JP2915261B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

(Contents) Industrial application field Conventional technology Problems to be solved by the invention Means for solving the problems (FIG. 1)

Embodiment (a) Description of an image forming apparatus (FIGS. 2 to 9) (b) Description of a developing device (FIGS. 10 to 14) (c) Description of another embodiment

[0003]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for reducing an installation area of the apparatus. Copiers, printers,
2. Description of the Related Art In an image forming apparatus such as a facsimile apparatus, a latent image forming apparatus such as an electrophotographic apparatus has been used due to a request for recording on plain paper. In such an image forming apparatus, an electrostatic latent image is formed on a photosensitive drum. Next, the electrostatic latent image on the photosensitive drum is developed into a visible image by developing with a powder developer. Furthermore, the powder developed image of the photosensitive drum is transferred to a sheet, the sheet is separated,
This is to fix the powder developed image on the sheet.

[0004] In such an image forming apparatus, it is desired to make the apparatus compact so that the installation space of the apparatus can be reduced.

[0005]

2. Description of the Related Art In order to reduce the installation area of an image forming apparatus, an image forming apparatus which is used by being vertically installed or an image forming apparatus which operates even when installed horizontally or vertically (for example,
Japanese Unexamined Patent Publication No. Hei 4-323125) is disclosed. Such an image forming apparatus is used by being connected by an external cable. 2. Description of the Related Art A cable connector is provided beside a normal device to connect to an external cable. Further, when the length of a stacker for storing printed paper is set to be equal to or less than the maximum length used by the apparatus, a method of providing a fixed paper guide has been adopted.

[0006]

However, the prior art has the following problems. As the size of the image forming apparatus is reduced, the size of the cable is relatively increased. Therefore, when a cable is provided beside the device, the effective occupation area of the device increases, and the effect of reducing the size of the device decreases.

In the method in which the fixed guide is provided on the stacker, the paper guide always projects from the stacker, the effective occupation area of the apparatus increases, and the effect of reducing the size of the apparatus decreases.

Accordingly, it is an object of the present invention to provide an image forming apparatus for preventing an increase in the effective occupied area of the apparatus even when external components are connected.

Another object of the present invention is to provide an image forming apparatus for preventing an increase in the effective occupied area of the apparatus even when a cable is connected.

Further, according to the present invention, even if an external guide is provided,
It is an object of the present invention to provide an image forming apparatus for preventing an increase in the effective occupied area of the apparatus.

[0011]

FIG. 1 is a diagram illustrating the principle of the present invention. The first aspect of the present invention is an image forming apparatus for forming an image on a sheet.
Image forming mechanisms 20 to 26, and image forming mechanisms 20 to 26
Is provided at the top of the printer and accommodates a sheet on which an image is formed.
In the image forming apparatus having the stacker 14, the stacker 14 is provided on the outer peripheral surface of the apparatus .
It includes a cutout portion 5 4 which is extendable in the formation of the cable from the stacker face, and a cable connector 19 provided at the bottom of the notch 5 4, from the stacker face of the device
The cable 17 is inserted into the cutout 54 and connected to the cable connector 19.

[0012] Claim 2 of the present invention is based on claim 1,
Image forming mechanisms 20 to 26 for forming an image on the sheet
And a stacker 14 provided above the image forming mechanisms 20 to 26 and containing a sheet on which an image is formed, wherein the cutout portion 54 is provided on the opposite side to the stacker 14. It is characterized by.

[0013] Claim 3 of the present invention is based on claim 2,
An image forming operation can be performed both in the horizontal installation of the apparatus and in the vertical installation with the cutout 54 side as the installation side.

According to a fourth aspect of the present invention, in the second or third aspect, a button switch 52 for opening the top cover 51 constituting the stacker 14 and a slope provided on a pressing portion of the button switch 52 are provided. 52a.

According to a fifth aspect of the present invention, in the second, third or fourth aspect, a manual insertion slot 10a for manually inserting a sheet into the image forming mechanisms 20 to 26 and the manual insertion slot 10a are provided. And a sheet holding plate 53 that displays the sheet size on the left and right sides.

According to a sixth aspect of the present invention, there is provided an image forming mechanism for forming an image on a sheet;
And a stacker 14 that is provided on the upper part of the sheet stacker 26 and accommodates the sheet on which the image is formed.
The stacker 14 is formed to be shorter than the maximum length of a sheet on which an image is to be formed, and the stacker 14 is provided with a sheet guide plate 30 that can be accommodated in the apparatus.

