JPH0355565A - Electrostatic recording device - Google Patents

Abstract

PURPOSE:To improve space-saving design by providing a bias member which applies a bias having the opposite polarity from the electrostatic charging polarity of toner to a circumscribed roller provided at a position behind a transfer process. CONSTITUTION:An endless beltlike photosensitive body 20 is provided longitudinally long by an inscribed driving roller 70, a transfer roller 72 and a driven roller 71, and at least one circumscribed roller 73 so that the interval of the center part in the belt is narrow in width. There is therefore no unnecessary space and respective processes unit are only arranged around the photosensitive body 20, so a device main body becomes a thin type and the space-saving design is enabled. The circumscribed roller 73 provided at the position behind the transfer process is applied with the bias having the opposite polarity from the toner, so an electrostatic discharging cleaning function can be displayed to the photosensitive body 20 and a layout which improves the space-saving design according to the intrusion position of a cleaning means is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to electrostatic recording devices such as copying machines, facsimile machines, printers, and the like.

2. Description of the Related Art In general, desktop electrostatic recording devices require a compact design. Conventionally, this type of electrostatic recording device with a compact design is, for example, disclosed in Japanese Patent Application Laid-open No. 1986-
There is one shown in Publication No. 12563. In this system, a photoreceptor in the form of an endless belt is stretched in a substantially inverted triangular loop, and electrostatic process units such as a developing means and a static eliminating cleaning means are arranged around the photoreceptor.

Problems to be Solved by the Invention In general, when considering miniaturization when laying out each process unit that executes an electrostatic photographic process, it is preferable to use a belt-shaped photoreceptor as in the above publication, rather than using a drum-shaped photoreceptor. It can be said that it is more advantageous to use. However, according to the structure of the above-mentioned publication, a wasted space is required within the loop-shaped belt, which is one reason why miniaturization is insufficient.

Means for Solving the Problem The surface of an endless belt-shaped photoreceptor is uniformly charged by a charging means, and then exposed to light by an exposure optical system to form an electrostatic latent image on the photoreceptor. The image is visualized by a developing means using charged toner, the visualized toner image is transferred onto a transfer paper by a transfer means, the toner image transferred to the transfer paper is fixed by a fixing means, and the toner image after the transfer is In an electrostatic recording device in which the surface of the photoreceptor is cleaned by a cleaning means, the photoreceptor is in a vertically elongated state, and a drive roller connected to a drive source, and a transfer roller disposed at a position facing the transfer means. and a driven roller disposed in a position such that the photoreceptor is orthogonal to the driving roller with respect to the imaging optical axis of the exposure optical system. At least one circumscribing roller is provided in circumferential contact with the photoreceptor in a state where the interval between the parts is narrowed, and the circumscribing roller provided in the position after the transferring process is biased with a polarity opposite to the toner charging polarity. A bias member was provided to apply .

a driving roller, a transfer roller and a driven roller that are in contact with each other;
With at least one circumscribed circumscribed roller, the photoreceptor in the form of an endless belt is provided in a vertically elongated state with a narrow interval at the center of the belt, eliminating wasted space within the belt. After that, it is only necessary to arrange each process unit around such a photoreceptor, so that the main body of the apparatus can be made thin, and a space-saving design is possible. In particular, for the circumscribed roller installed at the position after the transfer process among the circumscribed rollers, a bias of toner of opposite polarity to the toner is applied by the bias member, so that the photoreceptor can perform a static elimination cleaning function. Its recessed arrangement as a cleaning means allows for a more space-saving design layout.

Example An embodiment of the present invention will be described based on the drawings.

First, the overall schematic structure and operation will be explained with reference to FIGS. 2 to 4. FIG. 2 is a perspective view showing the overall appearance when not in use, FIG. 3 is a perspective view showing the appearance in a standby state for copy processing, and FIG. 4 is a cross-sectional structural diagram showing an outline of the process structure. As shown in FIG. 2, the copying machine of this embodiment is constructed as a vertical and thin copying machine that is mainly used by leaning it against a wall.

As shown in FIG. 2, the copying machine of this embodiment has a document transport table l, which also serves as an exterior cover, a front cover 2, a paper feed table 3, left and right side covers 4,
5 and a rear cover 6. Louvers 7 are provided on the left and right side covers 4 and 5, respectively.

To change from such an unused state to a standby state for copy processing, first open and rotate the handle 8 provided at the upper part of the outer surface of the document transport table l toward the front side, as shown in FIG. Open to the designated position.

In this open state, a pair of side guides 9 on the inner surface of the document transport table l are exposed and serve as guides for inserting a set of documents. The pair of side guides 9 move toward and away from each other in conjunction with each other, so that they can be adjusted to the width of the document. A size mark 10 indicating the document size and center position is attached to the innermost side of the document conveying table l, and is used as a guide for inserting and setting the document. Also, due to the opening rotation of the document transport table 1, the paper ejection roller l1 located on the internal surface,
The document discharge table l2, which also serves as a document transport cover, is exposed as shown in FIG.

When the outer surface of the paper feeding table 3 is pressed, a locking means (described later) is released, and a damper means (described later) provided at the fulcrum section linearly rotates the sheet feeding table 3 to a predetermined position as shown in FIG. It is fixed in the open position.

This paper feed table 3 is used to stack and set transfer paper to be copied on its surface, and similarly to the original W4 transport table 1, it approaches and separates in conjunction with the paper size, and guides the curling of the leading edge of the paper. - A pair of side guides 13 are provided. A size mark 14 indicating the paper size and center position is attached to the front side of the paper feed table 3, and is used as a guide for inserting and setting the transfer paper. Also,
A friction pad l6 is provided in the center of the odoriest part of the paper feed table 3 to face and contact the calling roller 15. When the paper feed table 3 is opened, an inner cover 17 provided on the inner surface thereof and covering the fixing section and the like is exposed.

When the document transport table 1 and the paper feed table 3 are opened in this manner, the main power supply of the apparatus is activated and the apparatus enters a standby state in about 20 seconds. Therefore, the operation from this startup to the end of copying will be explained with reference to FIG.

Here, as the basis of an electrostatic recording type copying machine, as schematically shown in FIG. Accordingly, a charging charger (charging means) 21, an exposure optical system 22, a developing device (developing means) 23, a transfer charger (transfer means) 24, a fixing device (fixing means) 25, a cleaning device (cleaning means) 26, and a static elimination LED array. 27 process units are provided in sequence. Further, a document feeding and conveying means 28 is provided above the exposure position by the exposure optical system 22, and a transfer sheet feeding and conveying means 29 is provided below the transfer position by the transfer charger 24. In this embodiment, the photoreceptor 20 is provided in a vertically elongated state approximately in the center of the case, with narrow intervals at the center of the belt, and the above-mentioned process units are arranged upwardly around the photoreceptor 20. The widths are arranged in order from the top to the bottom in a narrow state. A cooling fan 30 is also provided at the bottom of the cleaning device 26.

First, when the document conveyance table 1 is rotated open, this opening is detected by the document conveyance table opening/closing switch 3l. Further, when the paper feed table 3 is pushed, the lock means is released and the paper feed table 3 is semi-automatically opened by the damper means, and the second opening is detected by the paper feed table opening/closing switch 32. These open/close switches 31.3
By performing an AND of 2, the warm-up of this device is started. Here, a fixing heater 33 and a fluorescent lamp heater 3 are installed.
4 and the cooling fan 30 complete warming up after about 20 seconds. In this state, transfer paper of the same size as the original or the size to be copied is set on the paper feed table 3 against the leading edge guide 35 using the side guide 13 as a guide. Then, the paper presence/absence sensor 36 provided on the paper feed table 3 is turned on, and a display unit (not shown) displays that the paper has been set. As a result, the machine becomes ready for copying and waits for the original to be inserted and set.

