JPH0830175A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To facilitate the cleaning of an exposure means and to separate and remove only consumables such as a photoreceptor roller from the exposure means. CONSTITUTION:A carriage 1 constituted of an exposure unit 20 and a process unit 40 is attached to a sliding plate 11 moving in a direction perpendicular to the carrying direction of a recording paper P. The process unit 40 is fixed on the sliding plate 11 by a screw member 44 and the exposure unit 20 is fixed on the process unit 40 by a screw member 27 as well. An exposure unit positioning mechanism for accurately positioning an exposing device 50 with respect to the sliding plate 11 is provided between the exposure unit 20 and the sliding plate 11 and a process unit positioning mechanism for accurately positioning a photoreceptor roller 51 with respect to the exposing device 50 is provided between the exposure unit 20 and the process unit 40 as well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus in which a carriage equipped with an electrophotographic process is moved in a direction orthogonal to the conveying direction of recording paper and recording is performed on the recording paper by serial scanning.

[0002]

2. Description of the Related Art In recent years, as electrophotographic printers, serial scanning type electrophotographic apparatuses (so-called electrophotographic serial printers) have been developed due to demands for miniaturization and cost reduction.

16 and 17 are each shown in Japanese Patent Application Laid-Open No. Sho 56-56.
FIG. 1 is an overall plan view of a serial scanning type electrophotographic apparatus disclosed in Japanese Patent Publication No. 152463 and a sectional view showing a schematic configuration of a carriage.

This electrophotographic apparatus is equipped with a carriage 91 on which a process device (that is, a photosensitive roller 51, a charger 52, an exposure device 50, a developing device 53, etc.) is mounted and which is supported by a guide rod 90. The surface of the photosensitive roller 51 is uniformly charged by 52, and the photosensitive roller 51 is rotated in the same direction as the moving direction X of the carriage 91 while moving the carriage 91 in the direction X orthogonal to the transport direction Y of the recording paper P. At the same time, the peripheral speed of the photosensitive roller 51 is synchronized with the moving speed of the carriage 91, the exposure device 50 sensitizes the light to form an electrostatic latent image on the photosensitive roller 51, and the developing device 53 causes the toner to adhere. The electrostatic latent image is visualized.

Then, the photosensitive roller 51 is sandwiched between the recording papers P.
A toner image is transferred onto the recording paper P by a transfer electrode 62 disposed opposite to the transfer electrode 62, and the toner image is fixed by a fixed fixing device 60 provided apart from the carriage 91.

When printing characters, one to several lines are normally printed for each forward path of the carriage 91, and the recording paper P is conveyed by a predetermined size while the carriage 91 is moving back.

FIG. 18 is a sectional view showing a schematic structure of a carriage 91 in the electrophotographic apparatus disclosed in Japanese Utility Model Laid-Open No. 61-145649. In this electrophotographic apparatus, a conductive rubber blade is used as the transfer electrode 62, and a fixing roller 60 as a fixing device is installed in the carriage 91, and the fixing roller is provided immediately after the toner image is transferred to the recording paper P. The point that the fixing operation is performed by 60 is the difference from the electrophotographic apparatus disclosed in Japanese Patent Laid-Open No. 56-152463, and the other configurations are the same.

[0008]

The above-mentioned conventional electrophotographic apparatus has the following problems. In this type of electrophotographic apparatus, toner scattering is unavoidable in the carriage 91. However, if the scattered toner adheres to the exposure device 50, the image quality deteriorates. Therefore, the exposure device 50 needs to be cleaned regularly.

In order to clean the exposure device 50 with the conventional electrophotographic apparatus, it is necessary to remove the carriage 91 from the guide rod 90, disassemble the carriage 91 and remove the exposure device 50. The preparation work of was extremely complicated.

After the cleaning, the exposure device 50 is attached to the carriage 91, and the carriage 91 is attached to the guide rod 90.
The position of the exposure device 50 must be accurately set when assembling the device, but the position adjustment was delicate and difficult.

If a position error occurs in the exposure device 50, the following problems will occur. (1) If the distance between the exposure device 50 and the photosensitive roller 51 is inaccurate, the image becomes unclear and a so-called out-of-focus state occurs. (2) If the conveyance direction Y of the carriage 91 and the longitudinal direction of the exposure device 50 are not positioned so as to be orthogonal to each other, the image recorded on the recording paper P for each forward path becomes discontinuous. (3) If the position of the exposure device 50 with respect to the carriage 91 along the movement direction X of the carriage 91 is inaccurate, the recording start point and the end point of recording an image on the recording paper P will be inaccurate.

Further, since the photosensitive roller 51 and the like mounted on the carriage 91 are a kind of consumables that deteriorate with long-term use, it is necessary to replace them appropriately. In such a case, conventionally, the carriage 91 in which the process equipment is mounted and unitized is completely replaced with another carriage. Also in this case, it is difficult to accurately position the exposure device 50, as described above.

Further, when the exposure device 50 composed of a light emitting diode (hereinafter abbreviated as LED) has a long life, and the exposure device 50 can be sufficiently used even when it is time to replace the photosensitive roller 51 and the like. Is mostly. Moreover, the exposure device 50 including an LED or the like is expensive, and it is uneconomical to dispose of the expensive exposure device 50 that can be used together with the photosensitive roller 51, which is a consumable item.