[0017] Claim 7 of the present invention is based on claim 6,
The tip of the sheet guide plate 30 is inclined.

According to an eighth aspect of the present invention, in accordance with the sixth or seventh aspect, the horizontal installation of the apparatus and the stacker
The image forming operation can be performed both in the vertical installation with the opposite side to the installation side.

According to a ninth aspect of the present invention, there is provided the upper cover 5 constituting the stacker 14 according to the sixth, seventh or eighth aspect.
It is characterized by having a button switch 52 for releasing 1 and a slope portion 52a provided on a pressing portion of the button switch 52.

According to a tenth aspect of the present invention, in the sixth or seventh or eighth or ninth aspect, a manual insertion slot 10a for manually inserting a sheet into the image forming mechanisms 20 to 26 is provided.
A sheet holding plate 53 is provided in the manual insertion slot 10a and displays a sheet size on the left and right sides.

According to the first aspect of the present invention, the notch 54 is provided on the outer peripheral surface of the device, and the cable connector 19 is provided at the bottom of the notch 54. Thereby, the cable can be accommodated in the device, and an increase in the effective installation area of the device can be prevented. At the same time, the notch 54 is provided in the stacker 14.
The cable is formed so that it can be pulled out from the
Cut the cable 17 from the stacker surface of the device.
Can be inserted into the part 54 and connected to the cable connector 19,
Cables without protrude from the device, can prevent an increase in the effective installation area of more devices. That is, the outer peripheral surface of the stacker surface
Both can be installed on indoor walls.
There are no restrictions on the placement direction and location.

According to the sixth aspect of the present invention, since the sheet guide plate 30 which can be accommodated in the apparatus is provided in the stacker 14, when the sheet guide plate 30 is not required, it can be accommodated in the apparatus, and the effective installation area of the apparatus. Can be prevented from increasing.

[0023]

【Example】

(A) Description of Image Forming Apparatus FIG. 2 is a configuration diagram of an image forming apparatus according to an embodiment of the present invention, FIG. 3 is a horizontal installation state view of the apparatus of FIG. 2, FIG. 5 is a perspective view as viewed from the opposite side of the apparatus in FIG. 3, FIG. 6 is an explanatory view of the operation of the paper guide plate, FIG. 7 is an explanatory view of the cover opening operation, FIG. 8 is a top view of the paper holding plate, and FIG. FIG. 3 is a vertical installation view of the apparatus of FIG. 2. An electrophotographic printer is shown as the image forming apparatus.

As shown in FIG. 2, the photosensitive drum 20 is formed by coating a function-separable organic photosensitive member on an aluminum drum to a thickness of about 20 microns. Its outer diameter is 24 mm, and it is rotated at a peripheral speed of 25 mm / s in the counterclockwise direction indicated by the arrow. The pre-charger 21 is a non-contact type charger composed of a scorotron. Then, the pre-charger 21 uniformly charges the surface of the photosensitive drum 20, and charges the surface of the photosensitive drum 20 by -5.
It is charged to 80V.

The optical unit 22 forms an electrostatic latent image on the photosensitive drum 20 by imagewise exposing the uniformly charged photosensitive drum 20. This optical unit 22 has L
LE combining ED array and Selfoc array
A D optical system is used. The image exposure of the optical unit 22 causes the photosensitive drum 20 to have a voltage of -50 to -100 V
Is formed.

The developing unit 23 supplies charged toner to the electrostatic latent image on the photosensitive drum 20 to visualize the electrostatic latent image.
This will be described below. The developing roller 24 of the developing device 23 transports the developer to the photosensitive drum 20. The toner cartridge 25 of the developing device 23 is filled with magnetic toner. This toner cartridge 25 is replaceably attached to the developing device 23. The toner cartridge 25 is replaced when the toner is empty, and supplies the magnetic toner to the developing device 23.

The transfer unit 26 is constituted by a corona discharger. The transfer device 26 electrostatically transfers the toner image on the photosensitive drum 20 to a sheet. That is, by applying a voltage of +3 to +6 kV from the power supply to the corona wire, charges are generated by corona discharge, the back surface of the paper is charged, and the toner image on the photosensitive drum 20 is transferred to the paper P. The power source is desirably a constant current power source that can reduce a reduction in transfer efficiency due to the environment by supplying a constant amount of electric charge to the paper.

The fixing device 27 includes a heat roller having a halogen lamp as a heat source therein and a pressure roller (backup roller). Then, by heating the paper, the toner image is fixed on the paper.