Therefore, using the side guides 9 and size marks 10 as guides, the original is inserted and set onto the original transport table 1 with the original surface facing downward, and is brought into contact with a pair of original transport rollers 37 and 38. This type of document insertion set uses the entrance roller 37.
This is detected by a document presence/absence sensor 39 provided in front of the document.

After this detection, after a certain pulse time, the transport rollers 37, 3
8 is driven, and document conveyance is started. That is, the output of the document presence/absence sensor 39 regulates the driving start time of the transport rollers 37 and 38, and this waiting time causes the leading edge of the document to follow the registration rollers.

In other words, the skew correction time is secured. However, this is limited to documents where the leading edge of the document is perpendicular to the conveyance direction.

The document conveyed by the conveyance rollers 37 and 38 is further conveyed to the back over a contact glass 41 while being held down by an internal document pressing plate 40. During this conveyance, the leading edge of the document is detected by a leading edge detection sensor 42 provided at the bottom of the contact glass 4l. In order to allow the sensor 42 to detect the leading edge of the document, a circular hole or notch is formed in the document holding plate 40 at a position facing the sensor 42.

The exposure optical system 22 is located downstream of such a sensor 42.
is provided. The exposure optical system 22 includes a fluorescent lamp 43 that exposes the surface of the document conveyed on the contact glass 41.
, a reflection plate 44 that efficiently reflects a portion of the light from the fluorescent lamp 43 onto the document surface, and a reflection plate 44 that reflects light from the document surface to the photoreceptor 20
It consists of a rinse (imaging optical element) 45 that irradiates condensed light onto the lens.

On the other hand, the document inserted and transported by the transport rollers 37 and 38 is transported by a pair of transport rollers 46 and 47 provided further back than the contact glass 41, and is formed by an inner guide 48 and an outer guide 49. After passing through the reversing conveyance path 50, the document is discharged onto the document discharge table l2 by the discharge rollers l1. The outer guide 49 is formed by a part of the rear cover 6, and also serves as an exterior cover. These rollers 11, 37, 38, 46, 47, reversing conveyance path 50, tables 1, 12, etc. constitute the document feeding and conveying means 28.

The transfer charger 24, the LED array 27, and the fluorescent lamp 43 are turned on in synchronization with the start of driving of the photoreceptor 20 in conjunction with the drive motor as a result of the document detection by the document presence/absence sensor 39.

When the position of the photoreceptor 20 corresponding to the position where the leading edge of the document reaches the optical axis of the rinser 45 reaches the position of the charger 21 after the start of driving, the charger 2
1 is turned on, and the surface of the photoreceptor 20 is uniformly charged, that is, a uniform potential is applied.

Then, the rinse 45 removes the reflected light from the original onto the photoreceptor 2.
0, forming an electrostatic latent image.

This electrostatic latent image is developed by a developing device 23, and this visualized toner image is transferred onto transfer paper at a transfer charger 24 position. After the transfer, the toner remaining on the photoreceptor 20 is scraped off by a cleaning device 26.

Furthermore, the residual potential on the surface of the photoreceptor 20 is removed by light irradiation from the LED array 27.

Here, the photoreceptor 20 has a seam, and in order to prevent the image from appearing across the seam position, a reflective mark 52 and a developing device 23 are provided on the surface edge of the photoreceptor 20 as shown in FIG. The home position of the photoreceptor 20 is detected by a seam sensor 53 provided at the bottom of the belt, and the belt drive, that is, the drive motor is turned off.

On the other hand, the detection signal from the document presence/absence sensor 39 transmits the drive to the clutch on the paper feed table side in conjunction with the drive motor, and the detection signal from the document leading edge detection sensor 42 turns on the paper feed solenoid, and the clutch shaft The transfer paper stacked on the paper feed table 3 is fed and conveyed by the paper feed roller 55 and the calling roller 15 that engage with each other. At this time, only the topmost sheet of the stacked transfer papers is separated and conveyed by the friction pad 56 pressed against the paper feed roller 55. Further, the leading end guide 35 is also moved downward to the downward retracted position at a timing linked to the downward feeding operation of the calling roller 15.

The transfer paper conveyed by the paper feed roller 55 passes through a reversing conveyance path 59 that is made up of an inner guide 57 and an outer guide 58 and serves as a reversing conveyance guide means, and then passes onto the photoreceptor 2 in an inverted state.
Head to the transfer position of 0. Here, a registration roller 60 and a driven roller 61 are provided in front of the transfer position, and the transfer paper is temporarily stopped at the positions of these rollers 60 and 61, and the timing is adjusted so that it coincides with the leading edge of the image on the photoreceptor 20. controlled. That is, the clutch engaged with the shaft of the registration roller 60 is interlocked with the drive motor in the same manner as the drive transmission of the paper feed clutch described above, and the drive is transmitted to the registration roller 6o by the detection signal of the document leading edge detection sensor 42. Synchronization with visualization is achieved. Further, it is also possible to use the detection signal of the seam sensor 53 as the registration start signal.

Further, a paper presence/absence detection sensor 62 for detecting a jam is provided at a position immediately in front of the registration roller 60.

The transfer paper conveyed at a predetermined timing by the registration rollers 60 receives the transfer of the toner image on the photoreceptor 20 by the transfer charger 24 . Thereafter, the transfer paper is conveyed while being thermally fixed by a fixing roller 63 and pressure roller 64 pair of the fixing device 25, peeled and guided by a peeling claw 65, and discharged from the machine by a paper discharge roller 66. That is, the transfer paper conveyance path in the transfer paper feed conveyance means 29 of this embodiment includes the paper feed path of the paper feed means including the paper feed table 3, the calling roller 15, the paper feed roller 55, and the friction pad 56, and the reversal conveyance path. 59, a registration roller 60 and a driven roller 61 pair,
Transfer path by transfer charger 24 and fixing roller 63
- Consists of 64 pairs of pressure rollers and a paper ejecting path by a paper ejecting roller 66, and is set so that the operation side (front side) is the paper insertion and paper ejection side, similar to the case of the document feeding and transporting means 28. has been done.

That is, the reversing conveyance paths 49 and 59 are for reversing and conveying the paper clockwise in FIG.
The direction of movement of the original and the transfer paper is made to coincide with the direction of movement of the photoreceptor at each working position by exposing the original and the transfer paper to light before reversing on the transfer paper feeding and conveying device 29 side and subjecting the transfer paper to transfer after reversal. There is. Therefore, all operations on the original and the transfer paper can be performed only on the operating side of the apparatus, resulting in good operability.

At this time, the paper discharge detection sensor 6 provided near the paper discharge roller 66
7 is used to detect a jam from the sensor 63 of the registration section, and the off signal (when the trailing edge passes) is used to send a signal to the seam sensor 53, which detects the reflective mark 52 on the photoreceptor 20 and drives the sensor 63. Turn off the motor. The transfer charger 24, the static elimination LED array 27, and the fluorescent lamp 43 are turned off in synchronization with the turning off of the drive motor.

Furthermore, the charger 21 is turned off at the corresponding position of the photoreceptor 20 when the position at which the document presence/absence detection sensor 39 is turned off reaches the optical axis of the rinser 45 . The paper feed solenoid is turned off in synchronization with the on of the registration solenoid, and the registration solenoid is turned off in synchronization with the off of the paper discharge detection sensor 67.

This completes the copy processing operation and enters a standby state. Therefore, by closing the document transport table l and the paper feed table 3 as shown in FIG. 2, the open/close switches 31 and 32 are turned off, and in synchronization with this, the fixing heater 33, fluorescent lamp heater 34, and Cooling fan 30 is turned off.

