JPH1184770A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of obtaining a fixed image whose glossiness is low and whose appearance is excellent. SOLUTION: An image surface roughening means 9 having a roller-shaped image surface roughening roller 10 and an image surface roughening pressure roller 11 is arranged on the downstream side in a carrying direction of a recording material from a fixing part 6. The image surface roughening roller 10 is formed of silicone rubber whose the surface roughness Ra is >=0.2 μm and the image surface roughening pressure roller 11 is brought into press-contact with the image surface roughening roller 10 by a specified pressure so that the recording material passing through the fixing part 6 is held by compression and carried between the press-contacting parts of both rollers. At this time, the image surface roughening roller 10 is arranged so as to abut on the fixing image surface of the recording material so that the glossiness of the fixing image surface of the recording material is lowered by roughening the fixing image surface through the image surface roughening roller 10 when the recording material passes through the image surface roughening means 9.

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 or a laser beam printer for fixing an unfixed image on a recording material by a fixing unit.

[0002]

2. Description of the Related Art Conventionally, various image forming apparatuses have been known. Among them, an electrophotographic image forming apparatus that performs image exposure on a photosensitive member with a laser beam and develops the image to obtain an image is often used. Have been. Such an image forming apparatus has advantages such as high image quality and high speed, and is widely used as an output device such as a copying machine, a color laser beam printer, and the like.

In the image forming apparatus as described above, for example, as shown in FIG. 9, a photosensitive drum 1 for forming an electrostatic latent image on a surface, and an electrostatic latent image on the photosensitive drum 1 are developed. The image forming apparatus includes a developing device 2 for developing a visible image, a transfer unit 3 for transferring a developed image on the photosensitive drum 1 to a recording material, and a fixing unit 6 for fixing an unfixed image on the recording material.

In the above-described image forming apparatus, the photosensitive drum 1 is charged by a charging unit (not shown), and the charged photosensitive drum 1 is exposed by an exposure unit (not shown). An electrostatic latent image is formed on the photosensitive drum 1, and the electrostatic latent image on the photosensitive drum 1 is developed by a developing device 2 using a toner as a developer by a developing method such as a magnetic brush method or a jumping method. The transfer unit 3 transfers the visualized toner image on the photosensitive drum 1 onto a recording material. At this time, the recording material is conveyed at a predetermined timing to a position where the photosensitive drum 1 and the transfer unit 3 face each other, and charges having a polarity opposite to that of the toner are charged on the back surface of the recording material by the transfer unit 3. By electrically attracting the toner forming an image on the photosensitive drum 1 onto the recording material, the toner image is transferred onto the recording material.

[0005] The recording material to which the unfixed image formed by the toner is transferred is separated from the transfer unit by the separation unit 4, conveyed toward the fixing unit 6 via the conveying unit 5, and The toner image is fixed on the recording material by heating and pressing the unfixed toner image.

The fixing unit 6 for fixing an unfixed image has a fixing roller 7 having a built-in heater as a heating source, and a pressure roller 8 arranged to be in pressure contact with the fixing roller 7. The recording material carrying the unfixed toner image is conveyed by the pressure contact portion between the roller 7 and the pressure roller 8 so that
By heating and pressing the toner on the recording material, an unfixed toner image can be fused and fixed on the recording material. At this time, the recording material is conveyed so that the surface on which the toner image is carried and the fixing roller 7 are in contact with each other.

Fixing roller 7 in direct contact with unfixed toner
In the fixing process, a part of the unfixed toner image may adhere to the surface of the fixing roller 7 without being fixed to the recording material, and a phenomenon called so-called offset may occur. Therefore, in order to prevent the offset of the fixing roller 7, an oil application device may be provided as a release agent applying unit for applying a release agent to the fixing roller.

[0008] As shown in FIG.
Is provided in the fixing section 6 to prevent the offset by improving the releasability of the fixing roller 7 from the toner. The oil application device 30 is configured to supply oil in an oil pan 31 to an oil pumping roller 32 and an oil application roller 3.
3, the amount of oil and the oil on the flora 33 is regulated by the oil application amount adjusting blade 34 so that the oil is applied to the fixing roller 7 in contact with the oil and the flora 33. In the apparatus shown in FIG. 10, an oil application amount of 40 mg / A4 is applied.

Here, the amount of oil applied by the oil applying device 30 is determined as follows. First, the weight of 50 sheets of A4 size white paper is defined as A1 (g). Then, in a state where the image is not transferred onto the white paper and the toner is not transferred, and in a state where the oil is not applied to the rubber layer of the fixing roller, the distance between the fixing roller and the pressure roller is set to 50.
The weight of 50 blank sheets after passing the sheets and passing the paper is B (g).
And

Next, the weight of another 50 blank sheets of the same size is set to A2 (g), and the image is not transferred onto this blank sheet. The weight of 50 blank papers is defined as C (g).

Using the above A1, B, A2, and C, A4
The amount X (g) of oil applied per blank sheet of size can be determined by the following equation: X = (C + A1-B-A2) / 50.

However, when the amount of the release agent is about 40 mg / A4, if a transparent resin OHP sheet is used,
There are problems such as a feeling of sliminess of the release agent remaining on the surface of the OHP sheet after fixing and a decrease in light transmittance. This can be solved by reducing the consumption of the release agent. Therefore, various devices have been devised to minimize the consumption of the release agent.

For example, as shown in FIG. 11, a felt-like fiber member 40 whose end is immersed in an oil pan is brought into contact with the fixing roller 7, and the fiber member 40 is located on the downstream side in the rotation direction of the fixing roller 7 with respect to the fiber member 40. A release agent supply unit in which a blade 41 is brought into contact with the surface of the fixing roller 7 has been proposed. In a system in which the fiber member 40 is brought into contact with the fixing roller 7 to apply a release agent to the fixing roller 7 and the blade 41 regulates the amount of the release agent applied, a small amount of the release agent of 10 mg / A4 or less can be applied. Became.

[0014]

However, when the amount of the release agent applied is 40 mg / A4, the glossiness of the fixed image is 20%.
On the other hand, when the amount of the release agent applied is reduced by the above-described method of controlling the amount of the release agent by the fiber member and the blade on the felt, if the applied amount is 10 mg / A4 or less, the oil shown in FIG. As can be seen from the graph showing the relationship between the coating amount of the fixed image and the glossiness of the fixed image, the glossiness of the fixed image exceeds 30%. When the glossiness of the fixed image exceeds 30%, the visual impression of the fixed image deteriorates.

Here, the glossiness is measured by a recording material surface glossiness detecting means comprising a light source, a light receiving device and a lens.
The measurement was performed according to the method specified in Z8741. As shown in FIG. 13, the measuring method is such that a light beam having a specified opening angle is incident on a surface of the recording material P from a light source 50 at a specified incident angle θ, and a light beam having a specified opening angle reflected in a mirror reflection direction is obtained. It is measured by the light receiver 53. The light beam emitted from the light source 50 passes through the lens 51 on the light source side and is incident on the surface of the recording material P at an angle θ, and the light beam reflected in the mirror reflection direction is detected by the light receiver 53 through the lens 52 on the light receiver side. Thereby, the surface gloss of the recording material and the fixed image can be detected.
The surface gloss was detected at an incident angle θ of 60 °.

