JPS62262066A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To suppress the jamming of recording paper by forming linearly carrying passages for communicating with a paper feeding part and a paper discharging part, respectively, so as to extend and exist in the tangential direction of a photosensitive body. CONSTITUTION:Recording paper in paper feeding cassettes 14, 14A is carried between a photosensitive drum 2 and a transfer device 8 through transfer passages 17C, 17D and a carrying passage 17, and a corona discharge is executed from the back part of the recording paper by the transfer device 8, by which a visible image on the photosensitive drum 2 is transferred to the recording paper. The recording paper to which the visible image is transferred is carried to the diagonal lower part with its image forming surface down along the carrying passage 17, and subsequently, the transferred visible image is fixed by a fixing device 18 and the last image is obtained. Thereafter, the recording paper passing through the fixing device 18 is discharged onto a discharge paper tray 28. In such way, the frequency of jamming of recording paper P can be decreased.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to printers such as laser printers, LED printers, and liquid crystal printers used as terminal equipment such as computers and facsimile machines, and copying machines using an electrophotographic method. The present invention relates to an electrophotographic apparatus for forming and covering images, and particularly to improvements in its conveying means and its +i+ series arrangement.

[Conventional technology]

The above-mentioned electrophotographic method was originally used in copying machines, but in recent years, it has come to be widely used as an image output device, that is, a printer, due to its high print quality, high speed printing performance, and low noise.

First, such a conventional electrophotographic apparatus will be explained with reference to FIGS. 3 and 4.

FIG. 3 shows an example of a conventional electrophotographic device.
Inside the housing 1 of the electrophotographic apparatus, a photosensitive drum 2 as an example of a photosensitive member is arranged so as to rotate in the direction of the arrow. Charge 2 that gives an electrostatic charge to 2! S3
is installed.

Further, in the housing 1 on the side of the charger 3, an optical writing member 4 is disposed for forming an electrostatic latent image on the photosensitive drum 2 charged by the charger 3. Further, a developing device 5 is disposed in the housing 1 on the side of the photosensitive drum 2, and the developing device 5 causes the toner T filled in the casing 6 to be attracted to the photosensitive drum 2 by a developing sleeve 7. 5, the toner T is attracted onto the photosensitive drum 2 in correspondence with the electrostatic latent image to form a visible image. Furthermore, a transfer device 8 for transferring a visible image formed on the photosensitive drum 2 to recording paper is disposed in the housing 1 below the photosensitive drum 2. Disposed on the side are a static eliminator 9 that removes the residual charge on the photosensitive drum 2 after the visible image has been transferred, and a cleaner 10 that removes the toner remaining on the photosensitive drum 2. This cleaner 10 includes a sponge roll 12 and a magnet roll 13 which are disposed within a casing 11 and are connected to each other.

This back sponge roll 12 is connected to the photosensitive drum 2 to remove the residual toner T on the photosensitive drum 2, and the magnet roll 13 is used to adsorb the toner T that the sponge roll 12 is adsorbing. The liquid is stored in the casing 11.

A large capacity paper feed cassette 14 is provided at the bottom of the housing 1.
is installed, and this paper feed cassette 14
The bottom wall 15 of is located below the bottom wall 16 of the housing 1. Further, a conveyance path 17 is formed in the housing 1 for conveying the recording paper supplied from the paper feed cassette 14 so as to pass between the photosensitive drum 2 and the transfer device 8 . The conveyance path 17A on the downstream side between the photosensitive drum 2 and the transfer device 8 passes through a fixing roller 318, which is disposed at the lower part of the housing 1 and includes a pair of fixing rollers 19.19 and a delivery roller 20.20. The fixing device 18 fixes the visible image attached to the recording paper onto the recording paper using heat, pressure, or the like. Furthermore, the conveyance path 17B on the downstream side of the fixing device 18 is formed to convey the recording paper almost directly above it in the housing 1, and a pair of conveyance rollers 521° 21 are provided in this portion of the conveyance path 17B.
is provided.