The present invention has been made in view of the above problems of the prior art, and a first object of the present invention is to provide an electrophotographic apparatus capable of easily cleaning the exposing means. It is in.

A second object of the present invention is to provide an electrophotographic apparatus in which the exposure means can be accurately positioned and which can be attached very easily. A third object of the present invention is to provide an electrophotographic apparatus in which only the process equipment except the exposure means can be replaced.

[0016]

The present invention adopts the following means in order to solve the above problems. <Summary of the Invention> In a first invention of the present application, a carriage transport mechanism moves a carriage in a direction orthogonal to a transport direction of a recording sheet, and the carriage is synchronized with the carriage movement direction in the same direction. Rotating the photosensitive roller, charging means for uniformly charging the surface of the photosensitive roller, exposing means for forming an electrostatic latent image on the photosensitive roller whose surface is uniformly charged, and electrostatic means formed on the photosensitive roller. A developing means for visualizing a latent image with toner; and a toner visualized on the surface of the photosensitive roller by a transfer means arranged so as to face the photosensitive roller with a recording paper sandwiched therebetween. In an electrophotographic apparatus for transferring an image onto a recording sheet, the carriage can be separated into an exposure unit having the exposure unit, and a process unit having the photosensitive roller, a charging unit and a developing unit. The process unit is detachably attached to the carriage transport mechanism by fixing means, and the exposure unit is detachably attached to the process unit by another fixing means. The exposure unit is provided between the exposure unit and the carriage transport mechanism. The electrophotographic apparatus is provided with a positioning mechanism, and the process unit positioning mechanism is provided between the exposure unit and the process unit (corresponding to claim 1).

The exposure unit positioning mechanism has a function of regulating the attitude of the exposure means in the direction orthogonal to the moving direction of the carriage, and makes the exposure means immovable in a direction parallel to the recording paper. It is preferable to have a function.

On the other hand, the process unit positioning mechanism has a function of making the axial direction of the photosensitive roller the same as the longitudinal direction of the exposing means, and sets the distance between the surface of the photosensitive roller and the exposing means to a set dimension. It is preferable to have a function (corresponding to claim 2).

It is preferable that the exposure unit is attached to the process unit so that the exposure unit and the photosensitive roller can be adjusted in position so as to approach and separate from each other.
Corresponding to).

The process unit positioning mechanism can be composed of engaging portions provided on the process unit and the exposure unit, which can be engaged and disengaged from each other (corresponding to claim 4).

In the process unit positioning mechanism, the shaft portion of the photosensitive roller is used as an engaging portion on the process unit side, and a positioning body that straddles the shaft portion and abuts against the shaft portion is provided in the exposure unit. It is also possible to achieve this by using an engaging portion (corresponding to claim 5).

The carriage transport mechanism includes a moving body arranged substantially parallel to the recording paper, an opening is formed in the moving body, the process unit is inserted into the opening, and the process unit is provided with a frame. The exposure unit may be inserted into the provided opening (corresponding to claim 6).

By doing so, the work of attaching and detaching the exposure unit and the process unit can be performed from above the carriage transport mechanism, and the workability is good.

The exposure unit positioning mechanism can also be achieved by providing a frame on the exposure unit and providing an engaging projection and an engaging hole which engage with each other on the frame and the movable body of the carriage transport mechanism. (Corresponding to claim 7). In that case, the frame may be provided with the engaging hole and the moving body may be provided with the engaging projection, or the frame may be provided with the engaging projection and the moving body may be provided with the engaging hole.

The exposure unit may be rotatably attached to the carriage transport mechanism (corresponding to claim 8).
By doing so, not only is there no risk of losing the exposure unit, but workability is also improved.

In the second invention of the present application, the carriage transport mechanism moves the carriage in a direction orthogonal to the transport direction of the recording paper, and the carriage is synchronized with the carriage movement direction in the same direction. A rotating photosensitive roller, a charging unit that uniformly charges the surface of the photosensitive roller, an exposure unit that forms an electrostatic latent image on the photosensitive roller whose surface is uniformly charged, and an electrostatic latent image formed on the photosensitive roller. A toner image visualized on the surface of the photosensitive roller by a transfer means disposed opposite to the photosensitive roller with a recording paper sandwiched therebetween, and a developing means for visualizing the image with toner. In an electrophotographic apparatus for transferring a sheet onto a recording sheet, the exposing means is removably attached to the carriage conveying mechanism by a fixing means, and positioning is performed between the exposing means and the carriage conveying mechanism. An electrophotographic apparatus characterized by structure is provided (corresponding to claim 9).

That is, the electrophotographic apparatus of the second invention can be considered to have the process unit of the electrophotographic apparatus of the first invention irremovably fixed to the carriage transport mechanism.

<Additional Constituent Elements of the Present Invention> The present invention can be realized even if the following configurations are added. That is, a fixing means for fixing the toner image transferred on the recording paper may be installed in the carriage transport mechanism, and the fixing means may be moved together with the carriage.

The additional components are the first invention and the second invention.
The invention can be added to any of the electrophotographic apparatuses of the invention.