The reason why the glossiness is low when the coating amount of the release agent is large is that when the coating amount of the release agent is large, a thick release agent film is formed on the surface of the fixing roller, and this release agent layer is insulated. By working as a material. Because of the layer formed by the release agent, the heat of the fixing roller is not sufficiently transmitted to the toner, and the image is output after the fixing process is completed without sufficiently dissolving the toner.
The image surface after the fixing step was in a rough state, and the glossiness of the fixed image was low.

On the other hand, when the amount of the release agent is small, for example, 10 mg / A4 or less, the thickness of the release agent film formed on the surface of the fixing roller is small, and in the fixing step, Since the toner is sufficiently melted by the heat of the fixing roller, the surface property of the fixed image is increased, and the glossiness exceeds 30%. In this case, by lowering the fixing temperature of the fixing roller or the like, it is possible to reduce the amount of heat transferred to the toner to lower the glossiness of the fixed image. In some cases, the surface temperature is lower than the fixable temperature, and there is a problem that low-temperature offset occurs.

Therefore, the present invention can suppress the rise in gloss due to the reduction in the amount of the release agent applied by providing a means for roughening the surface of the fixed image, and obtain a fixed image with low gloss and good appearance. It is an object to provide an image forming apparatus. It is another object of the present invention to provide an image forming apparatus capable of reducing glossiness in accordance with glossiness of a fixed image on a recording material. Still another object of the present invention is to provide an image forming apparatus capable of canceling the operation of the image surface roughening means according to the glossiness of a fixed image of a recording material and the recording material to be used.

[0019]

According to a first aspect of the present invention, there is provided an image carrier for forming an electrostatic latent image on a surface thereof, and an electrostatic latent image formed on the image carrier. A developing device for developing the image with a developer, a transfer unit for transferring a developer image on the image carrier developed by the developing device to a recording material,
It has a plurality of fixing members which are pressed against each other and are rotatably arranged, and have a plurality of fixing members which are rotatably arranged. And a fixing unit for fixing an unfixed image on the recording material, the recording unit having a predetermined surface roughness downstream of the fixing unit in the recording material conveyance direction and recording after passing through the fixing unit. This is achieved by providing an image surface roughening means capable of roughening the surface of the fixed image by being pressed against the fixed image on the material with an arbitrary pressing force.

Further, according to the second invention of the present application, the above object is achieved by the image surface roughening means, wherein the roller-shaped image surface roughening member is pressed into contact with the image surface roughening member with an arbitrary pressing force. The surface roughness Ra of the image surface roughening member that contacts the fixed image of the recording material has a surface roughness Ra of 0.1 mm.
This is achieved by setting the thickness to 2 μm or more.

Further, according to the third aspect of the present invention, the above object is achieved by an image surface roughening means, comprising: a plate-shaped image surface roughening member; And a roller-shaped image surface roughening pressure member, and the surface roughness R of the image surface roughening member that comes into contact with the fixed image of the recording material.
a is achieved by setting it to 0.2 μm or more.

Further, according to the fourth aspect of the present invention, the above object is provided between the fixing section and the image surface roughening means.
Glossiness detection means for detecting the glossiness of the fixed image on the recording material after passing through the fixing unit is provided, and the image surface roughness means is added to the image surface roughness means according to the glossiness detected by the glossiness detection means. This is achieved by providing a pressure adjusting means for changing the pressure.

According to a fifth aspect of the present invention, the above object is to provide an image forming apparatus which can detect or estimate the amount of developer of an unfixed image transferred onto a recording material. Detecting means, and glossiness estimating means for estimating the glossiness of the fixed image on the recording material after the fixing step based on a signal from the developer sizing amount detecting means, wherein the glossiness estimating means comprises: This is achieved by providing a pressing force adjusting means for changing the pressing force of the image surface roughening means according to the estimated glossiness.

Further, according to the sixth aspect of the present invention, the above object is provided between the fixing section and the image surface roughening means.
A glossiness detecting means for detecting the glossiness of the fixed image on the recording material after passing through the fixing unit is provided, and the image surface roughening means includes a plurality of image surface roughening members having different surface roughness according to the glossiness. ,
An image surface roughening member selecting means for selecting one of a plurality of image surface roughening members in accordance with the glossiness detected by the glossiness detecting means and pressing the selected image surface roughening member against a fixed image on a recording material; Is achieved by

According to a seventh aspect of the present invention, the above object is to provide an image forming apparatus which can detect or estimate the amount of developer of an unfixed image transferred onto a recording material. Detecting means, and a gloss estimating means for estimating the gloss of the fixed image on the recording material after the fixing step based on a signal from the developer sizing amount detecting means. A plurality of image surface roughening members having different surface roughnesses, and one of the plurality of image surface roughening members is selected according to the glossiness estimated by the glossiness estimation means, and is fixed on a recording material. This is achieved by providing an image surface roughening member selecting means for pressing against the image.

According to an eighth aspect of the present invention, the object is to provide an image surface roughening means, comprising: a plurality of image surface roughening members having different surface roughness according to glossiness; An image surface which selects one of a plurality of image surface roughening members in accordance with the glossiness detected by the detection means or the glossiness estimated by the glossiness estimation means and presses against the fixed image on the recording material. This is achieved by providing roughening member selection means.

According to a ninth aspect of the present invention, the above object is achieved by providing the image surface roughening means with pressure releasing means capable of releasing the pressed state of the image surface roughening means in accordance with the degree of gloss. This is achieved by:

Further, according to the tenth aspect of the present invention, the object is to provide an image surface roughening means, in which a plurality of types of recording materials are used, according to the type of the recording materials. This is achieved by providing a pressure contact releasing means capable of releasing the pressure contact state of the pressing means.

That is, according to the first aspect of the present invention, the image surface roughening means provided on the downstream side in the recording material conveyance direction from the fixing unit is provided on the surface of the fixed image on the recording material after the fixing step. By being pressed, the surface of the fixed image is roughened,
The glossiness of the fixed image is reduced.

According to the second aspect of the present invention, the roller-shaped image surface roughening member having a surface roughness Ra of 0.2 μm or more is pressed against the image surface roughening member with an arbitrary pressing force. By transporting the recording material to the portion where the image surface is roughened and pressed against the pressing member, the glossiness of the fixed image can be reduced with a simple configuration even when the glossiness of the fixed image of the recording material is high.