Hereinafter, the structure and operation of each process unit constituting the present machine, which performs the above-mentioned general operation, will be individually explained in detail.

[Photoreceptor 201...see FIGS. 1, 5, and 6.

The endless belt-shaped photoreceptor 20 is supported in an inverted triangular vertically elongated state by a plurality of rollers disposed on its inner circumferential side and inscribed therein, that is, a driving roller 7o, a driven roller 7l, and a transfer roller 72. , and for the outer peripheral surface, a developing roller (circumferential roller) 73 and a cleaning roller (circumferential roller) 7
4 are circumscribed in a concave manner so that the interval between the center portions within the belt is narrowed. When the drive motor 75 (see FIG. 6) is turned on, the drive roller 70
A drive gear 76 that engages with the photoreceptor 20 rotates at the same speed as the document conveyance roller 37 . Here, the driving roller 70 is made of a material with high frictional resistance, such as a rubber roller or a flocked roller, and is provided at a position downstream from the image forming position by the rinser 45 with respect to the photoreceptor 20 but upstream from the developing roller 73. There is. Drive roller 7 is placed in such a position.
0, the photoreceptor 20 is given tension to always give flatness to the image forming position, and the developing roller 73 side becomes the slack side, so that the developing roller 73 and the photoreceptor 2
The stress at the nip with 0 is alleviated, and followability of both can be achieved.

The transfer roller 72 is disposed at a position downstream of the developing roller 73 and facing the transfer charger 24 . The photoreceptor 20 is recessed by the driving roller 70, the developing roller 73, and the transfer roller 72, which are located at almost the same position on the same vertical line, so that the developing nip in the developing roller 73 is wide, and the intermediate Since the developing roller 73 is wedged in to minimize the empty space on the inner peripheral side of the photoreceptor 20, the device can be made thinner.

The driven roller 7l is disposed at the same height as the driving roller 70, that is, at a position opposite to the driving roller 70 such that the imaging portion of the photoreceptor 2o is perpendicular to the imaging optical axis formed by the rinse 45. There is. The cleaning roller 74 is pressed to make the photoreceptor 20 concave at an intermediate outer peripheral position M between the driven roller 7I and the transfer roller 72 (that is, a position after the transfer process but before the charging process). There is. In this way, the photoreceptor 20 is provided in a vertically elongated state and in a narrow state in which the central portion is recessed as much as possible.

The transfer roller 72 has a smooth surface and low friction. Therefore, in order to prevent the photoreceptor 20 from shifting,
A deviation prevention guide protrusion 77 is formed on both sides of the inner circumference of the photoreceptor 20 (see FIG. 5, etc.), and is configured to be regulated at the end of the transfer roller 72 (see FIG. 33). reference)
. The guide protrusion 77 is mainly made of a urethane rubber material, and does not interfere with the flexibility of the loop of the photoreceptor 20 and prevents deterioration due to the environment. Transfer roller 7
2, a porous hollow roller that does not cause problems with the surface properties of the photoreceptor 20 is suitable in order to prevent a rise in temperature within the loop of the photoreceptor 20.

Note that a means for imparting flatness, such as a tension plate, may be provided on the inner surface of the image forming position of the photoreceptor 20 to prevent image blur. However, according to this embodiment, the span between the drive roller 70 and the driven roller 7l is minimized due to the above configuration, and the image formation position is located on the tension side of the drive roller 70, so this is especially true. Image blurring can be prevented even without providing a tension plate or the like.

Incidentally, as shown in FIG. 5, conductive layers 78 painted black are provided on both sides of the effective image area on the surface of the photoreceptor 20, which is formed into a loop shape by the seam. A static eliminating brush 80 is provided in the casing 79 of the photoreceptor 20 in the vicinity of the drive roller 70 and is in opposing contact with the conductive layer 78 . A leaf spring 8l is in contact with the static elimination brush 80, and the conductive layer 78 is grounded via the static elimination brush 80 and the leaf spring 81. The detection mark 52 for seam detection is gold-colored and provided on a portion of the conductive layer 78.

An opening 82 is formed in the casing 79 at a position facing the seam sensor 53 at a position on the trajectory of the detection mark 52, so that the seam sensor 53 can detect the detection mark 52, and the seam position is always kept in a non-image area. It is subject to control to ensure that

In addition, a portion of the surface of the photoreceptor 20 has a 3.
An uncharged layer portion 83 for forming a blank portion at the leading edge of the transfer paper is formed over the entire width at a position corresponding to ±2.5+++m. This uncharged layer portion 83 is formed by coating a black conductive material, and its position is controlled by a detection signal from the seam sensor 53. Generally, in this type of electrostatic recording device, the image on the photoreceptor 20 is transferred to transfer paper, and the image on the photoreceptor 20 is
After separation from 0, post-processes such as fixing are performed, but it is necessary to form a blank area at the leading edge of the transfer paper to prevent a fixing jam due to the transfer paper wrapping around the fixing roller 63. After uniformly charging the surface of the photoreceptor 20, an image is obtained on the transfer paper through the processes of exposure, development, transfer, and fixing.
Even if it is uniformly charged by , it will not be charged and no electrostatic latent image will be formed, so it is equivalent to erasing the charge with an eraser. Therefore, by matching the timing of the position of the uncharged layer portion 83 and the leading edge of the transfer paper, a white spot can be formed at the leading edge of the transfer paper without using an eraser.

Therefore, the device can be made more compact. Further, as described above, it is easy to provide such an uncharged layer portion 83 in a belt-shaped photoreceptor by painting or the like.

The casing 79 that supports and covers the mechanism around the photoreceptor 20 rotatably supports each of the rollers 70 to 72 via sliding bearings, and the casing 79 is bent due to the loop configuration of the photoreceptor 20. In consideration of the possibility that contact with the inner surface may occur, an inner surface treatment (low-friction treatment) to prevent deterioration of the photoreceptor 20 or low-friction members are provided at key points within the casing 79 .

In addition, the casing 79 has a bearing of the transfer roller 72 fitted into a lower guide (not shown) provided on the main body side plates 85 on both sides, and an upper guide (not shown) which similarly engages with the main body side plate 85. By rotating and mounting the bearing of the driven roller 71, positioning with an exposure optical system, which will be described later, is achieved.

[Original feeding and conveying means 28]...See FIGS. 7 and 8.

The document feed conveyance means 28 is arranged at the uppermost position above the photoreceptor 20. First, when you manually push the document transport table l whose outer surface also serves as an exterior cover, the lock 90 provided inside it is released, and when you grasp the handle 8 and lift it up, the relay fulcrum 91, rotation fulcrum 92, arm 93 The document transport table l is then rotated and guided to the set open position.

As shown in FIG. 8, the pair of side guides 9 provided on the document transport table 1 have rack gears 94.95 connected to each other and arranged inside, and a rack gear 94.95 located in the center. When one side guide 9 is moved, the other side guide 9 is also moved in the opposite direction by the same amount in conjunction with the pinion gear 96 that meshes with the pinion gear 95.

Inside, conveyance rollers 37 and 46 rotatably supported by the main body side plate 85 via bearings are provided at front and rear positions of the contact glass 41.

Driven rollers 38 and 47 are provided above these conveyance rollers 37 and 46 to rotate in a driven manner.

The document holding plate 40 located on the upper surface of the contact glass 41 is rotatably supported by a bearing of a driven roller 47 and is positioned on the contact glass 41 by its own weight. Further, the lower surface of the document holding surface 40 is white and made of a low-friction material.