A protrusion 22 is integrally provided on the housing 1 at a position directly above the conveyance passage 17B, and a pair of ejection rollers 23 are arranged at the ends of the conveyance passage 17B within this protrusion 22.
．． 23, the recording paper is discharged onto the upper wall 24 of the housing 1 in a face-down state with the printed side, that is, the image forming side facing downward.

According to the above-described configuration, the photosensitive drum 2 is charged to a constant potential by corona discharge by the charger 3, and an electrostatic latent image is formed by exposure on the surface of the photosensitive drum 2 by the optical writing section 444 according to image information. Thereafter, the toner T uniformly charged by charge injection by friction or an electric field is conveyed by the developing sleeve 7 to a position facing the photosensitive drum 2, and the toner T is selectively transferred onto the photosensitive drum 2 in accordance with the electrostatic latent image. Apply suction to form a visible image. Next, the recording paper in the paper feed cassette 14 is conveyed between the photosensitive drum 2 and the transfer device 8 via the conveyance path 17, and the transfer device 8 discharges corona from the spine of the recording paper, thereby transferring the recording paper onto the photosensitive drum 2. The visible image is transferred to a recording paper, and the transferred visible image is fixed on the recording paper by a ruler 18 to obtain a final image. Then, the recording paper that has passed through the fixing 2S18 is conveyed upward through the conveyance path 17B.
The discharge rollers 23, 23 discharge the paper onto the upper wall 24 of the housing 1 face down.

On the other hand, the residual surface potential of the unexposed area of the photosensitive drum 2 is optically reduced to zero potential by the static eliminator 9, and on the other hand, the toner T remaining on the photosensitive drum 2 without being transferred is removed by the cleaner 10. is removed from the printer, completing one printing process.

Further, FIG. 4 shows the other side of a conventional electrophotographic apparatus, and particularly shows an electrophotographic apparatus in which toner can be reused. A photosensitive drum 2 is arranged in a housing 1 of this electrophotographic apparatus so as to be rotatable in the direction of the arrow.
A charger 3 that also serves as a transfer device is disposed in the housing 1 on the side of the photosensitive drum 2. Further, a laser head 2 is provided in the housing 1 above the photosensitive drum 2.
In the housing 1 on the side of the photosensitive drum 2, a developing device 5 which also serves as a cleaner is provided. A blade 26 that is connected to the photosensitive drum 2 and functions as a cleaner is disposed in the upper part of the casing 6 of the developing device 5, and a blade 26 that is connected to the photosensitive drum 2 and functions as a cleaner is disposed in the lower part of the casing 6. A developing sleeve 7 for adhering the image to the photosensitive drum 2 is provided. Furthermore, a static eliminator 9 is provided in the housing 1 below the photosensitive drum 2.

A hopping roller 27 is disposed at the bottom of the housing 1 for feeding recording sheets one by one from the JA semi-type paper feed cassette 14A. Further, within the housing 1, conveyance rollers 21, 21, .
A conveyance path 17 is formed. Furthermore, each pair of fixing rollers 19 is provided at a downstream position of this conveyance path 17.
19 and a fuser 18 with output rollers 20, 20
is arranged so that a visible image formed by the toner adhering to the recording paper is fixed on the recording paper by heat and pressure. Furthermore, the recording paper that has passed through the fixing device 18 is transferred to a paper output tray 2 which is protruded from the housing 1.
The paper is discharged with the image formed on the surface of the paper 8 facing upward.

According to the above-described configuration, the photosensitive drum 2 is charged to a constant potential by corona discharge by the charger 3, and the photosensitive drum 2 is charged by the radar head 25 of the optical writing member 4 according to image information.
An electrostatic latent image is formed on the surface by exposure. Thereafter, the toner T is conveyed in the casing 6 by the developing sleeve 7 to a position facing the photosensitive drum 2, and the toner particles are selectively attracted and adhered to the photosensitive drum 2 in correspondence with the electrostatic latent image, thereby forming a visible image. form. Next, the recording paper in the paper feed cassette 14A is transported between the photosensitive drum 2 and the converter 5, which also serves as a transfer device, by the hopping roller 27 and the transport roller 21. The visible image formed by the toner T on the photosensitive drum 2 is transferred to the recording paper by corona discharge from the back of the recording paper by the developing device 5, and whether the visible image has been transferred or not is transferred to the recording paper. ! The image is fixed on the recording paper by a fixing device 18 to obtain a final image.