[0030]

[Action]

<Operation of the first invention of the present application> When it is desired to clean the exposure unit, only the exposure unit can be detached from the process unit and the carriage transport mechanism while the process unit remains mounted on the carriage transport mechanism.

On the other hand, when the device mounted on the process unit, for example, the photosensitive roller is worn out, only the process unit can be replaced, and the exposure unit can be remounted without replacement.

When assembling the exposure unit and the process unit into the carriage transport mechanism, first, the process unit is placed in the carriage transport mechanism. At this time, the process unit is made movable with respect to the carriage transport mechanism.

Next, the exposure unit is attached to the carriage transport mechanism. At this time, the exposure unit positioning mechanism positions the exposure unit with respect to the carriage transport mechanism, and the process unit positioning mechanism positions the process unit with respect to the exposure unit.

In this way, the exposure unit is first accurately positioned with respect to the carriage transport mechanism, and then the process unit is accurately positioned with respect to the correctly positioned exposure unit.

By doing so, the longitudinal direction of the exposure means can be accurately oriented in the direction orthogonal to the moving direction of the carriage, and the recording start point and the recording start point on the recording paper are set to the same position as before the disassembly. Further, the axial direction of the photosensitive roller can be made to exactly coincide with the longitudinal direction of the exposing means, and the gap size between the photosensitive means and the photosensitive roller is preset over the entire length of the exposing means in the longitudinal direction. Can be of constant size.

In the electrophotographic apparatus assembled in this way, so-called defocusing does not occur when recording on the recording paper after reassembly, and the toner image recorded on the recording paper may become discontinuous. In addition, the recording start point and the recording end point on the recording paper are not different from those before the replacement.

<Operation of the second invention of the present application> When it is desired to clean the exposing means, the exposing means with the process equipment other than the exposing means, that is, the photosensitive roller, the charging means and the developing means attached to the carriage conveying mechanism. It can be removed from the carriage transport mechanism, and when reattached, it can be positioned at the same position as before disassembly by the positioning mechanism.

In the electrophotographic apparatus assembled in this way, so-called out-of-focus does not occur during recording on the recording paper after reassembly, and the toner image recorded on the recording paper may become discontinuous. In addition, the recording start point and the recording end point on the recording paper are not different from those before the replacement.

<Operation when Additional Components are Added>
The toner image transferred onto the recording paper can be immediately fixed on the recording paper by the fixing means.

[0040]

Embodiments of the present invention will be described below with reference to the drawings of FIGS. [First Embodiment] A first embodiment of the electrophotographic apparatus of the present invention will be described with reference to FIGS.

<Structure of Electrophotographic Apparatus> FIG. 4 is a plan view of the electrophotographic apparatus according to the present invention, and FIG. 5 is a sectional view taken along line I--I of FIG. Further, FIG. 1 is an enlarged view of a main part of FIG.
2 is a II-II sectional view of FIG. 1, and FIG. 3 is a III-III sectional view of FIG.

This electrophotographic apparatus is of a so-called serial scanning type, and has a recording sheet conveying mechanism 80 for conveying the recording sheet P,
The carriage 1 is moved in a direction X orthogonal to the recording paper P conveyance direction Y.
A carriage transport mechanism 10 for moving the carriage is provided.

The recording paper conveying mechanism 80 sandwiches the recording paper P from above and below by a pair of driving rollers 81 and 82 arranged in parallel with each other and a pair of driven rollers 83 and 84 arranged in parallel with each other, and a predetermined distance. The recording paper P is intermittently conveyed by a predetermined size in the Y direction in the drawing at a timing. The carriage transport mechanism 10 is installed above the recording paper transport mechanism 80.

The carriage transfer mechanism 10 includes support members 12a, 12 fixed to a slide plate (moving body) 11.
b and 12c slidably engage two guide rods 13a and 13b installed in parallel with each other, and a belt 15 reciprocally moved by a motor 14 is fixed to the support member 12b. ing.

The guide rods 13a and 13b are accurately positioned in advance above the recording paper P so as to be orthogonal to the transport direction Y of the recording paper P. In this carriage transport mechanism 10, when the motor 15 is normally or reversely rotated to reciprocate the belt 15, the slide plate 11 reciprocates together with the belt 15. At this time, slide plate 1
Since 1 moves by being guided by the guide rods 13a and 13b, it moves along the direction X that is exactly orthogonal to the transport direction Y of the recording paper P. Further, during this movement, the guide rods 13a and 13b are accurately positioned in advance so that the slide plate 11 is always in a posture parallel to the recording paper P.

An opening 11a is provided substantially at the center of the slide plate 11, and the carriage 1 is inserted through this opening 11a and fixed to the slide plate 11.

The carriage 1 is composed of an exposure unit 20 and a process unit 40. The process unit 40 has a box-shaped frame 41 having openings 41a and 41b in the upper and lower portions, and in this frame 41, process equipment except the exposure device 50, that is, a photosensitive roller 51 and a contact type charger (charging means). ) 52, a developing device (developing means) 53, a cleaner 54, etc. are mounted.