According to the third aspect of the present invention, a plate-shaped image surface roughening member having a surface roughness Ra of 0.2 μm or more is pressed against the image surface roughening member with an arbitrary pressing force. By transporting the recording material to the portion where the image surface is roughened and pressed against the pressing member, the glossiness of the fixed image can be reduced with a simple configuration even when the glossiness of the fixed image of the recording material is high.

Further, according to the fourth aspect of the present invention, the glossiness of the fixed image on the recording material by the glossiness detection means provided between the fixing unit and the image surface roughening means is determined by Since the pressing force of the image surface roughening means is changed by the pressing force adjusting means, the glossiness is appropriately reduced according to the glossiness of the fixed image.

Further, according to the fifth aspect of the present invention, there is provided a developer amount detecting means for detecting or estimating a developer amount of an unfixed image transferred onto a recording material, and a developer amount detecting means. The glossiness of the fixed image is estimated by the glossiness estimation means which can estimate the glossiness of the fixed image on the recording material after the fixing process based on the signal from the means, and the glossiness is estimated according to the glossiness estimated by the glossiness estimation means. Since the pressing force of the image surface roughening means is changed by the pressure adjusting means, the glossiness is appropriately reduced in accordance with the glossiness of the fixed image.

Further, according to the sixth aspect of the present invention, a plurality of fixed images are provided in accordance with the glossiness of the fixed image detected by the glossiness detection means provided between the fixing unit and the image surface roughening means. Select one of the image surface roughening members of
Since the fixed image surface on the recording material is roughened by the selected image surface roughening member, the glossiness can be appropriately reduced according to the glossiness of the fixed image.

Further, according to the seventh aspect of the present invention, there is provided a developer amount detecting means for detecting or estimating the amount of developer of an unfixed image transferred onto a recording material, and detecting the amount of developer amount. The glossiness of the fixed image is estimated by the glossiness estimation means capable of estimating the glossiness of the fixed image on the recording material after the fixing process based on the signal from the means. One of the image surface roughening members is selected, and the fixed image surface on the recording material is roughened by the selected image surface roughening member, so that the glossiness is appropriately reduced according to the glossiness of the fixed image. Let me do.

According to the eighth aspect of the present invention, a plurality of image surface roughening members are provided in accordance with the glossiness detected by the glossiness detection means or the glossiness estimated by the glossiness estimation means. By selecting one of them or changing the pressing force of the image surface roughening means, the fixed image surface on the recording material is roughened by the selected image surface roughening member. Glossiness is appropriately reduced.

Further, according to the ninth aspect of the present invention, the case where the glossiness does not need to be reduced is selected by activating the press-contact releasing means according to the glossiness of the fixed image on the recording material. An image with an appropriate gloss is formed.

Further, according to the tenth aspect of the present invention, when a plurality of types of recording materials are used, the image contact surface roughening means is operated by activating the press-contact releasing means according to the type of the recording material. Is selected, and an image with an appropriate gloss is formed.

[0039]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) First, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the image forming apparatus according to the present embodiment is, for example, a photosensitive drum 1 which is an image carrier that forms an electrostatic latent image on a surface, and develops the electrostatic latent image on the photosensitive drum 1. A developing device 2 for developing a visible image, a transfer unit 3 for transferring a developed image on the photosensitive drum 1 to a recording material, a fixing unit 6 for fixing an unfixed image on the recording material, and a recording material rather than the fixing unit 6. The image surface roughening means 9 and the like are arranged on the downstream side in the transport direction.

In the image forming apparatus having the above structure, the photosensitive drum 1 is charged by a charging unit (not shown), and the charged photosensitive drum 1 is exposed by an exposure unit (not shown). An electrostatic latent image is formed on the photosensitive drum 1, and the electrostatic latent image on the photosensitive drum 1 is developed by a developing device 2 using a toner as a developer by a developing method such as a magnetic brush method or a jumping method. To visualize. Developing device 2 of the present embodiment
Is provided with four developing containers each containing toner of each color of cyan, magenta, yellow, and black so that full-color image formation can be performed, and one of the developing containers of each color is selected. Is made to face the photosensitive drum 1 so that the toner is carried on the developing sleeve provided in the developing container, and the toner adheres to the surface of the photosensitive drum 1.

The visualized toner image on the photosensitive drum 1 is transferred onto a recording material by the transfer unit 3. At this time, the recording material is conveyed at a predetermined timing to a position where the photosensitive drum 1 and the transfer unit 3 face each other, and charges having a polarity opposite to that of the toner are charged on the back surface of the recording material by the transfer unit 3. By electrically attracting the toner forming an image on the photosensitive drum 1 onto the recording material, the toner image is transferred onto the recording material.

The recording material to which the unfixed image formed by the toner is transferred is separated from the transfer unit by the separation unit 4, is conveyed toward the fixing unit 6 via the conveyance unit 5, and is fixed on the recording material by the fixing unit 6. The toner image is fixed on the recording material by heating and pressing the unfixed toner image.

The fixing section 6 for fixing an unfixed image is a rotatable fixing roller having a built-in heater as a heating source as a plurality of fixing members that are rotatably arranged while being pressed against each other and press. And a pressing roller 8 rotatably provided and pressed against the fixing roller 7 by pressing means such as a spring (not shown).
The recording material carrying the unfixed toner image is supported and conveyed by the pressure contact portion between the fixing roller 7 and the pressure roller 8, so that the toner on the recording material is heated and pressurized, and the unfixed toner image is formed on the recording material. It can be fused and fixed. At this time, the recording material is conveyed so that the surface on which the toner image is carried and the fixing roller 7 are in contact with each other. Although not shown, the fixing roller 7 is provided with a releasing agent coating device of a type in which the amount of oil as a releasing agent is 10 mg / A4 or less and the amount of oil applied is small.
To prevent toner offset.

As shown in FIG. 2, the image surface roughening means 9 provided on the downstream side of the fixing unit 6 in the recording material conveying direction is, for example, a roller having a diameter of 10 mm as an image surface roughening member. An image surface roughening roller 10 made of silicone rubber with Ra = 0.2 μm, and an image surface roughening pressing member, for example, a roller 10 mm in diameter and formed by a pressing unit 12 using a spring or the like as a pressing member. And a pressure roller 11 for roughening the image surface which is brought into pressure contact with the roller 10 for roughening the image surface.

An image surface roughening roller 10 and an image surface roughening pressure roller 11 are rotatably provided, and one or both of them are driven by a driving unit (not shown). The recording material is rotated in a predetermined direction by a force and conveyed from the fixing unit 6.

The image surface roughening roller 10 is disposed so as to contact the surface of the recording material passing through the fixing section 6 on the fixed image side, and includes an image surface roughening roller 10 and an image surface roughening pressure roller. The recording material that has passed through the fixing unit 6 is pinched and conveyed to the press contact portion with the image forming unit 11, so that the image surface roughening roller 10
Is capable of forming irregularities on the surface of the recording material on the fixed image side immediately after the fusion and fixing to roughen the fixed image surface and reduce the glossiness of the fixed image.