Further, the outer guide 49 is formed as a guide fin by a rib on the back cover 6 of the main body.

An inner guide 48 is provided at a constant distance from the outer guide 49 and guides the document conveyed by the pair of rollers 46 and 47 toward the paper discharge side.

In addition, a reversal conveyance path 50 by these guides 48 and 49
The document being conveyed is discharged by a paper discharge roller 11 attached to the document feed conveyance means 28 side and a plurality of driven rollers 97 attached to the rear cover 6 side of the main body and pressed against the paper discharge roller 11. It is something.

As the document conveyance and ejection path is simplified and shortened as described above, when copying the maximum number of copies, trouble may occur when the transfer paper is conveyed after the registration position, and jam detection is activated, causing the drive motor 75 to shut down. Even if it stops, the document will be completely ejected, so there is no need to maintain the document when the transfer paper jams. Furthermore, if a jam occurs during paper feeding before the registration position of the transfer paper, the document will be present in the document feeding and conveying means 28 because it is being conveyed, but in this case, the inner cover The contact glass 41 or outer guide 49 portion is opened by rotating the document ejection table 12, which forms the main body, about the hinge 98, and by lifting the document holding plate 40 by its handle around the axis of the driven roller 47. The image is exposed and the original can be removed. Furthermore, cleaning on the contact glass 4l becomes possible.

[Exposure optical system 22]...See FIGS. 9 to 11.

The exposure optical system 22 is disposed directly above the photoreceptor 20 and below the document feeding and conveying means 28 .

In this exposure optical system 22, each constituent part is laid out on one floor by an optical unit base lOO attached to a main body side plate 85. First, a socket 101 that holds both ends of a fluorescent lamp 43 that illuminates a document transported by the document transport roller 37 when it passes over a contact glass 4l having a thickness of 3 mm is positioned on a rising piece of the optical unit base 100. installed. Fluorescent lamp 43
Since the image density changes depending on the temperature of the tube wall, it takes a long time to stabilize before reaching the set light amount. This changes depending on the environment and manual notch operation, so in this embodiment, a fluorescent lamp heater 34 is provided on the bottom surface of the fluorescent lamp 43, and the tube wall of the fluorescent lamp 43 is warmed up in synchronization with the start of warming up the main body. I try to do this. This fluorescent lamp heater 34 is also supported on the optical unit base 100 and is pressed against the fluorescent lamp 43 side by a spring 102. When considering the temperature of the tube wall of the fluorescent lamp 43, according to this embodiment, the unit section is formed into one floor by the optical unit base lOO, and the fluorescent lamp 43
By preventing cooling due to heat dissipation, the warm-up time is shortened and fluctuations due to the external environment are also reduced.

The aperture angle of the fluorescent lamp 43 is set in a range of approximately 60 to 80', which is most efficient for the amount of light. A lightweight and low-cost aluminum bright alloy plate is used for the reflection plate 44 for condensing the reflected light from the document surface, and a side erase-shaped portion 44a that reflects the light to a position outside the maximum effective copying width of the photoreceptor 20 is also used. It is integrally bent.

By side erasing the outside of the image area on both sides using such side erase shaped portions 44a, the burden of preventing toner scattering near both sides of the cleaning device 26 is reduced.

An automatic light control sensor 103 is mounted on the optical unit base 100 on the back side of the reflector 44, facing an opening 44b formed in the reflector 44. This automatic dimming sensor 103 receives and detects the light intensity of the fluorescent lamp 43, converts it into voltage, compares it with the base i11 voltage specified in advance by the manual notch using CP[J, and outputs a dimming control signal according to the comparison result. Output to fluorescent light ballast. The fluorescent lamp ballast converts the dimming control signal into a lighting signal to vary the light emission output of the fluorescent lamp 43, and by repeating this, the light amount of the fluorescent lamp 43 is controlled to be stabilized at a pre-specified notch. Ru. The emitted light color of the fluorescent lamp 43 is green, and the peak wavelength is 543 nm.
This is the most suitable wavelength for the spectral sensitivity of the photoreceptor layer of the photoreceptor 20.

Note that the document leading edge detection sensor 42 is connected to this automatic light control sensor 1.
It is housed in the same case as 03.

The optical unit base 100 is provided with brackets 104 that support and position the contact glass 41 and support both sides of the rinse 45 as a positioning holder. A leaf spring (not shown) for fixing the rinse 45 in proximity to the bracket 104 is also provided. A soft polyurethane foam 105 is provided around the rinse 45 to block reflected light.
In addition to preventing flare light toward the exposure slit 106 side formed on the optical unit base 100 facing the optical unit base 5, resonance from the main body side is also prevented.

[Electrical charger 2l and static elimination LED 27]...See FIG. 1 and FIGS. 12 to 17.

The charger 21 is disposed above the photoreceptor 20 and upstream of the rinse 45 .

More specifically, it is located on the lower surface of the optical unit base 100 and upstream of the exposure slit 106 with respect to the moving direction of the photoreceptor 20 . The electrification charger 21 includes a casing 110, a charge wire 111, and a grid 112. The casing 110 is the optical unit base 10
Using the cut and bent portion 113 formed in the shape O as a guide, the casing claw 114 facing the cut and bent portion 113 is fitted, and the casing claw 114 is fitted onto the optical unit base 100.
The casing arm portion 115 on the opposite side is fixed. A leaf spring 116 is provided on the optical unit base 100 and presses the casing 110 at a position close to the casing claw 114 to position it. Openings 117 are formed at three locations in the longitudinal direction on the upper surface of the casing 110, and ozone 0.0. is made to escape from inside the casing 110 to the outside.

The grid 112 for applying a uniform charging potential to the photoreceptor 20 applies tension to the bracket 118 engaged with the casing 79 via a spring 119, as shown in FIG. A constant gap is always maintained. A varistor 120 is provided on the optical unit base 110 to perform constant discharge without being affected by uneven discharge of the charger 21, environmental fluctuations, power supply fluctuations, etc. This barista 120
The connection is made by a leaf spring 122 provided through an insulating holder 121. This prevents uneven charging due to external factors. Further, the static elimination brush 80
A grounding leaf spring 8l is also supported by the optical unit base 100.

The static elimination LED array 27 is disposed upstream of the charger 2l and is used to remove residual potential remaining on the surface of the photoreceptor 20 after the transfer process.

This 1t LED array 27 is connected to the optical unit base 10.
It is positioned and supported by a holder 123 attached to 0. This static elimination LED array 27 is irradiated with a light intensity of 23 to 46 μW/c over a wider area than the charging width of the charger 2l.

[Developing device 23]...See FIGS. 18 to 22.

After being uniformly charged, the electrostatic latent image formed on the photoreceptor 2o by the exposure optical system 22 is approximately reversed at the position of the drive roller 70, and then located approximately directly below the drive roller, and is located on the operating side. The rear cover 6 at the opposite innermost portion is developed by a developing device 23 provided on the rear cover base 130. Here, since the developing device 23 has the developing roller 73 in contact with the belt-shaped photoreceptor 20 in a concave state,
It is possible to ensure a sufficient developing nip and perform stable developing operation. Further, wasted space within the belt is minimized, and the developing device 23 can be placed around the concave shape of the developing roller 23, making it possible to make the belt even thinner and more compact. Further, by arranging only the developing device 23 on the back side of the photoreceptor 20, developer stains and the like can be reduced on the operation side that involves opening and the like.

The developing device 23 uses a one-component magnetic roll developing system, and is configured to replenish consumed toner using a toner cartridge 131. This toner cartridge 131 has guide grooves 1 formed on both sides of the developing unit side plates 132.
33 to fit and position the rotating shaft 134 of the toner cartridge 131, and while rotating the toner cartridge 131, the bins 135 at both ends are attached to the developing unit side plate 13.
It is fitted into the positioning groove 136 of No. 2 for positioning.