The frame 41 comprises a pair of mounting arms 42, 4
I have three. The mounting arms 42 and 43 are mounted on the carriage 1
Are arranged in parallel along a direction orthogonal to the movement direction X of the recording paper P (that is, the same direction as the conveyance direction Y of the recording paper P), and the respective ends of the mounting arms 42 and 43 are placed on the slide plate 11. It is fixed to the slide plate 11 by one screw member (fixing means) 44.

That is, the male screw portion 44a of the screw member 44 is inserted into the holes provided at the ends of the mounting arms 42 and 43, and screwed into the screw holes provided in the slide plate 11 to tighten the mounting arm 42. , 43 are sandwiched and fixed by the slide plate 11 and the non-screw portion 44b of the screw member 44. As a result, the process unit 40 is fixed to the slide plate 11.

The holes provided at the ends of the mounting arms 42 and 43 have a diameter slightly larger than that of the male screw portion 44a of the screw member 44, and when the screw member 44 is loosely tightened, The unit 40 can be finely moved in the horizontal direction (that is, the Y direction and the X direction), and the position can be adjusted.

The photosensitive roller 51 is attached to the frame 41 with its axis along the direction orthogonal to the moving direction X of the carriage 1 (that is, the same direction as the conveying direction Y of the recording paper P). It is rotationally driven by a mounted motor (not shown).

The peripheral speed of the photosensitive roller 51 is set to the same speed as the moving speed of the carriage 1, and the photosensitive roller 51 rotates in the same direction in synchronization with the forward movement of the carriage 1. The photosensitive roller 51 is exposed from the lower opening 41b of the frame 41 and runs on the recording paper P between the driven rollers 83 and 84 of the recording paper transport mechanism 80.

The charger 52 uniformly charges the surface of the photosensitive roller 51. The developing device 53 is the photosensitive roller 5.
Toner is attached to the electrostatic latent image formed on 1 to form a visible image into a toner image. The cleaner 54 removes the toner remaining on the photosensitive roller 51 after the transfer of the toner image.

The exposure unit 20 is the process unit 4
It is attached to the slide plate 11 and the process unit 40 in a state of being inserted into the upper opening 41a of the frame 41 of No. 0.

The exposure unit 20 includes a frame 21,
An exposure device 50 is installed below the center of the frame 21. The exposure unit 20 has its longitudinal direction aligned with the carriage 1.
Are arranged along a direction orthogonal to the moving direction X of (i.e., the same direction as the transport direction Y of the recording paper P). Exposure device 50
Forms an electrostatic latent image on the photosensitive roller 51 whose surface is uniformly charged, and is composed of a large number of LEDs arranged in a line along the longitudinal direction of the exposure unit 20.

The frame 21 has positioning arms 2 at both ends.
The positioning arms 22 and 23 are provided with positioning holes (engagement holes) 24 through which a pair of positioning projections (engagement projections) 16 provided on the upper surface of the slide plate 11 can be inserted. Has been. When the positioning protrusion 16 is inserted into the positioning hole 24, there is almost no gap between the two, so that the frame 21 moves in the horizontal direction (that is,
It cannot move in the X and Y directions. However,
The frame 21 is movable in the vertical direction indicated by the arrow Z in the figure. The positioning protrusion 16 and the positioning hole 24 constitute an exposure unit positioning mechanism.

The exposure unit 20 is positioned in the horizontal direction by inserting the positioning protrusions 16 into the positioning holes 24 and making the frame 21 unable to move horizontally. That is, in this state, the longitudinal direction of the exposure device 50 becomes strictly parallel to the direction orthogonal to the moving direction X of the carriage 1 (that is, the transport direction Y of the recording paper P), and the recording start set in advance is started. The exposure device 50 is accurately positioned at the initial setting position so that recording is performed on the recording paper P from the point.

At both ends of the frame 21, a pair of positioning plates (positioning bodies) 2 extending vertically downward are provided.
5, 26 are provided. This positioning plate 2
Semi-circular recesses (engagement portions) 25a are provided at the lower ends of
26a is formed, and the recesses 25a and 26a are engaged so as to straddle the shaft portion (engagement portion) 51a of the photosensitive roller 51. Although there is almost no gap between the shaft portion 51a and the recessed portions 25a and 26a, the recessed portions 25a and 26a are in contact with the shaft portion 51a and are relatively slidable. Recess 2
5a, 26a and the shaft portion 51a constitute a process unit positioning mechanism.

The positioning plates 25 and 26 are arranged so that the axial direction of the photosensitive roller 51 and the longitudinal direction of the exposure device 50 coincide with each other when the recesses 25a and 26a are engaged with the shaft portion 51a. There is.

Further, the both concave portions 25a and 26a are
When the central upper surfaces of a and 26a are brought into contact with the shaft portion 51a,
Gap D between the exposure device 50 and the photosensitive roller 51 (see FIG. 6)
However, the position is set so as to have a preset gap size over the entire length of the exposure device 50 in the longitudinal direction.

The frame 21 of the exposure unit 20 is fixed to the frame 41 of the process unit 40 by two screw members (fixing means) 27 so as not to move vertically. That is, as shown in FIG. 1, by inserting the male screw portion 27a of the screw member 27 into the hole provided in the frame 21 and the packing 28, and screwing it into the screw hole provided in the frame 41 to tighten the frame. 21 and packing 28 are the non-screw portion 27b of the screw member 27 and the frame 41
It is clamped and fixed by. As a result, the exposure unit 20 is fixed to the process unit 40. In other words, the exposure unit 20 is fixed to the slide plate 11 via the process unit 40.