According to the image surface roughening means 9 having the above structure,
The recording material to which the unfixed toner image is transferred is nipped and conveyed to the fixing unit 6 so that the toner on the recording material is melted and fixed. The sheet is conveyed to a pressure contact portion between the surface roughening roller 10 and the image surface roughening pressure roller 11. Image surface roughening roller 10
The recording material conveyed while being nipped and conveyed between the press-contact portion of the roller and the image surface roughening roller 11 is pressed against the surface of the fixed image by the image surface roughening roller 10 to roughen the surface of the fixed image. To reduce the glossiness.

FIG. 3 shows a state in which the image surface roughening roller and the image surface roughening pressure roller are pressed against each other with a pressing force of 30 kgf. 4 is a graph showing the relationship between the surface roughness and the glossiness of a fixed image. It is also desirable to suppress the glossiness to 20% or less from an impression for viewing. As can be seen from FIG. 3, when the pressing force is 30 kgf, the surface roughness Ra of the image surface roughening member needs to be 0.2 μm or more. . The glossiness was measured by a recording material surface glossiness detection means including a light source, a light receiving device, and a lens according to a method defined in JISZ8741. The measuring method is such that a light beam having a specified opening angle is incident on a surface of a recording material from a light source at a specified incident angle θ, and a light beam having a specified opening angle reflected in a mirror reflection direction is detected by a light receiver.

In the present embodiment, when a release agent application device having a small amount of release agent applied to the fixing portion is used, for example, when the application amount of the release agent is 10 mg / A4 or less, the toner passes through the fixing portion. Even when the glossiness of the fixed image immediately after the fixing exceeds 30%, the fixed image having a glossiness of 20% or less is formed by the image surface roughening means having the above-mentioned configuration provided on the downstream side of the fixing unit in the recording material conveyance direction. Thus, it is possible to form an image which is beautiful in appearance.

In the present embodiment, the image surface roughening pressure roller is brought into contact with the image surface roughening roller by the pressing portion. However, the present invention is not limited to this. It is also possible to provide a pressurizing section using such a method as to make the image surface roughening roller contact the pressurizing roller with the image surface roughening, or to provide a pressurizing section to both rollers and pressurize from both. Good. Further, instead of using a roller-shaped image surface roughening pressure roller, a long plate-shaped member may be pressed against the image surface roughening roller.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIG. In this embodiment, a long plate-shaped image surface roughening member is used instead of the image surface roughening roller used as the image surface roughening member in the first embodiment. Members such as an image surface roughening pressing member and a fixing unit have the same configuration and operation as those in the first embodiment.

As shown in FIG. 4, an image surface roughening means 15 is provided downstream of the fixing section 6 in the recording material conveyance direction.
The image surface roughening means 15 is, as an image surface roughening member, for example, an image surface roughening plate made of silicon rubber having a width of 5 mm, a length of 323 mm, and a thickness of 5 mm and a surface roughness Ra of 0.2 μm. 16 is provided, and as a pressing member for roughening the image surface, for example, a pressing unit 1 formed in a roller shape of φ10 mm and using a spring or the like.
2, an image surface roughening pressure roller 17 which is pressed against the image surface roughening roller 10 with a predetermined pressing force is provided. The image surface roughening pressure roller 17
The fixing unit 6 is rotatably provided and rotates in a predetermined direction by a driving force from a driving unit (not shown).
The recording material sent from the direction can be conveyed.

The image surface roughening plate 16 is arranged such that the surface having a surface roughness Ra = 0.2 μm abuts on the surface of the recording material which has passed through the fixing unit 6 on the fixed image side.
The recording material that has passed through the fixing unit 6 is pinched and conveyed to the pressure contact portion between the image surface roughening plate 16 and the image surface roughening pressure roller 17 so that the contact surface of the image surface roughening plate 16 with the recording material is changed. Irregularities are formed on the surface of the recording material on the fixed image side immediately after the fusion and fixing, whereby the surface of the fixed image is roughened, and the glossiness of the fixed image can be reduced.

According to the image surface roughening means 15 having the above structure, the recording material to which the unfixed toner image has been transferred is nipped and conveyed to the fixing section 6 so that the toner on the recording material is melted and fixed. The recording material on which the fixed image is formed after passing through the unit 6 is conveyed to a pressing portion between the roller 10 and the pressing roller 11 for roughening the image surface. The recording material conveyed by being nipped and conveyed by the press-contact portion between the image surface roughening roller 10 and the image surface roughening pressure roller 11 is pressed against the fixed image surface on the surface, and the surface of the fixed image is pressed. To lower the glossiness of the fixed image.

In the present embodiment, similarly to the first embodiment, when a release agent applying device having a small amount of the release agent applied to the fixing unit is used, for example, the applied amount of the release agent is 10 m.
g / A4 or less, even when the glossiness of the fixed image immediately after passing through the fixing unit exceeds 30%, the image surface roughening means provided on the downstream side of the fixing unit in the recording material conveyance direction can reduce the glossiness to 20%. It is possible to obtain a fixed image having the following glossiness, and to form an image that is visually attractive.

Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIGS. In this embodiment,
A gloss detection means for detecting the glossiness of the fixed image is provided between the fixing unit and the image surface roughening means, and the pressing force of the image surface roughening means is changed according to the glossiness detected by the glossiness detection means. In addition to providing the pressing force adjusting means in the image surface roughening means, when it is not necessary to roughen the surface of the fixed image,
The apparatus is provided with a press-contact releasing means for releasing the pressed state of the image surface roughening means. The members such as the photosensitive drum and the fixing unit have the same configuration and operation as those of the first embodiment.

As shown in FIG. 5, an image forming apparatus is provided with a fixing section 6 having a fixing roller 7 and a pressure roller 8, and an image surface roughening means 21. A gloss detection unit 20 is provided between the roughening unit 21 and the gloss detection unit 20 that detects the gloss level of the fixed image on the recording material on which the image has been fixed by passing through the fixing unit 6.

The glossiness detecting means 20 includes, for example, the light source 20.
a and a light receiver 2 for receiving light emitted from the light source 20a
0b, and two lenses provided on a light source side and a light receiver side (not shown). The light source 20a passes through the lens on the light source side to the surface of the recording material at a predetermined incident angle. The luminous flux having the specified opening angle is incident, and the luminous flux having the specified opening angle reflected in the mirror reflection direction is detected by the light receiver 20b through the lens on the light receiver side, and the glossiness can be measured. The gloss level detected by the gloss level detection unit 20 is input to a control unit (not shown), and can be used for controlling a pressure adjustment unit and a pressure release unit described later.

