JPH01251071A - Image forming device - Google Patents

Abstract

PURPOSE:To achieve excellent image formation by intentionally separating the unfixed surface of a sheet from a line connecting an image transfer part with the contacting part of a pair of fixing rollers. CONSTITUTION:A sheet guide 48 is arranged near the upstream of the contacting part of a heat roller 41 and a pressurizing part 42 and surely leads the edge of the sheet P led to a fixing unit 33 to a place between the heat roller 41 and the pressurizing roller 42. An angle theta2 is set smaller than 90 deg., which is made by a line L2 connecting the center of the heat roller 41 with the center of the pressurizing roller 42 and the line L1. The sheet P is carried out downward and the unfixed part of the sheet P is floated by its stiffness so as not to bring an unfixed image on the down side of the sheet P into contact with a memory eliminating means 25 and a pre-exposure means 26. Thus, excellent image formation can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an image forming apparatus such as a laser printer, and particularly to an image forming apparatus that forms images using an electrophotographic process.

(Conventional technology) Typically, this type of image forming device uses charging and exposure.

The paper on which the image has been transferred by passing through an image transfer section of an electrophotographic process unit that performs development, transfer, peeling, cleaning, etc. is passed between a pair of fixing rollers to fix the image on the paper. .

Conventionally, in this type of image forming apparatus, the pair of fixing rollers of the fixing unit are tilted so that a line connecting their centers intersects at right angles to a line connecting the image transfer portion and the contact portion of the pair of fixing rollers. The structure is arranged in such a way that

(Problems to be Solved by the Invention) Conventionally, the fixing roller pair of the fixing unit is arranged such that the line connecting their centers is perpendicular to the line connecting the image transfer section and the contact section of the fixing roller pair. Since the sheets are arranged at an angle so that they intersect with each other, it is impossible to actively separate the unfixed side of the paper from the line connecting the image transfer section and the contact section of the fixing roller pair. If the paper is of a type that is transported in such a state that it is not stiff enough, there is a serious problem in that if the paper is even slightly stiff, the unfixed surface may come into contact with members placed near the paper transport path, damaging the image. was there.

The present invention has been made based on the above circumstances, and its purpose is to actively separate the unfixed surface of paper from the line connecting the image transfer section and the contact section of the pair of fixing rollers, while having a simple configuration. Even if the paper is of a type that is transported with the image forming side facing down, even if the paper is somewhat stiff or weak, the unfixed surface will come into contact with a member placed near the paper transport path. It is an object of the present invention to provide an image forming apparatus that can perform good image formation without causing problems.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides an image forming apparatus that forms images using an electrophotographic process, including an electrophotographic process unit and an electrophotographic process unit. a fixing unit that fixes the image to the paper by passing the image onto the paper by passing the image transfer unit between the pair of fixing rollers, and the pair of fixing rollers of the fixing unit are arranged so that their centers are mutually aligned. The unfixed surface of the paper is placed so that the line connecting the image transfer section and the contact area of the fixing roller pair intersects at a non-perpendicular state with respect to the line connecting the image transfer section and the contact area of the fixing roller pair. It is configured so that it is separated from the line connecting the two.

(Function) That is, by having the above-mentioned structure of the present invention, the unfixed surface of the paper can be actively separated from the line connecting the image transfer section and the contact section of the fixing roller pair, so that the image forming surface becomes the bottom surface. Even if the paper is of a type that is conveyed in a fixed state, even if the paper is somewhat stiff or weak, the unfixed surface will not come into contact with members placed near the paper conveyance path, and good image formation will be possible. Become.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 2 shows the external appearance of an electrophotographic image forming apparatus using a semiconductor laser, and FIG. 3 shows its internal configuration.

This image forming apparatus (laser printer) is connected to a host system (not shown), which is an external output device such as an electronic computer or a word processor, via a transmission controller such as an interface circuit. When a print start signal is received from the host system, the image recording operation is started, and the image is recorded on paper as a transfer material and output.

This image forming apparatus has the following configuration.

That is, numeral 1 in the figure is a main body of the apparatus, and a main control board 2 is disposed in the center of the main body 1, as shown in FIG. An electrophotographic process unit 3 for forming images is placed behind the main control board 2 (toward the right side in the state shown in Figure 3), and at the lower front there are multiple sheets for adding functions. A control board accommodating section 5 for accommodating a plurality of control boards 4 and a paper ejection section 6 are formed at the upper front part.

