JPH0721664B2 - Openable image forming device - Google Patents

Description

The present invention relates to an image forming apparatus, and more particularly, to a configuration of an image forming apparatus that forms an image on a transfer material such as a copying machine or a printer.

[Conventional technology]

2. Description of the Related Art Conventionally, a copying machine, an LBP, or the like has a transfer material transport path that transports a transfer material into the apparatus, guides it to an image forming unit, and discharges it outside the apparatus after image formation. Then, the transfer material transport path is opened in order to remove the transfer material at the time of trouble in the apparatus of the transfer material, for example, JAM (jam paper jam),
It is configured to be easy for the operator to process.

FIG. 10 shows an example in which the front cover is opened, a part of the conveying path is detached from the image forming means, for example, the photosensitive drum, and the operator puts his / her hand into the opened space to take out the jammed paper. Further, in FIG. 11, the conveyance path is fixed to the lower part of the main body of the apparatus, and the image forming means including the photosensitive drum is detached to the upper part to open the conveyance path so that the operator can easily take out the jammed paper. is doing. It is called a clam shell structure or an alligator type.

[Problems to be solved by the invention]

However, in the conventional example and the first example, since the conveyance path is opened inside the apparatus, the operator has to put his / her hand through the opening hole formed on the front plate side to remove the jammed paper. There was a drawback that it was difficult to remove the paper.

Since the image forming means is also pulled out from the open hole portion of the front side plate, a large hole is formed in the front side plate, which is disadvantageous in terms of strength and vibration.

Further, in the second example, since the upper unit of the image forming means such as the photosensitive drum is detached upward, the upper unit has a conveying path and is lower than the lower unit having a heavy object such as radio waves on the bottom plate. It is vulnerable to vibration, and the weight of the upper unit cannot be increased so much that image defects such as image blurring due to vibration of the image forming means occur. Further, since the image forming means is composed of precise and high-precision parts, the shock due to the opening and closing of the upper unit has a bad influence, and the shock easily causes troubles such as the developer being wiped out.

[Means for solving problems]

The present invention has been made in view of the above-mentioned conventional example, and sends a sheet feeding unit, a sheet fed by the sheet feeding unit to an image forming unit, and a sheet on which an image is formed by the image forming unit. Transporting means arranged in a substantially vertical direction, and partially holding the transporting means, swinging downward with respect to the apparatus main body to open the transporting path, and closing the apparatus main body. And a supporting means which constitutes a lateral exterior cover of the apparatus main body.

〔Example〕

FIG. 1 shows the first embodiment of the present invention. First, the conveyance to the image forming means will be described with reference to FIGS.

A large number of cut sheets P are stacked on the paper feed tray 1,
The leading end of the cut sheet P is pressed against the feeding roller 4 and the idler roller 5 by the stacking plate 3 which is biased by the sheet feeding pressure spring 2 and rotates. The feeding roller 4 is a roller having a portion with a partially reduced diameter, and has a shape capable of taking an initializing (initial) position in which the cutting sheet P and the conveying roller 6 are not pressed against each other at least once in one rotation. Further, near the both ends of the feeding roller 4, an idler roller 5 that smoothly rotates around the feeding roller shaft 7 is disposed, and the outer diameter of the idler roller 5 is slightly smaller than the maximum diameter of the feeding roller 4. It is configured.

Further, the roller width may be set so as to be smaller than the minimum paper size width lmin in the width direction, and the roller width may be divided into two as in the present embodiment.
The feeding roller 4 is fixed to a drive shaft 7, and the drive shaft 7 can be controlled to rotate once by a spring clutch 51 and a solenoid 52 at the shaft end.