The distribution (uniform) brush 28 is constituted by a conductive brush. The scattering brush 28 comes into contact with the photosensitive drum 20 to disperse the concentration of the residual toner on the photosensitive drum 20, thereby facilitating the collection of the residual toner in the developing device 23. Further, by applying an AC voltage to the distribution brush 28, a reciprocating motion is generated in which the residual toner on the photosensitive drum 20 is peeled off and returned again.
Thereby, the residual toner can be appropriately dispersed.
Furthermore, by applying a voltage higher than the discharge starting voltage,
It also has the effect of eliminating the charge on the photosensitive drum 20, and removes a positive afterimage due to residual charges.

As shown in FIG. 2, the paper cassette 10
It accommodates paper and is detachable from the device. The paper cassette 10 is provided at the lower part of the apparatus, and can be detached from the front of the apparatus on the left side of the drawing. The manual insertion slot 10a is for manually inserting paper into the apparatus. In order to use the manual insertion slot 10a, a sheet may be placed on the sheet holding plate 53 and inserted. The pick roller 11 is for picking a sheet from the sheet cassette 10. The registration roller 12 aligns the leading edge of the sheet by abutting the picked or manually inserted sheet, and then conveys the sheet to the transfer device 26. The discharge roller 13 discharges the sheet after fixing to the stacker 14. The stacker 14 is provided on the upper surface of the apparatus, and stacks discharged sheets.

The printed board 15 mounts a control circuit of the apparatus. The power supply 16 supplies power to each part of the apparatus. The I / F (interface) connector 17 is connected to an external cable, inserted into the device,
It is connected to a connector on the printed board 15. The option board 18 includes another type of emulator circuit,
This is for mounting a font memory and the like. The connector 19 is provided on the printed board 15 and at the bottom of a cutout 54 provided on the outer periphery of the apparatus, and is connected to the cable connector 17 described above.

The operation of this embodiment will be described. The surface of the photosensitive drum 20 is reduced by -5 using the scorotron charger 21.
After being uniformly charged to 80 V, image exposure is performed by the LED optical system 22 so that the background portion of the photosensitive drum 20 has a negative value.
At 580 V, an electrostatic latent image having a printing portion of -50 to -100 V is formed. Sleeve 2 of developing roller 24 of developing unit 23
41 (described later with reference to FIG. 10), the developing bias voltage (−4
50V) is applied. For this reason, the photosensitive drum 20
The electrostatic latent image is developed by the developing unit 23 with a magnetic polymer toner negatively charged by stirring with the carrier in advance, and becomes a toner image.

On the other hand, the sheet is picked from the sheet cassette 10 by the pick roller 11, the leading ends thereof are aligned by the registration roller 12, and then, the registration roller 12 is driven to be conveyed toward the transfer device 26. Then, the toner image on the photosensitive drum 20 is transferred to a sheet by a transfer device 26 by electrostatic force. The toner image on this paper is supplied to the fixing device 27.
And is discharged onto the stacker 14 by the discharge rollers 13 through a U-shaped conveyance path.

On the other hand, the transfer rate of the toner image to the paper is 10
Some toner other than 0% remains on the photosensitive drum 20. As a method for removing the residual toner, a known cleaner-less process from which a cleaner has been removed is used (for example, Journal of the Institute of Electrophotography, Vol. 30, No. 3, No. 29).
Pages 3 to 301, dissertation, "Cleanerless laser printer using one-component non-magnetic development method", etc.).

In the cleaner-less process, the cleaner is removed, and the transfer residual toner is collected by the developing device 23, so that the transfer residual toner is used again for printing. In the cleanerless process, the cleaner is removed, and a conductive uniformizing brush 28 is provided instead. In this recording process, the transfer residual toner on the photoconductor 20 is dispersed by a scattering (uniform) brush 28. Thereafter, with the toner adhered to the photosensitive drum 20, the toner is uniformly charged by the corona charger 21, image exposure is performed by the optical unit 22, and development is performed simultaneously with collection of the transfer residual toner by the developing device 23. I do.

The toner is dispersed by the uniforming brush 28 by reducing the toner per unit area by dispersing the toner concentrated on a part of the toner.
3 facilitates recovery. Further, it is possible to prevent non-uniform charging due to the residual toner serving as a filter for ion shower in the corona charger 21 and to prevent non-uniform charging due to serving as a filter in the image exposure process. It has the effect of suppressing.