The image surface roughening means 21 is, for example, a φ10
image formed of silicon rubber having a predetermined surface roughness in the form of a roller having a surface roughness of 21 mm, and an image formed with a roller having a diameter of 10 mm and a pressing portion 22 using a spring or the like with a predetermined pressing force. Surface roughening roller 2
An image surface roughening pressure roller 21b that is brought into pressure contact with 1a is provided so as to be rotatable and slidable along the pressing direction of the pressing unit 22. One or both of the image surface roughening roller 21a and the image surface roughening pressure roller 21b rotate in a predetermined direction by a driving force from a driving unit (not shown) and are sent from the fixing unit 6 direction. The recording material can be transported.

The image surface roughening roller 21a is disposed so as to abut the surface of the recording material that has passed through the fixing section 6 on the fixed image side, and the image surface roughening roller 21a and the image surface roughening roller 21a The recording material that has passed through the fixing unit 6 is pinched and conveyed to the pressure contact portion with the pressure roller 21b, so that the image surface roughening roller 21a forms irregularities on the surface of the recording material on the fixed image side immediately after fusion and fixing, thereby fixing the image. The surface can be roughened and the glossiness of a fixed image can be reduced.

The pressing portion 22 which presses the image-roughening pressure roller 21b against the image-roughening roller 21a is, for example, a support plate which is in contact with the rotating shaft 21d of the image-roughening pressing roller 21b. Spring member 22b having one end locked to 22a
The end of the spring member 22b on the side opposite to the support plate 22a is engaged with a support plate of a pressing force adjusting means, which is provided to be slidable in the pressing direction by the pressing unit 22 and is described later. Then, the surface of the image is roughened with a predetermined pressing force.
1b can be pressed against the image surface roughening roller 21a.

The image surface roughening means 21 is provided with a pressing force adjusting means 23 which can adjust the pressing force of the image surface roughening means 21. The pressing force adjusting means 23 supports an end of the spring member 22b of the pressing unit 22 on the opposite side of the image surface roughening side of the pressing roller 21b and a support plate 23a slidable in the pressing direction by the spring member 22b. And a cam 23b whose outer peripheral surface is in contact with the surface of the support plate 23a. The cam 23b is rotated according to the glossiness detected by the glossiness detection means 20, and the support plate 23a is pressed by the spring member 22b. The pressing force applied to the pressure roller 21b can be adjusted by sliding in the direction.

Here, the cam 23b of the pressing force adjusting means 23
Is rotated appropriately by an operation signal from the control unit to which the glossiness is input. When the surface roughness Ra of the image surface roughening roller 21a is Ra = 0.5 μm shown in FIG. Based on a graph representing the relationship between the pressing force of the image surface roughening means and the glossiness of the fixed image after passing through the image surface roughening means, the image surface is pressed with a pressing force corresponding to the glossiness detected by the glossiness detecting means 20. The roughening pressure roller 21b can be pressed against the image surface roughening roller 21a.

The image surface roughening means 21 is provided when the surface of the fixed image does not need to be roughened.
Is provided. The press-contact releasing means 24 is, for example, an image surface roughening pressure roller 21b of the rotating shaft 21c of the image surface roughening roller 21a.
One end is locked to the flat plate abutting on the side, and the other end is locked to an arbitrary position of the image forming apparatus main body, and a pressing force is applied in a direction to separate the image surface roughening roller 21a from the surface of the recording material. , A cam member 24b abutting on an outer peripheral position of the rotating shaft 21c of the image roughening roller 21a opposite to the flat plate, and a pressing roller 2 for roughening the image surface.
And a stopper 24c capable of restricting the movement of the first member 1b in the pressing direction.

The cam member 24c of the pressure releasing unit 24 is connected to a driving unit (not shown) and can be appropriately rotated by an operation signal from the control unit. For example, when the glossiness is equal to or less than 20%, the cam member 24b is rotated in a predetermined direction so that the outer peripheral surface of the cam member 24b is closest to the rotation center of the cam member 24b. Is brought into contact with the rotating shaft 21c of the roller 21a, whereby the image surface roughening roller 21a is lifted by the spring force in the tension direction of the spring 24a.

At this time, the image surface roughening pressure roller 21b also moves following the movement of the image surface roughening roller 21, but the rotating shaft 21d of the image surface roughening pressure roller 21b comes into contact with the stopper 24c. Image surface roughening pressure roller 2
1b is regulated, and the image surface roughening roller 21a and the image surface roughening pressure roller 21b are separated from each other to form a gap therebetween. The recording material is passed through the gap to form the image surface roughening roller 21a. And the surface of the recording material can be prevented from contacting.

In order to roughen the surface of the fixed image by the image surface roughening means 21 and the glossiness detecting means 20 having the above structure, the image surface roughening roller 21a has a surface roughness Ra = 0.2 μm. When the glossiness of the fixed image detected by the glossiness detection means 20 exceeds 20%, for example, when the glossiness of 30% is detected, the image surface roughening roller 21a and the image surface roughening pressure roller 21b are connected. Total pressure 30k at the pressure contact part
The cam 23 of the pressing force adjusting means 23 so as to be able to pressurize with gf
Activate b.

When the glossiness changes, a fixed image having a glossiness of 20% or less can be obtained by changing the total pressure applied to the pressed portion according to the glossiness value from the graph shown in FIG. Obtainable. When the glossiness does not exceed 20%, the pressing / releasing means 24 is actuated by a signal from the glossiness detection means 20 so that the gap between the image surface roughening roller 21a and the image surface roughening pressure roller 21b is increased. Is released, the image surface roughening roller 21a is released.
Does not come into contact with the surface of the recording material so that the fixed image surface of the recording material is not roughened by the image surface roughening roller 21a in the case of a fixed image having a good glossiness.

According to this embodiment, the image surface roughening roller and the image surface roughening pressure roller are pressed against each other with an appropriate pressing force depending on the glossiness of the fixed image fixed on the recording material. The image surface roughening roller roughens the surface of the fixed image on the recording material by the pressing force according to the glossiness of the recording medium, and can form a good image.

In place of the image surface roughening roller, a second
It is possible to use a long plate-shaped image surface roughening plate used in the embodiment.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, as the image surface roughening member, a plurality of image surface roughening members having a surface roughness difference according to the glossiness and an image surface roughening member according to the glossiness detected by the glossiness detection means are selected. And a means for selecting an image surface roughening member to be provided, wherein the surface of the fixed image is roughened by an image surface roughening member having a surface roughness difference according to the glossiness. Each member such as an image surface roughening pressing member and a fixing unit has the same configuration and operation as in the third embodiment.

As shown in FIG. 7, the image surface roughening means 25 of the present embodiment includes three image surface roughening rollers 26a, 26 as image surface roughening members having different surface roughnesses Ra.
Image surface roughening member selecting means 2 provided with 6b, 26c
6 are provided. The surface roughness of each of the three image surface roughening rollers depends on the glossiness of the fixed image immediately after passing through the fixing step, which is expected in consideration of the use conditions of the apparatus, etc., after the image surface roughening means. Is selected such that the glossiness of the image on the recording material is 20% or less.