Further, rocking cams 53, 53 'for rocking the stacking plate 3 are disposed on the outer side of the maximum width lmax of the paper-passable size of the drive shaft 7, and the above-mentioned rocking cams of the stacking plate 3 are arranged. Since the cam followers 54, 54 'are fixed at the positions corresponding to 53, 53', the cut sheets P stacked up and down by the stacking plate 3 are selectively fed by the rotation control of the drive shaft 7. And the idler roller 5 can be pressed. Therefore, when the operator loads the cutting sheet into the apparatus, the stacking plate 3 is in the lowered state as shown in FIGS. 1 and 3 (a), so that the cutting sheet can be smoothly loaded. Further, after the cut sheet sent out to the conveying roller 6 part by the feeding roller 4 is conveyed by the conveying roller 6 and the idler roller 5, the stacking plate 3 is lowered so that the uppermost cut sheet being conveyed is moved downward. It is also possible to prevent the cut sheets that are loaded from being pulled out. The transport roller 6 swings around a drive input shaft 8 by a swing arm 9 and can be pressed against the feed roller 4 and the idler roller 5 by the force of a spring 11 applied between the transport roller 6 and the apparatus base 10. . The driving force applied to the transport roller 6 is transmitted by the drive gear 112 fixed to the drive input shaft 8 and the transport gear 113 fixed to the transport roller 6. As in the present embodiment, the gear pair of the drive gear 112 and the transport gear 113 is the transport roller 6
If it is arranged in the central portion of the above, there will be no imbalance of the conveying roller 6 due to the driving force, and stable pressure contact is possible.

A central portion of the feeding roller 4 and the idler roller 5 is rotatably supported, and a friction pad constituted by pressing the central portion with a spring while equalizing, for example, a separation pad 12 made of a rubber material containing cork, is brought into pressure contact. Cut sheet is separated. Except for the separating pad 12 part of the feeding path, the cut sheet is guided by the paper guide shape part 10a formed by the apparatus base and guided to the conveying roller 6. The apparatus base 10 is provided with a second cut sheet inlet 10b in the nip portion N of the transport roller 6 and the idler roller 5 for introducing the paper from a portion other than the feed tray 1. As a result, it is possible to guide the cut sheet from other feeding means such as options such as a large number of decks and cassettes to the lower part of the main body of the apparatus, and the apparatus has a structure with excellent expandability.

Paper conveyance of the feeding / conveying unit of the present invention will be described step by step.

Before the feeding operation, when the motor M fixed to the device base 10 which is the drive source starts to rotate, the transport drive gear 55 fixed to the drive input shaft 8 of the transport roller 6 rotates, The rotation is transmitted to the transport roller 6 via the drive input shaft 8, the drive gear 12, and the transport gear 13, and the transport roller 6 is in pressure contact with the idler roller 5. Therefore, the transport roller 6, the idler roller 5
Rotate in pairs. At that time, even if the idler roller 5 and the cut sheet P are in contact with each other, the frictional force between the cut sheet P and the separating pad 12 is larger than the frictional force between the idler roller 5 and the cut sheet P. It will not be sent.

Further, during standby (standby), the stacking plate 3 is in a position pushed down by the swing cams 53, 53 'and the cam followers 54, 54', so that the cutting sheet P is not in contact with the idler roller 5. On the other hand, the rotation of the transport drive gear 55 causes the drive gear 5 fixed to the drive input shaft 8 to rotate.
6, and the drive is transmitted to a coupler gear 58 which is pivotally supported by a coupler arm 57 which rotates about the drive input shaft 8 and which meshes with the drive gear 56. The coupler gear 58 is formed with a flange portion, and abuts on the flange portion of the sheet feeding drive gear 59 forming the spring clutch 51, so that the backlash between the gears can be guaranteed. And, up to the coupler gear 58 part is arranged on the main body device base 10 side, and the paper feed drive gear 59 is pivotally supported by the feeding roller shaft,
The external cover unit K is provided with a sheet feeding / conveying and fixing unit, and the drive is coupled and released by attaching / detaching the external cover unit K to / from the apparatus main body.

The rotation of the paper feed drive gear 59 is transmitted to the feed roller shaft 7 via the spring clutch 51. Spring clutch 51 is solenoid 52
When is off, the claw 6 of the spring clutch control ring 60
The claw portion 52a of the solenoid 52 is engaged with 0a, and the paper feeding drive gear 59
Is not transmitted to the feeding roller shaft 7. solenoid
When 52 is turned on, the claw portion 52a of the solenoid 52 is disengaged from the claw portion 60a of the control ring 60, and the driving force of the sheet feeding drive gear 59 is transmitted to the feeding roller shaft. In this way, one rotation control of the feeding roller shaft is performed.