On the other hand, the residual surface potential of the last exposed portion of the photosensitive drum 2 is optically reduced to zero potential by the static eliminator 9, and on the other hand, the toner T remaining on the photosensitive drum 2 without being transferred is removed onto the photosensitive drum 2 by the blade 26. It is removed from the casing 6, falls into the casing 6, and is provided for reuse, completing about 1.

[Problem that the invention seeks to solve]

In the prior art shown in FIGS. 3 and 4 described above, paper is fed from the paper feed set 14.14A provided at the bottom of the housing 1 from the top of the paper feed cassette 14.14△. Therefore, as shown in Figure 3, a large capacity paper feed cassette 1 is required.
4, the bottom of the paper feed cassette 14 protrudes downward from the housing 1, which increases the overall height of the printer and increases its size. In particular, the one shown in Fig. 4 uses a large one that uses a laser head 25 as the optical writing member 4, so if the paper feed cassette 14 shown in Fig. 3 is used in the one shown in Fig. 4, The size of the electrophotographic device becomes even larger.

In addition, in the conveyance path 17 of FIGS. 3 and 4,
There is a portion in which the recording paper is conveyed from the bottom to the top against gravity, and the overall length of the conveyance path 17 is long, so there is a problem that the recording paper tends to jam in the conveyance path 17.

The present invention overcomes the problems of the conventional ones described above, and does not increase in height even when using a large-capacity paper feed cassette.
Moreover, it is an object of the present invention to provide an electrophotographic apparatus that does not cause jamming of recording paper.

[Means for solving problems]

A first aspect of the present invention provides an image forming means for forming an image using a developer on a photoreceptor, a transfer means for transferring the image formed on the photoreceptor by the image forming means onto a recording paper, and this transfer means. In an electrophotographic apparatus, the electrophotographic apparatus includes a conveying means for supplying recording paper from a paper feeding section and for discharging the recording paper onto which an image has been transferred by the transfer means to a paper discharge section. In addition to arranging the paper feed section,
The paper discharge section is disposed obliquely below the photoconductor, and the conveyance path of the conveyance means that communicates with the paper feed section and the paper discharge section, respectively, is arranged in a substantially straight line so as to extend in the tangential direction of the photoconductor. It is characterized by being formed in

A second aspect of the present invention provides an image forming means for forming an image using a developer on a photoreceptor, a transfer means for transferring the image formed on the photoreceptor by the image forming means onto a recording paper, and the transfer means. In an electrophotographic apparatus, the electrophotographic apparatus includes a conveying means for supplying recording paper from a paper feeding section and discharging the recording paper onto which an image has been transferred by the transfer means to a paper discharging section. Along with setting up a paper distribution department,
The paper discharge section is disposed obliquely below the photoconductor, and the conveyance path of the conveyance means that communicates with the paper feed section and the paper discharge section, respectively, is arranged so as to extend in a direction tangential to the photoconductor. A first sheet discharge section is formed in a ridge line shape and is placed below the end of the conveyance path, and the recording paper is placed thereon so that the image forming surface faces upward; A second paper discharge section is formed on which the recording paper is placed, and a guide member is movably disposed to introduce the recording paper discharged from the conveyance path into either one of the paper discharge sections.

[For production]

According to the first feature of the present invention, since the paper feed section is disposed diagonally above the photoreceptor, even if a large paper feed cassette is installed, this paper feed cassette will not fit inside the housing. The paper can be easily accommodated, avoiding an increase in size, and since the conveyance path conveys the recording medium diagonally downward in a nearly straight line, gravity can be used to convey it.Furthermore, the conveyance path can be shortened, making it possible to reduce the size of the recording medium. The frequency of jamming can be reduced.

Further, according to the second aspect of the present invention, in addition to the effects of the first aspect described above, it is possible to perform the blowing in either the face-up or face-down state simply by moving the guide member.

〔Example〕

The present invention will be explained below with reference to embodiments shown in the drawings. Note that functions that are the same as or correspond to those of the conventional device described above will be described with the same reference numerals in the drawings.