The point of this recording process is to collect the toner on the photosensitive drum 20 simultaneously with the developing step. This will be described with the photosensitive drum 20 negatively charged and the toner also negatively charged. The surface potential of the photosensitive drum 20 is set to −580 V by the charger 21, and the exposed portion whose potential has decreased by image exposure decreases the potential to 0 to −several 10 V to form an electrostatic latent image. At the time of development, a developing bias voltage (for example, -450 V) substantially intermediate between the surface potential and the latent image potential is applied to the developing roller 2 of the developing unit 23.
4 is applied.

In the developing step, the negatively charged toner adhering to the developing roller 24 adheres to the electrostatic latent image on the photosensitive drum 20 by an electric field formed by the developing bias and the latent image potential. A toner image is formed. In the cleaner-less process, the transfer residual toner dispersed on the photosensitive drum 20 in the uniformizing process by the scattering brush 28 at the same time as the developing process is caused by the electric field formed by the surface potential and the developing bias. The toner is collected by the developing roller 24 from above.

In such a cleanerless process,
There is no need for a mechanism for discarding toner, so that the apparatus can be downsized. No space is required for storing waste toner, and there is no toner that does not contribute to printing, so it is economical. Therefore, in order to remove the toner from the photosensitive drum with a cleaner, the photosensitive drum is scraped with a cleaner, which is in line with environmental protection. However, since the cleaner is not used, there is an advantage that the life of the photosensitive drum is extended. .

This device can be made extremely small because it does not have a cleaner, and can be easily installed on a desk as a printer for personal use. Further, as shown in FIG. 3, the paper cassette 10 can be horizontally installed so as to be horizontal with the installation surface. In this figure, reference numeral 50 denotes an operation panel for displaying the state of the apparatus and for instructing the apparatus to operate.

A paper guide 30 is provided at the tip of the stacker 14. The paper guide 30 is provided in the stacker 1
4 can be accommodated in the guide accommodation block 30a. That is, as shown in FIG. 3, the paper guide 30 is pulled out of the storage block 30a for the paper that requires the paper guide. Thereby, as shown in FIG. 6, the leading end of the sheet exceeding the length of the stacker 14 is guided, lifted, and accommodated.

On the other hand, when the paper guide is not required, the paper guide 30 is stored in the storage block 30a as shown in FIG. Thus, when the paper guide is not required, the occupied area of the apparatus is not increased.

Reference numeral 51 denotes a cover, which forms the stacker 14 and is rotatable upward in FIG. Reference numeral 52 denotes a button switch for opening the cover 51 when pressed. As shown in FIG.
Has an inclined portion (concave surface) 52a formed on the operation surface.
The button switch 52 is attached to the cover 51 so as to be rotatable about a fulcrum 52-2. Also, the cover 51
Is provided with a leaf spring 52-3 for urging the button switch 52 counterclockwise.

On the other hand, a hook block 58 is provided on a frame 57 of the apparatus. This hook block 58
The claw 52-1 of the button switch 52 is engaged with
The cover 51 is fixed. To open the cover 51,
The button switch 52 is depressed, and the button switch 52 is turned around the fulcrum 52-2 in the direction of the arrow in the figure. As a result, the claw 52-1 of the button switch 52 comes off the hook block 58, and the cover 51 is opened.

At this time, the operation surface of the button switch 52
Since the inclined portion 52a is provided, even if the cover 51 is inclined as the cover 51 is opened, the force of the finger is easily applied and the operability can be improved. Similarly, when the cover is closed, the operability can be improved.

The paper holding plate 53 shown in FIG.
The paper size is displayed on the left and right sides as shown in FIG.
In this example, the letter size is the largest, and five levels of paper sizes are displayed up to the smallest envelope size.
When the paper size is displayed on both sides in this way, errors in the insertion position of the manual paper are reduced as compared to only one side, and operability can be improved. Further, when the photosensitive drum 20 forms an image on the basis of the center, it is necessary to make the paper left and right from the center in the width direction. Therefore, the operability is further improved by displaying the paper size on the left and right sides in this manner.

Next, the notch 54 will be described. As shown in FIG. 5, the notch 54 is open at the top and left. And the connector 19 is provided in the bottom part. In the figure, the lid 55
Is provided. The lid 55 has a plug-in structure. Then, the lid 55 is removed, and the cable connector 17 is inserted from above the cutout portion 54 as shown in FIG. Further, the cable connector 17 is connected to the connector 19.

According to such a configuration, even if the cable connector is large, the cable connector does not protrude from the apparatus 1, so that it is possible to prevent the effective occupied area of the apparatus from increasing. or,
As described below, it does not hinder vertical installation. FIG.
Reference numeral 56 denotes a power connector.

In this embodiment, as shown in FIG. 3, the paper cassette 10 can be removed from the front of the apparatus. Then, the discharged paper is also discharged to the front of the apparatus.

Further, as shown in FIG. 9, the I
The / F connector 17 side is provided on the installation surface, and the paper cassette 10
The image can be formed by vertical installation in which is perpendicular to the installation surface. Thereby, the installation area can be made smaller. At this time, by providing the sheet presser 31 for suppressing the falling of the sheet discharged to the stacker 14 on the stacker 14, the sheet can be prevented from falling even when the stacker 14 is installed vertically. In addition, since the I / F connector 17 faces sideways in a vertical installation,
Does not hinder vertical installation.

Further, even if a cleanerless process is used, the pre-charger 21 and the transfer device 26 are constituted by non-contact type dischargers, so that the toner on the photosensitive drum 20 does not adhere to these units and is stable. And uniform charging and transfer can be performed.

(B) Description of the developing device FIG. 10 is a structural view of the developing device of FIG. 2, FIG. 11 is a cross-sectional view of a main part of the developing device of FIG. 10, FIG. FIG. 13 is an explanatory diagram of the toner supply operation, and FIG. 14 is a characteristic diagram of the present invention.

As shown in FIG. 10, the developing roller 24
It is composed of a metal sleeve 241 and a plurality of magnetic pole magnets 240 provided therein. The developing roller 24 fixes the magnet 240 inside the sleeve 241 and conveys a magnetic developer described later by rotation of the sleeve 241. The developing roller 24 has a diameter of 16 mm, and is three times (75 times) the peripheral speed of the photosensitive drum 20.
mm / s).

Around the developing roller 24, a developing chamber 230
Is formed, and the developing chamber 230 is filled with a 1.5-component developer which is a mixture of a magnetic carrier and a magnetic toner. The developing chamber 230 includes an upper partition member 230-
1 and a lower part 230-2, which has a constant volume.

Therefore, when a certain amount of magnetic carrier is put into the developing chamber 230, the amount of the magnetic toner in the developing chamber 230 becomes constant. Therefore, since the amount of the developer in the developing chamber 230 is constant, when the consumed magnetic toner is supplied from the toner hopper 231, the toner concentration becomes constant,
Control of toner density can be eliminated. That is, by filling the developing chamber 230 with a carrier amount corresponding to the toner density control point, the toner density is automatically controlled to a predetermined range.

The developing chamber 230 always contains the developer,
Since the space around the developing roller 24 is filled, even if the apparatus is installed vertically, it is possible to prevent a situation in which the developer in the developing chamber 230 is biased and a sufficient developer cannot be supplied to the developing roller 24.

The developer is added to the magnetic carrier with an average particle diameter of 35.
Micron magnetite carriers are used, and a magnetic toner having an average particle diameter of 7 microns manufactured by a polymerization method is used as a magnetic toner. This polymerized toner has a uniform particle size,
Since the particle size distribution is sharp, the adhesion between the toner image on the photosensitive drum 20 and the paper becomes uniform in the transfer process. For this reason, since the electric field in the transfer section becomes uniform, the transfer efficiency can be improved as compared with the toner obtained by the conventional pulverization method. The transfer efficiency from 60 to 90% for the pulverized toner is improved to 90% or more for the polymerized toner. The appropriate toner concentration is 5 to 60 wt%, but in this embodiment, it is set to 30 wt%.

The doctor blade 234 is
Numeral 4 adjusts the amount of developer to be supplied to the photosensitive drum 20 so that the supply of the electrostatic latent image on the photosensitive drum 20 does not become excessive, and conversely, the supply does not become insufficient. The adjustment is performed by using the edge of the doctor blade 234 and the developing roller 24.
It is performed in the gap with the surface, usually the gap is 0.1 to
It is adjusted to about 1.0 mm.

The toner hopper 231 is filled only with magnetic toner, and has a supply roller 232 inside. The rotation of the supply roller 232 supplies the toner to the developing chamber 230.

The toner supplied into the developing chamber 230 is agitated in the developing chamber 230 by the developer conveying force of the sleeve of the developing roller 24, the magnetic force of the developing roller 24, and the developer regulating function of the doctor blade 234. By rubbing with the carrier, the carrier is charged to a predetermined polarity and a charge amount. In this embodiment, the charging sequence of the carrier and the toner is adjusted so as to be negatively charged.

Further, as shown in FIG.
On the upstream side of 4, the spacing with the developing roller 24 is made smaller than the spike height of the magnetic brush formed on the developing roller 24 by the partition member 230-1. Here, as shown in FIG. 11, the interval a is set to 2.0 mm. As a result, the magnetic brush on the developing roller 24 is
−1, and by the rotation of the developing roller 24,
The magnetic brush receives the force. For this reason, the stirring property of the developer in the developing chamber 230 is enhanced, and a stable toner charge amount can be obtained even in a range where the toner concentration is high.

Further, by making this interval constant around the developing roller 24, the charging effect does not change regardless of whether the charging device is installed horizontally or vertically.

Between the toner hopper 231 and the developing chamber 230, the tip of the partition member 230-1 and the bottom 230-2
Are provided.
The width b of the toner supply path 235 is 1.5 mm as shown in FIG. The toner in the toner hopper 231 is supplied to the developing chamber 230 through the toner supply path 235.

The bottom 230-forming this developing chamber 230-
2, a protruding portion 230-3 protruding from the toner hopper 231 at the position of the toner supply path 235.
It has. Further, the bottom 230-2 forms an oblique surface that faces upward from the photosensitive drum 20 side. As shown in FIG. 11, the distance c between the tip of the protruding portion 230-3 and the tip of the partition member 230-1 is c = 1.0 to
It is set to 1.5 mm. That is, it is inclined by this amount. Further, the distance d between the tip of the partition member 230-1 and the developing roller 24 is set to 4.5 to 6.0 mm.

As shown in FIG. 10, the angle F between the wall surfaces of the toner cartridge 25 and the toner hopper 231 is set to approximately 45 degrees with respect to the direction of gravity G, and the flow direction of the toner is 45 degrees. As a result, as described later, even when the apparatus is installed vertically, the toner is supplied smoothly.

Next, the operation of the developing device will be described. FIG.
0 indicates the state of the developing device when the apparatus shown in FIG. 3 is installed horizontally, and the toner cartridge 25 and the toner hopper 23
The angle F of the wall surface is about 45 degrees with respect to the direction of gravity G. Thus, the toner flows toward the bottom of the toner hopper 231 and is smoothly supplied to the supply roller 232.

In this horizontal installation, the toner has fluidity in the bottom direction in the toner hopper 231 due to gravity, so that the supply roller 232 is
The toner on the bottom side of No. 1 is scraped up. At this time, FIG.
As shown in (A), the toner pushed up by the supply roller 232 once hits the partition member 230-1 by the protrusion 230-3 of the bottom 230-2, and enters the toner supply path 235. Accordingly, only the toner supplied by the toner supply roller 232 is supplied to the toner supply path 2.
35, the portion of the partition member 230-1 serves as a buffer, and the toner supply roller 23
2 does not directly affect the toner supply path 235. Therefore, it is possible to prevent excessive pushing of the toner,
Toner is supplied by the amount of toner that has become insufficient in the developing chamber 230.

In this case, the bottom 230-2
Is tilted upward with respect to the rotation direction of the developing roller 24, so that the developing roller 24
Of the magnetic brush and the carrier detached therefrom
There is no leakage from the toner supply path 235 to the toner supply chamber 231 through 0-2. For this reason, the starter carrier in the developing chamber 230 can be prevented from being reduced, and stable 1.5-component development can be performed.

On the other hand, even when the apparatus shown in FIG. 9 in FIG.
5 and the angle F of the wall surface of the toner hopper 231
On the other hand, since the angle is set to about 45 degrees, the toner can be smoothly supplied to the supply roller 231 even when the toner is supplied vertically.

At this time, as shown in FIG.
The partition member 230-1 stays on the toner hopper 231 side and easily falls from the toner supply path 235 to the developing chamber 230. However, as shown in FIG. 13B, since the protrusion 230-3 of the bottom 230-2 restricts the toner from dropping in the toner supply path 235, the toner hardly drops. Therefore, the supply of the toner depends on the rotational force of the toner supply roller 232.

In other words, as shown in FIG. 13B, the toner pressed by the supply roller 232 is temporarily separated by the protrusion 230-3 of the bottom 230-2.
1 and enters the toner supply path 235. As a result, only the toner supplied by the toner supply roller 232 enters the toner supply path 235, and the corresponding portion of the partition member 230-1 functions as a buffer, and the pushing force of the toner supply roller 232 directly reduces the toner supply. It doesn't help. Therefore, excessive pushing of the toner can be prevented, and the toner is supplied by the amount of the toner that has become insufficient in the developing chamber 230.

This means that there is no change in the ability to supply toner to the developing chamber 230 whether the apparatus is installed horizontally or vertically. Therefore, regardless of whether the apparatus is installed horizontally or vertically, the toner density in the developing chamber 230 does not change, and a change in image density can be prevented.

That is, most of the toner supplied to the developing chamber 230 is supplied by the toner supply roller 232.
The toner supply can be realized without being affected by the fluidity of the toner in the gravity direction. Therefore, even if the installation direction of the apparatus changes, the toner supply amount does not change, so that a stable developing operation can be performed.

If the developer is set vertically, the developer may fall from the developing unit 23. However, since the magnetic two-component developer is used as the developer, the developer is Because it is held by, even if installed vertically
The developer hardly drops. In particular, when a magnetic carrier and a magnetic toner are used, both the carrier and the toner
Since it is held by the magnet roller of the developing roller 24,
It can further prevent the developer from falling, and even if it is installed vertically,
Stable development is possible.

FIG. 14 is a characteristic diagram showing a change in toner density Tc when the apparatus is installed horizontally (horizontally) and printing is performed, and then the apparatus is installed vertically (vertically) and printing is performed. .

First, the apparatus was installed horizontally, a predetermined amount of start carrier was put into the developing chamber 230 of the developing unit 23, and the developing unit was operated to perform printing. As a result, the developing room 2
Since the toner is gradually supplied from the toner hopper 231 to the toner container 30, the toner density increases as the number of printed sheets increases, and when the carrier and the toner are full in the developing chamber 230, the toner density is 30 wt%. Thereafter, even when the number of printed sheets increased, the toner density did not change.

Next, in this state, the apparatus was changed to the vertical installation, and printing was performed. As a result, the toner concentration did not change from that at the time of horizontal installation. On the other hand, JP-A-3-252686
In the configuration of the conventional 1.5-component developing device disclosed in Japanese Patent Application Laid-Open No. H10-209, the toner density increases when the device is installed vertically, as indicated by the white circle in the figure. In the horizontal installation and the vertical installation, the toner density changed, and the image density changed. This supports the above-described stabilization of toner supply. Accordingly, it is possible to form an image with no change in image density regardless of whether the apparatus is installed horizontally or vertically, and an image forming apparatus that can perform both horizontal installation and vertical installation can be realized.

Next, the angle between the toner cartridge 25 and the wall surface of the toner hopper 231 will be described. Taking the vertical direction into consideration, about 45 ° ± 15 ° with respect to the direction of gravity is appropriate, and preferably about 45 ° ± 5 ° provides good results.

(C) Description of Other Embodiments In addition to the above-described embodiments, the present invention can be modified as follows. In the above-described embodiment, a 1.5-component developer composed of a combination of a magnetic carrier and a magnetic polymer toner is used as the developer, but a magnetic pulverized toner may be used as the magnetic toner.

In the developing roller 24, only the sleeve is rotated, but the magnet may also be rotated.

Although the LED optical system is used as the image exposure unit, a laser optical system, a liquid crystal shutter optical system, an EL (electro-luminescence) optical system, or the like may be used.

Although the latent image forming mechanism has been described with reference to the electrophotographic mechanism, the latent image forming mechanism can also be used for a latent image forming mechanism (for example, an electrostatic recording mechanism) for transferring a toner image. Media can be used. Further, the photosensitive drum is not limited to the drum shape, but may be a belt shape.

Although the image forming apparatus has been described using a printer,
Other image forming apparatuses such as a copying machine and a facsimile may be used.

The present invention has been described with reference to the embodiments.
Various modifications are possible within the scope of the present invention, and these are not excluded from the scope of the present invention.

[0085]

As described above, according to the present invention,
The following effects are obtained. The notch 54 is provided on the outer peripheral surface of the device, and the cable connector 19 is provided at the bottom of the notch 54, so that the cable can be accommodated in the device and the effective installation area of the device can be prevented from increasing.

At the same time, the notch 54 is
Cable can be pulled out from the stacker surface with mosquito 14
Cable 17 from the stacker surface of the device.
Into the notch 54, and the cable connector 19
Connection can be, without protrude from the cable apparatus can prevent an increase in the effective installation area of more devices. That is, the stacker surface
All of the outer peripheral surface of the
And there are no restrictions on the installation direction and location.

Since the sheet guide plate 30 that can be accommodated in the apparatus is provided in the stacker 14, when the sheet guide plate 30 is not required, it can be accommodated in the apparatus, and an increase in the effective installation area of the apparatus can be prevented.

[Brief description of the drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration diagram of an embodiment of the present invention.

FIG. 3 is a horizontal installation view of the apparatus of FIG. 2;

FIG. 4 is an explanatory view when the paper guide of FIG. 3 is accommodated.

5 is a perspective view from the opposite side of the device of FIG. 3;

FIG. 6 is a diagram illustrating the operation of the paper guide of FIG. 3;

FIG. 7 is an explanatory diagram of the operation of the button switch of FIG. 3;

FIG. 8 is an explanatory diagram of the sheet holding plate of FIG. 3;

FIG. 9 is a vertical installation view of the apparatus of FIG. 2;

FIG. 10 is a configuration diagram of the developing device of FIG. 2;

11 is a sectional view of a main part of the developing device of FIG. 10;

FIG. 12 is a vertical installation state diagram of the developing device of FIG. 11;

FIG. 13 is an operation explanatory diagram of the developing device of FIG. 10;

FIG. 14 is a characteristic diagram according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Registration roller 17 Cable connector 19 Connector 20 Photosensitive drum (latent image carrier) 21 Pre-charger (latent image forming unit) 22 LED optical system (latent image forming unit) 23 Developing device 26 Transfer device 30 Paper guide 30a Guide housing block 52 Button switch 54 Notch

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor: Ken Tasagawa, 1015 Uedanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Kazuhiro Saito 1015, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited ( 72) Inventor Toshio Toda 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (56) References JP-A-4-199157 (JP, A) JP-A-6-255203 (JP, A) 5-201096 (JP, A) JP-A-6-15900 (JP, A) JP-A-6-79935 (JP, A) JP-A-1-184179 (JP, A) JP-A-63-172654 (JP, A) U) Japanese Utility Model 4-60443 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41J 29/00 G03G 21/16

Claims (10)

(57) [Claims] 1. An image forming mechanism for forming an image on a sheet.
(20-26) and the image forming mechanism (20-26).
The upper part is provided with a sheet for storing a sheet on which an image is formed.
An image forming apparatus having a stacker (14), provided on an outer peripheral surface of the apparatus , wherein the stacker (14)
Cables can be pulled out from the provided stacker surface
Wherein the notches (54) that is, the notch and has a cable connector (19) provided in the bottom (54), said from the stacker face of the device Ke <br/> Buru (17) Insert into the notch (54)
An image forming apparatus connected to the cable connector (19). Wherein said notch (54), the image forming apparatus according to claim 1, characterized in that provided on the opposite side to the stacker (14). 3. The image forming apparatus according to claim 2, wherein an image forming operation can be performed in both the horizontal installation of the apparatus and the vertical installation with the cutout (54) side as the installation side. Forming equipment. 4. A button switch (52) provided on an openable top cover (51) constituting the stacker, and provided on a pressing portion of the button switch (52) for opening the top cover . claim and having a slope portion (52a) 1 or
2 or 3 image forming apparatus. 5. A manual insertion slot (10a) for manually inserting a sheet into said image forming mechanism (20-26).
If the provided manual feed inserting opening (10a), the image forming apparatus according to claim 1 or 2 or 3 or 4, characterized in that it has a sheet holding plate that displays the sheet size (53) in symmetrical. 6. An image forming mechanism (20-26) for forming an image on a sheet, and a stacker (14) provided above the image forming mechanism (20-26) and containing the sheet on which the image is formed. Wherein the stacker (14) is formed to be shorter than the maximum length of a sheet on which an image is to be formed, and the stacker (14) is provided with a sheet guide plate (30) that can be accommodated in the apparatus. Characteristic image forming apparatus. 7. The image forming apparatus according to claim 6, wherein an image forming operation can be performed in both the horizontal installation of the apparatus and the vertical installation in which the opposite side of the stacker (14) is the installation side. Forming equipment. 8. An image forming apparatus according to claim 6, wherein a tip of said sheet guide is inclined. 9. A button switch (52) provided on an openable top cover (51) constituting the stacker (14) for opening the top cover, and a pressing portion of the button switch (52). The image forming apparatus according to claim 6, further comprising a slope portion provided. 10. A manual insertion slot (10a) for manually inserting a sheet into the image forming mechanism (20 to 26).
The image forming apparatus according to claim 6, further comprising: a sheet holding plate (53) provided in the manual insertion slot (10a) and displaying a sheet size in a left-right symmetrical manner.