The hole provided in the frame 21 of the exposure unit 20 has a diameter slightly larger than that of the male screw portion 27a of the screw member 27, and when the screw member 27 is loosely tightened, The process unit 40 can be relatively finely moved in the horizontal direction (that is, the Y direction and the X direction), and the relative horizontal position of both can be adjusted.

On the slide plate 11, the carriage 1
A fixing roller (fixing means) 60 is installed on the downstream side (left side in FIG. 1) of the slide plate 11 in the forward movement direction. The fixing roller 60 also rotates in the same direction in synchronization with the forward movement of the carriage 1, and the peripheral speed thereof is set to the same speed as the moving speed of the carriage 1.

The fixing roller 60 heats and fixes the toner image transferred onto the recording paper P, and has a halogen lamp (not shown) inside. The temperature of the fixing roller 60 is detected by the thermistor 61, and is controlled by a control unit (not shown) so that the temperature is normally maintained at about 180 degrees.

Under the orbit of the photosensitive roller 51 of the carriage 1 and below the recording paper P, a transfer device (transfer means) is provided.
62 is installed. The transfer device 62 transfers the toner image formed on the photosensitive roller 51 onto the recording paper P.
The length of the transfer unit 62 along the X direction is longer than the width of the recording paper P, and the width of the transfer unit 62 along the Y direction is the photosensitive roller 51.
It has almost the same size as the length of.

<Recording Operation> Next, the recording operation of this electrophotographic apparatus will be described. When the recording paper P is stationary, the carriage 1 and the fixing roller 60 are moved forward in the X direction together with the slide plate 11 by the carriage transport mechanism 10, and recording is performed on the recording paper P during this forward movement. Here, the forward movement refers to the movement to the right in FIG. 5, and conversely the movement to the left is referred to as the backward movement.

That is, the charger 52 uniformly charges the surface of the photosensitive roller 51 which rotates in synchronization with the carriage 1,
The exposing device 50 forms an electrostatic latent image on the charged photosensitive roller 51 by exposure to light, and the developing device 53 attaches toner to the electrostatic latent image to visualize the electrostatic latent image into a toner image, The transfer device 62 transfers the toner image onto the recording paper P, and the fixing roller 60 fixes the transferred toner image onto the recording paper P. During this time, the cleaner 54 scrapes off and removes the toner remaining on the photosensitive roller 51 even after the transfer of the toner image.
The charger 52 charges the cleaned surface of the photosensitive roller 51 again and repeats the same recording operation as described above.

When the slide plate 11 reaches the end point of the forward movement, the recording operation is interrupted, the slide plate 11 moves back in the direction opposite to the arrow X, and the carriage 1 and the fixing roller 60 are moved to the start end side ( It is conveyed to the left side in FIG.

At the same time, the recording paper conveyance mechanism 80 conveys the recording paper P in the Y direction (upper surface in FIG. 5) by a predetermined size and stops. Then, the carriage 1 and the fixing roller 60 are again moved forward in the X direction by the carriage transport mechanism 10 to start recording on the recording paper P from a preset recording start point.

<Replacement of Process Unit 40> When the electrophotographic apparatus is used for a long period of time, the equipment mounted on the process unit 40 may be worn out, such as abrasion of the photosensitive roller 51. In such a case, only the process unit 40 is replaced as follows, and the exposure unit 20 including the expensive exposing unit 50 is reused without replacement.

First, the exposure unit 20 is removed from the slide plate 11 and the process unit 50. For this purpose, as shown in FIGS. 8 and 9, the two screw members 27 are removed, the exposure unit 20 is removed from the process unit 40, and the frame 21 of the exposure unit 20 is removed.
The positioning protrusion 16 of the slider frame 11 is removed from the positioning hole 24 of FIG.

Next, as shown in FIGS. 10 and 11, the screw member 44 is removed and the process unit 40 is removed from the slide plate 11. Then, a new process unit 40 prepared separately is placed on the slide plate 11, and the four screw members 44 are screwed in loosely. That is, the process unit 40 is set in a state in which it can be finely moved in the horizontal direction (that is, the X direction and the Y direction) with respect to the slide plate 11 without completely tightening the screw member 44.

Next, the exposure unit 20 is attached to the slide plate 11. That is, the positioning protrusion 16 of the slide plate 11 is inserted into the positioning hole 24 of the frame 21 of the exposure unit 20. As a result, the exposure device 50
The longitudinal direction of the recording sheet P is accurately oriented in the direction orthogonal to the movement direction X of the carriage 1 (that is, the conveyance direction Y of the recording sheet P), and the recording start point and the recording end point on the recording sheet P are the same as those before the process unit replacement. It will be possible to set the same position.

When the exposure unit 20 is attached to the slide plate 11, the recesses 25a and 26a of the positioning plates 25 and 26 of the exposure unit 20 are inserted into the photosensitive roller 5.
It can be straddled over one shaft portion 51a. At this time, since the process unit 40 is in a state of being capable of finely moving in the horizontal direction with respect to the slide plate 11, the process unit 40 is guided to the exposure unit 20 by the engagement of the recesses 25a and 26b with the shaft portion 51a. Slide plate 1
1 and the exposure unit 20 are positioned.