FIG. 1 shows an embodiment of the first invention of the present invention,
A photosensitive drum 2, which is an example of a photosensitive member, is arranged at a position slightly lower than the center in the vertical direction inside the housing 1 so as to be able to rotate in the direction of the arrow. includes a charger 3 that applies an electrostatic charge to the photosensitive drum 2, an optical writing member 4 that forms an electrostatic latent image on the photosensitive drum 2 charged by the charger, and a casing 6 filled with the charger 3. A developing device 5 is provided for applying the toner under the developed toner onto the photosensitive drum 2 by means of a developing sleeve 7. Among these, a light-weight and compact solid-state light emitting element array, optical shutter array, etc. are suitable as the light J: concave portion t144. Further, in the housing 1 on the right side of the photosensitive drum 2, a transfer device 8 for transferring the toner T on the photosensitive drum 2 onto the recording paper is disposed in an inclined manner above the center of the photosensitive drum 2. On the other hand, at a position below the center of the photosensitive drum 2, a static eliminator 9 for removing electric charge remaining on the photosensitive drum 2 is arranged in an inclined manner.

On the left side of the housing 1, there is a paper feed cassette 1 for the human capacity port.
4 and a standard type paper feed cassette 14A are installed so that the paper feed cassette 14A is located above. It is mounted so as not to protrude from the lower end of the housing 1. Inside this paper feed cassette 14, a placement plate 29 on which recording paper P is placed is arranged so as to be movable up and down, and this VCD plate 29 is kept in a horizontal state by a plurality of springs 30, 30... maintained and biased upward. A hopping roller 27.27 for feeding the recording paper P in the paper feed cassette 1/1.14A one sheet at a time is disposed on the upper part of the housing 1. It will be placed at the top.

Near the hopping roller 27 of the paper feed cassette 14, one end of a transport path 17C extending in the horizontal direction faces, and near the hopping roller 27 of the paper feed cassette 14A, a transport path ff117D extending in an inclined direction faces. One end is facing, and both conveyance passages 17C and 17D are connected to the housing 1.
They merge at a junction point 31 within the area. A substantially straight conveyance path 17 for conveying the recording paper P diagonally downward is provided at the confluence point 31 of the conveyance paths 17C and 17D, and this conveyance path 17 is provided with the photosensitive drum 2 and the photosensitive drum 2 at an intermediate position. It passes between the transfer devices 8. This conveyance path 17 includes conveyance rollers 21, 21 and 21.
... and a conveyor belt 33 wound around a pair of pulleys 32, 32 are disposed, and the recording paper P is conveyed obliquely downward by these conveyor rollers 21 and conveyor belt 33.

A fixing device 18 equipped with a pair of fixing rollers 19 and 19 is disposed at the downstream end of the conveyance path 17, and fixes the visible image formed by the toner T on the recording paper P by heat and pressure on the recording paper. It has become established in P. Further, a paper discharge tray 28 is provided at the lower end of the housing 1 and faces diagonally below the stone setter 18, and the recording wiP that has passed through the stone setter 18 is placed on the paper discharge tray 28 by a discharge roller 2.
3, the paper is ejected.

Next, the operation of the embodiment described above will be explained. The photosensitive drum 2 is charged to a constant potential by a charger 3 by corrope discharge, and an electrostatic latent image is formed on the surface of the photosensitive drum 2 by exposure using an optical writing member 4 according to image information. Thereafter, the toner T in the casing 6 is conveyed by the developing sleeve 7 to a position facing the photosensitive drum 2, and toner 1 to toner T are selectively attached to the photosensitive drum 2 by suction corresponding to the electrostatic latent image. Form a visual image. Next, the recording paper P in the paper feed cassette 14 or 14Δ is conveyed between the photosensitive drum 2 and the transfer device 8 via the conveyance path 17C or 17D and the conveyance path 17, and the back of the recording paper P is conveyed by the transfer device 8. [1] The visible image on the photosensitive drum 2 is transferred to the recording paper P by discharging. The recording paper P on which the visible image has been transferred is conveyed diagonally downward along the conveyance path 17 with the image forming surface facing downward, and then the transferred visible image is fixed by a fixing device 18 to obtain a final image. Then, the recording paper P that has passed through the fixing device 18 is discharged onto a replacement paper tray 28.