Toner is replenished from the toner cartridge 131 by winding up the shield in the current manner, engaging the attached winch 137 with the shield, and chucking the toner onto a roller 138 that is rotatably supported by the toner cartridge 131. This is done by rotating it manually. As a result, the shield is rolled up and peeled off by the roller 138, the lower surface of the toner cartridge l3l is fully opened, and the toner inside falls.

The fallen toner is deposited in a developing housing consisting of a developing unit side plate 32, a casing 139, and a blade holder 140. Toner scattering, which is a problem during this falling pile transfer step, is prevented by sealing the casing installation portions of the casing 139, the blade holder 140, and the developing unit side plate 132 with soft polyurethane foam 141, respectively.

The toner deposited in the developing housing is agitated by an agitator 142 rotatably supported by the developing unit side plate 132 via a shield bearing, thereby preventing blocking due to toner accumulation.

Below this agitator 142 and at the lowest point in the housing, two two-blade rollers 143 and 144, which are rotatably supported by the developing unit side plate 132 via a shield bearing, are provided side by side with the developing roller 73, similar to the agitator 142. It is being Here, since the bottom of the casing 139 is formed into a curved shape along the rotation locus of these two-blade rollers 143, 144, the rotating two-blade rollers 143, 144 have a width difference between them and the casing 139. These two-blade rollers 143,
The toner that has fallen onto the portion 144 is transferred in the direction of rotation. As a result, the toner is transferred from the agitator 142 to the two-blade roller 144 via the two-blade roller 143, and is smoothly supplied to the developing roller 73 by the two-blade roller 144.

The developing roller 73 has a built-in magnet for conveying toner. Further, a metal blade plate 145 for frictionally charging the toner is attached to the blade holder l40, and its lower side is attracted to the surface of the developing roller 73 by the magnetic force of the built-in magnet. That is, the blade plate 145 is positioned with respect to the developing roller 73 by the blade holder 140 attached to the developing unit side plate 132. As described above, the blade holder 140 also serves as a casing for the agitator 142, improving toner agitation performance.

Therefore, as the developing roller 73 rotates, the blade plate 145 vibrates due to the magnetic force of the magnets whose polarities are arranged inside the blade plate 145, so that gaps are intermittently generated between the blade plate 145 and the developing roller 73. When the toner is conveyed from this gap by magnetic force, it is frictionally charged to a positive polarity, and a substantially uniform toner layer is formed on the surface of the developing roller 73. Here, a ring 146 made of soft urethane foam is interposed in the journal portion of the developing roller 73 to seal a gap between the developing roller 73 and the developing unit side plate l32. Therefore, toner scattering and falling from the gap between the developing roller 73 and the developing unit side plate 132 is also prevented. Furthermore, the under case 1
47 (here, it is integrally formed with the casing 139) is provided downstream of the developing roller 73 and having the same width as the developing unit side plate 132. Further, within the undercase 147, a static eliminating brush 148 for removing potential remaining on the surface of the developing roller 73 after development is provided over almost the entire length of the developing roller 73 in a state of being in contact with the surface. Further, since the upper opening of the under case 147 is provided at a position where the developing roller 73>photoreceptor 20
3 side (linear velocity ratio is 4:1).

In addition, in order to transfer the toner on the surface of the developing roller 73 to the photoreceptor 20 side for development, the electrode plate 149 provided on the side plate 132 of the developing unit is connected to 1! This electrode pin 150 is connected to the ground via the electrode pin 150, while the electrode pin 150 is connected to the main body development bias power supply.
A potential difference is created by applying a voltage to the developing roller 73 via the developing roller 73. Further, although a potential remains on the surface of the photoreceptor 20 after exposure, at a location corresponding to the paper background, toner transfer is prevented by controlling the application of the developing bias voltage, so the background stain after transfer is prevented. Prevented.

Incidentally, by repeating such development processing, the toner in the unit is consumed, and the state of consumption is detected by a toner end sensor l51 provided in the main body. This toner end detection will be explained with reference to FIGS. 20 and 21.

First, a gear 152 is provided on the axis of the agitator 142. This gear 152 has a groove, and a spring 153 on the inner circumference for engaging with the agitator 142.
is mediated. Further, a disk l54 that engages with the spring 153 and the shaft of the agitator 142 and has a notch 154a formed therein is provided. This disc 1
A roller 157 of an actuator 156 biased by a spring 155 is rotatably provided on the outer periphery of the actuator 54 .

This ensures that when toner is present, the agitator 142
rotates later than the gear 152 due to the toner load. Therefore, the notch l54a of the disk 154 and the gear 152
(Fig. 20(a) and 2l)
(state shown in Figure (a)), the rollers 157 follow on the outer circumferences of both sides.
Since the load on the disc 154 is reduced, the notch 154 of the disc 154
a and the groove of the gear 152 (the state shown in FIGS. 20(b) and 21(b)), and the roller 157 is fitted, so the actuator 157 turns on the photo-interrupter type toner end sensor 151. let

Then, the toner replenishment display will be lit.

By the way, the driving of the developing device 23, especially the rotational driving of the developing roller 73, is directly rotationally driven by the driving motor 75, and as shown in FIGS. 22 and 19, the driving on the axis of the driving motor 75 is The developing roller 73 is connected to the gear 160.
The gears 161 are substantially directly connected via gears 162a and 162b having different diameters. In addition, other members in the developing device 23, namely the agitator 142, the two-blade roller 143,
144 is a gear 163 that is integral with the gear 161 and has a different diameter.
In addition, gears 164, 165, 166, 167a, 167
b, 152. The gear 165 is provided on the axis of the two-blade roller 144, the gear 166 is provided on the axis of the two-blade roller 143, and the gear 152 is provided on the axis of the agitator 142, as described above. On the other hand, the driving members in each process unit other than the developing device 23 are also driven by the single drive motor 75 as a driving source, but the driving members are driven by a different route from the drive transmission relay to the developing device 23 as shown in FIG. It is driven via a relay transmission means l68 using a gear group. In this way, since the developing roller 73 is driven almost directly to the drive motor 75 and is performed independently of other process units, vibrations from other units etc. are not transmitted to the developing roller 73 ( (no resonance), and development defects such as uneven image density are also prevented.

[Paper feeding section of transfer paper feeding and conveying device 29]...See FIGS. 23 to 30.

The transfer paper feeding and conveying device 29 is provided directly below the photoreceptor 20 . First, the paper feed table 3 is supported by unit side plates 170 on both sides via support shafts 171 so as to be rotatably openable and closable. At this time, a sector gear 172 is provided on the support shaft 171 and meshes with an oil damper gear 173 fixedly supported on the unit side plate 170, forming a gear damper structure. Further, a locking member 174 is provided on the unit side plate 170, and hooks 175 protruding from both sides of the paper feed table 3 are engaged and disengaged.
It is configured so that it can be opened by being locked or unlocked. That is, when the outer surface of the closed paper feed table 3 is manually pushed, the hook l75 comes off from the locking member 17.4, and the lock is released, and the paper feed table 3 is moved to the support shaft 17.
1 as the center of rotation, and the sector gear 172 and the oil damper gear 173 are engaged to semi-automatically open the opening state linearly. At this time, the safety switch 32 is pressed and turned on by a part of the paper feed table 3, and the switch 3l is turned on.
A warm-up state is entered by ANDing with the ON signal of . Further, the sheet feeding table 3 is positioned in the open state by a portion of the sheet abutting against a stopper 176 provided on the main body side.