The function addition control board 4 is used to add functions (for example, typeface,
Up to three sheets can be installed depending on the degree of addition of types of kanji, etc. Further functions can be added by inserting an IC card 17 for adding functions into the Ic secretion connector 16. In addition, two interfaces (
(not shown) are arranged, and these interfaces face an opening 18 (see FIG. 2) formed on the left side of the main body 1 of the apparatus.

Further, a lower portion inside the apparatus main body 1 is a cassette accommodating section 8 that accommodates a paper feed cassette 7.

As shown in FIG. 2, the paper ejecting section 6 consists of a recess formed on the front upper surface of the main body 1 of the apparatus, and the front edge of the paper ejecting section 6 is folded over the paper ejecting section 6 or has a recess as shown in the figure. A rotatable paper discharge tray 9 that can be unfolded is provided. Further, a notch 9a is formed in the center of the front end of the paper ejection tray 9, and a rotatable U-shaped auxiliary member that can be accommodated in the notch 9a or unfolded as shown in FIG. A paper discharge tray 10 is provided. The size of the paper discharge section 6 can be adjusted according to the size of the paper P to be discharged.

Furthermore, on the upper surface of the left frame portion 1a of the main body of the apparatus located on the left side of the paper ejecting portion 6, there is a display LED 11.7 segments 12.2 for displaying the status in two digits. A control panel 14 on which switches 13 and switches 13 are arranged is disposed, and a manual feed tray 15 is attached to the rear side of the main body 1 of the apparatus.

Next, charging, exposure, development, transfer, peeling, and cleaning.

The electrophotographic process unit 3 that performs electrophotographic processes such as fixing and fixing will be described with reference to FIGS. 3 and 4.

A drum-shaped photoreceptor 20 serving as an image carrier is disposed approximately in the center of the unit accommodating portion, and this photoreceptor 2
Charging means 21.0 consisting of a scorotron is arranged around the rotating direction of the charging means. An exposure section 22a of a laser exposure unit 22 as an electrostatic latent image forming means, a magnetic brush type development unit 23 that performs a development process and a cleaning process at the same time, and a transfer unit 24 consisting of a scorotron. Memory removing means 25 consisting of a brush member. and pre-exposure means 26 are arranged in this order.

Also, inside the apparatus main body 1, paper P fed from the paper feed cassette 7 via the paper feed means 27 and the manual feed tray 15 are stored.
A paper conveyance path 29 is formed which guides the paper P manually fed from the photoreceptor 20 and the transfer means 24 to the paper discharge section 6 provided on the upper surface side of the apparatus main body 1 via the image transfer section 28. ing.

A pair of transport rollers 30. Aligning roller pair 31. A pair of transport rollers 32 are arranged, and a fixing unit 33 and a paper ejection roller unit 34 are arranged on the downstream side. Furthermore, above the location where the pair of conveyance rollers 32 are provided,
A cooling fan unit 35 is now installed.

Note that an aligning switch 36 is provided near the aligning roller pair 31, and an aligning switch 36 is provided near the aligning roller pair 31.
A conveyance guide 37 is provided near 8.

When a print start signal is received from the host system, the drum-shaped photoreceptor 20 rotates and the photoreceptor 20 rotates.
is charged by the charging means 21. Next, the laser beam a modulated in response to dot image data from the host system is scanned and exposed onto the photoreceptor 20 using the laser exposure unit 22, thereby forming an electrostatic latent image on the photoreceptor 20 corresponding to the image signal. form. This electrostatic latent image on the photoreceptor 20 is developed and visualized by the toner t in the developer magnetic brush D' of the developing unit 23.

Meanwhile, in synchronization with this toner image forming operation, paper P taken out from the paper feed cassette 7 or manually fed from the manual feed tray 15 is fed through a pair of aligning rollers 31, and is formed on the photoreceptor 20 in advance. The resulting toner image is transferred onto the paper P by the action of the transfer means 24. Then, the paper P passes through two paper conveyance paths and reaches the fixing unit 33.
The toner image is fused and fixed onto the paper P.

Thereafter, the paper is discharged to the paper discharge section 6 via the paper discharge roller unit 34.

Note that after the toner image is transferred onto the paper P, the residual toner remaining on the photoreceptor 20 is removed by a memory removing means 25 consisting of a conductive brush, thereby performing memory removal.

