating a recording material to fix an unfixed image transferred to the recording material, a coating means for coating a releasing agent on the heating roller, and a holding means for holding the releasing agent. Holding means for collecting, a collecting means for collecting excess release agent of the release agent applied to the heat roller to the holding means, and a supply means for supplying the release agent held by the holding means to the coating means. In the image forming apparatus including, a first holding unit that collects and holds the excess release agent collected by the collecting unit and an unused release agent that is newly supplied to the holding unit. A second holding part for holding is provided separately, and the excess release agent held by the first holding part and the second holding part are held.
An image forming apparatus comprising: a mixing unit that mixes an unused release agent held by the holding unit of the. 2. The mixing means comprises two pump means for independently sucking and mixing the release agent held in the first and second holding parts through the first and second suction flow paths. The image forming apparatus according to claim 1, wherein: 3. The mixing ratio of the release agent supplied from the first and second holding parts is changed by changing the suction amounts of the two pump means independently. Image forming device. 4. The mixing means comprises first and second suction passages communicating with the first and second holding parts, and one supply communicating with the first and second suction passages and the coating means. The image forming apparatus according to claim 1, further comprising flow path switching valve means for selectively communicating with the passage. 5. The image forming apparatus according to claim 1, wherein the mixing unit is a filter member provided on a partition wall that separates the first and second holding units.