The image surface roughening member selecting means 26 holds the respective rotating shafts of the image surface roughening rollers 26a, 26b and 26c at three vertex positions of a substantially triangular holding member 26d so as to be rotatable. At the same time, a rotation shaft provided at the position of the center of gravity of the holding member 26d is rotatably held at an arbitrary position of the image forming apparatus main body, and is held by rotating the holding member 26d in a predetermined direction by driving means (not shown). Three image surface roughening rollers 2 held by member 26d
One of 6a, 26b and 26c is brought into contact with the fixed image surface of the recording material. The rotating shaft of the holding member 26d is slidably held in the up-down direction, and the press-contact releasing means used in the third embodiment is provided on the rotating shaft of the holding member 26d. The holding member 26d can be moved upward when rotating the holding member 26d to select an image surface roughening roller to be brought into contact with the recording material surface.

A pressing unit (not shown) formed in a roller shape and rotatably held at a position facing the image surface roughening roller brought into contact with the recording material and using a spring or the like. Thus, an image surface roughening pressure roller 27 which is brought into pressure contact with the image surface roughening roller with a predetermined pressing force is provided, and an image surface roughening means 25 is configured.

Although not shown, the gloss detecting means used in the third embodiment is provided between the image surface roughening means 25 and the fixing section 6, and the gloss detecting means is provided. Is transmitted to the control unit of the image forming apparatus.

Here, the control unit, which has received the detection signal from the glossiness detecting means, sets the image surface roughening roller having the surface roughness corresponding to the glossiness to a portion facing the image surface roughening pressure roller 27. An operation signal can be transmitted from the control unit to the image surface roughening member selecting means 26 so as to be arranged, and the holding member 26d of the image surface roughening member selecting means 26 is operated by an operation signal corresponding to the glossiness. Thus, an image surface roughening roller corresponding to the glossiness can be selected from the three image surface roughening rollers 26a, 26b, and 26c to be brought into contact with the recording material surface.

With the image surface roughening means 25 having the above structure,
The surface according to the glossiness among the three image surface roughening rollers such that the glossiness after passing through the image surface roughening means 25 is 20% or less of the glossiness detected by the glossiness detection means. Select an image surface roughening roller with roughness,
The glossiness of the fixed image can be reduced. If the glossiness detected by the glossiness detection means does not exceed 20%, the pressure release means is activated to separate the image surface roughening roller from the recording material surface.

The pressing roller for adjusting the image surface used in the third embodiment may be provided on the pressing roller for roughening the image surface. In this case, one roller for roughening the image is used. The range of possible gloss levels is widened, and an image with an appropriate gloss level can be formed corresponding to the gloss level immediately after the fixing step.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to FIG. In the present embodiment, instead of the glossiness detected by the glossiness detection means provided in the third or fourth embodiment, a developer adhesion amount detection means for detecting or estimating the toner adhesion amount on the recording material is provided. Changing the pressing force of the image surface roughening means according to the glossiness estimated from the amount of developer applied by the developer amount detecting means,
The pressure contact state of the image surface roughening means can be released. The members such as the image surface roughening member, the image surface roughening pressing member, and the fixing unit may have the same configuration as those of the third or fourth embodiment.

The image forming apparatus of the present embodiment uses a digital image forming apparatus that digitally processes data obtained by scanning an image and forms an electrostatic latent image on a photosensitive drum based on the digital data. Further, similarly to the third embodiment, an image surface roughening unit including an image surface roughening roller and an image surface roughening pressure roller is provided downstream of the fixing unit in the recording material conveyance direction. In the same manner as in the third embodiment, it is necessary for the image surface roughening means to change the pressing force of the image surface roughening means according to the glossiness, and to roughen the surface of the fixed image. When there is no image contacting means, there is provided a pressure contact releasing means for releasing the pressure contact state of the image surface roughening means.

FIG. 8 is a graph showing the relationship between the amount of applied toner on the recording material and the glossiness of the fixed image immediately after passing through the fixing unit. As can be seen from FIG. 8, in image formation, the glossiness of the fixed image increases if the amount of toner applied to the unfixed image is large. As shown in the graph of FIG. 8, in the image forming apparatus of the present embodiment, when the amount of toner applied per A4 size sheet is 0.32 g, the glossiness of the fixed image is 30%. When the glue amount is 0.90 g, the glossiness of the fixed image is 60%.

In the present embodiment, the glossiness is estimated by detecting or estimating the amount of toner application by using the fact that the above-described relationship is established between the amount of toner application and the glossiness. The pressing force of the image surface roughening means can be changed according to the glossiness, and the pressed state of the image surface roughening means can be released.

Here, in order to detect the amount of applied toner, when the exposure unit is driven by a control unit in the image forming apparatus after digitally processing a signal obtained by scanning a document such as a digital copying machine, the document is scanned. A digitally processed signal later or an image signal transmitted from the control unit to the exposure unit can be used.

The signal obtained by scanning and digitally processing can be used for estimating the amount of applied toner because the toner in the developing device adheres to the electrostatic latent image formed on the photosensitive drum to form an image. Therefore, by scanning a document serving as data for forming an electrostatic latent image on the photosensitive drum and monitoring a digitally processed signal or an image signal transmitted from the control unit to the exposure means, The amount of toner applied to the toner image formed on the drum can be estimated, whereby the amount of toner applied to the unfixed image transferred from the photosensitive drum to the recording material can be estimated.

In an analog image forming apparatus or the like, instead of using document data read by a scanner,
It is arranged downstream of the developing device in the rotation direction of the photoconductor drum so as to face the surface of the photoconductor drum, and detects the toner density of the toner image formed on the photoconductor drum 1 to determine the amount of toner deposition. The toner density detecting means that can be obtained may be used as a developer amount detecting means. The toner concentration detecting means is constituted by, for example, a light emitting member that irradiates light at a predetermined angle to the surface of the photoconductor drum, and a light receiving member that receives light emitted from the light emitting member and reflected from the surface of the photoconductor drum. In addition, the amount of reflected light received by the light receiving unit changes according to the amount of toner applied on the photosensitive drum. Further, the toner density detecting means may be arranged at a position facing the unfixed image surface on the recording material immediately after passing through the transfer step, so as to directly detect the amount of applied toner of the unfixed image.

In the present embodiment, the processing section that digitally processes the signal obtained by scanning the document functions as a developer amount detecting unit. The developer amount detecting unit can correct the digitally processed signal as needed to estimate the amount of toner applied, and can transmit a signal corresponding to the amount of toner applied to the control unit.

Further, the control unit is provided with a glossiness estimating means for estimating the glossiness from a signal from the developer gluing amount detecting means based on, for example, the relationship between the amount of applied toner and the glossiness as shown in FIG. . The glossiness estimating means is provided in the image surface roughening means, and a pressing force adjusting means for changing the pressing force of the image surface roughening means according to the glossiness, and when it is not necessary to roughen the surface of the fixed image. It is connected so as to be able to input a signal to the pressure contact releasing means for releasing the pressure contact state of the image surface roughening means,
The pressing force adjusting means which has received the signal corresponding to the glossiness estimated by the glossiness estimating means can adjust the pressing force of the image surface roughening means, and has received the signal corresponding to the glossiness estimated by the glossiness estimating means. The press-contact releasing means can release the press-contact state of the image surface roughening means.