On the other hand, the residual surface potential of the unexposed area of the photosensitive drum 2 is optically reduced to zero potential by the static eliminator 9, and on the other hand, the i~lunar remaining on the photosensitive drum 2 without being transferred is removed by the sponge roll of the cleaner 10. 12, it is removed from the photosensitive drum 2, completing one printing step.

According to the embodiment described above, the paper feed cassettes 14 and 14
Since A is installed in the housing 1 so that the paper feed section is located at the upper part of the housing 1, the paper feed cassette 14A fits within the housing 1 in the height direction, and therefore the printer can be configured compactly. Can be done.

Further, since the conveyance path 17 is designed to convey the recording paper P diagonally downward in a substantially straight line, the conveyance distance of the recording paper P is short, and the recording paper P can be conveyed without going against the force of gravity. This makes it possible to reduce the frequency of jamming of the recording paper P.

FIG. 2 shows an embodiment of the second invention of the present invention,
The second invention will be explained below using this example. In addition, the second
Components in the drawing that are the same as those in FIG. 1 are designated by the same reference numerals in the drawing, and their explanation will be omitted.

In this embodiment, two standard type paper feed cassettes 14A, 14A are attached to the upper right side of the housing 1, and both paper feed cassettes 148.

Hopping roller 27.2 that feeds recording paper P from 14Δ
One end of the conveyance passage 17C117D faces each of the passageways 17C and 117D. Junction point 31 of both conveyance passages 17C217D
A substantially linear conveyance path 17 for conveying the recording paper P obliquely downward is provided, and this conveyance path 17 is arranged at an intermediate position so as to pass between the photosensitive drum 2 and the transfer device 8. It has become. In this example,
In particular, the image forming surface of the recording paper P is conveyed through the conveyance path 17 upward.

Below the opening 34 at the lower end of the conveyance path 17 is a first paper tray 28A for discharging the recording paper P in a seven-eighth up state.
and paper ejection 1 that ejects the recording paper P face down.
- Rays 28B are connected to both sides below the opening 34. Directly below the opening 34, there is a guide member 36 protruding from a post 35 that is movable in the left-right direction. It is formed in the shape of a triangular prism, including an inclined guide surface 37A that guides the recording paper P to the paper discharge tray 28B, and an inclined guide surface 37B that guides the recording paper P to the paper discharge tray 28B. Further, a drive source (not shown) is provided for moving the guide member 36 along with the branch 35 in a substantially horizontal direction so as to move toward and away from both the paper discharge trays 28Δ, 28B.

The operation of the above-mentioned configuration is basically the same as that of the first embodiment described above, so only the operation peculiar to this embodiment will be explained. Since printing is carried out by conveying the recording paper P in a substantially straight line through the conveyance path 17 and obliquely downward without going against gravity, the conveyance distance of the recording paper P is short and the frequency of jamming of the recording paper P can be reduced. Furthermore, since the recording paper P is conveyed in the conveyance path 17 with the image forming surface facing toward the side and diagonally downward, all that is required is to contact the temporary guide for conveying the recording paper P with the '7S side of the image forming surface. The recording paper P can be conveyed at , and the composition is in the middle of a song. Furthermore, by simply moving the guide member 36 to the left and right, the recording paper P can be discharged face-up into the paper output tray 28A along the guide surface 37A of the guide member 36, and the recording paper P can also be discharged face down into the paper discharge tray 28B along the guide surface 37B of the guide member 36. Furthermore, since a large space is formed in the housing 1 below the lower paper feed cassette 14A, a large capacity paper feed cassette 14 can be installed in this space, thereby avoiding an increase in the size of the entire device. can do.

Note that the present invention is not limited to the two embodiments described above, and various modifications are possible.

〔Effect of the invention〕

As explained above, according to the first aspect of the present invention, the structure can be made compact even when using a large-capacity paper feed cassette, and jamming of recording paper is less likely to occur. According to the second invention of the present invention, in addition to the effects of the first invention described above, there is an effect that face-up and face-down paper discharge can be freely selected.