When the solenoid 52 is turned on by the paper feed start signal, the claw portion 60a of the control ring 60 is disengaged, and the driving force of the paper feed drive gear 59 is transmitted to the drive shaft 7 via the spring clutch 51. Then, when the drive shaft 7 starts to rotate, the swing cam 53 also rotates and the stacking plate 3 is pushed up by the sheet feeding pressure spring 2 as shown in FIG. 3B, and the cut sheets P stacked are fed. It is pressed by the feed roller 4 and the idler roller 5. At this time,
Even if it comes into contact with the rotating idler roller, it is not sent out because the mating force between the paper and the paper is larger than the mating force between the idler roller and the paper. Since the portion of the feeding roller 4 having an outer diameter larger than that of the idler roller 5 rotates to a portion in contact with the cutting sheet, the feeding sheet feeds the cutting sheet.

Next, the cut sheet reaches the separation pad 12 part, but due to the friction coefficient, the cut sheet is led to the downstream part of the separation pad 12 by only one uppermost sheet. Shortly thereafter, the cut sheet reaches the nip portion N of the driven conveying roller 6 and idler roller 5, and thereafter, the conveying speed of the cutting sheet is stabilized by the conveying roller 6.

A sensor lever 13 is arranged downstream of the conveying roller 6 and the idler roller 5 at the nip portion N. The sensor lever 13 is pivotally supported by a swing arm 9 to rotate, and a leading edge of a cutting sheet is detected by a photo interrupter 14. To do. As shown, the paper detection sensor includes a sensor lever 13 and a photo interrupter 14
In addition to the above configuration, a transmissive sensor or a reflective sensor may be used. After detecting the leading edge of the paper, the cut sheet is conveyed to the vicinity of the photosensitive drum 15 of the image forming means by the conveying roller 6 and the idler roller 5. At this time, as in the present embodiment, the photoconductor drum 15 uses the guide-shaped portion 16a in which a part of the developing device casing 16 of the developing portion D has a rib shape as a guide material.
By leading to, there is an effect that highly accurate transportation is possible, cost is low, and assemblability is good. The toner image formed on the photoconductor drum 15 by the image forming process described later is pressed by the photoconductor drum 15 with a total pressure of 300 g (gram) to 1000 g, and by the gear 15a arranged at the end of the photoconductor drum 15. A transfer roller 17 that is a semi-conductive rubber roller (10 ^{2 to 5} Ω · cm) that is driven or follows the photoconductor drum 15.
Is transferred to the transfer material. At that time, the transfer roller 17 applies a bias of about DC500V to 1.5KV, which is the reverse polarity of the toner, and transfers the transfer material by interposing the transfer material between the transfer roller 17 and the photosensitive drum 15 to transfer the toner image on the photosensitive member. It is transferred by the cut sheet P which is a material. After the transfer, the cut sheet P is conveyed by the transfer roller 17, and the larger the absolute value of the bias applied to the transfer roller 17, the dryer the transfer material, and the lighter the transfer material, the lighter the transfer material is after transfer. Since the cut sheet P of FIG. 3 tends to be adsorbed to the photosensitive drum 15 side, as a means for separating the cut sheet P from the photosensitive drum 15 side, the transfer entrance guide portion 16a is a sheet passing portion at the paper reference end and a few mm in the non-image portion. A sheet material 18, such as mylar, which comes close to or comes into contact with the photosensitive drum 15 is arranged between the transfer roller and the photosensitive drum to the downstream side from the nip portion. At that time, the transfer roller 17 has a shape such that the diameter of the sheet material 18 is smaller than the thickness of the sheet material and the transfer force of the transfer roller 17 is not given to the sheet material 18.