As a result, the axial direction of the photosensitive roller 51 of the process unit 40 exactly coincides with the longitudinal direction of the exposure device 50 and is orthogonal to the moving direction X of the carriage 1 (that is, the conveying direction Y of the recording paper P). Exactly suitable for.

Next, the screw member 44 is completely tightened,
The process unit 40 is securely fixed to the slide plate 11. Finally, the screw member 27 is attached to the process unit 4
0 is screwed into the screw hole of the frame 41, and the screw member 27 is tightened until the central upper surfaces of the recesses 25a and 26a of the positioning plates 25 and 26 come into contact with the shaft portion 51a of the photosensitive roller 51.

When the central upper surfaces of the recesses 25a and 26a are brought into contact with the shaft portion 51a of the photosensitive roller 51, the gap dimension D between the exposure device 50 and the photosensitive roller 51 is set in advance over the entire length of the exposure device 50 in the longitudinal direction. It becomes the set constant size.

As described above, in this electrophotographic apparatus, first, the exposure unit 20 is accurately positioned on the slide plate 11 so that the longitudinal direction of the exposure device 50 is orthogonal to the moving direction Y of the carriage 1. The recording start point and the end point are accurately positioned at X and the initial setting position.

Then, the process unit 40 is accurately positioned with respect to the exposure unit 20, so that the axial direction of the photosensitive roller 51 is accurately aligned with the longitudinal direction of the exposure unit 50, and the exposure unit is also exposed. The size of the gap between 50 and the photosensitive roller 51 is the set size.

In the electrophotographic apparatus reassembled in this way, so-called defocusing does not occur during recording on the recording paper P after reassembly, and the toner image recorded on the recording paper P becomes discontinuous. The recording start point and the recording start point on the recording paper P are not different from those before the replacement.

<Cleaning of the exposure device 50> When an electrophotographic apparatus is used, toner may adhere to the exposure device 50, resulting in poor image quality. In that case, leave the process unit 40 attached to the slide plate 11,
Only the exposure unit 20 is removed from the slide plate 11 and the process unit 40, and the exposure unit 50 is cleaned. The procedure for removing the exposure unit 50 is the same as the procedure described above.

As described above, since the exposure unit 20 can be removed in this electrophotographic apparatus, the exposure unit 50
Can be cleaned efficiently and reliably. Moreover, since it is not necessary to remove the process unit 40 from the slide plate 11 when cleaning the exposure device 50, the exposure device 50 can be easily cleaned.

The procedure for attaching the exposure unit 20 after cleaning is the same as that for replacing the process unit 40 described above. Therefore, the longitudinal direction of the exposure device 50 is set to the carriage 1
Can be accurately oriented in the direction orthogonal to the moving direction X of the recording paper P (that is, the conveyance direction Y of the recording paper P), and the photosensitive roller 5
Exactly coincides with the axial direction of 1. Further, the gap dimension D between the exposure device 50 and the photosensitive roller 51 can be set to a predetermined constant dimension over the entire length of the exposure device 50 in the longitudinal direction.

As a result, at the time of recording on the recording paper P after reattachment, so-called blurring does not occur, the toner image recorded on the recording paper P does not become discontinuous, and recording on the recording paper P does not occur. The start point and end point are the same as before cleaning.

[Second Embodiment] Next, a second embodiment of the electrophotographic apparatus of the present invention will be described with reference to FIGS.

The difference between the second embodiment and the first embodiment lies in the structure of the process unit positioning mechanism provided between the exposure unit 20 and the process unit 40, and the other structures are the same as those of the first embodiment. Same as the example.

In the second embodiment, the exposure unit 20
Positioning plate 2 extending downward from the frame 21 of
At the lower ends of 5, 26, semicircular convex portions (engaging portions) 25b,
26b are formed. Further, a pair of brackets 46 and 47 through which the shaft portion 51a of the photosensitive roller 51 slides through are fixed to the frame 41 of the process unit 40, and the convex portions (engaging portions) are attached to the upper ends of the brackets 46 and 47. ) Recesses 46a and 47a into which 25b and 26b are fitted are formed.

In the second embodiment, the positioning plate 2
5, 25 and 26, and the bracket 4
The process unit positioning mechanism is configured by the recesses 46a and 47a of 6, 47.

Convex portion 25 of positioning plates 25, 26
b, 26b to the recesses 46a, 47 of the brackets 46, 47
By being fitted in a, the axial direction of the photosensitive roller 51 coincides with the longitudinal direction of the exposure device 50, and the projections 25b and 26 are formed.
By abutting the central lower surface of b with the central upper surfaces of the recesses 46a and 47a, the gap size between the exposure device 50 and the photosensitive roller 51 becomes a predetermined constant size over the entire length of the exposure device 50. ing. Therefore, also in the second embodiment, it is possible to obtain the same effect as that of the first embodiment.

Third Embodiment Next, a third embodiment of the electrophotographic apparatus of the present invention will be described with reference to FIGS. 14 and 15.