Here, in the open paper feed table 3, a pair of side guides 13 are attached as in the case of the document transport table l.
The rack gears 177, 178 and the pinion gears 179 are combined to move in the width direction in conjunction with each other. Further, a friction pad l6 provided at the center of the innermost part of the paper feeding table 3 is paired with a calling roller l5 to ensure that the stacked transfer papers are fed to the last one.

Transfer paper is set on the paper feed table 3, and the paper feed solenoid 180 provided on the unit side plate 170 is turned on in response to a document leading edge detection signal on the document feed conveyance side, and the claw 181a of the clutch claw 181 moves from the sleeve 182. As it separates, the claw 18lb separates from the protrusion 183 and the main motor 7
The driving force of the five rollers is transmitted to the feed roller 15 via the paper feed roller 55 and the square belt 184, and is also transmitted to the cam portion 186 of the feed clutch 185, and each is driven to rotate. As the cam portion 186 rotates, the bin 187a
The sector gear 187 joined to the outer periphery of the cam portion 186 rotates counterclockwise, and the big up arm 189 is rotated clockwise via the pinion gear 88. This kick-up arm 189 has a cam shape, and is pressed into contact with an arm 191 connected to a support 190 of the feed roller 15 (which is rotatable around the axis of the paper feed roller 55).

Therefore, when the pickup arm 189 rotates clockwise, the calling roller 15 is displaced downward onto the transfer paper. Further, the shaft of the tip fence 32 is connected to the big up arm 189 via a pinion gear 192 and a sector gear 193.
By rotating clockwise, the leading edge fence 35 is also rotated to a forwardly tilted state, making it possible to feed the transfer paper. moreover,
When the cam portion 186 rotates, the sector gear 187 rotates.
rotates clockwise, the calling roller 15 is displaced upward, and the tip fence 35 is also returned to its raised state. This prevents double feeding.

Here, feed clutch 1. 8 6 and cam part 186
The function is that when the paper feed solenoid 180 is turned on, the second
As shown in FIG. 9(a), the clutch pawl 18lb is
83, and the cam portion 186 rotates counterclockwise.

Further, the clutch pawl 181a also separates from the sleeve 182. When the cam portion 186 further rotates, as shown in FIG. 29(b), . The protrusion 194 hits the clutch pawl 181c and stops the rotation of the cam portion l86. At this point, the sector gear 187 has completed one reciprocating operation, and the calling roller 15
has finished rising. When the paper feed solenoid 180 is turned off, as shown in FIG. 29(c'), the clutch pawl 18l
b hits the convex portion 183, and the clutch pawl l8la also hangs on the sleeve 182.

Next, the paper separation and feeding operation will be explained with reference to FIG.

First, the tip fence 35 is pushed forward and the calling roller l
5 contacts the transfer paper 195 on the paper feed table 3. This rotation of the calling roller l5 is transmitted to the transfer paper 195, and only one sheet is fed from the paper feed table 3 by the friction butt 16. The fed transfer paper 195 is transferred to the paper feed roller 55
Conveyance continues as it is, and feed clutch 1
By the rotation of the cam portion 186 of 86, the calling roller l5 is separated from the transfer paper, and the tip fence 35 is also raised.
The next transfer paper 195 is prevented from being sent out. Then, the paper feed solenoid 180 is turned off with a certain amount of slack detected by the registration sensor 62, and the paper is on standby for synchronization with the developed image on the photoreceptor 20.

When not in use, the hook l-75 is engaged with the locking member 174 and locked in the closed state by manually lifting the paper feeding table 3 and rotating it in the closing direction.

[Near transfer charger 24]...Figures 31 to 3
See Figure 3.

The transfer charger 24 is disposed directly below the photoreceptor 20 and facing the transfer roller 72 . A registration roller 60 is supported on the main body side plate 85 via a bearing 200 at an upstream position of the transfer charger 24 .

A transfer casing 201 is provided which is fitted and supported by the sliced portion of the bearing 200 and is rotatable around the outer diameter of the sliced portion. The opening of the transfer casing 201 is provided with a driven roller 6 that is in pressure contact with the registration roller 60 and rotates as a result.
1 is provided via a bearing 202 and a bracket 203, and forms a lower guide for transporting the transfer paper. The transfer paper 195 conveyed by a pair of registration rollers 6o and driven rollers 6l is guided by a transfer casing 201 provided with a mylar 204 serving as an entrance guide in close proximity to the photoreceptor 20. This Mylar 204 has a convex central portion in the width direction so that the leading edge of the transfer paper can be synchronized with the developed image on the photoreceptor 20, so that the surface of the transfer paper can follow the transfer paper uniformly. Further, the transfer casing 201 is provided with an end block 206 at a position 2Of0.2 mm directly below the center of the transfer roller 72 for holding both ends of a charge wire 205 in a tensioned state for discharging a polarity opposite to that of the toner. As a result, the transfer paper 195 faces the developing image and is electrostatically attracted and conveyed, so that the toner image on the photoreceptor 20 is transferred to the transfer paper 1.
It will be transferred to the 95 side.

Here, in the opening of the transfer casing 201 as the transfer charger 24, a nylon wire 207 is stretched in such a manner that it expands in the paper conveyance direction in order to prevent the transfer paper from getting caught inside. .

Further, after the transfer, it is necessary to separate the transfer paper 195 from the photoreceptor 20. In this respect, separation is generally performed using a separation charger or the like, but in this embodiment, separation is performed using the curvature of the transfer roller 72, and no separate dedicated separation means is required. Photoreceptor 20 after transfer
A guide fin 208 for guiding the transfer paper 195 peeled off from the transfer paper 195 to the fixing nip portion of the fixing device 25 is attached using a part of the transfer casing 201 similarly to the nylon wire 207.

[Fixing device 25]...See FIGS. 34 to 36.

The fixing device 25 heats and fixes the unfixed toner on the transfer paper 195 that enters from the transfer section side using a roller pair consisting of a fixing roller 63 and a pressure roller 64. It is placed in the front position. First, the fixing roller 63 has a gear 210 on its axis that is rotationally driven by a drive motor 75, and is supported by the unit side plate 170 via a sliding bearing 211. Further, the pressure roller 64 side is supported by a unit side plate 170 via a sliding bearing 212 so as to be slidable up and down, and a pressure lever 214 is engaged with a spring 213.
The fixing roller 63 is urged to come into pressure contact with the fixing roller 63. When the transfer paper 195 passes through the pair of rollers 63 and 64, it is fixed at a constant temperature (180 to 185° C.) and a constant pressure (18 to 21 kg).

Here, the fixing roller 63 is a Teflon-coated thin AQ tube roller with a high thermal conductivity integrally molded with a journal part, and a fixing heater 33 is built in on the axis. Both ends of the fixing heater 33 are supported by bracket terminals 215 and energized. At this time, in order to improve thermal efficiency, the inner wall surface of the fixing roller 63 may be painted black or the like.

Incidentally, a thermistor 220 is provided in contact with a part of the upper circumference of the fixing roller 63 to control the temperature of the fixing heater 33. Further, a thermostat 221 is also provided in contact with the upper peripheral portion of the fixing roller 63 to prevent the temperature of the fixing heater 33 from rising excessively due to some kind of accident or the like. More specifically, these thermistor 220 and thermostat 221 are mounted and supported at separate positions in the width direction via a heat shield plate 222. The heat shield plate 222 is located near the outer periphery of the fixing roller 63 and reflects the radiant heat from the fixing roller 63. Further, a heat insulating cover 224 is provided to face the heat shield plate 222 with a space 223 in between. In other words, around the fixing roller 63, the heat shield plate 2
It has a two-layer insulation structure consisting of a space 22 and a space 223.

