JPH03119366A - Electrophotographic image forming device - Google Patents

Abstract

PURPOSE:To prevent a malfunction by disposing an actuator on the surface of a photosensitive drum cartridge mounted on a turning part and providing a base part with a switch which turns on/off a driving power source and is operated by the actuator. CONSTITUTION:An interlocking switch 550 is disposed on the base part 800 of a clam shell type device 1, and the circuit of the switch 550 composes an on/off circuit for the power source circuit of the device 1. The drum cartridge 500 loaded to the turning part 700 is provided on a position in which the projecting actuator 520 faces the interlocking switch 550. When the turning part 800 equipped with the drum cartridge 600 is depressed with respect to the base part 800 to be closed, the projecting top of the actuator 520 enters the interlocking switch 550 and is connected to the circuit for the driving power source. Consequently, the malfunction caused by non-mounting of the drum cartridge 500 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for preventing malfunctions of a clamshell type electrophotographic image forming apparatus due to the attachment and detachment of a photosensitive drum cartridge therein.

[Conventional technology]

Conventionally, in electrophotographic image forming apparatuses, a photoreceptor drum and a developing device are included in one removable unit, or they are separated into one unit including the photoreceptor drum and one unit including the developing device. Some were made to be removable.

In addition, the developing device unit is such that only the developing device is removable, and the toner replenishment tank and toner replenishment device are not attached or removed while attached to the image forming device.
There is also a system in which the tank and the toner replenishing device are not particularly provided, and when the toner contained in the developing device is used up, the developing device is replaced with a new one and the developing device is discarded.

By making the photoreceptor drum and developing device removable in this way, it becomes easier to inspect and clean every inch of the interior, and each unit can be removed externally independently for inspection and cleaning. This allows you to work very efficiently.

Furthermore, each unit has a durability limit on the number of times it can be used repeatedly, and a method has been taken in which the entire unit is replaced at a certain limited number of times, that is, the durability limit.

Conventionally, the electrophotographic image forming apparatus (hereinafter simply referred to as an image forming apparatus) configured in this manner is divided into a rotating part and a base part, called a taram shell, which can be opened and closed, and when opened, the above-mentioned operations can be performed. There was one that had a structure that made it easy to do so, and it was quite compact. When the image forming apparatus is closed, a main drive switch provided in the image forming apparatus is turned on, and after a predetermined setup process, a required copying switch is turned on, thereby starting the image recording operation of the apparatus. .

[Problem to be solved by the invention]

Normally, as described above, the image forming apparatus requires maintenance when it has been used a certain number of times. Therefore, for example, in the above-mentioned apparatus that performs frequent recording, the charging electrode and photoreceptor in particular become dirty or deteriorate, so that the drum cartridge is often removed from the rotating section to perform predetermined maintenance such as cleaning or replacement. In this case, the maintenance work may sometimes be completed by mistake without attaching the drum cartridge to the rotating part.

Conventionally, to drive an image forming apparatus, the rotating part is attached to the base part without the drum cartridge being attached to the rotating part, the main switch for driving the image forming apparatus is turned on, and the required copy button is pressed. Then, the image recording operation of the device is started. Therefore, for example, the recording paper transport device built into the image forming apparatus operates, and the recording paper is transported according to a predetermined sequence regardless of whether or not the drum cartridge is present. Naturally, if the drum cartridge is not installed, no image will be recorded on the recording paper. Further, depending on the conveyance state of the recording paper, the recording paper may quickly become jammed in the image forming apparatus, causing a jam. This is considered to be a serious structural defect in the image forming apparatus. Furthermore, if a jam occurs as described above, repairing it requires a great deal of effort and cost. Further, if only the developing cartridge is installed but no drum cartridge is installed, the inside of the device will be contaminated with toner. An object of the present invention is to provide an image forming apparatus that can solve these problems and prevent malfunctions of the image forming apparatus.