According to the developer amount detecting means and the gloss estimating means having the above construction, a signal corresponding to the toner amount detected or estimated by the developer amount detecting means is transmitted to the gloss estimating means, and the gloss amount is determined. The gloss estimating means estimates the glossiness corresponding to the signal corresponding to the amount of applied toner, and transmits a signal corresponding to the estimated glossiness to the pressing force adjusting means or the pressure releasing means, and the pressing force adjusting means or the pressure releasing means. Operates so that the glossiness can be suppressed to 20% or less as described in the third embodiment.

According to the present embodiment, the glossiness is estimated using data obtained by reading an original with a scanner and digitally processing. Therefore, a separate device is not required for detecting the glossiness, and the glossiness can be estimated without increasing the cost. Image formation with low image quality.

The image surface roughening means has the same configuration as that of the third embodiment, and uses the image surface roughening means having a plurality of image surface roughening members of the fourth embodiment. Is also good.

(Sixth Embodiment) Next, a sixth embodiment of the present invention will be described. In the present embodiment, when a plurality of types of recording materials are used in the image forming apparatus,
A special recording material such as an OHP sheet is provided for the image surface roughening means so that the image surface roughening means is provided with a pressure releasing means capable of releasing the pressed state of the image surface roughening means according to the type of the recording material. When conveyed, the pressed state of the image surface roughening means is released so that the fixed image surface of the recording material is not roughened. Members such as an image carrier and a fixing unit are the same as those in the above-described embodiments, and thus detailed description is omitted.

In the present embodiment, for example, an image surface roughening roller having a predetermined surface roughness, an image surface roughening pressure roller pressed against the image surface roughening roller, and an image An image contact roughening means is provided by providing a pressure contact releasing means capable of releasing the pressed state of the surface roughening means. Note that the image surface roughening means is arranged downstream of the fixing unit in the recording material conveyance direction.

The pressure releasing means is provided, for example, between the flat plate contacting the rotating shaft of the image surface roughening roller described in the third embodiment and an arbitrary position of the image forming apparatus main body. A spring capable of applying a pressing force in a direction to separate the roughening roller from the surface of the recording material, a cam member abutting on an outer peripheral position of a rotating shaft of the image surface roughening roller facing the flat plate, and an image surface roughening And a stopper capable of restricting the movement of the pressure roller in the pressure direction.

The cam member of the pressure releasing means is rotatably connected to a predetermined driving means, and the driving means is connected to the control section of the image forming apparatus. The control unit detects when a special recording material such as a sheet is used, and transmits an operation signal in the pressure release direction from the control unit of the image forming apparatus to the driving unit that drives the cam of the pressure release unit, thereby performing pressure contact. The releasing means allows the image surface roughening roller to be separated from the fixed image surface side of the recording material.

The OHP sheet can be detected by providing a glossiness detecting means capable of inputting a signal to the control unit at an arbitrary position on the upstream side of the recording material conveying direction with respect to the image surface roughening means.
A white plate is arranged on the conveyance path opposite to the gloss detection unit to constitute a recording material determination unit, and it is detected that the amount of light reflected by the light receiving unit of the gloss detection unit is the amount of light reflected by the white plate. Sometimes it is determined that an OHP sheet is being used. In addition, O which stores OHP sheets
It is also possible to provide a recording material holder dedicated to the HP sheet and to operate the pressure release means when the operator selects the recording material holder for the OHP sheet.

Further, as a recording material discriminating means, a button for activating the pressure contact releasing means to release the pressure contact of the image surface roughening means is provided on an operation panel or the like of the image forming apparatus. The operator may arbitrarily select the operation of roughening the fixed image surface by the image surface roughening means.

According to the present embodiment, the pressure release means is operated in accordance with the recording material, for example, by detecting the OHP sheet whose surface is not to be roughened or the surface of the fixed image on the recording material. Thereby, it is possible to obtain a glossiness corresponding to the recording material.

The image surface roughening means of this embodiment includes:
A long plate-shaped image surface roughening member described in each of the above embodiments, a pressing force adjusting unit that changes the pressing force of the image surface roughening unit, and a plurality of image surface roughening members may be provided. In this case, each member or means can be operated according to the glossiness of the fixed image on the recording material.

[0100]

As described above, according to the second aspect of the present invention, the image surface roughening means provided on the downstream side of the fixing unit in the recording material conveyance direction is provided on the recording material after the fixing step. By being pressed against the surface of the fixed image, the surface of the fixed image can be roughened to reduce the glossiness of the fixed image, and the image forming apparatus can obtain a good image.

According to the second aspect of the present invention, a roller-shaped image surface roughening member having a surface roughness Ra of 0.2 μm or more is pressed against the image surface roughening member with an arbitrary pressing force. By conveying the recording material to a portion where the image surface is roughened and pressed against the pressing member, the glossiness of the fixed image can be reduced with a simple configuration even when the glossiness of the fixed image of the recording material is high.

Further, according to the third aspect of the present invention, a plate-shaped image roughening member having a surface roughness Ra of 0.2 μm or more is pressed against the image roughening member with an arbitrary pressing force. By conveying the recording material to a portion where the image surface is roughened and pressed against the pressing member, the glossiness of the fixed image can be reduced with a simple configuration even when the glossiness of the fixed image of the recording material is high.

Further, according to the fourth aspect of the present invention, the glossiness of the fixed image on the recording material by the glossiness detection means provided between the fixing unit and the image surface roughening means, Since the pressing force of the image surface roughening means is changed by the pressing force adjusting means, the glossiness can be appropriately reduced in accordance with the glossiness of the fixed image, so that good image formation can be performed.

Further, according to the fifth aspect of the present invention, a developer amount detecting means for detecting or estimating the amount of developer of an unfixed image transferred onto a recording material, and detecting the amount of developer amount The glossiness of the fixed image is estimated by the glossiness estimation means which can estimate the glossiness of the fixed image on the recording material after the fixing process based on the signal from the means, and the glossiness is estimated according to the glossiness estimated by the glossiness estimation means. Since the pressing force of the image surface roughening means is changed by the pressure adjusting means, the glossiness can be appropriately reduced according to the glossiness of the fixed image.

Further, according to the sixth aspect of the present invention, a plurality of fixed images are provided in accordance with the glossiness of the fixed image detected by the glossiness detection means provided between the fixing unit and the image surface roughening means. Select one of the image surface roughening members of
Since the fixed image surface on the recording material is roughened by the selected image surface roughening member, the glossiness can be appropriately reduced according to the glossiness of the fixed image.