Further, as shown in FIG. 4, the fixing unit 33 includes a heat roller 41 having a built-in heater lamp 40, and a pressure roller 42 that is in pressure contact with the heat roller 41. The toner image is fused and fixed on the paper P as the paper P passes between them.

Further, the heat roller 41 and the pressure roller 42' are surrounded by a lower casing 43 and an upper casing 44, and are designed to prevent heat from escaping to the outside as much as possible to ensure a favorable temperature atmosphere necessary for fixing. It has become.

A cleaner 45 is in contact with the heat roller 41, and the temperature is controlled by a thermistor 46 to maintain the temperature necessary for fixing. The structure is such that

Further, a paper guide 48 is disposed within the upper casing 44 and near the upstream side of the contact portion 47 between the heat roller 41 and the pressure roller 42, and the paper guide 48 is arranged to ensure that the leading edge of the paper P guided to the fixing unit 33 is guided to the heat roller. 41 and the pressure roller 42. A paper guide 49 is provided on the paper exit side of the fixing unit 33 and is integrated with the lower casing 43 to guide the fixed paper P to the paper discharge roller unit 34.

Further, as shown in FIG. 1, the paper guide 48 is attached at an angle el with respect to a line L1 connecting the image transfer section 28 and the contact section 47 between the heat roller 41 and the pressure roller 42. 1#-, the generation of slug wrinkles on the paper P due to unnecessary rubbing is prevented.

Further, the intersection angle between the line L2 connecting the center of the heat roller 41 and the center of the pressure roller 42 and the above line is 02 and 90.
It is set to be smaller than the degree (e2; Δda ~ 0),
The paper P is conveyed downward so that the unfixed portion of the paper P is floated by its waist, and the unfixed image on the bottom side of the paper P is prevented from coming into contact with the memory removal means 25 and the pre-exposure means 26. ing.

At this time, the transport guide 37 is located on the transport direction side of the transfer means 24 and guides the non-image side of the paper P.
is in a grounded state and acts to electrostatically attract and float the paper P.

Further, the paper ejection roller unit 34 includes a lower roller 50
and an upper roller 51, and the paper P is
A static eliminating brush 52 is provided in contact with the non-image forming surface of the image forming apparatus.

The upper half including the upper roller 51 and the static elimination brush 52 is
The conveyance guide 37. The transfer means 24 and the like are attached to the lower surface side of the top cover 60 of the main body 1 of the apparatus.

The top cover 60 can be rotated up to a maximum of about 120'', as shown in FIG. This allows most of the paper transport path 29 to be exposed, and also allows the equipment facing the paper transport path 29 to be exposed.

This makes it easy to remove paper jams and perform maintenance, inspection, and replacement of equipment.

In addition, 62 shown in FIG. 5 is an ozone filter, and 63
is a toner cartridge.

Further, the rear cover 64 of the apparatus main body 1 shown in FIG. The curved conveying section can be opened, and the paper P stuck in this section can be easily removed.

Next, the main electrophotographic process components mentioned above will be explained in detail.

First, as shown in FIGS. 6 to 9, the charging means 21
consists of a scorotron. shield case 70
within 60. A corona wire 71 with a diameter of x is stretched, and the surface of the corona wire 71 is made of white tungsten to prevent negative corona from being generated unevenly.

One end of the corona wire 71 is fixed to a metal fitting 74 to which a power supply pin 73 serving as a charging means supply 76 is screwed. The power supply pin 73 and the metal fitting 74 are fixed within the power supply terminal 75. On the other hand, the other end of the corona wire 71 is secured to a terminal 77 by a plastic hook 76 via a tension spring 72. The terminals 75 and 77 are each covered with terminal covers 78 and 79 so that the parts to which high voltage is applied are not exposed.

The shield case 70 is made of stainless steel with a thickness of 0.3 mm, and has a mesh on the side facing the photoreceptor 20, as shown in FIG. 6, and serves as a grid 70a of the scorotron charger. Also, grid 7
0a can maintain sufficient accuracy such as flatness without using special parts for integration with the side cases 70b and 70c.

Furthermore, since the same bias voltage is applied to both side cases 70b and 70c when corona discharge is performed, the corona current flowing through both side cases 70b and 70c is reduced, resulting in a charger with good current efficiency.