[Brief explanation of drawings]

FIGS. 1 and 2 are longitudinal sectional front views showing an embodiment of an electrophotographic apparatus according to the present invention, and FIGS. 3 and 4 are schematic vertical sectional front views showing a conventional electrophotographic apparatus, respectively. . DESCRIPTION OF SYMBOLS 1...Housing, 2...Photosensitive drum, 3...Charging device, 4...9 charging member, 5...Developing device, 7...
・Developing sleeve, 8... Transfer device, 9... Static eliminator, 1
0...Cleaner, 14.14A...Paper feed cassette,
17... Conveyance path, 18... Fixing device, 28.28A
, 28B... Paper output tray, 29... Placement plate, 36...
...Guide member.

Claims (1)

[Scope of Claims] 1) An image forming means that forms an image using a developing material on a photoreceptor, a transfer means that transfers the image formed on the photoreceptor by the image forming means onto a recording paper, and this transfer means In an electrophotographic apparatus, the electrophotographic apparatus includes a conveying means for supplying recording paper from a paper feeding section and discharging the recording paper onto which an image has been transferred by the transfer means to a paper discharge section. A paper feeding section is disposed, and the paper discharging section is disposed diagonally below the photoconductor, and a conveying path of a conveying means communicating with the paper feeding section and the discharging section, respectively, is arranged in a tangential direction of the photoconductor. 1. An electrophotographic apparatus characterized in that the electrophotographic apparatus is formed in a substantially straight line so as to extend into a straight line. 2) The electrophotographic apparatus according to claim 1, wherein the conveyance path conveys the recording paper so that the image forming surface faces upward. 3) The electrophotographic apparatus according to claim 1, wherein the conveyance path conveys the recording paper so that the image forming surface faces downward. 4) The image forming means has an optical writing member comprising an array of solid-state light emitting elements that forms an electrostatic latent image on the photoreceptor, as described in any one of claims 1 to 3. electrophotographic equipment. 5) The electronic device according to any one of claims 1 to 3, wherein the image forming means has a writing member consisting of an optical shutter array that forms an electrostatic latent image on the photoreceptor. Photographic equipment. 6) An image forming means that forms an image using a developer on the photoreceptor, a transfer means that transfers the image formed on the photoreceptor by the image forming means onto recording paper, and a recording device that transfers the image from the paper feed section to the transfer means. In an electrophotographic apparatus, the electrophotographic apparatus includes a conveying means for supplying paper and discharging the recording paper onto which an image has been transferred by the transfer means to a paper discharging section, wherein the paper feeding section is disposed diagonally above the photoreceptor. At the same time, the paper discharge section is disposed diagonally below the photoconductor, and a conveyance path of a conveyance means that communicates with the paper feed section and the paper discharge section, respectively, extends in a tangential direction of the photoconductor. A first paper discharge section is formed in a substantially straight line and is placed below the end of the conveyance path, on which the recording paper is placed with the image forming surface facing upward; an electrophotographic apparatus, characterized in that a guide member is movably arranged to form a second paper discharge section on which the paper is placed, and guide the recording paper discharged from the conveyance path into one of the paper discharge sections. . 7) The electrophotographic apparatus according to claim 6, wherein the conveyance path conveys the recording paper so that the image forming surface faces upward. 8) The electrophotographic apparatus according to claim 6, wherein the conveyance path conveys the recording paper so that the image forming surface faces downward. 9) The image forming means has an optical writing member comprising an array of solid-state light emitting elements that forms an electrostatic latent image on the photoreceptor, as described in any one of claims 6 to 8. An electrophotographic device as described in . 10) The electronic device according to any one of claims 6 to 8, wherein the image forming means has a writing member consisting of an optical shutter array that forms an electrostatic latent image on the photoreceptor. Photographic equipment. 11) The electronic device according to any one of claims 6 to 10, wherein the guide member has a triangular prism shape and is movable in a substantially horizontal direction so as to move toward and away from both paper discharge sections. Photographic equipment.