The non-image portion of the cut image P on the transfer image side is guided by the sheet material 18 at the above-mentioned paper reference end. However, in this embodiment, the non-image portion guide material 19 is provided in the post-transfer conveyance path at a point slightly away from the photosensitive drum. Is formed, and the end of the cut sheet separated from the photosensitive drum 15 by the sheet material 18 is guided instead of the sheet material 18. As a result, it is possible to prevent deformation by making the sheet material 18 such as Mylar, which is soft and easily bent, deformed, and easily affected by heat, as small as possible. The side opposite to the transfer image surface is guided by the conveyance guide 20 which also serves as a fixing entrance guide, and guides the cut sheet to the fixing portion T. The fixing unit T is a fixing roller 21 which is driven by an aluminum pipe material having a Teflon coating on its surface and is rotated by being driven.
And a halogen heater as a heat source inside the fixing roller 21.
Contains 22. The temperature of the fixing roller 21 is detected by a thermistor 23 which is in contact with the fixing roller at or near the paper reference side end portion, the sheet passing portion of the non-image portion, and the DC controller 24 and the AC controller 25 in the electrical component portion of the apparatus main body. The temperature is controlled by. As a safety measure against non-runaway, the fixing roller 21 is provided with a non-contact thermo switch 26 which is close to the center of the maximum paper feed width lmax of the fixing roller 21.
It is located above. The fixing roller 21 of the thermo switch 26
The distance from the surface can be adjusted by providing a leaf spring 27 on the thermoswitch and applying a force in a direction to always leave the thermoswitch, and bringing the thermoswitch 26 close to the fixing roller 21 from the back surface by adjusting means such as a screw 28. In order to press the cut sheet against the fixing roller 21, the pressure roller 29 having silicon rubber on the surface is pressed against the fixing roller 21 with a total pressure of 3 to 6 kg.
It is driven by the fixing roller 21. Heated fixing roller
When the cut sheet P passes through the nip portions of 21 and the pressure roller 29, the transferred toner image on the cut sheet P is fixed. After fixing, the cut sheet P approaches the fixing roller 21 within 1 mm or less in a non-contact manner to prevent the cut sheet P from wrapping around the fixing roller 21 and also serves as a separation guide.
Guided by the sheet 30, the sheet is guided to the sheet discharge paddle 31 located downstream of the pair of the fixing roller 21 and the pressure roller 29. The paper discharge paddle 31 is made of an elastic body made of rubber or elastomer having several feather-shaped projections. In this paper ejection paddle 31, the tip of the wing-shaped projection is inserted between the ribs of the fixed paper ejection upper guide 30 so as to overlap the rib tip, and the cut sheet P is ejected by the paper strainer and the elastic force of the paper ejection paddle 31. Since the sheet is pressed against 31, the cut sheet P is conveyed by the frictional force of the wing-shaped projections by the rotation of the sheet discharge paddle 31. And the cut sheet P
Are discharged to the outside of the apparatus and stacked on the discharge tray 32 at the discharge port. The paper discharge tray 32 is easily removable.

The above-mentioned paper feed, conveyance, fixing, and paper ejection units are provided on the apparatus base 10 along the axis A.
It is pivotally supported by and is divided at the position of the alternate long and short dash line in FIG. 4 so that it can be opened and closed. FIG. 5 is a view when opened. At this time, the discharge tray 32 is removed, and the cut sheets loaded on the paper feed tray 1 are removed.
It is a figure of the folded state.

Next, the image forming unit-optical system will be described.

As described above, the apparatus base 10 has means for pivotally supporting the exterior cover portion K having the sheet feeding / conveying and fixing portion with the A axis and for guiding and positioning the cartridges such as the photosensitive drum 15 which is an electrophotographic image forming portion which will be described later. And the photosensitive drum
A laser beam optical system L for imagewise exposing to 15 is also constructed on the apparatus base 10.

In the laser beam optical system L, a polygon mirror 102 of a rotating polygon mirror is fixed on the rotation axis of a polygon motor 101 rotating at high speed, and a semiconductor laser 103 is attached to the polygon mirror surface.
From the laser through the collimator lens 104,
Reflected on the surface of the polygon mirror 102, then the spherical lens 105,
Laser light is irradiated onto the photosensitive drum 15 via the Fθ lens 106. By rotating the polygon mirror 102, the photosensitive drum 15 is scanned in the generatrix direction, and the semiconductor laser 103 is turned on and off.
Dots can be formed on the generatrix of the photosensitive drum 15 by the F drive. At that time, in order to obtain a reference for laser scanning (referred to as main scanning) in the bus line direction of the photosensitive drum 15 by the polygon mirror 102, a beam detector mirror 107 is provided outside the image width starting in the scanning direction to reflect laser light and expose it. A laser receiving surface 108a of the optical fiber 108 is provided at a position substantially equivalent to the drum, and the optical fiber 108 guides the laser light to the laser receiving element on the DC controller 24.

With such a configuration, the beam scanning is performed to obtain the reference timing of the laser scanning on the image output timing, and the image signal is output to the semiconductor laser 103 by the clock from this reference timing, thereby performing the scanning in the main scanning direction. .

As described above, the laser beam optical system L has many high-precision components such as a lens, a high-speed rotation motor, and a mirror, and causes an image defect such as an image shift due to a position shift from the photoconductor drum 15, an image blur, and a right angle defect. There is a fear. Therefore, in this embodiment, a polygon motor 101 having a photosensitive drum 15 and a polygon mirror of the laser beam optical system L, a lens base 109 for positioning the spherical lens 105 and the Fθ lens 106, a beam detector mirror 107, and a beam detect. Since the semiconductor laser unit LU including the optical fiber receiving unit 108a, the semiconductor laser 103, the semiconductor laser substrate 110, and the collimator lens 104 is fixed to the apparatus base 10, the accuracy can be improved. Also, the device base 10
By fixing three points R ₁ R ₂ R _{3 to} the device bottom plate 33, a structure that is strong against distortion and twist of the bottom surface is obtained.

Next, the image forming section-electrophotographic section will be described.

The image forming means of this embodiment has a cartridge shape in which the photosensitive drum 15, the cleaner portion C, the primary charger T, and the developing portion D are integrated.

In this embodiment, the primary charging portion T is a semi-conductive elastic body of about 10 ^{1 to 3} Ω · cm, for example, DC-600 on the rubber roller 34.
By applying a bias of -700V, AC1200-1800V _pp , the OPC drum, which is the photosensitive drum 15, can be charged to -600V to -700V. The rubber roller 34 is driven by the photosensitive drum 15 and is in contact with the photosensitive drum 15 with a pressure of several hundred g. next,
Image exposure is performed by the laser beam optical system L described above, and the potential of the image exposure portion becomes -50V to -150V. Next, the developing section D
Is a toner container portion D ₁ filled with toner having the same polarity as that of the primary charge, the toner is pumped up and conveyed to the vicinity of the developing sleeve 36 by the stirring means 35, and the surface of the developing sleeve is contacted by the rubber blade portion 37 in contact with the developing sleeve 36. The toner is coated on 36, and by applying an AC bias in a state of being close to the photosensitive drum 15 at 200 μ to 300 μ, the toner is reversely developed on the image-exposed portion of the photosensitive drum 15 (jumping development).
Then, the toner image on the photoconductor is transferred to the transfer material as described above. The toner remaining on the photosensitive member after transfer passes through the scooping sheet 38 made of a Mylar sheet of about 50 to 100 μ in the cleaner section C, and is scraped off from the photosensitive drum 15 by the cleaning blade 40 adhered to the cleaner casing 39. . The scraped waste toner is accumulated in the waste toner container portion C ₁ by the movement of the toner as shown by the arrow in the figure.

The cleaned photosensitive drum 15 is ready for the next image forming process. The cartridge is configured to be replaced with a new one after a certain amount of image formation, considering the life of the photosensitive drum 15, the life of the cleaning blade, and the absence of toner. At the time of replacement, the cartridge is configured so that it can be fed to the side where the exterior cover K having the paper feeding, conveying and fixing portions is opened. By opening the outer cover K, the operator can take out the cartridge from the main body at a right angle to the drum generatrix direction. Further, by inserting a new cartridge and then closing the exterior cover portion K, the cartridge is securely set to a predetermined position by the pressure of the transfer roller or the like.

FIG. 6 is a diagram showing how the cartridge CG is positioned on the device base.

The cartridge CG includes a drum pin 201 that pivotally supports the photosensitive drum 15 (dotted line), a guide portion 202a formed on the outer frame 202 of the cartridge CG, and a click spring portion 202b having a spring property on both side surfaces. On the other hand, the device base 10 is provided with guide hole portions 10c for guiding the guide portions 202a, a click recess portion 10d into which the click spring 202b is inserted, and a positioning portion 10e for positioning the photosensitive drum 15 on both side surfaces. The drive to the photosensitive drum 15 is performed by a drum drive gear 70 that is axially supported on the side surface of the device base 10.

The cartridge is provided with contact portions 203, 204 for high voltage or the like on the side surface opposite to the drum drive gear surface, and is configured to be electrically connectable with a contact portion (not shown) on the apparatus base side. The position of the photosensitive drum of the cartridge is positioned with respect to the apparatus base 10 by the drum pin 201, and the rotation direction is also positioned with respect to the apparatus base 10 by the guide portion 202a.

[Other Examples]

In the above-mentioned embodiment, the laser beam optical system and the electrophotographic unit were combined as the image forming means, but the present invention is not limited to this, and in the case of an analog optical system such as an optical system using an LCD or LED or a copying machine using a lens mirror. Can also be applied to.

FIGS. 7A and 7B are sectional views of an ink jet type non-pact printer. The transfer material transporting means transports the cut sheet P or roll paper from the paper insertion port K1 to the image forming section G having the ink jet nozzle 303 by the pair of transport rollers 301 and 302, and forms an image on the cut sheet P by the ink jet nozzle, and then the heater. Part 400
After the ink is defused by, the ink is ejected outside by the ejection roller pair 401, 402. This paper feed transport roller 301,30
2 and the paper pressing member 403 facing the nozzle, the heater 400 of the drying means, and the pair of discharge rollers 401 and 402 are rotated by the fulcrum A of the apparatus main body base 10 as shown in FIG.
And the jam treatment can be easily performed. The ink jet nozzle 303 and the ink tank 307 of the image forming section G are configured to be replaceable as shown. Further, not only the conveying means may be rotated about the fulcrum A, but the rotation center may be held upward.

〔The invention's effect〕

In the image forming apparatus according to the present invention, the transporting means are arranged in the lateral direction of the apparatus main body in a substantially vertical direction, and these can be opened by swinging them downward from the lateral side. Since the transport path is opened close to the user and wide open, there is an effect that the jammed sheet material in the transport path can be easily removed.

Also, by setting the paper feed port and the paper ejection port to be in the same direction, the paper feed port and paper ejection port face can be used as the front, and jam handling, paper replenishment, and paper ejection can be performed from the front of the front surface. There is an effect that becomes possible.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a laser beam printer embodying the present invention, FIG. 2 is a detailed view of a paper carrying section of the laser beam printer embodying the present invention, and FIGS. 3 (a) and 3 (b) are embodying the present invention. FIG. 4 is a cross-sectional view of the sheet feeding portion of the laser beam printer, FIG. 4 is a top view of the laser beam printer embodying the invention, FIG. 5 is a transfer means release diagram of the laser beam printer embodying the invention, and FIG. FIG. 7 is a detachable view of maintenance parts of a laser beam printer embodying the present invention, FIG. 7 is a front sectional view showing a paper transporting portion released state of another embodiment, and FIG. 8 is a perspective view showing a jammed state of a conventional example. FIG. 9 is a perspective view showing a jammed state of a conventional example. 1 ... Paper feeding tray 4 ... Feeding roller 6 ... Conveying roller 12 ... Separation pad 15 ... Photosensitive drum 20 ... Conveying guide 21 ... Fixing roller 29 ... Pressure roller 32 ... Paper ejection tray K

Claims (2)

[Claims] 1. A sheet feeding unit, a sheet fed by the sheet feeding unit, fed to an image forming unit, and further fed a sheet on which an image is formed by the image forming unit, arranged in a substantially vertical direction. And a conveying means for holding the conveying means partially and swinging downward with respect to the apparatus body to open the conveying path in the conveying means, and when the conveying means is closed to the apparatus body. An openable image forming apparatus, comprising: a supporting unit that constitutes a lateral exterior cover. 2. The releasable image according to claim 1, wherein an opening of a sheet material supply port and an opening of a sheet material discharge port are provided on the opening side of the supporting means. Forming equipment.