[Means to solve the problem]

The purpose of this is to create a clamshell type electronic device with a structure in which the rotating part rotates around a common spindle with respect to the base part, and the structure is divided into two parts, the base part and the rotating part, which can be opened and closed. In the photographic image forming apparatus, the rotating part has an actuator disposed at an arbitrary position on a surface of a photoreceptor drum cartridge mounted on the rotating part, and the base part is a power source for driving the apparatus. turn on the circuit
This is achieved by an electrophotographic image forming apparatus characterized by having a switch that is turned OFF and operated by the actuator.

〔Example〕

One embodiment of the invention is shown in FIGS. 1-5.

1 and 2 are side sectional views showing the structure of the electrophotographic image forming apparatus of the present invention, and FIG. 'It also represents a cross-sectional view. FIG. 4 is a perspective view of the first embodiment of the present invention when the clamshell is opened. FIG. 5 is a side sectional view showing the installed state of the drum cartridge detection switch of the Talam shell type electrophotographic image forming apparatus of the present invention.

In the figure, lO is a drum-shaped image carrier, ie, a photosensitive drum, which is driven and rotated clockwise in FIG. 2 and counterclockwise in FIG. Reference numeral 20 represents a charging electrode that applies an electric charge to the photoreceptor on the circumferential surface of the photoreceptor drum 10, and 30 represents a laser writing system unit that is an exposure optical system.

When a laser writing signal is input to the laser writing system unit 30, in the laser writing system unit 30, a laser beam generated by a semiconductor laser (not shown) is applied to a polygon mirror 3 rotated by a drive motor 31.
2, the optical path is bent by three mirrors 34A, 34B, and 34G through an fθ lens 33, and the image is projected onto the circumferential surface of the photoreceptor drum 10 to which a charge has been previously applied by the charging electrode 20. .

On the other hand, when scanning is started, the laser beam is detected by the index sensor, modulation of the laser beam by the first color signal is started, and the modulated laser beam scans the circumferential surface of the photoreceptor drum 10. Therefore, a latent image of the first color is formed on the circumferential surface of the photosensitive drum 10 by the main scanning by the laser beam and the sub-scanning by the rotation of the photosensitive drum 10. This latent image is developed as a $1 color, for example, by a developing means containing a yellow developer, and a yellow toner image is formed on the circumferential surface of the photosensitive drum 10. The obtained toner image, while being held on the circumferential surface of the photoreceptor drum 10, passes under the cleaning means which is separated from the surface of the photoreceptor drum IO, and enters the next copy cycle.

That is, the photosensitive drum 10 is charged again by the charging electrode 20, and then the second
A color signal of
Writing is performed on the peripheral surface using the second color signal to form a latent image. The latent image is developed by a developing means containing developer of a second color, for example magenta.

This magenta toner image is formed over the previously formed yellow toner image.

The toner image thus obtained, while being held on the peripheral surface of the photoreceptor drum 10, passes under the cleaning means which is separated from the surface of the photoreceptor drum IO, and enters the next copy cycle.

Similarly, writing using the third color signal is performed on the photoreceptor drum 10 to form a latent image. This latent image is developed by a developing means containing a developer of a third color, for example cyan. This cyan toner image is formed superimposed on the yellow magenta toner image described above.

As described above, a color toner image is formed on the photoreceptor drum IO using the three color toners, but a high-quality color image can be obtained by further overlapping a black toner image in the same manner.

Reference numerals 611A, 611B, 611G, and 611D are developing devices which are developing means that contain yellow, magenta, cyan, and black developers, respectively, for performing the above-mentioned development.

As shown in the example of the developing device 611A, each of the developing devices includes a developing roller (developing sleeve) 612 having a magnetic pole fixed on the inside facing the circumferential surface of the photoreceptor drum IO with a predetermined gap therebetween. It is equipped with a pair of stirring rollers 614 and 615 having conveying force in opposite directions, and the stirring roller 614
The developer is supplied to the circumferential surface of the rotating developing roller (developing sleeve) 612 after the toner and carrier components are made uniform by the mixing action of and 615.