In the third embodiment, the exposure unit 20 is rotatably attached to the guide rod 13b of the carriage transport mechanism 10. That is, one end of the frame 21 of the exposure unit 20 is a support arm 28 extending in a direction approaching the guide rod 13b, and the guide rod 13b penetrates through a long hole 28a provided in the support arm 28 so as to be relatively slidable. are doing.

Further, the process unit positioning mechanism has the same structure as that of the second embodiment, and the exposure unit 20 is fixed to the process unit 40 by the screw member 27 as in the first embodiment.

The elongated hole 28a of the support arm 28 is formed in the following shape and size. That is, as shown in FIG. 14, when the exposure unit 20 is placed on the process unit 40 and the screw member 27 is loosened, the exposure unit 20 causes the guide rod 13b to expose the exposure unit 50 and the photosensitive roller 51. Can be moved in a direction in which the carriage 1 moves closer to and away from the carriage 1 (that is, the Z direction), and cannot move in the Y direction orthogonal to the moving direction X of the carriage 1.

Then, as shown in FIG. 14, when the exposure unit 20 is arranged in a horizontal posture, the longitudinal direction of the exposure device 50 is orthogonal to the movement direction X of the carriage 1 (that is, the recording paper P conveyance direction Y). It is supposed to be exactly parallel to.

Further, by engaging the convex portions 25b and 26b of the process unit positioning mechanism with the concave portions 46a and 47a,
The axial direction of the photosensitive roller 51 can be made coincident with the longitudinal direction of the exposure device 50, and the gap dimension D between the exposure device 50 and the photosensitive roller 51 is set to a predetermined constant dimension over the entire length of the exposure device 50. You can do it.

In the electrophotographic apparatus of the third embodiment, the exposure device 50 is cleaned or the process unit 4 is used.
When replacing 0, the screw member 27 is removed and the exposure unit 20 is tilted about the guide rod 13b as shown in FIG.

Also in the case of the third embodiment, like the first embodiment, the exposure unit 50 can be easily and surely cleaned and only the process unit 40 can be replaced. Further, at the time of recording on the recording paper P after reassembly, so-called defocusing does not occur, and the toner image recorded on the recording paper P does not become discontinuous, and the recording start point and the recording end point on the recording paper P are finished. The points are the same as before the cleaning of the exposure device 50 and before the replacement of the process unit 40.

[Fourth Embodiment] In the first to third embodiments, the process unit 40 is removably installed on the slide plate 11, but the process unit 40 is not removable on the slide plate 11. Even if the exposure unit 20 is fixedly installed and detachably installed on the slide plate 11 and a positioning mechanism is provided between the exposure unit 20 and the slider plate 11, the exposure unit 50 is easier to clean than before. In addition, the reattachment after cleaning can be performed easily and accurately.

[0099]

As described above, according to the present invention,
When it is desired to clean the exposure unit, only the exposure unit can be detached from the process unit and the carriage transfer mechanism while the process unit remains mounted on the carriage transfer mechanism. Therefore, the exposure unit can be easily and reliably cleaned. The excellent effect that it is possible is exhibited.

Further, according to the present invention, when the equipment mounted on the process unit, for example, the photosensitive roller is worn out,
Since only the process unit can be replaced and the exposure unit can be mounted again on the process unit and the carriage transport mechanism without replacement, an excellent effect that expensive exposure means is effectively used and is economical is achieved. To be done. Further, by providing the exposure unit positioning mechanism and the process unit positioning mechanism, the longitudinal direction of the exposure means can be accurately oriented in the direction orthogonal to the moving direction of the carriage when reassembling, and recording on the recording paper. Start point and end point can be in the same position as before disassembly,
The axial direction of the photosensitive roller can be accurately aligned with the longitudinal direction of the exposing means, and the gap between the photosensitive means and the photosensitive roller can be set to a predetermined constant dimension over the entire length of the exposing means in the longitudinal direction. it can. As a result, at the time of recording on the recording paper after reassembly, so-called defocusing does not occur, the toner image recorded on the recording paper does not become discontinuous, and the recording start and end points on the recording paper are The excellent effect is the same as before reassembly.

Further, when the fixing means is installed in the carriage conveying mechanism, there is an effect that the toner image transferred onto the recording paper (P) can be immediately fixed on the recording paper.

[Brief description of drawings]

FIG. 1 is an enlarged longitudinal sectional view of an essential part of an electrophotographic apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a plan view of the electrophotographic apparatus according to the first embodiment of the present invention.

5 is a cross-sectional view taken along the line II of FIG.

FIG. 6 is a side view of the process unit positioning mechanism in the first embodiment.

FIG. 7 is a front view of a process unit positioning mechanism in the first embodiment.

FIG. 8 is a front view of the first embodiment with an exposure unit removed.

FIG. 9 is a side view showing a state in which the exposure unit is removed in the first embodiment.

FIG. 10 is a front view of the first embodiment with a process unit removed.

FIG. 11 is a side view showing a state in which a process unit is removed in the first embodiment.

FIG. 12 is a side view of a process unit positioning mechanism in the second embodiment.

FIG. 13 is a front view of a process unit positioning mechanism in the second embodiment, (A) is an assembled front view,
(B) is an exploded front view.