The outer surface side of the heat insulating cover 224 is flocked.

By the way, this heat insulating cover 224 includes a fixing roller 63.
A plurality of slits (vents) 22 are located almost directly above the
5 is provided, in which two cooling fans 30 are mounted and held. That is, the cut and bent portion forms a vent hole and also serves as a cooling fan bracket. The two cooling fans 30 are installed between the minimum copy size end and the maximum copy size end when viewed in the axial direction of the fixing roller 63. Further, a first duct 226 is provided above to shield almost the entire area of the heat insulating cover 224, including the cooling fan 30. A heat insulating material 227 such as polyurethane foam is interposed between the first duct 226 and the heat insulating cover 224. This prevents thermal deformation. In particular, in this embodiment, this abutting surface, that is, the outer surface of the heat insulating cover 224 is treated with flocking, resulting in a high heat insulating effect.

Further, the cooling fan 30 is installed in the upper part of the duct 226.
A pair of left and right second ducts 228 and 229 are provided that communicate with the exhaust port side and guide the exhaust flow toward the side surface of the main body.

A filter 230 is provided near the exhaust exits of these second ducts 228 and 229.

Note that the first duct 226 and the second ducts 228, 229
A third duct 231 for upward exhaust is provided at the upper center of the duct, and the duct is formed by fitting into a rib 232 formed on the back surface of the front cover 2 forming the exterior cover (see Fig. 12). ).

According to the heat insulation/cooling structure around the fixing roller 63 of this embodiment, the radiant heat of the fixing roller 63 is transferred to the heat shield plate 222.
The heat in the space 223, which is the second air layer, is absorbed by the heat insulating cover 224. Moreover, at this time, since the heat shield plate 222 has a duct shape, the air whose temperature has increased due to suction by the cooling fan 30 is exhausted to the outside of the machine through the 1.2.3 ducts 226, 228, 229, and 231. , it is possible to prevent the temperature of each part located on the side of the photoreceptor 20 from rising. Furthermore, ozone generated from the transfer section is also removed from the cooling fan 30 and the 1.2 ducts 226, 2.
28 and 229, and can prevent deterioration of the photosensitive layer on the surface of the photoreceptor 20 due to ozone and temperature rise.

A plurality of peeling claws 65 are rotatably provided to peel off the transfer paper 195 after fixing from the fixing roller 63 and guide it to the paper discharge roller 66 side, and are biased toward the fixing roller 63 side by a spring 240. . The paper discharge roller 66 is supported by a guide plate 241 that is disposed close to the pressure roller 64 and also serves as an exterior cover. Further, a paper ejection sensor 67 is also provided near the paper ejection roller 66 using the guide plate 241, and is used to detect transfer paper conveyance time from the registration position, and is also responsible for jam detection in this span. has been done.

By the way, if the transfer paper 195 stops due to some kind of accident at the fixing nip between the fixing roller 63 and the pressure roller 64, the transfer paper 195 may be stopped by engaging the gear 243 provided on the axis of the pressure roller 64. The knob 245 having the gear 244 that can be rotated manually may be used. In addition, for processing when the transfer paper 195 stops at a position in front of the fixing nip, first, the pressure spring 213 engaged with the unit side plate 170 and the pressure lever 214 for the pressure roller 64 are relayed. Bracket 24 to engage
7 is provided.

This bracket 247 has a lock lever 24 that fits into a positioning pin 248 provided by caulking on the side plate 85 of the main body.
9 are connected by a bin 250. Further, a handle 251 is fixed to the center of the front side of the bracket 247. Therefore, hold this handle 251 and remove the bracket 2.
When the lock lever 249 is pulled toward the front, the lock lever 249 is rotated in the opposite direction and removed from the positioning bin 248, and the lock is released. When this lock is released, the unit side plate 2
The unit of the transfer paper feeding conveyance section and the fixing section supported by 52 slides toward the front via a guide 253 provided on the main body side plate 85 and guiding the movement of the bin 250.

At this time, a lever 254 whose one end is connected to the bin 250,
A holding lever 256, which holds and holds this lever 254 in a slidable manner in its longitudinal direction and whose end is connected to the main body side plate 85 via a pin 255, also moves integrally.
Since the bottle 255 is guided by the guide hole 257 of the main body side plate 85, it is in the state shown by the dashed line in FIG. 36. Furthermore, when the unit side plate 252 moves toward the front, the support member 259 provided on the main body base 258 also moves toward the front. These 25 supporting members and 25 unit side plates
A rotation lever 261 is interposed between the pin 260 and the pin 260 so that the unit including the unit side plate 252 can be rotated downward eight times around the pin 260 when the unit is pulled out. Therefore, by rotating the unit near the paper feed section downward as shown by the two-dot chain line in FIG.
The surface of the reversing conveyance path 59 is largely exposed, and the transfer paper 195 can be removed. In this open state, the unit is held by the levers 254, 256 extending to the state shown by two-dot chain lines.

Furthermore, since it is supported by the guide 253 even when it is installed after opening for jam clearance, it is guided in the closing direction as it is, and the lock lever 249 engages with the positioning bin 248 by the action of the pressure spring 213. locked again. When installed in this way, the transfer charger 2
4 is pressed against and positioned by a leaf spring 262 (shown in FIG. 1) provided on the casing 79 relative to the photoreceptor 20.

[Cleaning device 26]...See FIG. 1 and FIGS. 37 to 41.

The cleaning device 26 is for cleaning and removing toner remaining on the photoreceptor 20 after the transfer process using a cleaning roller 74, and is disposed on the upper front side of the photoreceptor 20.

The position of the cleaning roller 74 is downstream of the transfer position and upstream of the charging position, and does not affect the latent image and developed image on the photoreceptor 20. Good too. In order to prevent deterioration of the surface of the photoreceptor 20, the cleaning roller 74 is preferably a soft touch roller such as a brush roller or a surface flocked roller (in this embodiment, it is a brush roller). The flocking material is preferably an acrylic polymer-based carbon-arrayed organic conductive fiber.

Here, a bias roller 270 serving as a bias member is provided on the near side of the greening roller 74. The bias roller 270 is rotatably supported by a cleaning case 271, and is supported by an arm 272 so as to be in constant contact with the cleaning roller 74. In addition, as shown in FIG. 38, a bias roller 270
has a gear 274 that is supported on the side plate of the main body and meshes with a drive gear 273 to which drive is transmitted from the main body. - This gear 274 meshes with a gear 276 on the shaft of the cleaning roller 74 via an idle gear 275, so that the cleaning gear 74 is rotated in the opposite direction to the photoreceptor 20 as the drive gear 273 rotates. It is set. Furthermore, this bias roller 270 is conductive, and as shown in FIGS. 40 and 4l, its shaft 270a
It is connected to the power supply section of the main body through the connecting terminal 277 that is in contact with the toner between the bias roller 270 and the cleaning roller 74 to apply a bias having a polarity opposite to that of the toner charged in the developing device 23 from the bias roller 270. It is. Furthermore, a blade 278 that is always in biased contact with the surface of the bias roller 270 is attached to the cleaning case 271.
installed on.

As a result, when the residual toner on the photoconductor 20 comes to the cleaning roller 74 position, it receives a potential of opposite polarity to the charged polarity of the residual toner, and is electrically neutralized, and the remaining toner remains on the photoconductor 20.
It is scraped off by the cleaning roller 74 by rotation in the opposite direction to the zero movement direction. Cleaning roller 7
The toner collected by step 4 is transferred to a bias roller 27 that is always in contact.
0 and is scraped into the cleaning case 271 by the blade 278.