A direct current or even alternating current bias is applied to the developing roller (developing sleeve) of each developing device that carries developer.
Non-contact reversal development is performed using a two-component developer.

Charging by the charging electrode 20 provided on the photoconductor drum IO and its periphery, exposure by the laser writing system unit 30 for each color, and developing units 611A, 611B, 6
11C and 6110 is performed four times for each color, and a color toner image is formed on the circumferential surface of the photoreceptor drum 10 by overlapping.

Reference numerals 61 and 62 are a first paper feed roller and a second paper feed roller, respectively, which are in a constantly rotating state, and 71 and 72 are paper feed guides having an arcuate shape and a linear shape, respectively.

The recording paper is carried out one by one from the paper feed cassette, and is sent along the paper feed guide 71 by the first paper feed roller 61 to the U.
After turning, that is, turning upside down, it comes into contact with the rising portion of the paper feed shutter S that interrupts the conveyance path of the paper feed guide 72 and temporarily stops. In this case, the second paper feed roller 62 continues to rotate while slipping on the surface of the recording paper that is in a stopped state.

When the paper feed shutter S retracts downward in synchronization with the rotation of the photoreceptor drum 1O carrying the toner image, the recording paper is synchronized with the circumferential speed of the photoreceptor drum 10 by the frictional force of the second paper feed roller 62. and is fed to the transfer section.

Reference numeral 80 denotes a rotatable transfer roller, which is charged with a voltage applied thereto, and constitutes a transfer section that transfers the toner image to the recording paper side via the conveyor belt 80B at the point of contact with the circumferential surface of the photoreceptor drum IO. do. A conveyor belt 80B is stretched between the transfer roller 80 and a driving roller 80A which rotates counterclockwise, and the recording paper is transferred while being conveyed by the conveyor belt 80B. Note that 80C is a cleaning means for cleaning the surface of the conveyor belt 80B.

Reference numeral 90 denotes a front charging electrode located upstream of the cleaning device 100, which charges the electrode to a state where it is easy to remove the residual toner on the circumferential surface of the photosensitive drum 10 from which the toner image has been transferred to the recording paper.

100 is a cleaning device; 110 and 120 are a conductive bristle brush and a conductive collecting roller which are cleaning means of the cleaning device 100; and 130 is a waste toner collecting section that stores the toner collected by the cleaning device 100.

The photosensitive drum 10 that has passed the front charging electrode 90 is brought into sliding contact with the conductive bristle brush 1 by a signal from the control section.
The residual toner is removed by the conductive brush 10, and the residual toner adhering to the conductive brush 110 is adsorbed by the conductive collection roller 120.
Sent to 30.

The waste toner collecting section 130 is provided with a waste toner sending rod 131 and a deformable toner collecting bag 132, and the residual toner, that is, waste toner sent by the collecting roller 120 is sent through the waste toner sending rod 131. Bag member 1
It is housed in 32.

The photosensitive drum IO whose circumferential surface has been cleaned in this way
is charged again by the charger 20 and starts forming a new image, and at the same time the conductive bristle brush 110 is released from the rubbing state.

On the other hand, the recording paper to which the toner image has been transferred in the transfer section is separated from the circumferential surface of the photoreceptor drum 10 and transferred to the fixing device 16.
0. Reference numeral 163 denotes a pair of heat rollers for fixing, and numeral 64 denotes a pair of paper ejecting rollers. The recording paper on which the toner is melted and fixed by the pair of heat rollers 163 is ejected from the fixing device by the pair of ejecting rollers 64.

73 and 74 are paper ejection guides for guiding the recording paper ejected by the paper ejection roller pair 64 to the upper part of the apparatus main body, and the recording paper is guided by the relays of the paper ejection transport roller pair 65, 66 and 67. The sheets are discharged and stacked on the tray 75 with the image surface facing downward.

Next, the configuration of the developing device 600 will be explained.

As described above, the device 600 includes a developing device 611A containing a Y (yellow) developer, a developing device 611B containing an M (magenta) developer, a developing device 611G containing a C (cyan) developer, and a developing device 611B containing a C (cyan) developer. It consists of a developing device 611D that accommodates a BL (black) developer. The Y, M, and C developing devices are housed in a frame 602 of one cartridge to form a color developing device, and are guided by guide rails 713A and 713B to form a base portion 800 of the image forming apparatus l. Clamshell rotating part 7 formed at the top
It is set so that it can be attached and detached from the entrance/exit window 713 provided in the frame 701 of 00. On the other hand, the black developer accommodating developing device 611D is set so as to be detachable from the other developing devices of the rotating section 700 from the entrance/exit window 713 along the guide rail 713G.

Since the configuration of each of the four developing units is the same, the configuration of 611A will be explained. Inside the container 603 of the developing device is the aforementioned developing roller (developing sleeve) 612fln.
O-5614,615 6 Lillet, fJ, lla
- An outer diameter portion 613 that is larger than the outer diameter of the row 2612 by a certain amount is provided at both ends of the row 2612. Further, a gear train 630 for transmitting drive to each of the rollers is provided on the right side of the container 603, and a toner receiving port 621 is provided on the left side of the container 603.

Then, a spring 618 is applied along a rail 619 provided in the container 603 so as to close the receiving port 621.
A mouth opening/closing member 618 is provided which is biased by a guide bin 616.

The container is connected to the developing unit 611 by a spring 625 (this may be a plate spring or a helical spring).
A is the outer diameter portion 613 at both ends of the developing roller 612 and the photoreceptor 10
It is designed so that it comes into pressure contact with the peripheral surface of. This allows the gap between the developing roller 612 and the photoreceptor drum 10 to maintain an optimum gap for forming a magnetic brush.

Next, the toner replenishment tank 200 and toner replenishment device 250
I will explain about.

As shown in FIGS. 2 and 3, the tank 200 stores toner in a frame 701 of a clamshell rotating section 700.
Y, M, C, BL (7) Identical containers 201A for each color.

201B, 201C, and 201D are arranged in one row. Then, the drive motor 205 drives the gear 205A,
The stirring shaft and spiral rotating shaft 208 of each of the toner containers 201A, 201B, 201C, and 201D are made rotatable via 206, 207, and 208A. The spiral rotation shaft 208 is provided at the toner supply port 209 of the tank 200, and the toner supply port 209 has a toner shaft 272.
One end of each hose represented by ^, 272B, 272C, and 272D is connected, and a flexible spiral member 271 connected to the spiral rotation shaft 208 is provided in the hose, and the rotation of the spiral rotation shaft 208 is As a result, rotation is freely transmitted to the member 271 in the rotational direction of the shaft, and toner is conveyed.

The other end of each of the hoses is connected to an introduction pipe 259 to a distribution container 251 for each color toner of the toner supply unit [250]. A toner supply port 257 is opened in the container 251 . The container 251 is provided with a rail 254 and an opening/closing member 258 that slides on the rail 254. The opening/closing member 2 is provided with a pin 252 and a spring 255 provided on an extension 251A at the bottom of the container 251.
58 is always biased to the right. The supply port 257 is normally closed and blocked by the port opening/closing member 258.

The bottom extension portion 251A of each distribution container 251 of this toner replenishing device is provided with pins 266, 267, and 264 that fit into long holes 708 and 709 provided in the frame 701 of the Talam shell rotating portion 700, and , is coupled and fixed to a bent portion 262 of a plate 261 that is slidable in the direction of the elongated hole.

On the other hand, the frame 701 of the Taramsiel rotation part 700 is connected to the bearing part 802 provided on the frame 801 of the base part 800.
The opening/closing operation is made possible by the rotation support shaft 702 that fits into the opening/closing operation. Note that the rotation support shaft 702 is constituted by a torsion bar, and is always biased in the direction in which the rotation portion 700 is opened. Although not shown, the latch is automatically opened by pressing the opening button and removing the latch, and when the rotating part 700 is manually closed, the latch is automatically engaged and locked in the closed state. It has become.

Also, bottle fitting i1t 703A, 703B, 703G
, 703D, the cam lever 703 has pins 704, 7 fixed to the frame 701 of the clamshell rotating section 700.
05 It is provided so as to fit with the pin 266 fixed to the plate 261 and the pin 805 fixed to the frame 801 of the base section 800.

When the Talam shell rotating portion 700 is opened from the state shown in the side view of FIG. 1 to the state shown in the perspective view of FIG. 4, the cam lever 703 changes its position to the state shown in the figure. and 264 move through the long holes 708 and 709, and the plate 261 with those pins moved to the left.

In this way, the dispensing container 252 of the toner replenishing section, which is fixed to the bent portion 262 of the plate 261 by the bottom extension 252A, can also be moved to the left. As a result, the container 252 is separated from the container 603 of the developing device, and the opening/closing member 258 closes the replenishment hole 257 by the biasing force of the spring 255 to prevent toner from spilling from the distribution container 251. .

On the other hand, the toner receiving port 621 of the container 603 of the developing device 600
The mouth opening/closing member 618 slides on the rail 61Q by the biasing force of the spring 617 and is closed. And developing device 6
The toner in the container 603 of 00 is also prevented from spilling.

In this way, when the taram shell rotating section 700 is open, the toner supply section 250 moves backward and closes the toner supply port 257, and the toner receiving port 621 of the container 603 of the developing device 600 is also closed, so that toner spillage is automatically prevented. completely prevented.

When the Taram shell rotating section 700 is open in this manner, the cartridges consisting of the three color developing units of Y, M, and C are combined into one cartridge and integrated as a unit from the entry/exit window 713 of the clam shell to the guide rail. 713
It can be easily attached and detached by being guided by A and 713B.

In addition, the developing device 6110 for black toner is also independently installed as one cartridge by the 7 reams 701 of the rotating part of the Talam shell.
It is guided by the guide rail 713G of the entrance/exit window 713 to enable easy attachment and detachment.

Also, Cleaner 100. Charger 20. Front charge electrode 90. As shown in the perspective view of FIG. 4, the photosensitive drum cartridge 500 including the toner collecting section 130 and the like is also connected to the guide rail introducing section 7 when the clam shell rotating section is opened.
12A and the guide rails 712, guide members 510A and 510B on both sides of the cartridge 5000 are guided and slid to facilitate attachment and detachment, and the drum center bin If is guided by the guide members 510A and 510B on both sides of the frame.
It can be set so that it fits in a predetermined position approximately along 1.

The opening angle of the rotating part 700 that opens and closes with respect to the base part 800 is approximately 45 degrees. When the rotating portion 700 is opened, the guide rail introducing portion 712A becomes almost horizontal, and the guide rail 712 is placed at an angle of 45° with respect to the horizontal. In this state, the guide blocks 510A on both sides of the photoreceptor drum cartridge 500
, 510B near the drum center on the horizontal guide rail introduction part 712A, push it in the horizontal direction, and slide it on the guide rail introduction part 712A until it stops against the guide surface on the back side of the guide rail 712. At this point, the guide block 5 is removed by lifting the rear part of the drum cartridge 500 and tilting it by 45''.
Are 10A and 510B guide rails? 12 and slides downward on the 45'' slope of the guide rail 712. At the same time, the drum center pins 11 on both sides of the photosensitive drum also fit into the guides 711 provided on both sides of the frame 701. It moves along the same line and is set at a predetermined setting position, completing the wearing process.

Further, FIG. 5 is a side sectional view of a mechanism for preventing malfunctions due to the drum cartridge not being installed in the image forming apparatus. In the figure, the fixing device 1 is disposed integrally with the base portion 800 of the clamshell image forming apparatus l.
The rotating portion 70 on the surface of the upper frame 162 of the outer frame 161 of 60
An interlock switch 550 is disposed near the center of the right end when viewed from the opening side of 0. and the switch 5
Although the circuit 50 is not shown, the power supply circuit of the image forming apparatus 1 is turned on.

