JP2002182513A - Electrophotographic equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent the oil from leaking from the oil storage tank when the fixing device is removed from the printer main body or when the printer main body is inclined, the fixing is small, low cost, and easy to handle. Provide equipment. The oil storage tank includes a first storage unit that stores oil scraped off by a blade, and a second oil storage unit that stores oil replenished from the oil bottle, The bottom surface of the oil reservoir is located above the bottom surface of the second oil reservoir.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus for printing color image recording information on a recording medium.

[0002]

2. Description of the Related Art There are many known methods for recording a color image in accordance with image information from a computer or the like.
Among these methods, a method using electrophotography is effective as a method capable of recording a high-quality color image at a relatively high speed.

[0003] In color image recording using electrophotography, yellow, magenta, cyan, and black toner images are formed on a recording medium, which is a photoreceptor, and the formed toner images are recorded on a recording medium such as paper. After superimposing and synthesizing, the toner image on the recording medium is fixed by a fixing device including a fixing roller having a built-in heater and a pressure roller which presses against the toner image to form a color image.

In such a fixing device of a color electrophotographic apparatus, the fixing roller and the pressure roller are constituted by an elastic roller in which a hollow core is covered with an elastic material such as silicone rubber, and both rollers are pressurized. The nip is secured by contact, and heat is applied at the nip to fix the nip.

[0005] However, in a color image, the toner is superimposed on multiple layers, and thus the toner tends to be offset to the fixing roller. For this reason, it is common practice to apply silicone oil or the like to the surface of the fixing roller to ensure releasability.

[0006] In this case, the oil is applied to the fixing roller by providing an oil storage member such as an oil bottle on the rear or lower part of the fixing roller, to which oil is supplied from the outside.
A part of felt, such as Nomex, is immersed in the felt, oil is soaked in the felt, and the other end of the felt is pressed against the surface of the fixing roller to apply oil to the surface of the fixing roller. This is performed so that a uniform oil layer is formed by the applied blade. Excess oil scraped off by the blades is collected, stored and reused in an oil storage tank.

[0007]

However, in the above-described configuration, the oil that is replenished from the outside, such as an oil bottle, and the oil that has been scraped off by the blade and collected are stored in the oil storage tank. For this reason, there is a problem in that a larger amount of oil is stored than is required for supplying the fixing roller surface, and the oil overflows and leaks to the outside, thereby contaminating the inside of the printer device.

In particular, when the fixing device is detached from the printer body, the oil tends to leak from the oil storage tank when the fixing device is tilted or when the printer body is tilted.

To prevent this, means such as increasing the capacity of the storage tank or using a pump or the like to minimize the amount of external supply are used. There was also a problem that the cost would be increased.

[0010] Regarding oil leakage, see Japanese Utility Model Application Laid-Open No. 9-14.
As in the prior art described in Japanese Patent No. 6402, an oil tank for storing oil to be supplied to the felt and an oil recovery tank below the oil tank via a partition plate are provided, and excess oil is stored in the oil recovery tank. There is something like that.

However, when the fixing device is removed from the printer main body or when the printer main body is inclined, it is rare to open the partition plate in consideration of the partition plate, which is inconvenient in terms of handling.

An object of the present invention is to provide a fixing device which is small in size and low in cost, prevents oil leakage, and has good handleability.

[0013]

An object of the present invention is to provide a fixing roller, a pressure roller, a wick type oil applying means for applying oil to the fixing roller, and a method for uniformly applying oil applied by the oil applying means. In a fixing device including a blade for scraping off excess oil, an oil storage tank for supplying oil to the oil application unit, and an oil bottle for replenishing the oil storage tank with oil, the oil storage tank is controlled by the blade. A first storage unit for storing the scraped oil, and a second oil storage unit for storing the oil to be replenished from the oil bottle,
This is achieved by a configuration in which the bottom surface of the first oil storage portion is located above the bottom surface of the second oil storage portion.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a color laser printer 1 provided with the present invention. In FIG.
Is a driven roller that also serves as a driving roller 22 and a tension roller that applies tension to the belt. Reference numeral 2 denotes a photosensitive belt that is stretched in the vertical direction by the driven roller 21 and rotates at a constant speed in the direction of the arrow. Reference numeral 3 denotes an intermediate transfer member that is arranged in contact with the photosensitive belt 2. Reference numeral 4 denotes a charger for uniformly charging the surface of the photoreceptor belt 2. Reference numeral 5 denotes an exposure device for exposing the uniformly charged surface of the photoreceptor belt 2 to form an electrostatic latent image on the surface.

Reference numerals 61, 62, 63, and 64 denote four developing machines which are arranged in contact with the horizontal surface of the photoreceptor belt 2 to develop an electrostatic latent image to form a toner image. Reference numeral 10 denotes a cassette that stores a transfer material such as paper. A paper feed roller 11 feeds a transfer material such as paper from the cassette 10. Reference numeral 12 denotes a registration roller for correcting the posture of a transfer material such as a sheet fed from the cassette 10. Reference numeral 13 denotes a transfer roller for transferring the toner image to a transfer material such as paper.
Numeral 14 denotes a fixing device which comprises a pair of elastic rollers and fixes a toner image transferred onto a transfer material such as paper. Reference numeral 17 denotes a paper discharge unit 17 for storing a transfer material such as a sheet fixed and discharged outside the apparatus.

Reference numeral 8 denotes a blade for removing toner remaining on the surface of the photosensitive belt 2 after the transfer. Reference numeral 9 denotes an erase lamp for removing charges remaining on the surface of the photoreceptor belt 2 after transfer of the toner image. Reference numeral 15 denotes a cleaner for removing toner remaining on the surface of the intermediate transfer member 3.

Next, the operation of forming a color image by the present apparatus will be described.

First, after a power supply is turned on, when a print signal is sent from an information processing device (not shown) to the printer 1 in a print standby state, the exposure device 5 emits laser light corresponding to a toner image in accordance with the signal. Irradiation is performed on the photosensitive belt 2 uniformly charged by the charger 4, and an electrostatic latent image is formed on the photosensitive belt 2.

Next, an electrostatic latent image corresponding to the yellow toner image is formed on the photoreceptor belt 2 by the exposure device 2 and developed by the yellow developing device 61 to form a toner image. Here, 61 is a developing machine using yellow toner, 62 is a developing machine using magenta toner, 63
Is a developing machine using a cyan toner, and 64 is a developing machine using a black toner. By controlling a bias voltage to each developing machine, a developing function is given or lost. ing. The toner image formed on the photoreceptor belt 2 is transferred to the surface of the intermediate transfer member 3 at a contact portion with the intermediate transfer member 3, and is held on the surface.

On the other hand, on the photoreceptor belt 2 after the transfer of the toner image, toner remaining without being transferred is removed by a blade 8 and then the electric charge remaining on the surface of the photoreceptor belt 2 is erased.
It is designed to be removed by a slump 9.

After the step of returning the surface of the photosensitive belt 2 to the initial state is completed, a magenta toner image of the next color is similarly formed on the surface of the photosensitive belt 2 and held on the surface of the intermediate transfer member 3. And transferred onto the intermediate transfer member 3 while being superimposed on the yellow toner image.

The same process is repeated for the cyan and black colors, and the toner images of four colors are superimposed on the intermediate transfer member 3 and simultaneously held on the surface.

In order to transfer the four-color toner image formed on the surface of the intermediate transfer body 3 onto the paper 16, the paper feed roller 11 is rotated and the paper 16 stored in the cassette 10 is rotated. Are transported to the registration roller 12 to correct the skew of the paper 16 and then stopped.

Next, the rotation of the registration roller 12 is started at such a timing as to match the toner image on the intermediate transfer member 3. At the same time that the leading edge of the conveyed paper comes into contact with the intermediate transfer member 3, the transfer roller 13 is pressed from the back of the paper,
The four-color toner images on the surface of the intermediate transfer member 3 are formed on a sheet 16 at a time.
Electrostatic transfer on top.

The four-color toner images thus formed on the paper 16 are transferred to the fixing roller 143 of the fixing device 14 and the pressure roller.
Then, the paper passes through the paper 146 and is fixed on the paper 16 and is discharged to the paper discharge unit 17 at the top of the printer 1.

Here, as shown in FIG. 2, the fixing machine includes a fixing roller 143 having a core metal surface coated with silicone rubber;
Similarly, a pressure roller 146 whose surface is coated with silicone rubber is pressed by a pressure spring (not shown) to form a nip.

By the way, in the case of a color image, the toner is superimposed on several layers, so that the toner is easily offset to the fixing roller.
It is necessary to apply silicone oil to the surface of the fixing roller 143 to ensure releasability.

For applying oil to the fixing roller 143, oil is supplied from an oil bottle 142 into an oil storage tank 145 provided below the fixing roller 143, and the lower end of a suction felt 148 such as Nomex is immersed in the oil.
The fixing roller 1 is impregnated with oil into the suction felt 148 and at the same time, utilizing the capillary phenomenon of the felt 148.
This is performed via a supply felt 149 that sucks up to the vicinity of 43 and contacts the fixing roller 143.

On the other hand, if the applied oil is non-uniform, the fixed image will have gloss unevenness or the like, so that the applied oil is applied in an amount of 0.01 to 0.1 g per A4 transfer sheet. Thus, the excess oil is scraped off evenly while being regulated by the blade 150. The oil scraped off here is collected in the oil storage tank 145 and reused.

By the way, in order to obtain a coating amount of 0.01 to 0.1 g per A4 transfer paper by the blade 150 and to make the coating amount uniform, the amount applied to the fixing roller 143 by the supply felt 149 is required. At least twice the amount regulated by the blade is required. Therefore, the oil scraped off by the blade 150 is supplied to the supply felt 14.
One half of the amount applied in 9 is collected at the lower part of the blade of the oil storage tank 145.

On the other hand, an oil bottle 142 is disposed in the oil storage tank 145 on the opposite side of the suction felt 148, and the oil contained therein is replenished from the oil outlet 141. Here, the oil outlet 14
The oil storage tank 14 is located at one position by a stopper (not shown).
The oil storage tank 145 is always filled with oil up to the oil outlet 141 by being held so as to keep a constant distance from the bottom surface 5.

In such a fixing machine, the liquid level of the oil stored in the oil storage tank 145 is maintained at the same level as the oil outlet 141 in a stationary state where printing is not performed. However, when continuous printing is performed, the suction felt 1
Since the oil soaked in the oil 48 is consumed, the suction felt 148 is successively sucked up from the oil storage tank.

At this time, the oil level in the oil storage tank is lowered, so that the oil is replenished from the oil bottle. On the other hand, the oil scraped off by the blades returns to the storage tank. As shown in FIG. 3, the oil storage tank 1 below the blade with the suction felt 148 interposed therebetween.
The liquid level at 45a is higher by h1 than at rest. Such a state is maintained for a while until the suction felt 148 absorbs the oil.

Therefore, if the fixing device is removed from the printer main body or the printer main body is tilted in such a state, oil overflows and the apparatus is contaminated.

FIG. 4 shows an oil storage tank 14 below the blade.
The bottom surface 5a is configured at a position higher by h2 than the bottom surface of the oil storage tank 145b below the oil bottle. With such a configuration, the oil accumulated in the oil storage tank 145a flows into the oil storage tank 145b located at a lower position, and even when continuous printing is performed, the oil scraped off by the blade 150 is stored in the oil storage tank 145a. Will not accumulate to overflow. In addition, storage tank 145
Since the oil is located at a position higher than b, the oil stored in the storage tank 145a sucks up faster and soaks into the felt 148, so that the liquid level can be quickly lowered.
Accordingly, it is possible to provide a fixing device that is small in size, low in cost, prevents oil leakage, and has good handleability.

As described above, according to the present invention, the photosensitive member, the charging means for charging the photosensitive member, the exposing means for forming an electrostatic latent image on the photosensitive member, and the photosensitive member are arranged around the photosensitive member. Developing means, an intermediate transfer member that is partially in contact with the photoconductor and a toner image is transferred to the contact portion, a transfer unit that transfers an image held on the intermediate transfer member to a transfer material, and In an electrophotographic apparatus comprising a fixing unit for fixing the transferred transfer material, the fixing unit includes a fixing roller, a pressure roller, a unit for applying oil to the fixing roller, and an excess of the applied oil. A blade for scraping off the oil, an oil reservoir for supplying oil to the oil applying means, and an oil bottle for replenishing the oil reservoir with oil. The oil reservoir is scraped off by the blade. And a second oil storage unit for storing the oil supplied from the oil bottle, wherein the bottom surface of the first oil storage unit is the second oil storage unit. The storage unit is located above the bottom surface.

[0037] The bottom surface of the first oil reservoir is located above the oil outlet of the oil bottle.

Further, the first oil storing section and the second oil storing section are separated by the oil applying means.

Thus, the oil storage tank comprises a first storage section for storing the oil scraped off by the blades, and a second oil storage section for storing the oil replenished from the oil bottle. By configuring the bottom surface of the first oil storage unit to be located above the bottom surface of the second oil storage unit, it is possible to prevent oil from overflowing from the oil storage tank even when continuous printing is performed, and to reduce the size and the size. It is possible to provide a fixing device that is easy to handle at a low cost.

[0040]

According to the present invention, it is possible to provide a fixing device which is small in size, low in cost, prevents oil leakage, and has good handleability.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a color laser printer provided with the present invention.

FIG. 2 is a schematic diagram illustrating a conventional fixing device.

FIG. 3 is a schematic diagram illustrating a conventional fixing device.

FIG. 4 is a schematic diagram of a fixing device provided with the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Color laser printer, 2 ... Photoreceptor belt, 21 ...
Driven roller, 22 drive roller, 3 intermediate transfer belt, 4 charger, 5 optical device, 61 yellow developing machine, 62 magenta developing machine, 63 cyan developing machine, 64 ... Black developing machine, 8 ... Blade, 9 ...
Erase lamp, 10 paper cassette, 11 paper feed roller, 12 registration roller, 13 transfer roller, 14
Fixing machine, 15 cleaner, 16 paper, 17 discharge section,
141 ... oil bottle outlet, 142 ... oil bottle,
143: fixing roller, 145: oil storage tank, 145a
... first oil storage tank, 145b ... second oil storage tank, 146 ... pressure roller, 148 ... suction felt,
149: supply felt, 150: blade.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiromitsu Fukuda 502 Kandachi-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (72) Inventor Akira Mori 502-Kindachi-cho, Tsuchiura-City, Ibaraki Pref. Inside the Machinery Research Laboratory (72) Inventor Riki Hiraoka 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi Taga Electronics Co., Ltd. (72) Inventor Toru Hanashima 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture Incorporated Hitachi Taga Electronics Co., Ltd. (72) Inventor Katsuyoshi Onose 1-1-1, Higashitaga-machi, Hitachi City, Ibaraki Prefecture F-term in Hitachi Taga Electronics Co., Ltd. (reference) 2H033 AA09 AA39 BA44 BA45 BA46 4F040 AA05 AB08 AC01 BA02 CA11 4F042 AA03 AA06 AA10 CA03 CA04

Claims (3)

[Claims] A photoconductor, a charging unit for charging the photoconductor, an exposure unit for forming an electrostatic latent image on the photoconductor,
Developing means arranged around the photoreceptor, an intermediate transfer member partially contacting the photoreceptor and transferring a toner image to the contact portion, and an image held on the intermediate transfer member as a transfer material In an electrophotographic apparatus including a transfer unit for transferring and a fixing unit for fixing the transfer material on which the image has been transferred, the fixing unit applies oil to the fixing roller, the pressure roller, and the fixing roller. Means, a blade for scraping off excess oil of the applied oil, an oil storage tank for supplying oil to the oil application means, and an oil bottle for replenishing the oil storage tank with oil,
The oil storage tank has a first storage unit that stores oil scraped off by the blade, and a second oil storage unit that stores oil supplied from the oil bottle, and the first oil An electrophotographic apparatus, wherein a bottom surface of the storage unit is located above the bottom surface of the second oil storage unit. 2. The electrophotographic apparatus according to claim 1, wherein a bottom surface of said first oil storage portion is located above an oil outlet of said oil bottle. 3. An electrophotographic apparatus according to claim 1, wherein said first oil reservoir and said second oil reservoir are separated by said oil applying means.