Now, a mechanism for pressing the cleaning roller 74 against the photoreceptor 20 and releasing the pressure will be explained. First, a set lever 28l is provided that is connected to a lever 279 that is connected to the shaft of the cleaning roller 74 via a pivot shaft 280 on the lower end side. This set lever 28l is provided so as to be slidable in the front direction with respect to a guide bin 282 provided on the outer surface of the cleaning case 271 through an elongated hole 281a. On the other hand, the lower part of the set lever 281 is rotatably supported around a shaft 283, and a torsion spring 284 provided around this shaft 283 allows the lever 279 to
A tension lever 285 is provided for biasing upward. A convex portion 285 on a part of the upper end of the tension lever 285 interferes with the rotation support shaft 280 so that it can be climbed over.
a is formed. Further, a stopper 286 is provided to restrict upward rotation of the tension lever 285.

Therefore, in order to release the pressure from the contact pressurized state shown in FIG. 37 etc., the set lever 281 can be manually pulled in the direction of the arrow (towards the front). Then, the tension lever 285 is pushed by the pivot shaft 280 and rotates downward, and when the pivot shaft 280 passes over the convex portion 285a, the torsion spring 284
Although the tension lever 285 rises due to the action of the tension lever 285, it stops at the stopper 286 position, so that the biasing force against the lever 279 disappears. Therefore, the crevice roller 74 further rotates downward around the shaft 270a of the bias roller 270 due to its gravity, and the pressing force against the photoreceptor 20 is released. Thereby, the tension on the photoreceptor 20 caused by the cleaning roller 74 in the biting arrangement can be weakened. During normal operation, the set lever 281 may be pushed in.

[Electrical parts and their circuit configuration]...See Figure 42.

First, an interlock switch 301, a noise filter 302, a main switch 303, a triac 304, the thermostat 22l, a fixing heater 33, a drive motor 75, and two cooling fans 30 are connected to an AC line for an AC power source 300. Further, a power back 307 for the transfer charger 24 is connected to a DC line from a DC power source 306 connected to the AC line via a power transformer 305. Also, DC22V
The line is connected to the total counter 3 via the relay board 308.
09, paper feed solenoid 180, resist solenoid 31
Output for 0. The relay board 308 is the main PC
In response to the output from the board 311, the output of the fluorescent lamp 43, the fluorescent lamp ballast 312, the power bag 313, the static elimination LED array 27, and the fluorescent lamp heater 34 connected to the 22V line is controlled. The power back 313 is connected to the varistor 1
Power is supplied to the charger 21 via the charger 20. A paper feed section sensor 36, a paper discharge sensor 67, and a thermistor 220 are connected to the DC5V line via a relay board 308.

Similarly, output control for the automatic light control sensor 103, collected toner sensor 314, seam sensor 53, vanless generator 315, and toner end sensor 151 is performed on the 22V line from the main PC board 3l1.

Effects of the Invention As described above, the present invention enables a photoreceptor in the form of an endless belt to be vertically elongated by using a driving roller, a transfer roller, and a driven roller that are in contact with each other, and at least one external roller that is in contact with each other. Since the center of the belt is narrowly spaced, there is no wasted space within the belt, and all that is left is to arrange each process unit around the photoreceptor. Therefore, the main body of the device can be made thin, and a space-saving design is possible.In particular, for the external roller installed at the position after the transfer process among the external rollers, the bias member is used to bias the toner and the opposite polarity toner. is applied to the photoreceptor, it is possible to perform a static elimination cleaning function on the photoreceptor, and the cleaning means can be arranged in a biting manner that also serves as a tension roller, making it possible to create a layout that further improves space-saving design.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a schematic side view mainly showing the photoreceptor, FIG. 2 is an external perspective view when not in use, FIG. 3 is an external perspective view in a usable state, and FIG. 4 is a schematic side view of the entire structure, FIG. 5 is an external perspective view of the photoreceptor, FIG. 6 is a partially cutaway front view mainly showing the photoreceptor, and FIG. 7 is a schematic of the document feeding and conveying device. A side view, FIG. 8 is a plan view of the document transport table, and FIG. 9 is a schematic side view of the exposure optical system.
FIG. 10 is a schematic plan view thereof, FIG. 11 is a schematic front view with a part thereof cut away, FIG. 12 is a schematic side view of the vicinity of the charging/neutralizing section, and FIG. 13 is a schematic plan view of a part thereof. Figure 14 is a front view of a part of it, Figure 15 is a schematic plan view of the vicinity of the charger, Figure 16 is an exploded perspective view of the vicinity of the charger, Figure 17 is its front view, and Figure 18 is the vicinity of the developing device. 19 is a partially cutaway front view of the developing device, FIG. 20 is a side view showing the toner end detection operation, FIG. 21 is a perspective view thereof, and FIG. 22 is a diagram showing the developing device. A side view of the drive transmission system, FIG. 23 is a schematic side view of the vicinity of the transfer paper feeding unit, partially cut away, FIG. 24 is a plan view of the vicinity of the paper feeding table, and FIG. 25 is partially cut away. A plan view of the vicinity of the paper feed section, FIG. 26 is a front view thereof, FIG. 27 is a perspective view, FIG. 28 is a partial perspective view thereof, FIG. 29 is a side view showing paper feed control operation, and FIG. 30 is a side view showing the paper feeding operation, FIG. 31 is a plan view of the vicinity of the transfer unit, FIG. 32 is a side view thereof, FIG. 33 is a partially cutaway front view, and FIG. 34 is a partially cutaway view of fixing. 35 is a partially cutaway side view, FIG. 36 is a side view showing the opening operation in the event of a jam, FIG. 37 is a schematic side view showing the vicinity of the cleaning device, and FIG. 38 is a side view showing the vicinity of the cleaning device. is a horizontal cross-sectional view of a part of it, the third
9 is a bottom view, FIG. 40 is a schematic front view, FIG. 41 is a schematic plan view, and FIG. 42 is a block diagram showing electrical parts and their circuit configuration. 20... Photoreceptor, 2l... Charging means, 22... Exposure optical system, 23... Developing means, 24... Transfer means,
25...Fixing means, 26...Cleaning means, 7
o...Drive roller, 7l...Followed roller, 72...
・Transfer roller, 73.74... External roller, 270・
... Bias member applicant Rico Co., Ltd. 3 q ■ 1 2 3,15 嬌 3, 16 畷mu, j7 1, :%' d 1 J3 Immediate diagram (a) (b) 3d One figure for sending gourds, one cup for ¥1? -”

Claims (1)

[Claims] After uniformly charging the surface of the photoreceptor in the form of an endless belt by a charging means, it is exposed to light by an exposure optical system to form an electrostatic latent image on the photoreceptor, and this electrostatic latent image is transferred to a charged toner by a developing means. The visualized toner image is transferred onto a transfer paper by a transfer means, the toner image transferred to the transfer paper is fixed by a fixing means, and the surface of the photoreceptor after the transfer is cleaned by a cleaning means. In an electrostatic recording device that is designed to be cleaned, when the photoreceptor is in a vertically elongated state, a drive roller connected to a drive source, a transfer roller disposed opposite the transfer means, and a resultant image formed by the exposure optical system are provided. A driven roller is disposed in a position in which the photoreceptor is perpendicular to the drive roller with respect to the image optical axis, and is inscribed in the photoreceptor, and the interval between the center portions in the belt is narrowed. At least one circumscribing roller that is in circumferential contact with the photoconductor is provided at least at a position after the transfer process, and a bias member is provided for applying a bias having a polarity opposite to the toner charging polarity to the circumscribing roller provided at the post-transfer process position. An electrostatic recording device characterized by: