JPS61101354A - Image formation unit - Google Patents

Abstract

PURPOSE:To provide capability of preventing generation of erroneous signal giving false information of 'no paper', by providing, in the transport part of a large capacity paper feeder inserted in the paper feed section, a signal generation control means for controlling 'no paper' signal generated in a reflection type optical sensor belonging to the paper feed section. CONSTITUTION:A large capacity paper feeder 420 is mounted as necessary in place of a paper feed cassette in the bottom stage and paper sheets are conveyed to a separation means 288 one by one as the results of lifting of an elevator plate 424 effected by a motor 422 and an elevation means 423 and the rotation of a take-out roller 425. On the other hand, this paper-feed section is provided with a signal generation control means 428 so as to prevent a false signal erroneously giving the information of 'no paper sheet', while said signal generation control means 428 being able to excite a solenoid 495 to intercept the light passage by means of a shutter member 429 if a paper sheet P is present inside the large capacity paper feeder 420 and also able to allow transmission of light if no paper sheet is present there, owing to provision of a reflection type optical sensor 300 for detecting presence/absence of paper sheet(s) inside a cassette.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a paper feed section to which a paper feed cassette is attached/detached.
Paper-out detection means that enables large-capacity paper feeding (by inserting a conveying section of a large-capacity paper feeding device that stores a large amount of paper), and has a reflective optical sensor facing the paper feeding section. The present invention relates to an image forming apparatus that sends a "paper out" detection signal to the main body of the apparatus.

[Technical background of the invention and its problems]

In recent years, image forming devices have been put into practical use that can feed a large amount of paper by inserting the transport section of a large-capacity paper feeding device that stores a large amount of paper into the paper feeding section into which a paper cassette is attached and removed. has been done.

On the other hand, in this type of image forming apparatus, instead of the conventional detector with a set of detection levers corresponding to the paper feed section, a non-contact type detector is used.
In addition, paper out detection means equipped with a reflective optical sensor that can perform stable detection with little influence from external light are being developed to send a "paper out" detection signal to the main body of the device. be.

However, if a reflective optical sensor for detecting paper in the paper feed cassette is installed in correspondence with the paper feed section, a large-capacity paper feed device may be installed instead of the paper feed cassette. If you simply insert the transport unit, the paper on the elevator grate of the large-capacity paper feeder will not be detected.
There is a problem in that a erroneous signal indicating "no paper" is generated even though there is paper on the elevator grate of a large-capacity paper feeder.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to transport a large-capacity paper feeder containing a large amount of paper to a paper feed unit to which a paper feed cassette is attached/detached. An image forming apparatus that enables large-capacity paper feeding by inserting a paper feed section, and sends a "paper out" detection signal to the apparatus main body by a paper out detection means provided corresponding to the paper feeding section. Although it has a simple configuration, when a large-capacity paper feeder is installed in place of the paper cassette, an erroneous signal of "no paper" is sent even though there is paper on the elevator plate of the large-capacity paper feeder. It is an object of the present invention to provide an image forming apparatus in which no such phenomenon occurs.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention provides an easy-to-use paper feed system by inserting a transport section of a large-capacity paper feed device that stores a large amount of paper into a paper feed section into which a paper feed cassette is attached/detached. In an image forming apparatus in which a paper out detection signal is sent to the main body of the apparatus using a paper out detection means having a reflective optical sensor facing the front and distribution paper section, The paper out detection means is a reflective optical sensor, and a signal generation control means for controlling generation of a "paper out" signal from the reflective optical sensor is provided in the conveyance section of the large capacity paper feeder. It is something.

(Example of the invention) Hereinafter, one embodiment/example of the present invention will be described with reference to the drawings.

FIG. 1 shows the external appearance of an image forming unit employing the image forming apparatus of the present invention, and FIG. 2 is a schematic longitudinal sectional front view thereof.

In the figure, 1 is a copying device as an image forming device, and 2 is a mounting table on which the copying device 1 is placed. This is a direction changing conveyance device which receives the paper P and guides it to the copying apparatus 1 again in the same state or in a reversed state so as to form multiple or double-sided images on the paper P. Reference numeral 3 denotes an automatic document feeder that is attached to the top surface of the copying apparatus 1 and automatically supplies the document A.

The copying apparatus 1 is constructed as shown in FIG.

In other words, numeral 4 in the figure is a main body of the copying machine, and on the top surface of the main body 4 of the copying machine there is a document stacking section on which the document A fed by the automatic document feeder 3 is placed. A display glass 5 is provided, and an operation panel 6, which will be described later in FIG. 4, is provided at the front edge of the top surface.

Further, a paper feed cassette 7.
8.9 is installed. Also, the upper paper feed cassette 7
The cassette cover 10 serves as a manual paper feed stand 11 for manually feeding paper P as appropriate.

A drum-shaped photoreceptor 12 is arranged approximately in the center of the main body 4 of the copying apparatus. A charging device 1 is provided around the photoreceptor 12.
3. Exposure optical device 14, two-color color developing device 1 to be described later
5, a transfer wall 16, a peeling device 17, a cleaning device 18, and an afterimage erasing device 19 are arranged in this order.

In addition, paper feed cassettes 7, 8, .
Paper 2 supplied from the automatic paper feeder 20 to which 9 is attached
The paper P1 manually fed from the manual paper feed table 11 and the paper P led from the direction conversion conveyance device 2 are transferred to the copying machine main body 4 through the image transfer section 21 between the photoreceptor 12 and the transfer device 16. A paper conveyance path 23 leading to the discharge section 22 provided on the left side surface is formed.

Further, a pair of aligning rollers 24 is arranged on the upstream side of the image transfer section 21 of the paper transport path 23, and a fixing device 25 and a pair of paper ejection rollers 26 are arranged on the downstream side.

Further, the operation panel 6 is designed as shown in FIG. 4.

That is, there is a start button 30 on the right end side of the operation panel 6.
A numeric keypad 31 and a total counter 32 are arranged, and on the left end side there is a mode switching button 33 and a single-sided copy mode display L.
ED 34, double-sided copy mode display LED 35, double copy mode display LE036, density adjustment R button 37, automatic exposure? A tongue 38 and a first display section 39 are arranged. Also, in the center part, there is a reduced display section 40, a same size display section 41, an enlarged display section 42, a variable magnification button 43, and a zoom? tongue 44, colored finger and foot getan 45, and a second button for displaying the status.
A display section 46 is arranged.

As shown in FIGS. 5 and 6, the exposure optical device 14 also includes an exposure rung 51 as an exposure light source whose back part is surrounded by a reflector 50 and irradiates light onto the document placement surface 5&; a first optical unit 53 that has a first mirror 52 as a reflecting member that reflects the reflected light from 5h in a predetermined direction and is movable along the document placement surface 5&;
It moves in the same direction in synchronization with this first optical unit 53 at a speed that is half the speed of the first optical unit 53, and transfers the optical image reflected by the first optical unit 53 to the lens unit 54. The second mirror 55 and the third mirror 5 reflect
A second optical unit 57 with 6 is provided.

Furthermore, a third optical unit 60 having a fourth mirror 58 and a fifth midge 59 as reflecting members is provided after the lens unit 54, and the optical image reflected by this third optical unit 60 is transferred to the photoreceptor 12. The configuration includes a sixth mirror 61 as a fixed reflecting member that reflects sideward.

Note that 62 is a dustproof glass provided between the sixth mirror 61 and the photoreceptor 12, and 63 is an exposure run f5.
This is a heat ray absorbing glass provided on the front surface of 1.゛However, with the exposure run f51 turned on, the first optical unit 53 moves at a speed V along the document placement surface 5&, and in synchronization with this movement, the second optical unit 52 moves.
moves in the same direction at a speed that is half the speed V, thereby scanning the original A placed on the original placing surface 5a, on the photoreceptor 12 as the exposed part which has been rotated in advance. It is designed to form an image.

Then, the photoreceptor 1 is uniformly charged by the charging device 13.
An electrostatic latent image corresponding to the document A is formed on the document A.

The electrostatic latent image thus formed is developed by facing the developing device 15, and then sent to the image transfer section 2 facing the transfer device 16, and the developer image is transferred to the aligning roller. The image is transferred onto the paper P fed through the paper 24. Next, the sheet P on which the image has been transferred is peeled off from the photoreceptor 12 by the peeling device 17, and then guided to the fixing device 25 through the conveyance path 23 where the image is fixed. It can be discharged to the discharge section through the tube.

On the other hand, the surface of the photoreceptor 12 after the developer image has been transferred to the paper P faces a cleaning device 18 to clean residual developer (toner) remaining on the photoreceptor 12, and then an afterimage erasing device At step 19, the potential on the photoreceptor 12 is lowered below a certain level to enable the next copying operation.

Further, as will be described later, the lens unit 54 and two mirrors 513 arranged at an angle of 90 degrees are also included.
A third optical unit 60 having a lens 59 can be moved as shown by arrows AXB in FIG. 5 in order to change the object-to-image distance and the distance between the lens and the imaging plane in order to change the magnification. The structure is as follows.

Further, as shown in FIGS. 3 and 6, a first shielding member 65 that also serves as a lens cover is provided to cover the upper surfaces of the lens unit 54 and the third optical unit 6o, and The unit 7 57 has a first shielding member 6
A second shielding member 66 is provided so as to partially overlap the shielding members 65 and 5, and the upper surface of these shielding members 65 and 66 is partitioned to form a document placement surface and a cooling air conduction path 67 along 5a. It constitutes a partition means 68. When the second shielding member 66 is not attached, the end side thereof is guided over the first shielding member 65 via a support means 69 consisting of a roller or a sliding member, and special guiding means is required. It is designed not to.

Further, the first optical unit 57, the lens unit 5
4 and the lower surface side of the third optical unit 6° are covered with a partition plate 70 that partially holds the dustproof glass 62, and one end of this partition plate 70 is connected to a fan of an exhaust fan 71. It is connected to the casing 72 and substantially partitions the copying apparatus main body 4 into upper and lower sections.

Therefore, as shown by the arrow in FIG.
1, the cooling air introduced into the cooling air guide path 67 from the right side of the copying apparatus main body 4 is guided along the lower surface side of the image stand glass 5 by the first shielding member 65 and the second shielding member 66. After being guided to the left side of the vehicle, it is discharged to the outside. Therefore, the exposure lamp 51 can be sufficiently cooled, the exposure lamp 51 can be prevented from overheating and its life can be extended, and the adverse effects of heat on other parts can be prevented as much as possible. Further, heating is prevented over the entire area of the document table 5, so that the operator does not feel uneasy. Further, the second shielding member 66 blocks stray light as shown by arrow E, and image defects caused by stray light entering the lens unit 54 can be reliably prevented.

The first optical unit 53 and the second optical unit 57 are mounted and supported as shown in FIG. 57 is configured to be able to move at half the speed V.

That is, on the mutually opposing surfaces of the frame 75 and the front frame 76 arranged in parallel at a distance, there are guide frames 77 and 77 parallel to the upper horizontal pieces 75g and 76g.
are installed and these are the ID frames 77.77
The first optical unit 53 and the second optical unit 57 are installed in such a state that they are in sliding contact with sliders 78 attached to the lower surfaces of both ends thereof. In this way, the first optical unit 53 and the second optical unit 57, which are movably provided on the guide frames 77, 77, are moved in a predetermined direction at a predetermined speed by the optical unit actuating means 79. It has become.

The optical unit operating means 79 has the following configuration. That is, a drive shaft 80 is horizontally mounted corresponding to one end in the moving direction of the optical unit 53.57, and drive pulleys 8 and 8 are respectively attached to both ends of the drive shaft 80, that is, to the outside of both frames 75 and 76. ing. Further, a driven googly 82 is rotatably provided on the outside of the frame 75.76 via a support shaft 83 corresponding to the other end of the optical unit 53.57 in the moving direction.

On the other hand, both ends of the carriage 84 of the first optical unit 53 protrude outside the frame 75, 76, and
Both ends of the gouge 85 of the second optical unit 57 have gee mounting portions 85g, 85b that are vertically folded back along the outer surface of the frame 75, 76, and a pair of gouges 86. 87 are each attached.

Further, a midway portion of a wire 88 is wrapped around each gooley 81, 82, 86, and 87 in a predetermined state. That is, the wire 88 whose one end is fixed to the fixture 90 via the spring 89 is pulled out to the driven pulley 82 side, wrapped around the first pulley 86 of the second optical unit 57, and then folded back.
The drive boob IJ 8 J lc is wound several times and then folded back to the side of the driven pulley 82. Next, a wire 88 is wound around the driven googly 82 and then around the second googly 87 of the second optical unit 57 and folded back, and then the other end is fixed to a fixture 92 via a guide 91.

Further, both ends of the carriage 84 of the first optical unit 53 are directly fixed to a wire 88.

On the other hand, the drive shaft 80 is interlocked with a motor 93 and a timing belt 94 so that the drive gears 81, 81 around which the wire 88 is wound are driven in the forward or reverse direction. It has become. and,
First optical unit 53 fixed directly to wire 88
is the speed V, and the second optical unit 57 to which the pulleys 86 and 87, which are connected to the wire 88 and which function as movable pulleys, is attached, moves at a speed that is half of the speed ■. It becomes.

Further, as shown in FIG. 8, a pair of pulleys 86.8 are respectively attached to both ends of the second optical unit 57.
7 are attached to support shafts 95 and 96 that are independently arranged on a line parallel to the moving direction of the optical unit 57, that is, in a direction along the tension direction of the wire 88. A stable support state can be maintained for a long period of time in a state where no moment acts in a direction perpendicular to the direction and no vibration is generated.

Note that 97 is a connection reinforcing member that connects the free end sides of support shafts 95 and 96 that rotatably support the pulleys 86 and 87.

In addition, in order to change the copying magnification as described above, a third optical unit 6 including a lens unit 54 and two mirrors 5B and 59 arranged at a 90 degree angle is required.
0 must be moved by a predetermined amount, for example, when a lens with a focal length f of 21011II11 is used, approximately as shown in the table below.

However, the direction approaching the third optical unit is (-) and the direction away from the third optical unit is (+).
0 is mounted and supported as shown in FIG. K so that a predetermined copying magnification can be obtained.

That is, a pair of screw shafts 100 and 101 are rotatably installed in parallel across the movement path of each unit 54 and 60, and these screw shafts 10
0.101, the third optical unit 60 is supported in a freely slidable manner by fitting the slide pushers 103 attached to both ends of the caliper 102 to the outside.

Further, at one end of the carriage 102, a screw shaft 101 is engaged with a screw shaft 101.
4 is attached, and as the screw shaft 101 rotates forward and backward, the third optical unit 60 reciprocates using the screw shaft 101.100 as a guide.

The screw shaft 101 is configured such that the driving force of the mirror driving pulse motor 105 is transmitted through a set of gears 106 and 107.

On the other hand, one end of the carriage 108 of the lens unit 54 is held on the screw shaft 100 via slide pushers 120, 120, and the other end is attached to the slider 121 attached to the lower surface of the carriage 108 of the third optical unit 60. By placing it directly on the holder 102, it is supported in a slidable manner.

Further, a spiral housing 122 is disposed at one end of the carriage 108 and engaged with the screw shaft 100.
is attached so that it can reciprocate as the screw shaft 100 rotates in the forward and reverse directions.

The screw shaft 100 is driven by a pair of gears 124, 125, which is driven by the driving force of the lens driving lens motor 105.
It is intended to be transmitted via.

Thus, as the mirror drive pulse motor 105 rotates forward and backward, the third optical unit 60 moves a predetermined distance in a predetermined direction, and as the lens drive Nors motor 123 rotates forward and backward, the lens unit 54 moves in a predetermined direction. It will move only a predetermined distance. At this time, by changing the periods of the drive pulses of the mirror drive pulse motor 105 and the lens drive pulse motor 123, the third optical unit 6 can be moved less than the lens unit 54.
The amount of movement per unit time of 0 is determined by the lens unit 54.
The amount of movement is set to be smaller than the amount of movement. Since the change in focus and magnification for the same amount of movement of the lens unit 60 and the third optical unit 54 is larger for the third optical unit 54, the lens unit 60 and the third optical unit 54 are moved slowly to avoid the adverse effects of inertia. , high positional accuracy can be obtained.

The developing device 15 has a structure as shown in FIGS. 10 to 16. That is, as shown in FIG. 10, it has a developing roller 1301 as a first developing member and a developing roller 131 as a second developing member, and these developing rollers 2130, 13 are selectively driven, for example. It is possible to perform black or red development.

Further, the developing device 4 includes a first developing roller 130 .
The developing unit 132 is divided into two, and a second developing unit 133 including a second developing row 2131. The second developing unit 133 in the lower stage uses black developer Db, which is frequently used. Note that the developers D& and Db are two-component developers consisting of toner and carrier.

As shown in FIGS. 12 and 13, the first developing unit 132 that uses the red developer D& does not include a developing mechanism section 134, a developer stirring section 135, a developing roller 130, and this developing unit. a doctor 137 provided on the upstream side of the sliding contact portion of the developer magnetic brush Da' formed on the surface of the roller 130 with the photoreceptor 12, that is, the development position 136, and regulating the thickness of the developer magnetic brush Da'; A scraper A 139 is also provided on the downstream side of the developing position 136, and scrapes off the developer magnetic brush Da' on the surface of the developing row 2130 and guides it to the developer accommodating section 138, and the developer stored in the developer accommodating section 138 The agent agitator 140, 140 is housed in the casing 14.

Further, the first developing row 2130 has a magnetic roll 142 and a slot IJ-f 143 fitted onto the magnetic roll 142. The magnetic roll 142 has five magnetic pole parts 144 &~
144e, first, third, and fifth magnetic pole parts 144g,
144a.

144 is an N pole, and second and fourth magnetic pole portions 144b.

144d is an S pole, and each magnetic pole part 144a to 14
4. is arranged at an angle of about 50' to 70', the third magnetic pole part 144C facing the development position has an angle of 700 to 1000 Gauss, and the other magnetic pole part 144a.

144b, 144d, and 144a have a magnetic force distribution of 300 to 600 mm.

Therefore, in this first developing unit 132,
The rotary sleeve 143 is rotated clockwise in the figure to perform development, which is the so-called advanced mode, and the developer brush Da' held on the surface of the photoreceptor 12 is slid into contact with it in the direction opposite to the flow of the image on the photoreceptor 12. By doing so, the photoreceptor 12
The electrostatic latent image formed on the image is developed. By reducing the diameter of the developing row 2130, the space from the exposure position to the transfer position is reduced as much as possible, thereby making the copying machine more compact.

In the present invention, since the diameter of the photoreceptor 12 is 781 mm, the circumference from the exposure position to the transfer position is approximately 122 m1. It's fleeting. In order to widen the distance between the development position, that is, the exposure position and the transfer position, the charging device 13 and the cleaning device 18 must be made smaller, but there is a limit to this.

For the above reasons, the inventors of the present invention have already confirmed that it is possible to install a developing device in which the diameter of the developing roller 130 is 40 mm or less in terms of space.

Further, the first developing unit 132 and the second developing unit 1
The height of 33 is limited, and if the drum diameter is 78 gourd, it is 120f.
It has been confirmed that it must be less than or equal to i. That is, 1st. Together with the second developer unit 132, 133, it must be made thinner. For this reason, advanced mode developing devices are often used, which are advantageous in terms of space in the height direction, have a small number of poles, and are inexpensive in cost. In particular, in the first developing unit 132 installed at the top, the opening of the developing device faces downward, so in the with mode where the developer Da flows from the top to the bottom, problems such as the developer dripping out may occur. Occur. In this respect as well, the upper cylinder 1
It is advantageous for the developing unit 132 to be in the advanced mode.

Further, in the first developing unit 132, the developer magnetic brush Da' on the rotating shaft IJ-f 143 is removed by the developer removing means 145.

As shown in FIG. 12, this developer removing means 145 is an extremely simple and inexpensive method in which the developer is removed by simply rotating the rotary sleeve 143 in the opposite direction (counterclockwise) to that used during development.

The rotating sleeve 143 rotates in the opposite direction when copying is completed, and the developer D& is conveyed in the opposite direction. Therefore, all the developer D& on the rotating sleeve 143 is transferred to the doctor blade 137 and the scraper as shown in FIG. It is accumulated between 139 and 139.

Note that in the case where the magnetic pole part has five poles, the farther apart the first magnetic pole part (carrying pole) 144a and the fifth magnetic pole part (carrying pole) 144e are, the more efficiently the developer Da can be transported and disposed of. Since the conveyance can be controlled, the number of poles is preferably 5 or less.

In addition, an elastic thin plate member (not shown) such as Mylar (trade name) is attached to the scraper 139 with its tip in contact with the rotating sleeve 14'3) to prevent reverse conveyance of the developer Da. It greatly enhances the effect.

Further, the reverse rotation operation of the rotating sleeve 143, that is, the removal operation of the developer magnetic brush Da is performed not only after the development operation is completed (after the copy operation is completed) but also after the apparatus is inadvertently stopped. In other words, if the power is turned off or the apparatus suddenly stops due to a paper jam, etc., then the power is turned on, the jammed paper is removed, etc., and the optical exposure of the exposure optical device 14 is removed. At the same time as the system is returned to its initial state, the reversal is performed again. The structure is such that the developer Da does not exist at least near the developing position 136 on the rotating sleeve 143 during the "copyable" state, that is, during the resolving period.

Note that the diameter of the rotating sleeve 143 is about 40 mm or less, and the width is about 2 mm. In the case of a small device of about jOm or less, the method of controlling the conveyance and non-conveyance of the developer D& is to change the direction of rotation of the rotary sleeve 143 as described above, and to change the direction of rotation of the first magnetic pole portion 144a. This can also be carried out by rotationally displacing the magnetic roll 142 via a drive source such as a solenoid so that it faces the doctor grade 137 made of a non-magnetic material.

Further, as shown in FIGS. 13 and 14, the second developing unit 133 using the black developer Db consists of a developing mechanism section 146, a developer stirring section 147, a developing roller 131, and a developing roller 131. A doctor 149 is provided at the sliding contact portion of the developer magnetic brush Db' formed on the surface of the row 2131 with the photoreceptor 12, that is, on the upstream side of the development position 148, and regulates the thickness of the developer magnetic brush Db'. The developer Db scraped off by the doctor 149 is transferred to the developer storage section 15.
A casing 153 houses an ID 151 that leads to zero and a developer agitating body 152 housed in the developer accommodating section 150 .

Further, the developing row 2131 is composed of a magnetic roll 154 and a rotating sleeve 155 that is fitted onto the magnetic roll 154 and rotates counterclockwise in the figure.

In the second developing unit 133, the developing roller 131 is made larger than the first developing roller 130 in order to enable high-speed development, and the rotating sleeve 155 is made larger than the first developing roller 130.
is developed by rotating it counterclockwise in the figure, in a so-called with mode, in which the developer brush Da' held on the surface of the photoreceptor 12 is brought into sliding contact in a direction that follows the flow of the image on the photoreceptor 12. Please ensure sufficient development time and remove the photoreceptor 12.
The electrostatic latent image formed is developed in a high-quality image-sensitive state.

The magnetic roll 154 has six magnetic pole parts 156a to 156f, one more than the first image roller 130, to be suitable for the with mode, and has second, fourth, and sixth magnetic pole parts. 156b.

156d and 156f are N poles, and the first, third, and fifth magnetic pole parts 156IL, 156a, and 156e are S poles,
Each of the magnetic pole parts 156a to 156f is arranged at an angle of approximately 50° to 60°, and a fourth magnetic pole part 156d faces the developing position.
is 800-1000 Gauss, other magnetic pole parts 156&, 15
6b, 156c.

156e and 156f have a magnetic force distribution of 400 to 600 Gauss.

Further, in the second developing unit 133, the developer magnetic brush Db' on the rotating sleeve 155 is removed by a developer removing means 157.

As shown in FIGS. 13 and 14, the developer removing means 57 consists of a rotary sleeve consisting of a blade 158 made of an elastic member such as urethane rubber, and a blade moving mechanism 159 for horizontally moving the blade 158. 15
By pressing the grade 158 against the surface of the developer Db, the developer Db is prevented from being conveyed to the development position 148.

The blade moving mechanism 159 has a configuration in which a pinion 164 driven by a motor 163 is engaged with a rack 162 provided on a slider 161 that is integrated with a blade holder 160 . Then, the motor 163 is turned in the forward direction.
By rotating in the opposite direction, the system slider 161 is moved forward and backward, and the plaid 158 is brought into contact with the surface of the photoreceptor 12 as shown in FIG. 14, and separated from the surface of the photoreceptor 12 as shown in FIG. It has become.

The position where the plaid 158 is in pressure contact with the photoreceptor 12 still exists between the position of the doctor plaid 149 and the second magnetic pole portion (carrying pole) 156b. This means that the position of the second transport pole 156b is most efficient for scraping off the developer brush Db', but if the interval is widened, the grade 1
58 and the doctor blade 149, the developer Db accumulated during the next copying may be scraped off as the photoreceptor 12 rotates and contaminate the inside of the machine. Therefore, the pressure contact position of the blade 158 is set at a position where the amount of developer Db is small and scraping is performed efficiently, that is, between the doctor grade 149 and the second magnetic pole portion 156b.

Note that 166 and 167 are position detectors that detect the forward and backward positions of the slider 161, and these detection signals are used to stop the shimotor 163.

After copying is completed, the blade 158 touches the photoreceptor 12 immediately before the rotating sleeve 155 stops, as shown in FIG.
After that, the rotating sleeve 155 makes more than half a turn and stops, and then the blade 158 separates from the rotating sleeve f155 as shown in FIG. Therefore, at least the developer Db on the rotating sleeve 155 at the developing position is removed.

Further, the contact operation of the blade 158, that is, the removal operation of the developer magnetic brush Db is performed by the first developing unit 1 described above.
As in the case of No. 32, this is performed not only after the development operation is completed (after the copy operation is completed) but also after the apparatus is inadvertently stopped. In other words, in the event that the device suddenly stops due to the power being turned off, a paper jam, etc., the optical system of the exposure optical device 14 is then turned on, the paper jam is removed, etc. etc. are returned to the initial state, and at the same time, the blade 15 is turned on again.
8 contact operations are performed. And the state of "copyable",
In other words, the configuration is such that the developer Db is always absent at least near the developing position 148 on the rotating sleeve 155 during the resolving period.

Further, the first and second developing units 132 and 133 configured in this manner are configured to operate selectively in accordance with designations from a color designation section (not shown). That is, when red is specified, the first developing unit 1 is
The magnetic brush D& is formed only on the rotating sleeve 143 of the second developing unit 133, and when black is specified, the rotating sleeve 155 of the second developing unit 133 is formed as shown in FIG.
A magnetic brush Db is formed only on the top.

When the first developing unit 132 side is designated to be operated, the rotating sleeve 143 of the first developing row 2130 rotates clockwise as shown in FIG.
A developer magnetic brush D& is formed on the surface of the rotating sleeve 1430. Then, a latent image formed in advance on the photoreceptor 12 is developed with a red developer Da.

When the development of this still image is completed, the developer removing means 145 operates as described above, and the rotating sleeve 143
rotates in the opposite direction, and at least the developer D& at the developing position 136 is removed in preparation for the next developing operation. In addition,
At this time, the rotating sleeve 15 of the second developing unit 133
5 is also not provided with a developer magnetic brush Db', so that problems such as color mixing will not occur even if either of the developing units I32 and I33 is designated next.

Further, when the second developing unit 133 side is designated to be operated, the second developing unit 133 side is operated, as shown in FIG.
The rotating sleeve 155 of 131 rotates counterclockwise, and a developer magnetic brush Db is formed on the surface of the rotating sleeve 155. In order to cope with high-speed copying, the electrostatic latent image formed in advance on the photoreceptor 12, whose rotation is controlled at a higher speed than during development by the first developing unit 132, is transferred to the black developer D.
It will be developed in step b.

When the development of this electrostatic latent image is completed, the developer removing means 157 operates as described above, and the rotating sleeve 155
The blade 158 is in pressure contact with the surface of the developer Db, and at least the developer Db at the development position 148 is removed in preparation for the next development operation. Note that at this time, the first developing unit 13
The developer magnetic brush Da' is not formed in the rotating sleeve 143 of No. 2 either, and next, either of the developing units 132
．． Even if 133 is specified, problems such as color mixing will not occur.

For black copies, the grossing speed is high, and for color (red) copies, it is low, thereby improving the image quality of color copies.

Therefore, at the time of black copying, that is, during development in the second development unit 133, the peripheral speed of the drum-shaped photoreceptor 12 is 22.
3 m/s, 35 sheets/min, the peripheral speed of the drum-shaped photoreceptor 12 is 136+m/a, 2 during color copying for A4 landscape, that is, development in the first developing unit 132.
5 sheets/min, variable speed for A4 landscape, development row 2
The diameter of the developing row 130 is 38 sugars, which is smaller than the 50 m of the second developing row 2131, and by ensuring sufficient development time, a high quality color image can be obtained. Furthermore, the frequently used black copy enables high-speed copying. Also, each developing unit 132 configured as described above.
133 has a front cover 17 as shown in FIG.
When the developer receiving and transporting parts 132a and 133a are exposed when the developer receiving and transporting parts 132a and 133a are opened, a cartridge-type developer replenishing device 171 is connected to the developer receiving and transporting parts 132g and 133a. .172 is removably attached. And developer storage section 138.15
Based on the detection signal from the developer quantity detectors 173 and 174 (see Fig. 3) which detect the amount of developer (toner amount) of 0, the amount of developer D&, Db commensurate with the consumed amount is replenished as appropriate. The configuration is as follows.

Developer replenishing device 1 on the side of the second developing unit) J33
72 is constructed as shown in FIGS. 18 to 20. That is, 175 is a container that stores the developer D&, and at the bottom of this container 175 is a transfer screen 17 that is rotated to transport the developer Db in the axial direction.
6 is in a stored state.

Further, at the lower part of one end of the transfer screw 176 of the container 175 located in the developer transfer direction, there is a holder 17 as a mounting section connected to the developer receiving and conveying section 133a.
A fitting protrusion 175a is formed that can be freely inserted into and removed from 7. A developer discharge port 17B for discharging the developer Db transferred by the transfer screw 176 is formed on the lower surface side of the fitting protrusion 175&.

Further, the holder 177 is connected to the developer receiving and conveying section 133.
It is rotatably attached to the upper surface side of a, and a replenishment port 179 is formed on the bottom surface thereof corresponding to the developer transfer shaft (toner o, f) 1112 of the developer receiving and conveying section 133&. The situation is as follows.

Furthermore, one end of the transfer stop IJ, -176 has a connecting portion 176a that protrudes from the end surface of the holder 177 and connects to the driving force horn ring 181 of the driving device 180.

A developer discharge port 17 is provided on the lower surface side of the fitting protrusion 175&.
A lid 183 is provided to be slidable to open and close the lid 8. On the other hand, on the holder 177 side, there is a recess 18 as an engaging portion that engages with a retaining protrusion 183 formed on the lid body 183.
20 (&), (
As shown in b), the lid 183 slides to open and close the developer discharge port IFIO.

Further, as shown in FIGS. 17 and 18, the drive device 180 includes a gear 18 integrated with the coupling 181.
6, a worm gear 187 that meshes with this gear 186, and a motor 188 that drives this worm gear 1137, and is attached to a movable base 190 that is slidable in the direction of arrow F in FIG.

The motor 188 is driven for a predetermined period of time by the detection signal from the developer embossing detector 174, and the transfer screw 176 is rotated.

As a result, the developer Db in the p1 container 175 is sent to the developer discharge port 128 side, and is sent 9 to the replenishment port 179 of the developer receiving and conveying section 133a.

Next, the replenishment port 179 of the developer receiving and conveying section 133 &
The developer Db fed into the developer storage section 150 is transported upward into the developer storage section 150 as the developer transfer shaft 1820 rotates.

On the other hand, at the bottom of the developer f-id 200 that surrounds the developer transport shaft 182, a developer discharge port 201 &~20 is provided.
The developer agitating body 152 provided in the developer accommodating portion 150 is distributed over substantially the entire axial direction of the developer agitator 152 provided at certain intervals La to Lgf. The intervals La to Lg between the developer discharge ports 201h to 201h gradually become narrower in the developer transport direction, and the opening area of the developer discharge ports 201 and 201h is larger in the developer transport direction. Now, developer D.
b is evenly distributed.

In addition, when removing the cartridge-type developer replenishing device 172, such as when the developer Db runs out, first move the drive device 180 to the right in the state shown in FIG. Connection part 1 of screw 176
The engagement operation between 76a and coupling 181 is released.

Next, after rotating the entire developer replenishing device 172 toward the front about the holder 177, the fitting protrusion 175a is pulled out from the holder 177 by pulling toward the front.

Furthermore, when installing a new developer replenishing device 172, the above procedure can be reversed.

On the other hand, the developer replenishing device 171 on the first developing unit 132 side has approximately the same configuration as the developer replenishing device 172 on the second developing unit 133 side, as shown in FIGS. 18 and 19. There is. That is, 210 is developer D
A transport screw 211 is housed in the bottom of the container 210 to transport the developer Da in the axial direction by being rotationally driven.

Further, at the lower part of one end of the transfer screw 211 of the container 210 located in the developer transfer direction, there is a holder 21 as a mounted portion connected to the developer receiving and conveying portion 133h.
A fitting protrusion 210a that can be freely inserted into and removed from 2 is formed. A developer discharge port 213 for discharging the developer Da transferred by the transfer screw z211 is formed on the lower surface side of the fitting protrusion 21θa.

Further, the holder 212 is connected to the developer receiving and conveying section 133.
It is rotatably attached to the upper surface side of a, and a replenishment port 214 is provided on the bottom surface thereof corresponding to between the developer agitating body 140114θ consisting of a spiral shaft.
has been formed.

Further, one end of the transfer screw 211 has a connecting portion 211 & that protrudes from the end surface of the holder 212 and connects to the drive coupling 216 of the drive device 215.

A lid body 217 is provided on the lower surface side of the fitting protrusion 21 (11) so as to be slidable to open and close the developer discharge port 213.

On the other hand, on the holder 212 side, a recess 218 is formed as a retaining portion that engages with a retaining protrusion 217a formed on the lid body 217.
When the developer 101L is inserted and removed, the lid 217 slides to open and close the developer discharge port 213 in the same manner as described above.

Further, as shown in FIGS. 17 and 18, the drive device 21.5 includes a gear 2 integrated with the coupling 216.
19, and a worm gear 220 that meshes with this gear 219.
It has a motor 221 that drives this worm gear 220 and is attached to a movable pace 222 that can slide in the direction of arrow G in FIG. 18.

Note that 223' shown in FIG. 18 is a support member that supports the side end surface of the container 210.

Then, the motor 22) is driven for a predetermined period of time by the detection signal from the developer embossing detector 173, and the transfer screw 211 is rotated.

As a result, the developer D& in the container 2 is sent to the developer discharge port 213 side, and is sent to the replenishment port 214 of the developer receiving and conveying section 132&.

Next, the replenishment port 214 of the developer receiving and conveying section 132a is opened.
The developer Da fed into the developer container 138 is moved by developer agitators 140 and 140 consisting of 4-spiral shafts.
evenly distributed.

In addition, when removing the cartridge-type developer replenishing device 171, such as when the developer Da runs out, first displace the drive device 215 in the right direction in the figure in the state shown in FIG. Connecting part 21 of
The locking operation between 11L and coupling 216 is completely released.

Next, the entire developer replenishing device 17 is rotated toward the front about the holder 212, and then pulled toward the front to pull out the fitting protrusion 210a from the holder 212.

Furthermore, when installing a new developer replenishing device 17, the above procedure can be reversed.

Further, as shown in FIGS. 22 and 23, the developer Db
A stirring blade 225 is rotatably housed in the container 175 containing the stirring body 225, and a transfer screw 176 for transferring the developer Db to the developer discharge port 178 is connected to the periphery of one end surface of the stirring body 225. A plurality of pawls 227 are provided to protrude and mesh with the attached sprocket 226. and,
The stirring blade 225 rotates with the rotation of the transfer tube IJ, -176.
rotates to prevent the developer Db in the container 175 from clumping or shifting, thereby ensuring that the developer Db can be reliably supplied without remaining.

On the other hand, similarly, inside the container 210 containing the developer Da,
The stirring blade is in a housed state 9 and is configured to similarly stir the developer Da in the container 210.

Incidentally, reference numeral 228 shown in FIG. 17 is a collection box for collecting the developer scraped off by the cleaning device 18, and can be easily removed by opening the front cover 170. Further, 229 is a magnetic catch that attracts and holds the front cover 170.

Next, with reference to FIGS. 24 to 28, the automatic paper feeder 2
The configuration of 0 will be explained.

As shown in FIG. 28, paper feed cassettes 7, 8, 9 containing button papers P... are each mounted on the upper surface of the pace 240 via guides (not shown) so as to be freely insertable and removable.

As shown in FIG. 25, each of these paper feed cassettes 7, 8, 9 regulates the trailing edge position and both side edges of the paper P, supports the id 241, 242m, 242b, and the paper ejection end. The structure includes a support plate 243.

The paper support plate 243 is supported so as to be swingable by engaging a sloping end side opposite to the paper in a groove formed in the bottom surface of the cassette main body 244. In addition, through holes 245 and 245 are formed in the paper support plate 243, and the paper support plate 245 at the bottom of the cassette body 244
An opening 246 is formed at a position corresponding to .

In addition, the cover 10 of the paper feed cassette 7 in the uppermost stage constitutes a manual paper feed tray 11 as shown in FIG. A pair of guide members 247, 247 are provided. These pair of guide members 247, 247 are attached to the cover 10, as shown in FIGS. 27 to 29, and when one of the guide members 247 is moved, the other guide member 247 is moved. It is supposed to move.

FIG. 27 shows the cover 10 viewed from the back side, and a pair of racks 249 and 249 are arranged symmetrically around a rotatably arranged binion 248 in the axial center of the cover 10. One end of each meshes with a pinion 248, and the other end engages with a corresponding guide member 247.
247 via pins 250 and 251.

Therefore, when one guide member 247 is moved along the width direction H, the other guide member 247 slides toward or away from each other in conjunction with this. That is, the binion 248 and the rack 24
9 constitutes interlocking means for interlocking both guide members 247.

As shown in FIG. 28, the above-mentioned pins 250 and 251 are inserted into the corresponding guide slots 252 at intervals, so that
The rack 249 is thereby guided to move along the width direction H. In addition, guide pins 256 are further provided on both sides of the binion 248 to hold the cassette body 1.
0 and guide and hold the rack member 249 on the back surface of the corresponding rack 248 so that it does not come out of engagement with the shim union 248.

In the figure, reference numeral 257 denotes a guide reinforcing plate attached to the back surface of the cover 10 by appropriate means, and is provided in the width direction along the running path of the rack 249 which constitutes the interlocking means. This guide reinforcing plate 257 also has a long hole formed in a state that matches the long hole 252 of the cover 10.

Also, the pivot shaft portion 2 rotatably supports the binion 24B.
58 is provided protruding from the back surface of the cover 10 as shown in FIG. has been done. The left and right pair of cut-and-raised tongues 259a and 259m of this brake member 259 are bent and elastically frictionally engaged with the outer peripheral edge of the pinion 248, and both ends 259b of the brake member 2590.

259b is bent at right angle and has a cutout (
(not shown) are engaged with the guide pins 256, 256. Therefore, the pinion 248 is connected to the braking member 259
Since the tongues 259&, 259a apply a slight braking effect to the movement of the paper, blind movement such as excessive rotation is prevented.

Therefore, the entire movement of the interlocking means is also subjected to a light braking action, so that when the guide members 247, 247 are moved, it is possible to prevent blind movement due to the inertia of each moving member or positional shift due to vibration.

In addition, each paper support plate 243 of each paper feed cassette 7.8.9
is a support plate push-up mechanism 26 provided on each power run mounting part.
The uppermost sheet of paper P is selectively pushed up by the rotating operation of the push-up lever 264 of No.
Appropriate pressure is applied to the paper feed roller) 265 using force.

The support plate push-up mechanism 263 has a configuration as shown in FIG. 30. That is, 266 is a shaft rotatably supported by a bearing (not shown), and this shaft 266 has approximately 1
The push-up lever 264 and the operating lever 267 are attached with a phase shift of 80 degrees. Additionally, a spring 268 is connected to the operating lever 267 and is biased so that the lower surface of its free end is always in contact with the circumferential surface of the eccentric cam 2690.

Eccentric cam 269 sequentially meshes gears 2701271.2
The driving force of the motor 274 is transmitted through a gear mechanism 273 consisting of 72. And motor 2
As the eccentric cam 269 rotates, the maximum eccentric part of the eccentric cam 269 faces the actuating lever 267, so that the actuating lever 267
is pushed up against the urging force of Sugering 268 (
When the least eccentric portions face each other, the operating lever 267 is pulled by the force of the spring (the state shown by the two-dot chain line in FIG. 30).

Accordingly, the push-up lever 264, which is in an integral relationship with the actuating lever 267 via the shaft 266, is also rotated and displaced to the state shown by the solid line or the two-dot chain line in FIG. The sheets of paper P... accumulated on the paper are separated from the take-out roller 265, and some are brought into contact with the take-out roller 265.

As shown in FIG. 24, rollers 289 and 289, which roll into contact with each other, act as a separating means 288 for separating the second and subsequent sheets of molded paper P and preventing them from being taken out.As shown in FIG. 290 are provided. These rollers 289, 290 are constructed as shown in FIG.

That is, 291 in the figure is a motor, and this motor 29
1 is in mesh with gears 293 and 294 via gear 292.

The gear 293 is configured to interlock with the low 2289 via a shaft 295, and the gear 294 is connected to the low 229 via a shaft 297 with a spring clutch 296 in the middle.
It is configured to work in conjunction with 0.

Further, the spring clutch 296 has a roller 289
．． It is set to slip when the force at the contact portion of 290 exceeds Ta. Further, if the frictional force between the rows 2289 and 290 is Tb, it is set so that Ta>Tb, and the roller 289 rotates according to the row 290.

In addition, the frictional force between the paper P and the paper P is Tf, and the roller 26
If the frictional force between the roller 2 and the paper P is Tr, then generally the roller 2
65 is Tr)Tf because it is molded from a material with a high coefficient of friction such as rubber. And Ta is Tr ) Ta
) Tf.

Thus, during paper feeding standby, the paper P is in a state away from the take-out row 2265, as shown in FIG. 23(&). When feeding paper, as shown in FIG.
After being brought into rolling contact with the sheet P, the uppermost sheet P is taken out as the take-out row 2265 rotates and is fed between rollers 289 and 290 forming the separation means 288.

At this time, the second and subsequent sheets of paper P that are taken out by adsorption to the topmost paper P are placed in the row 229 as shown in FIG. 23 (, ).
The paper P is separated by the reverse rotation operation of 0, and only the uppermost paper P is taken out. This means that paper P is low 2289.2
90, the roller 289 moves the paper P (Tr) Tf
In the direction of arrow J, the roller 290 and paper P...
This is because Tr>Ta:>Tf K is returned in the opposite direction.

Note that when one sheet is started to be taken out, the push-up lever 264 is lowered as shown in FIG.
) will be on standby in the state shown.

Further, as shown in FIG. 33, at a position corresponding to the bottom side of the paper feed cassette 7, 8, 9 and a position corresponding to the paper conveyance path immediately before the separating means 288, there are paper sheets connected to a control section (not shown), respectively. reflective optical sensor 300 as a detector;
301 is provided. And both these sensors 3θ
A sheet no-paper detecting means 302 is configured to determine that there is no paper based on the sum of the no-paper detection signals of 0.301.

When the paper P is placed on the paper support plate 243 as shown in FIG. 33(a), it is possible to detect when the paper support plate 243 is lowered. As shown in Figure (b), when the last sheet separated by the roller 290 is held between the rollers 289 and 290, the position corresponds to the bottom side of the paper feed cassette 7 (8, 9). Although the sensor 3QO installed at the front cannot detect this, the sensor 301 installed at a position corresponding to the paper conveyance path immediately before the separating means 288 can detect this. Therefore, it is possible to prevent a determination that there is no paper even though there is paper P.

In addition, a reflective optical sensor 300.3 is used as a paper detector.
01, it is possible to detect the paper P in a non-contact state, and it is also less susceptible to external light and easier to install than when using a transmission type optical sensor. There are benefits.

Further, as shown in FIG. 24, the paper P that has passed through the separating means 288 is transferred to the roller 24 of the stopped registration roller pair 24.
& 24b, and after the inclination (skinny) of the tip is corrected, it is sent to the image transfer section 21 in synchronization with the image forming operation on the photoreceptor 12. .

Also, the uppermost separation means 288 and the registration roller pair 24
There is a transfer row 2 consisting of rows 2305 and 306.
The pair 305 is now placed.

The take-out roller 265..., the transfer roller 3 o s b of the transfer roller pair 305, and the reno roller pair 24
224g... is the power transmission system 30 shown in FIG.
It is configured to be driven via 6. That is, numeral 307 in the figure is a motor as a drive means, and a drive gear 308 attached to the drive shaft of this motor 307 is in mesh with a gear 310 via an intermediate gear 309. The gear 310 is attached to the shaft of one of the rows 224 of the pair of registration rollers 24 via a one-sided clutch 311.

Further, a Sugerocket 312 is integrally attached to the intermediate gear 309, and the driven gear 312 is connected to the intermediate gear 309 via a chain 313.
It is configured to work in conjunction with Suge Rocket 315, which is integrated with 14.

The sprocket 315 is attached to the shaft of the transfer roller 305b via a one-sided clutch 319, and a gear 314 is attached to the shaft of the transfer roller 305b. Gear 314 further includes intermediate gear 316 .
317 are successively valved to mesh with a gear 318 attached to the shaft of the take-out row 2265.

When the motor 307 rotates forward (in the direction of the solid line arrow), the one-way clutch 311 is turned off and the one-way clutch 315 is turned on, driving the take-out roller 265 and the roller 305b, and power is applied to the row 224&. It is not transmitted and becomes stopped. Furthermore, when the motor 307 rotates in the reverse direction (in the direction of the dashed arrow), the one-sided clutch 311
is on, the one-way clutch 315 is off, and only the roller 24h is driven, and the rollers 305b, 265
is in a stopped state with no power being transmitted due to the action of the one-sided clutch 319.

In this way, the top row roller is configured to selectively rotate the take-out row 2265 and one of the rollers 24 & of the reno stroke 2 pair 24 by the forward and reverse rotation of the master motor 307 as a driving means. In the paper cassette installation section,
A manual feed roller 321 is provided that sequentially takes out the sheets P set in the manual feed tray 11 one by one and sends them to the separation means side via the take-out row 2265 section. This manual feed roller 321 and take-out roller 265 are the 24th
By the roller contact/separation means 322 shown in FIGS.
The roller 265 is configured to be able to move toward and away from the paper transport path, and is configured to separate the take-out roller 265 from the paper transport path at least when manually feeding paper.

That is, the spindle 265a of the take-out roller 265 is attached to and supported by the free ends of arms 323, 323 which are rotatable about the spindle 289& of the roller 289 of the separation means 288 as a fulcrum. Also, the manual feed roller 321 is connected to the take-out roller 226.
The arm 324 is rotatable around the support shaft 265a of No. 5 as a fulcrum.
．． Attachment is supported at the free end of 324.

In addition, the free end portions of the arms 324 and 324 are integrally provided with latch protrusions 342a that are orthogonal to each other.
The lever 327 is attached to a rotating member 326 that is rotatably supported about 5 as a fulcrum, and the free end of the lever 327 extends upwardly.

The rotating member 326 is always biased counterclockwise by the spring 328 in the state shown in FIG. Projection part 324-1
324a is in a lifted state.

Further, a plunger 329& of a plunger-shear type solenoid 329 is connected to the rotating member 326 via a connecting member 330, and the rotating member 326 is connected to a spring 32.
The structure is such that it can be rotated against the urging force of 8.

Note that 3; 31d in FIG. 24 is a manual paper feed switch disposed on the front side of the manual feed roller 321. Also, the third
As shown in FIG. 5, a sedge rocket 332 is attached to the spindle 265a of the take-out roller 265, and a sprocket 333 is attached to the spindle 321a of the manual feed roller 321, so that they interlock with each other via a chain 334. It has become.

However, when the paper P is placed on the paper feed table 11, the manual paper feed switch 331 turns on...? Tan 30 on
The solenoid 329 is then turned on. and,
The rotating member 326 is rotated against the biasing force of the sliding ring 328, and the manual feed row 2321 is lowered, and in conjunction with this movement, the take-out row 2265, which is a perfect circular roller, is displaced upward to leave the paper conveyance path. .

Then, the renoid 329 through which the paper P is sent to the separating means 288 is turned off, the manual feed roller 321 is raised, and the take-out roller 2265 is accordingly lowered.

At this time, the push-up lever 264 that pushes up the paper support plate 243 of the paper feed cassette 7 is in a lowered state, and the paper P
is separated from the take-out roller 265.

Next, the fixing device 25 will be explained with reference to FIG.

The fixing device 25 is roughly divided into an upper roller unit 336 and a lower roller unit 337.

The upper roller unit 336 has a heat source (not shown) inside.
A heat roller 338, which houses the heat roller 338 and whose outer surface is coated with Teflon, is attached to a bracket 340 rotatably supported via a support shaft 339.

The lower roller unit 337 has a pressure roller 341, which is a rubber roller collar, attached to a bracket 343 that is always urged upward by a compression spring 342.

The bracket 343 has elongated holes 345 and 345 through which guide shafts 344 and 344 are inserted, and can move up and down within the range of the elongated holes 345.

A movable frame 346 is provided near the free end side of the bracket 340 of the upper roller unit 336. The movable frame 346 is a part of the frame of the upper unit, which is rotatably provided so as to be separated from the lower unit almost at the paper conveyance path 23 of the copying apparatus main body 4. As shown in FIG. 36(,), when the upper unit is overlapped with the lower unit, the movable frame 346 is in contact with the upper surface of the free end side of the bracket 340, and the heat roller 338 rolls into contact with the pressure roller 341 in a depressed state against the biasing force of the compression spring 342, so that a predetermined contact pressure is obtained.

In addition, the paper conveyance path 2 is
3, when the upper unit is separated from the lower unit to open the bracket 346, the movable frame 346 is far away from the upper surface of the free end side of the bracket 340, and as shown in FIG.
, ), the bracket 340 is configured to be able to rotate by a maximum of about 95 degrees using the support shaft 339 as a rotation fulcrum. Note that such a configuration makes it easy to replace the heat roller 338 and the pressure row 2341.

Next, the paper P ejected from the paper ejection section 22 of the image forming apparatus 1 configured as described above is received as necessary, and then returned to the image recording apparatus 1 in the same state or in a reversed state.
The configuration of the direction changing conveyance device 2 for conveying the image to the image forming section is as follows.
This will be explained with reference to FIGS. 7 to 41.

As shown in FIG. 37, this direction conversion conveyance device 2 is composed of a unit independent from the image recording device 1, and also serves as a mounting table on which the image forming device 1 is removably mounted.

This direction conversion conveyance device 2 is a discharge section 2 of an image forming apparatus 1.
2, a guide means 350 for introducing the ejected paper P as necessary, a carry-in path 351 for carrying in the paper P guided by the guide means 350, and a carry-in path 35 a temporary stacking section 352 that temporarily stacks the sheets P carried in through the temporary stacking section 352, a take-out means 353 that sequentially takes out the sheets P accumulated in the temporary stack 352 one by one, and a sheet taken out by the take-out means 353. A first conveyance section 355 that leads the image forming apparatus 10 to a paper introduction section 354 as an image recording body introduction section without changing its leading edge direction to form multiple images on P, and a first conveyance section 355 that branches off from this first conveyance section 355. In order to form a double-sided image on the paper P taken out by the taking out means 353, the conveying direction is changed so that the trailing end becomes the leading edge, and the paper introduction section 354 of the image forming apparatus 1 is again operated. A second conveyance section 356 that guides the paper P to the second conveyance section 356 and a sorting system that selectively distributes the paper P taken out by the takeout means 353 provided at the branching part between the second conveyance section 356 and the first conveyance section 355°. means 357, and the guide means 3501 according to multiplexed, double-sided switching signals from the motor switching methane 33 as an operation section of the image forming apparatus 1.
Drive means 35'8.359 for switching the distribution means 357, etc.
It has a configuration that has the following.

The guide means 350 consists of a dart 362 rotatably provided by a support shaft 361, and this f-)-36
2 is a linear conveyance path 365 that passes through the paper ejection section 22 of the image forming apparatus 1 and the paper ejection roller pair 363 and reaches the paper ejection tray 364.
It is provided at a branch of the carry-in path 366 leading to the temporary stacking section 352, and is driven by a driving means 358 to selectively guide the sheets P. That is, the dart 362 is always urged in a predetermined direction by the spring 367, and normally moves along the loading path 366.
The linear conveyance path 365 is in the "open" state. Further, a solenoid 369 is connected to the r-t 362 via a connecting member 378.
66 to "open" and the linear conveyance path 365 to "close".
362 can be rotated against the biasing force of the tin ring 367.

In addition, a first conveying roller pair 370 is provided in the carry-in path 366.
1 Second conveyance roller pair 371, third conveyance roller pair 37
2 is arranged to forcibly feed the paper P to the temporary stacking section 352. As will be described later, the third pair of transport rollers 372 is configured such that the receiving and discharging position of the paper P is movable with respect to the feeding direction of the paper P.
Regardless of the size, the tip thereof is configured to be compatible with the take-out means 353 provided corresponding to the end side of the temporary accumulation section 352 in the take-out direction.

Further, the temporary stacking section 352 is constituted by the upper surface part 9 of the side plate 373, and the actuator 374a of the sheet detecting means 374 faces the central part thereof.

The take-out means 353 includes a take-out row 2377 held at the free end of an arm 376 that is pivotally supported via a support shaft 375.
This take-out roller 377 is adapted to be displaced upward when the paper P is accumulated in the temporary accumulation section 352 so as not to interfere with the accumulation of the paper P.

That is, a protrusion 376a is formed on the pivot end side of the arm 376, which rotates using the solenoid 378 as a driving source and comes into contact with the solenoid 378.
78, the protruding portion 376a is removed by the row 2377, which is displaced upward as shown by the solid line in FIG.
The offJ operation causes the take-out row 2377 to move downward under its own weight, as shown by the two-dot chain line in FIG.

Further, a pair of conveying rollers 380 consisting of rollers 380g and 3130b is provided in the sheet taking out direction of the taking out means 353 configured as described above, and conveys the sheets P taken out from the temporary stacking section 352 to the sorting means 357. It is designed as follows:

Next, the configuration of the direction changing portion of the paper P taken out from the temporary stacking section 352 and fed through the pair of transport rollers 380 will be described with reference to FIG. 38.

That is, the roller pair 311 as the first conveying means
a first conveyance path 382 for conveying the paper P, and a second conveyance path 384 for conveying the paper P; A third conveyance path 386 is branched from the terminal end of the first conveyance path 382 and includes a pair of conveyance rollers 385 as a third conveyance means, and a third conveyance path 386 is connected to the third conveyance path 386. The fourth conveyance path 387 is branched from the base end of the second conveyance path 384.

Furthermore, the first conveyance path 382 and the third conveyance path 386
The paper P conveyed through the first conveyance path 382 is transferred to the second conveyance path 384 by the conveyance roller pair 380 provided at the branching point between the
Alternatively, a first guide means 388 selectively guides the third conveyance path 386 and a second conveyance means 383 provided at a branching point between the second conveyance path 384 and the fourth conveyance path 387.
The paper pf that has been reversely fed through the second conveyance path 3/83 by
, the second guide means 3 guiding to the fourth conveyance path 387 side
89 is provided and constitutes the distribution means 357.

Further, the second conveyance path 384 includes a first conveyance path 38
2 to the second conveyance path 384 reaches a predetermined position, and controls the conveyance roller pair 383 to reversely convey the sheet P.
is provided.

By switching the first and second guide means 388 and 389, the paper P transported through the first transport path 382 is transported without changing its leading edge in the transport direction, and the trailing end in the transport direction. The conveying direction is changed so that the paper is on the leading edge side, and the paper is conveyed again to the paper introducing section 3 of the image forming apparatus 1.
It has a configuration that allows it to be sent to 54 and 9.

Further, the first and second guide means 388 and 389 are
A ground gloss 392 of a plunger type solenoid 392 that is pivotally supported via a support shaft 391 and serves as a driving device.
a and a guide member connected to the connecting member 393 through a connecting member 393, respectively, and the on% of the solenoid 392.
The OFF operation causes rotational displacement as shown by the solid line or the two-dot chain line in FIG.

Next, the operation during double-sided copying will be explained.

(a) First, after operating the mode switching button 33 on the operation panel 6 to specify "duplex mode" and setting the number of sheets, exposure, magnification, etc. using separate operations, the start button (f-lint button) 30 is pressed.

(b) When the solenoid 369 of the y-id means 35θ is pulled
The single-coated sheet P is guided to the direction changing conveyance device 2.

(c) The sheets P on which one-sided copies have been made are accumulated in the temporary accumulation section 352.

(d) The solenoid 396 of the guide means 35θ returns.

(e) Replace the original, set exposure, etc., and press start button 30.

(f) The solenoid 378 of the take-out means 353 provided in the temporary accumulation section 352 is pulled, and the take-out roller 327 is lowered.

(g) Take-out row 2377, transport row 2 that also serves as separation means
vs. 380. And the conveyance roller pair (switchback roller pair) 383 rotates.

(h) When the leading edge of the paper P has sufficiently reached the transport roller pair 380, the take-out roller solenoid 378 returns and the take-out row 2377 rises.

(i) 1° at which the transport roller pair 380 stops when the leading edge of the paper P sufficiently reaches the transport roller pair 383 (however,
The transport roller pair 380 has a one-way latch and is rotated by the paper P until the rear end of the paper P pulled by the transport roller pair 383 separates. ) (j) When the trailing edge of the paper P passes the paper detection means 390, the transport roller pair 383 reverses, the solenoid 9392 of the sorting means 357 is pulled, and the transport roller pair (feed υ roller pair)
385 rotates.

(k) When the leading edge of the paper P reaches the aligning roller pair 24 located in front of the image transfer section 21 of the copying apparatus l, the transport roller pair 383 and 385 stop, and the paper P is aligned.

(1) When the paper P is sent to the image transfer section 2 and the trailing edge is separated from the distribution means 357, the solenoid 392 of the distribution means 357 returns.

(However, the roller 385a of the conveyance roller pair 385.

385b has a one-way latch and is rotated by the paper P pulled by the pair of aligning rollers 24. )) With the sorting means 357 in its returned position, the paper P with single-sided copies in the temporary stacking section 352 runs out (f)
The operations from (1) to (1) will be repeated.

Next, the double copy/temporary operation will be explained.

(a) First, change the mode on the operation panel 6? After operating the button 33 to specify "duplex mode" and setting the number of copies, exposure, magnification, etc. using separate operations, press the start button (Print button) 30 t[-j-.

(b) is when the solenoid 369 of the idle means 350 is pulled;
The copied paper p7j) is guided to the s-direction conversion conveyance device 2.

(e) The sheets P on which one-sided copies have been made are stacked in the temporary stacking section 352.

In (d), the solenoid 396 of the idle means 350 returns.

(e) Replace the original, set exposure, etc., and press start button 30.

(f) The solenoid 378 of the take-out means 353 provided in the temporary accumulation section 352 is pulled, and the take-out roller 377 is lowered.

(g) The solenoid 392 of the sorting means 357 is pulled, and the take-out roller 377 and the pair of conveyance rollers 380 that also serve as separation means
, and a pair of transport rollers (pair of transport rollers) 385 rotate.

(h) When the leading edge of the paper P has sufficiently reached the pair of transport rollers 380, the take-out roller lunoid 378 returns), and the take-out row 2377 rises.

(1) The transport roller pair 380 stops when the leading edge of the paper P reaches the transport roller pair 385 sufficiently.

(However, the transport roller pair 380 has a one-way latch and is rotated by the paper P until the trailing edge of the paper P pulled by the transport roller 2 pair 385 separates.) (j) The leading edge of the paper P is copied. When reaching the aligning roller pair 24 located in front of the image transfer section 21 of the apparatus 1, the transport roller pair 385 stops, and after aligning the paper P, the moon paper P is sent to the image transfer section 2.

[Yes]) While the guide means 35θ remains in its returned position, the paper with single-sided copies in the temporary stacking section 352 runs out.
The operations (f) to (j) above will be repeated.

Furthermore, if necessary, the paper P ejected from the paper ejection section 22 of the image forming apparatus 1 is received, and the image is transferred again as the image forming section of the image recording apparatus 1 in the same state or with the front and back reversed. By leading to section 21,
In the direction changing conveyance device 2 configured to form multiple or double-sided images on the paper P, one side (
The member located on the lower side) is moved outward (
It has a structure that allows it to be freely displaced to the lower side).

That is, the lower guide plates 400m of the guide plates 400h and 400b forming a part of the carry-in path 366, the lower roller jp 371m of the pair of transport rollers 371&, 371b, the ID plate 373 forming the temporary accumulation section 352, and the first, The lower part of the second conveyance path 382 and 383 is the ID plate 401, the pair of conveyance rollers 380m, and the lower roller 380* of 3110b.

The lower roller 383a of the transport roller pair 383&, 383b is rotatably provided on the negative side of the transport direction of the paper P and is attached to a support frame 402, and opens the paper passage path as the support frame 402 is displaced. The structure is such that they all move outward all at once.

Also, on the free end side of the support frame 402, there are holding means 403 and 403 for holding the skinned frame 402 in a predetermined state.
By operating these holding means 403, 403, the paper conveying section can be opened, making it possible to easily deal with paper jams and the like.

Further, as shown in FIGS. 39 to 41, the carrying means for receiving the first conveyed paper P and sending it to the temporary stacking section 352 is movable in the feeding direction of the paper P. It has become.

That is, the carrying means is composed of the two pairs of conveying rollers 372, each having a driving roller 2372a as a first conveying roller and a driven roller 2372b as a second conveying roller.

The drive roller 372a has a slit 40 as a side part.
The driven roller 2372b has a support shaft 407 which is movably supported horizontally by holding bearings (buttons) 406 and 406 at 5.405.
A drive row, 7372, to sandwich and convey paper P between
It is provided so as to be in continuous rolling contact with the drive roller 372a and is movable integrally with the drive roller 372a. The slit 405.4θ5 serving as the guide portion is connected to a pair of sites facing apart from each other across the paper conveyance path.
40B, respectively.

Further, the bearings 406, 406 held by the slits 405, 4θ5 are attached to the frames 40B, 401? The sheet P is fixed at a predetermined position according to the size of the sheet P by positioning means 409 and 409 provided on the outside of the sheet P.

Each positioning means 409 is provided along the movement path of the bearing 406, 406, as shown in FIGS. The structure includes a lever 41 as a positioning member having a diameter of .410. This lever 411 has one end rotatably attached to the frame 40B via a shaft 412, and a free end serving as a biasing member that constantly biases the concave portion 41σ to fit into the bearing 406. The spring 413 is in a connected state.

Note that 414 shown in FIGS. 39 and 41 is the bearing 4.
06.406 is a movable frame that moves together with the drive row 2372a, and 415 is a movable frame 41
This plate spring is attached to the drive roller 372a and urges the driven roller 372b toward the drive roller 372a.

Therefore, when setting the transport roller pair 407 that feeds the paper P to the temporary stacking section 352 at four positions depending on the size of the paper P, both levers 411 are rotated against the biasing force of the spring 413. The movable frame 41
4 and insert the bearing 406.40 into the predetermined recess 410.
It will be sufficient if ``6'' is fitted. In this way, paper P
The pair of conveying rollers 407 can be moved extremely easily to a position suitable for the size of the sheet P without using any tools such as a dryer, and the sheets P can be stacked in the temporary stacking section 352 in an orderly manner so that they can be taken out.

Further, as shown in FIG. 42, if necessary, a large-capacity paper feeder 420 that stores a large amount of paper P instead of the lowermost paper feed cassette 9 can also replace the paper ejection tray 364. It is designed so that 42 connecting devices can be installed.

In the large-capacity sheet feeding device 420, the movement of a machine plate 424 that can be raised and lowered is controlled by a lifting means 423 driven by a motor 422 so that the uppermost sheet P is always in rolling contact with the take-out row 2425. As the take-out roller 425 rotates, the uppermost sheets of paper P are taken out one after another. Further, the taken out paper P is transferred to a guide plate 420 provided in the transport section 420*.
．． 427 to the take-out row 2265 disposed in the cassette loading section, and then to the pair of aligning rollers 24 via the separating means 288.

On the other hand, as described above with reference to FIG. 33, a reflection-type optical sensor 300 as a paper-absence detector that sends a "paper-out" detection signal to the main body of the apparatus is disposed corresponding to the paper feed section. It is in a state. Therefore, this large capacity paper feeder 42
The conveyance unit 420h of No. 0 has a built-in signal generation control means 428 that controls generation of a signal indicating "no paper" even though paper P is present K.

As shown in FIGS. 43 and 44, this signal generation control means 428 has a shutter member 429 made of a reflective plate that can freely move in and out of the optical path of the reflective optical sensor 300. When there is paper P in 420, the shutter member 429 blocks the light, and when there is no paper P, the light is transmitted through the shutter mechanism. The shutter member 429 is provided at the free end of an arm 431 that is pivotally supported by a shaft 430, and is in a state where it can open and close an opening 432 formed at the bottom of the conveyance section 420a.

The arm 431 is urged by a spring 433 to a state in which it is always in contact with the striker 4434, that is, a position in which the shutter member 429 does not close the opening 432.

Further, a solenoid 34 is provided on the pivot end side of the arm 43.
5 are connected, the arm 43 is connected to the spring 43 by turning on the solenoid 345.
3, so that the shutter member 429 can be opposed to the opening 432.

〔Effect of the invention〕

As explained above, according to the present invention, large-capacity paper feeding is achieved by inserting the transport section of a large-capacity paper feeding device that stores a large amount of paper into the paper feeding section into which the paper cassette is attached/detached. In the image forming apparatus, the "paper out" detection signal is sent to the main body of the apparatus by a paper out detection means having a reflective optical sensor facing the paper feeding section. The paper out detection means is a reflective optical sensor, and a signal generation control means for controlling generation of a "paper out" signal from the reflective optical sensor is provided in the conveyance section of the large capacity paper feeder. It is something. Therefore, although the configuration is simple, when a large-capacity paper feeder is installed in place of the paper cassette, the error message "No paper" may occur even though there is paper on the elevator plate of the large-capacity paper feeder. This has the effect of providing an image forming apparatus in which no signal is generated.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of an image forming unit employing the image forming apparatus of the present invention, FIG. 2 is a schematic longitudinal sectional front view, FIG. 3 is a schematic vertical sectional front view of the image forming apparatus, and FIG. A plan view of the operation panel, Fig. 5 is an explanatory diagram of the configuration of the exposure optical device, Fig. 6
The figure is an explanatory diagram showing the cooling air conduction path, Fig. 7 is a perspective view showing the operating means of the first and second optical units of the exposure optical device, Fig. 8 is an explanatory diagram of the configuration of the main parts, and Fig. 9 are a plan view, a 10th side view, and a 20th (&L (b)
) is an explanatory diagram showing the opening/closing state of the developer discharge port when the container of the developer replenishing device is attached/detached, and FIG. 21 is a schematic plan view showing the configuration around the developer receiving and transporting section of the second developing unit. , FIG. 22 is a schematic cross-sectional view of the developer replenishing device;
Figure 3 is also a schematic exploded perspective view of the developer replenishing device, and the second
Figure 4 is a schematic front view of the paper feed device section, Figure 25 is a perspective view showing the paper feed cassette with the cover removed, Figure 26 is a perspective view of the feed cassette cover that also serves as a manual paper feed tray, 2
FIG. 7 is a schematic perspective view of the support plate push-up mechanism for pushing up the support plate when the guide member of the manual paper feed table is attached to the support state, FIG. Explanatory diagram showing the paper separation state of the separation means, Fig. 33(a), (
b) is an explanatory diagram showing the arrangement state of the no paper detector in the paper feed cassette mounting section, Fig. 34 is a configuration explanatory diagram showing the drive system of the take-out roller and aligning roller, and K2S diagram is the roller that approaches and separates the manual feed roller. A schematic plan view showing the configuration of the contact/separation means,
36(a) and 36(b) are schematic front views showing the structure of the fixing device, FIG. 37 is a schematic longitudinal sectional front view of the direction changing conveyance device, and FIG. 38 is a paper sorting section of the direction changing conveyance device. FIG. 39 is a partially cutaway front view showing the structure of the paper transport section to the temporary accumulation section of the direction conversion conveyance device;
Figure 0 is a perspective view of the main parts of the paper feed section, Figure 41 is a partially cutaway side view, and Figure 42 is a large-capacity paper feeder replaced with a paper output tray in place of the lowermost paper feed cassette. 43 is a plan view of the signal generation control means incorporated in the conveyance section of the collation device, and FIG. 44 is the same signal generation control means. FIG. 1... Image forming device (copying device), 9... Paper feeding power cent (lower), P... Paper, 300... Paper detector (reflection type optical sensor), 420... Large capacity Paper feed device, 4
20m...Transportation section, 428...Signal generation control means, 4
29...Shutter member. Applicant's Representative Patent Attorney Takehiko Suzue Figure 11 Figure 12 Figure 13 Figure 14 Figure 17 Figure ζ Figure 19 Figure 20 (a) (b) Figure 22 Figure 23 Figure 26 Figure 244'/ (El, 9) Fig. 27 24son 4b 24″:3 1UU3
08 Figure 31 Figure 32 (a) (b) Figure 32 (c) Figure 33 Figure 34... 0 Figure 35 Figure 43 Figure 44 4 JI JUU Procedure Amendment (Method) % Formula % 1. Indication of the case Patent Application No. 59-220511 2. Name of the invention Image forming device 3 o Person making the amendment Relationship to the case Patent applicant (307) Toshiba Corporation 4, Agent 1 Toranomon, Minato-ku, Tokyo Chome 26-5 No. 17jI Building February 26, 1985

Claims (3)

[Claims] (1) Large-capacity paper feeding is possible by inserting the transport unit of a large-capacity paper feeding device that stores a large amount of paper into the paper feeding unit where the paper cassette is attached and removed, and is compatible with the paper feeding unit. In an image forming apparatus, a detection signal indicating "out of paper" is sent to the main body of the apparatus by a paper out detection means provided as a paper out detection means. An image forming apparatus characterized in that a signal generation control means for controlling the generation of a "paper out" signal from the reflective optical sensor is provided in the conveying section of the image forming apparatus. (2) The signal generation control means has a shutter member that can freely move in and out of the optical path of the reflective optical sensor, and when there is paper in the large-capacity paper feeder, the signal generation control means blocks the optical path with the shutter member;
2. The image forming apparatus according to claim 1, further comprising a shutter mechanism that allows light to pass through when there is no paper. (3) The image forming apparatus according to claim 2, wherein the shutter member that blocks the optical path is made of a reflecting plate.