FIG. 14 is an assembled side view of the exposure unit positioning mechanism in the third embodiment.

FIG. 15 is an exploded side view of an exposure unit positioning mechanism in the third embodiment.

FIG. 16 is a plan view of a conventional electrophotographic apparatus.

FIG. 17 is a vertical sectional view of a conventional electrophotographic apparatus.

FIG. 18 is a vertical cross-sectional view of another conventional electrophotographic apparatus.

[Explanation of symbols]

1 Carriage 10 Carriage Conveying Mechanism 11 Slide Plate (Moving Body) 11a Opening 16 Positioning Protrusion (Exposure Unit Positioning Mechanism Engaging Protrusion) 20 Exposure Unit 21 Frame 24 Positioning Hole (Exposure Unit Positioning Mechanism Engaging Hole) 25, 26 Positioning Plates (positioning bodies) 25a, 26a Recesses (engaging parts of process unit positioning mechanism) 25b, 26b Convex parts (engaging parts of process unit positioning mechanism) 27 Screw members (fixing means) 40 Process unit 41 Frame 41a Opening 44 Screw Member (fixing means) 46a, 47a Recessed portion (engaging portion of process unit positioning mechanism) 50 Exposure device (exposure means) 51 Photosensitive roller 51a Shaft portion (engaging portion of process unit positioning mechanism) 52 Charger (charging means) 53 Developing device (developing means )

Claims (10)

[Claims] 1. A photosensitive roller that moves a carriage in a direction orthogonal to a conveying direction of a recording sheet, the carriage rotates in synchronization with the moving direction of the carriage, and the photosensitive roller. Charging means for uniformly charging the surface of the sheet, exposing means for forming an electrostatic latent image on the photosensitive roller whose surface is uniformly charged, and the electrostatic latent image formed on the photosensitive roller is visualized by toner An electrophotographic apparatus for transferring the toner image visualized on the surface of the photosensitive roller to the recording paper by a transfer means arranged opposite to the photosensitive roller with the recording paper sandwiched therebetween. In the process unit, the carriage is separable into an exposure unit having the exposure unit and a process unit having the photosensitive roller, a charging unit, and a developing unit. The fixing unit is detachably attached to the carriage transport mechanism, the exposure unit is detachably attached to the process unit by another fixing unit, and the exposure unit positioning mechanism is provided between the exposure unit and the carriage transport mechanism. An electrophotographic apparatus, wherein a process unit positioning mechanism is provided between the exposure unit and the process unit. 2. The exposure unit positioning mechanism has a function of regulating a posture of a longitudinal direction of the exposure unit in a direction orthogonal to a moving direction of the carriage, and an exposure unit immovable in a direction parallel to a recording sheet. The process unit positioning mechanism sets the axial direction of the photosensitive roller to be the same as the longitudinal direction of the exposing means, and sets the distance between the surface of the photosensitive roller and the exposing means. The electrophotographic apparatus according to claim 1, which has a function of dimensioning. 3. The electrophotographic apparatus according to claim 2, wherein the exposure unit is attached to the process unit so that the exposure unit and the photosensitive roller can be positionally adjusted in a direction of approaching and separating from each other. 4. The process unit positioning mechanism comprises:
4. The electrophotographic apparatus according to claim 1, wherein the electrophotographic apparatus comprises an engaging portion provided in the process unit and the exposure unit and capable of engaging and disengaging with each other. 5. The process unit side engaging portion of the process unit positioning mechanism is a shaft portion of a photosensitive roller,
5. The electrophotographic apparatus according to claim 4, wherein the engaging portion on the exposure unit side is a positioning body that straddles the shaft portion of the photosensitive roller and contacts the shaft portion. 6. The carriage transport mechanism has a moving body arranged substantially parallel to the recording paper, the process unit is inserted into an opening provided in the moving body, and the process unit has a frame having the opening. 6. The electrophotographic apparatus according to claim 1, wherein the exposure unit is inserted into the opening of the frame. 7. The exposure unit has a frame, and the exposure unit positioning mechanism is constituted by an engagement projection and an engagement hole provided on the movable body and the frame of the exposure unit. Item 6. The electrophotographic apparatus according to Item 6. 8. The electrophotographic apparatus according to claim 1, wherein the exposure unit is rotatably attached to the carriage transport mechanism. 9. A photosensitive roller that moves a carriage in a direction orthogonal to a conveying direction of a recording sheet, the carriage rotates in synchronization with the moving direction of the carriage, and the photosensitive roller. Charging means for uniformly charging the surface of the sheet, exposing means for forming an electrostatic latent image on the photosensitive roller whose surface is uniformly charged, and the electrostatic latent image formed on the photosensitive roller is visualized by toner An electrophotographic apparatus for transferring the toner image visualized on the surface of the photosensitive roller to the recording paper by a transfer means arranged opposite to the photosensitive roller with the recording paper sandwiched therebetween. The exposure means is detachably attached to the carriage transport mechanism by a fixing means, and a positioning mechanism is provided between the exposure means and the carriage transport mechanism. Electrophotographic apparatus according to claim. 10. The carriage conveying mechanism is provided with fixing means for fixing the toner image transferred onto the recording paper, and the fixing means moves together with the carriage. The described electrophotographic apparatus.