Further, the shield case 70 is connected to the anode of a 560V Zener diode 82 (see FIG. 13), and is connected to a charger guide 83 (see FIG. 13) through the cathode of the Zener diode 82. On the other hand, the charger guide 83 is coupled to the ground terminal of the main body. Therefore, when a high voltage (-5 kV) is applied to the corona wire 71 via the power supply pin 73 by a high voltage transformer (not shown) in the main body of the device, corona discharge occurs in the shield case 70 and current flows in the shield case 70. However, due to the rectifying characteristics of the Zener diode 82, the potential of the shield case 70 rises to -560V and is kept constant.

Therefore, since the grid 70a naturally becomes -560V, the surface potential of the photoreceptor 20 located 2u away from the grid 70a is kept constant at -500V, which is slightly lower than the potential of the grid 70a. Note that 80° 81 in the figure indicates a process cartridge 85 (described later in FIGS. 12 and 13) that represents the charging means 21.
(see figure), the process cartridge 8
This is an engaging portion that engages with an engaging portion 84 (see FIGS. 14 and 15) formed in the portion 5.

As shown in FIGS. 4 and 10, the laser exposure unit 22 includes a semiconductor laser oscillator 90 (not shown in detail), a polygon scanner 93 consisting of a polygon mirror 91 and a mirror motor 92, and a second lens for FE. 95
, a second lens 95 for FE, reflective mirrors 96 and 97 for scanning the scanned laser beam a to a predetermined position, and the like. An opening 99 formed in the base 98 located below the installation position of the laser exposure unit 22, that is, on the upper surface side of the cassette accommodating section 8, and an opening 100 formed on the lower surface side of the apparatus main body 1,
By pulling out the paper feed cassette 7 forward (in the direction of the arrow in FIG. 3), it can be attached or removed from below (see FIG. 10).

Moreover, the control board 101 of this laser exposure unit 22
is connected to the main control board 2 via a connector 102.

Furthermore, the laser exposure unit 22 is housed in a synthetic resin casing 103 whose bottom side is open, and the bottom opening of this casing 103 is connected to a metal shield plate 10.
4, and a metal shield cover 105 which also serves as a reinforcing plate is superimposed on the upper surface side of the casing 103. A conductive contact piece 106 is connected to the shield cover 105, and this contact piece 106 slidably guides the developing unit 23 when the laser exposure unit 22 is attached to a predetermined position via an attachment means (not shown). This is in contact with a metal guide rail 107, which prevents malfunctions due to electrostatic adverse effects from the charging means 21 and the like reaching the inside.

Note that the photoreceptor 20 uses an organic photoconductor,
It has a structure in which a charge generation layer and a charge transport layer covering this charge generation layer are formed on the surface of an aluminum tube.

Further, in order to simplify the electrophotographic process, the developing unit 23 employs a reversal developing method, and also employs a method in which the residual toner t after transfer is removed at the same time as the developing. This developing unit 23 is shown in FIG.
As shown in FIG. 1, a photoreceptor 20 and a developing roller 122 are provided in a casing 121 having a developer storage section 120.
20, toner (colored powder) t and carrier (magnetic powder) C
A two-component developer consisting of the following is housed. Further, the sliding contact portion of the developer magnetic brush D' formed on the surface of the developing roller 122 with the photoreceptor 20, that is, the developing position 12
A doctor 124 for regulating the thickness of the developer magnetic brush D' is provided upstream of the photoreceptor 3 in the rotational direction of the photoreceptor 2 degrees. Furthermore, in the developer storage section 120,
1st. Second developer stirring bodies 125 and 126 are housed.

A toner cartridge 63 (see FIG. 5) serving as a toner replenishing device is attached to the developing unit 23, and the toner t is appropriately replenished into the developer storage portion 120.

Further, the developing roller 122 has three magnetic pole parts 127.12.
8.129, and a non-magnetic sleeve 131 that is fitted around the magnetic roll 130 and rotates clockwise in the figure. magnetic roll 130
Of the three magnetic pole parts 127, 128, 129, the magnetic pole part 128 facing the development position 123 is the north pole, and the other magnetic pole parts 127, 128 are the south pole. Also, the angle e+ (see Figure 4) between the magnetic pole part 127 and the magnetic pole part 128, t150@, and the angle ez (see Figure 4) between the magnetic pole part 128 and the magnetic pole part 129 are set to 120°. has been done.

The electrostatic charge on the photoreceptor 20 is caused by the potential difference between the mechanical scraping force caused by the magnetic brush development using the two-component developer, the charging potential caused by the reversal development, and the development bias applied to the magnetic brush D'. At the same time as the latent image is developed, residual toner t is collected mechanically and electrically.