It constitutes an OFF circuit. A movable terminal 551 and a fixed terminal 55 within the interlock switch 550
2, the circuit between the image forming apparatus 1 and the driving power source is cut off.

On the other hand, the drum cartridge 500 mounted on the rotating part 700 is provided with a protruding actuator 520 integrally with the drum cartridge 500 at the right end in the same direction as the interlock switch 550. The actuator 520 is disposed so as to face the interlock switch 550 provided on the base portion 800. Then, the rotating part 700 with the drum cartridge 500 attached thereto is pushed down against the base part 800 against a torsion bar provided on the rotating support shaft 702, and the rotating part 700 is closed. The money is locked and ready for operation. At this time, if the drum cartridge is installed in the normal position, the tip of the protrusion of the actuator 520 will be aligned with the base portion 800.
The movable terminal 551 of the switch is pushed into the interlock switch 550 provided in the switch. The actuator 520 is connected to the fixed terminal 552 connected to the power supply circuit in the image forming apparatus l.
The movable terminal 551 pushed in comes into contact and the circuit with the drive power source is connected.

When the main switch in the image forming apparatus is turned on, setup of the apparatus is normally started, and then, when a required copy switch is pressed, a predetermined image recording operation is started. Further, if the drum cartridge 500 is not attached to the rotating section 700 and the rotating section 700 is closed to the base section 800, the actuator 520 is not present, so the image forming apparatus l The drive power supply circuit inside remains disconnected. Therefore, even if the main switch is turned on, the image forming apparatus 1 does not operate. With this configuration, the user can know in advance whether or not the drum cartridge 500 is installed. Therefore, malfunctions of the image forming apparatus are prevented.

〔Effect of the invention〕

According to the present invention, it has become possible to prevent malfunctions of the image forming apparatus. The reliability of the image forming apparatus has been significantly improved since serious problems such as non-recording on recording paper caused by malfunctions, paper conveyance jams, and toner dripping occurring within the image forming apparatus are eliminated.

[Brief explanation of drawings]

FIGS. 1 and 2 are a left side sectional view and a right side sectional view, respectively, of one embodiment of the present invention. FIG. 3 is a top view of one embodiment of the present invention. FIG. 4 is a perspective view of one embodiment of the present invention when the clamshell is opened. FIG. 5 is a side sectional view showing the installed state of the drum cartridge detection switch of the Talam shell type electrophotographic image forming apparatus of the present invention. DESCRIPTION OF SYMBOLS 10... Photosensitive drum 11... Drum center bin 20... Charging device 30... Laser writing system unit 160... Fixing device 73... Guide plate 80... Transfer roller 90... Front charger 100...Cleaning device 130...Toner collection section 200...Toner replenishment tank 250...Toner replenishment device 500...Photoconductor drum cartridge 503.50
4... Legs 510A, 510B... Guide member 515... Handle 515A... Back surface 515
B... Surface on which the finger rests 520... Actuator 55
0... Interlock switch 551... Movable terminal 552... Fixed terminal 60
0...Developer 602...Cartridge frame 611A...Y developer storage developer 611B...M developer storage developer 611G...C developer storage developer 611D...Black developer Housing developing device 700 -- Clamshell rotating section 701 -- Frame 702 -- Rotating shaft 7
11... Guide 712. 713A, 713B, 713C... Guide rail 712A... Guide rail introduction part 713... Entrance/exit window 800... Base part 802
・・・Bearing part

Claims (1)

[Claims] A clamshell type electrophotographic image forming apparatus having a structure in which a rotating part rotates around a common support shaft with respect to a base part, and is divided into two parts, the base part and the rotating part, to be opened and closed. The rotating part has an actuator disposed at an arbitrary position on the surface of the photoreceptor drum cartridge mounted on the rotating part, and the base part turns on the power supply circuit for driving the device. An electrophotographic image forming apparatus comprising a switch that is turned off and operated by the actuator.