Further, according to the seventh aspect of the present invention, a developer amount detecting means for detecting or estimating the amount of developer of an unfixed image transferred onto a recording material, and detecting the amount of developer amount The glossiness of the fixed image is estimated by the glossiness estimation means capable of estimating the glossiness of the fixed image on the recording material after the fixing process based on the signal from the means. One of the image surface roughening members is selected, and the surface of the fixed image on the recording material is roughened by the selected image surface roughening member, so that the glossiness is appropriately reduced according to the glossiness of the fixed image. Can be done.

Further, according to the eighth aspect of the present invention, a plurality of image surface roughening members are determined according to the glossiness detected by the glossiness detection means or the glossiness estimated by the glossiness estimation means. By selecting one of them or changing the pressing force of the image surface roughening means, the fixed image surface on the recording material is roughened by the selected image surface roughening member. Glossiness can be appropriately reduced.

Further, according to the ninth aspect of the present invention, the case where the glossiness does not need to be reduced is selected by activating the press-contact releasing means according to the glossiness of the fixed image on the recording material. An image having an appropriate gloss can be formed.

Further, according to the tenth aspect of the present invention, when a plurality of types of recording materials are used, the image contact surface roughening means is operated by operating the pressure contact canceling means according to the type of the recording material. By selecting a recording material on which is operated, an image with an appropriate gloss can be formed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram illustrating a fixing unit and an image surface roughening unit.

FIG. 3 is a graph showing the relationship between the magnitude of the surface roughness Ra of the image surface roughening member and the glossiness of a fixed image after passing through the image surface roughening means.

FIG. 4 is a schematic configuration diagram showing a case where a plate-shaped image surface roughening member is used.

FIG. 5 is a schematic configuration diagram illustrating a case where a glossiness detection unit is provided.

FIG. 6 is a graph showing a relationship between a pressing force of an image surface roughening unit and a glossiness of a fixed image after passing through the image surface roughening unit.

FIG. 7 is a schematic configuration diagram showing a case where a plurality of image surface roughening members are used.

FIG. 8 is a graph showing the relationship between the amount of applied toner and the glossiness of a fixed image after passing through a fixing unit.

FIG. 9 is a schematic configuration diagram illustrating a conventional image forming apparatus.

FIG. 10 is a schematic configuration diagram showing an oil application device using an oil application roller.

FIG. 11 is a schematic configuration diagram showing a case where a felt is used for an oil application device.

FIG. 12 is a graph showing a relationship between an oil application amount and a glossiness of a fixed image.

FIG. 13 is a schematic configuration diagram illustrating a gloss detection device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 photoconductor drum (image carrier) 2 developing device 3 transfer unit 6 fixing unit 9 image surface roughening means 10 image surface roughening roller (image surface roughening member) 11 image surface roughening pressure roller (image surface roughening) Pressing member)

Claims (10)

[Claims] An image carrier that forms an electrostatic latent image on a surface thereof;
A developing device for developing the electrostatic latent image formed on the image carrier with a developer, and a transfer unit for transferring the developer image on the image carrier developed by the developing device to a recording material; The recording material includes a plurality of rotatable fixing members to be pressed and a plurality of fixing members formed by the plurality of fixing members to press the recording material on which the unfixed image is transferred by the transfer unit. And a fixing unit for fixing the unfixed image on the recording material, having a predetermined surface roughness downstream of the fixing unit in the recording material conveyance direction and fixing the recording material after passing through the fixing unit. An image forming apparatus, comprising: an image surface roughening unit that is capable of roughening the surface of a fixed image by being pressed against an image with an arbitrary pressing force. 2. The image surface roughening means has a roller-shaped image surface roughening member and an image surface roughening pressure member pressed against the image surface roughening member with an arbitrary pressing force. The surface roughness Ra of the image surface roughening member in contact with the fixed image is 0.2
The image forming apparatus according to claim 1, wherein the thickness is not less than μm. 3. The image surface roughening means includes a plate-shaped image surface roughening member, and a roller-shaped image surface roughening pressing member pressed against the image surface roughening member with an arbitrary pressing force. Surface roughness Ra of an image surface roughening member that comes into contact with a fixed image of a recording material
The image forming apparatus according to claim 1, wherein the thickness is 0.2 μm or more. 4. A gloss detecting means for detecting the gloss of a fixed image on a recording material after passing through the fixing unit is provided between the fixing unit and the image surface roughening means. 4. A pressure adjusting means for changing a pressure applied to two steps of the image surface roughening device according to the glossiness detected by the glossiness detection means. The image forming apparatus according to one of the above. 5. An image forming apparatus, comprising: a developer amount detecting means for detecting or estimating an amount of developer of an unfixed image transferred onto a recording material; and a fixing step based on a signal from the developer amount detecting means. And a gloss estimating means for estimating the gloss of the fixed image on the recording material after the image is formed. The image surface roughening means is provided with a pressing force of the image surface roughening means according to the gloss estimated by the gloss estimating means. The image forming apparatus according to any one of claims 1 to 3, further comprising a pressurizing force adjusting means for changing the pressure. 6. A gloss detecting means for detecting the gloss of a fixed image on a recording material after passing through the fixing section is provided between the fixing section and the image surface roughening means. Selecting one of a plurality of image surface roughening members having different surface roughnesses according to the glossiness and a plurality of image surface roughening members according to the glossiness detected by the glossiness detection means; The image forming apparatus according to any one of claims 1 to 3, further comprising: an image surface roughening member selecting unit that presses against a fixed image on a recording material. 7. An image forming apparatus, comprising: a developer amount detecting means for detecting or estimating a developer amount of an unfixed image transferred onto a recording material; and a fixing step based on a signal from the developer amount detecting means. Glossiness estimation means capable of estimating the glossiness of the fixed image on the recording material afterward is provided, and the image surface roughening means includes a plurality of image surface roughening members having different surface roughnesses according to the glossiness, Image surface roughening member selecting means for selecting one of a plurality of image surface roughening members in accordance with the glossiness estimated by the glossiness estimating means and pressing the selected member against a fixed image on a recording material; The image forming apparatus according to any one of claims 1 to 3, wherein 8. The image surface roughening means includes a plurality of image surface roughening members having different surface roughness according to the glossiness, and the glossiness detected by the glossiness detection means or estimated by the glossiness estimation means. An image surface roughening member selecting means for selecting one of a plurality of image surface roughening members according to the glossiness and pressing the selected member against a fixed image on a recording material. The image forming apparatus according to claim 4. 9. The image surface roughening means according to claim 4, wherein said image surface roughening means is provided with a pressure releasing means capable of releasing a pressed state of said image surface roughening means in accordance with the glossiness. An image forming apparatus according to any one of the preceding claims. 10. When a plurality of types of recording materials are used, the image surface roughening means is provided with pressure contact release means capable of releasing the pressed state of the image surface roughening means according to the type of recording material. The image forming apparatus according to any one of claims 1 to 9, wherein