Further, as shown in FIGS. 11 to 14, this developing means 23 includes a photoreceptor 20. The charging means 21, the memory removing means 25, etc. are integrated into a process cartridge 85.
The cartridge can be inserted into and taken out of the main body 1 via a handle 132 (see FIGS. 13 and 14) at one end of the cartridge. Further, at the other end side, a developing bias power supply section 140. Memory removing means power supply section 141. A charging means power supply part 142 consisting of a power supply bottle 73 is provided protrudingly, and when this process cartridge 85 is pushed into a predetermined position in the apparatus main body 1, these power supply parts 140, 141.1
42 is inserted into a power supply connector provided inside the main body 1 of the apparatus.

Further, a foldable handle 143 for carrying is provided on the top side of the process cartridge 85, and a cleaning brush 144 for cleaning the lower roller 31a of the aligning roller pair 31 is attached.

Furthermore, as shown in FIGS. 12 and 15, on the other end side of the developing means 23, the developing sleeve 131, the first. A gear group 147 that is connected to the second developer stirring bodies 125, 126, a winding shaft 146 (see FIG. 11) for winding up the photoreceptor protection sheet 145, etc., and that interlocks with each other is provided. It becomes.

The gear 147a meshes with a drive gear (not shown) provided on the device main body 1 side, and by driving the gear 147a, each of the rotating members described above is rotated in a predetermined direction at a predetermined speed. It has become. Note that the photoreceptor protection sheet 145 wound around the winding shaft 146 is housed in a guide tube 148 surrounding the winding shaft 146, so that the end portion does not protrude to the outside.

Note that 150 shown in FIG. 13 is the process cartridge 8.
5 is a rod for pressing a presence detection switch (not shown), 151 is a shutter for a toner replenishing port that opens when the toner cartridge 63 is attached, and 152 is a spring for the shutter. Further, 153 is a pin for fixing the photoreceptor.

Further, as shown in FIG. 13, an auto toner sensor ring 160 is provided on one end side of the photoreceptor 2o.
The configuration is such that the developer concentration can be detected at this portion.

As shown in FIG. 17, this auto toner sensor ring 160 is connected to the doctor 124 via a conductive plate spring 161 made of phosphor bronze or the like, and further to the developing sleeve 131 via a conductive plate spring 162. Auto toner sensor ring 60. Doctor 124. and developing sleeve 13
1 have the same potential. In other words, power can be supplied to the auto toner sensor ring 160 without using a dedicated power supply means.

Further, as shown in FIG. 16, at one end of the photoreceptor 20,
A plated metal cap 170, a portion of which becomes the auto toner sensor ring 160;
Bearing member 171 fitted into the bearing member 171. A flange 174 equipped with an engaging member 173 made of a leaf spring member attached to the end face of this bearing member 171 via a fixing member 172...
is attached to the shaft insertion hole 1 of the flange 174 when the process cartridge 85 is assembled into the apparatus main body 1.
A photoreceptor drive shaft 175 provided on the apparatus main body 1 side is inserted into 74a. At this time, the locking tongue portions 173a, which are cut and formed on the engagement member 173 and supported by support protrusions (not shown) whose back side protrudes from the bearing member 171, are attached to the photoreceptor drive shaft. Engaged groove 176 made of knurling formed along the axial direction of 175
. . , so that the driving force of the photoreceptor drive shaft 175 is transmitted to the photoreceptor 20.

A flange (not shown) consisting of a cap and a bearing member is attached to the other end of the photoreceptor 20, and is pivotally supported by the photoreceptor drum fixing pin 153.

Further, as shown in FIGS. 18 to 21, the transfer means 24 is composed of a scorotron.

A corona wire 191 is stretched inside a shield case 190, and one end of this corona wire 191 is connected to a power supply terminal 19 as shown in FIGS. 18 and 19.
The other end is connected to a metal fitting 193 screwed to the second
As shown in FIG. 0, it is connected to a shaft 195 of a power supply terminal 194 via a tension spring 196. Further, a portion of the shield case 190 facing the photoreceptor 20 is a first
As shown in Figure 8, it is a mesh, and grid 19
It constitutes 0a.

18 and 2 on the power supply terminal 192 side.
As shown in FIG. 1, a grid voltage power supply section 197 and a wire high voltage power supply section 198 are provided.

Further, as shown in FIGS. 22 to 25, the memory removing means 25 includes a conductive brush 200. Backing member 201
．． and a holding fitting 202 that holds them. There are mounting holes 203 on both ends of the holding fitting 202.
, 203 are provided, and are fixed to the process cartridge 85 via set screws 204, 204 (see FIG. 13).

The brush 200 is, for example, made of rayon impregnated with carbon to have a specific resistance of 106Ω, and has a thickness of 6D (denier).
The fibers were made into bundles of 100 fibers, 82 bundles/1
It is constructed by making a satin weave with a density of nch, stacking two layers and removing the weft threads.

Further, the brush 200 has one side, as shown in FIG.
A backing member 201 made of a polyester film with a thickness of 1n (about 0.1B) is inserted from the tip of the brush 200
j! (approximately 0.1 m) Holding metal fitting 202 in a protruding state
It is designed to be attached to

The brush 200 is mounted upstream of the charging means 21 so that the brush surface is in contact with the photoconductor 20 at a corner three degrees from the tip thereof.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made without changing the gist.

[Effects of the Invention] As described above, according to the present invention, in an image forming apparatus that forms an image using an electrophotographic process, an image that passes through an electrophotographic process unit and an image transfer section of this electrophotographic process unit. and a fixing unit that fixes the image onto the paper by passing the paper onto which the image has been transferred between a pair of fixing rollers, and a line connecting the centers of the pair of fixing rollers of the fixing unit is the image transfer line. The paper is arranged so as to be inclined so as to intersect at a non-perpendicular state with respect to the line connecting the contact portion of the image transfer portion and the fixing roller pair, and the unfixed surface of the paper is separated from the line connecting the contact portion of the image transfer portion and the fixing roller pair. Because of this configuration, the unfixed surface of the paper can be actively separated from the line connecting the image transfer section and the contact section of the fixing roller pair, and the paper is of a type that is transported with the image forming surface facing downward. Moreover, it is possible to provide an image forming apparatus that can form good images without causing the unfixed surface to come into contact with members disposed near the paper conveyance path, even if the stiffness of the paper is slightly or weak. .

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an explanatory diagram of the main parts, FIG. 2 is an external perspective view of the entire image forming apparatus, and FIG.
The figures also show the internal configuration, Figure 4 is a configuration diagram of the main parts, Figure 5 is an external perspective view of the image forming apparatus with the top cover open, and Figure 6 is a view from the grid side of the charging means. 7 is a front view, FIG. 8 is a sectional view taken along line A-A in FIG. 6, FIG. 9 is a side view in the direction of arrow B in FIG. 7, and FIG. 10 is a laser exposure unit. 11 is a schematic sectional view of the process cartridge, FIG. 12 is a schematic perspective view, FIG. 13 is a schematic plan view, and FIG. 14 is a side view of one end. Figure, No. 15
16 is a cross-sectional view of the vicinity of the driving force transmission side of the photoconductor, FIG. 17 is a diagram schematically showing the power supply state to the auto toner ring, and FIG. The figure is a partially cutaway view of the transfer means as viewed from the grid side, FIG. 19 is a partially cutaway view of arrow A in FIG. 18, and FIG. 21 is a sectional view taken along line C-c in FIG. 18, FIG. 22 is a plan view of the memory removal means, FIG. 23 is a front view, and FIG. 24 is a bottom view. 25 is a sectional view taken along the line A--A in FIG. 22. 3... Electrophotographic process unit, 28... Image transfer section, 33... Fixing unit, 41... Fixing roller (heat roller), 42... Fixing roller (pressure roller), 47...・Contact area, P...Paper, Ll...Line connecting the image transfer area and the contact area between the fixing rollers, Ll...
A line connecting the centers of the fixing rollers. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 11 Figure 15

Claims (1)

[Claims] In an image forming apparatus that forms an image using an electrophotographic process, the paper on which the image has been transferred by passing through the electrophotographic process unit and the image transfer section of the electrophotographic process unit is passed between a pair of fixing rollers. a fixing unit that fixes the image on a sheet of paper; the pair of fixing rollers of the fixing unit are arranged such that a line connecting their centers is not perpendicular to a line connecting the image transfer section and the contact portion of the pair of fixing rollers; 1. An image forming apparatus characterized in that the image forming apparatus is arranged such that the unfixed surface of the paper is separated from a line connecting the image transfer section and the contact section of the pair of fixing rollers.