JP2580435B2 - Image forming system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming system.

[0002]

2. Description of the Related Art Conventionally, as described in JP-A-51-2433, a photoreceptor, a developing device and a cleaner are integrated into a single housing in a three-piece manner, and the electrophotographic copying machine main body is assembled. A configuration that can be detached is known. According to this configuration, the photoreceptor, the developing device, and the cleaner are integrated into the unit in a unit, so in order to maintain the required balance, the unit only needs to be replaced with a new unit. There is an advantage that it can be easily performed.

[0003]

The present invention is a further development of the prior art.

[0004]

Accordingly, an object of the present invention is to replace a unit by providing control means for determining an image forming condition so that an image is formed under an image forming condition corresponding to the unit, and making the units interchangeable. By,
An object of the present invention is to provide an image forming system capable of obtaining images of different colors.

[0006]

According to the present invention, there is provided an image forming system for forming an image on a recording medium, comprising: a. An image forming apparatus main body; b. A first unit having a first photosensitive member, first developing means for developing a latent image formed on the first photosensitive member, and a first photosensitive member and first developing means And the second
A second developing means for developing the latent image formed on the second photosensitive body in a different color from the first developing means; and a second developing means for developing the latent image formed on the second photosensitive body. And a second unit having a developing unit, and can be attached with compatibility.
Mounting means provided in the image forming apparatus main body; c. A control unit for determining whether the unit mounted on the mounting unit is the first unit or the second unit, and automatically determining an image condition so as to form an image under image forming conditions according to the determination result; , D. An image forming system, comprising: a conveying unit for conveying the recording medium.

[0007]

[0008]

[0009]

Embodiments of the present invention will be described below.

The embodiments described below relate to an image forming apparatus such as a copying machine or a recording apparatus to which the electrophotographic method or the magnetic recording method is applied, and a unit detachable from the apparatus.

More specifically, the embodiments described below are:
The present invention relates to a unit of an image forming apparatus, wherein a unit detachably mountable to a main body of the image forming apparatus has a unit for setting image forming conditions on the apparatus main body side according to an operation mode of the unit. is there. Still further, the present invention relates to an image forming apparatus having a control unit for automatically setting image forming conditions by an image forming condition setting unit of a unit detachable from a main body of the image forming apparatus.

In the embodiment described below, the image carrier and the part for setting the image forming conditions on the main unit in accordance with the characteristics of the image carrier or the purpose of use or the purpose of use and the characteristics of the unit are used. Configure the minimum unit. Therefore, the unit may include a part for setting image forming conditions, an image carrier, and a part or a plurality of image forming means disposed around the image carrier. The main unit for loading the unit receives the condition setting section of the unit, and as a result, forms an image on the image carrier under conditions corresponding to the condition setting section. That is, the condition setting unit has a configuration corresponding to the characteristics of the image carrier in the same unit or the purpose of use of the unit itself. Therefore, for example, if the units have photoconductors having the same characteristics and are used for the same purpose, the configuration of the condition setting unit of this unit will be the same. According to the above configuration, it is possible to automatically set image forming conditions suitable for the unit only by replacing the unit with the main unit without relying on a specialist.

Now, the present invention will be described with reference to a copying machine to which electrophotography is applied.

First, a method for preventing a change in an image due to a difference in characteristics of a photosensitive member according to an embodiment to which the background art of the present invention is applied will be described with reference to the drawings.

FIG. 1 is a sectional view of an electrophotographic copying machine to which one embodiment of the present invention is applied. In this copying machine, the main body can be divided into an upper main body 14 and a lower main body around one end, and the drawing shows a state in which the upper main body is opened to the lower main body in a sectional view. .

Reference numeral 1 denotes a photosensitive drum having a photoconductive layer of Se or the like on a cylindrical surface formed of aluminum or the like, which rotates in the direction of the arrow. When a copy image is formed, the upper body is lowered and fixed. Then, the surface of the photosensitive drum 1 is uniformly charged by the corona charger 2 having the grid 3. On the other hand, a document 5a on a transparent glass document table 5 illuminated by a light source 4 and held by a document cover is illuminated by an illumination lamp 4, and the image of the document is illuminated by a short-focus lens array 6 on the photosensitive drum 1. An image is formed in a slit shape on the downstream side of the corona charger, and an electrostatic latent image corresponding to the original image is formed on the photosensitive drum 1.

The electrostatic latent image on the photosensitive drum 1 is developed by a developing device 8. The developing device 8 is fixed to the lower main body, and the developing roller 8a has fibrous flocking 8b on the surface. The toner 8c is supplied from the toner supply cartridge 7 to the developing roller 8a. This toner replenishment causes a fixed amount of toner to drop from the opening of the cartridge 7 in conjunction with the rotation of the photosensitive drum. The latent image on the photosensitive drum 1 is developed by a developing roller 8a that rotates at the same peripheral speed as the drum 1.
Develops the electrostatic latent image, and a toner image is formed on the surface of the photosensitive drum 1. Then, the toner image formed on the surface of the photosensitive drum 1 is transferred by the transfer corona discharger 9 onto the transfer paper P conveyed to the surface of the drum 1. The transfer paper P is sent out of the cassette C by the feed roller R1, reaches the surface of the drum 1 by the transfer paper guides G1, G2 and the transport / timing roller R2, and the toner is transferred. Thereafter, the transfer paper P is discharged by the discharging roller R3 and separated from the surface of the drum 1. Then, the toner image reaches the fixing roller R5 by the transport belt R4. After the toner image is fixed on the transfer paper P by the fixing roller, the toner image is discharged onto the discharge tray T.

On the other hand, the toner remaining on the photosensitive drum 1 after the transfer step is rubbed and scraped off by a cleaning blade 10 fixed to the upper main body. The scraped toner is conveyed into the toner collecting container 11 by the toner conveying body 10a and collected.

In this embodiment, the toner cartridge 7 containing the replenishment toner and the toner collection container 11 are
A unit 13 is integrally formed with the photosensitive drum 1 by an arm 12. And this unit 1
3 is detachably mounted at a predetermined position on the lower main body side by a configuration described later.

Next, the case where the unit 13 is taken out from the main unit and a new unit 13a is loaded will be described.

First, when the retaining members 14a and 14b for retaining the lower main body portion and the upper main body portion are disengaged, the upper main body 14 is lifted by the push-up means 14c including a spring, and the apparatus main body is opened. State. So arm 12
Is lifted in the direction of arrow A by hand, the unit 13 in which the photosensitive drum 1, the toner cartridge 7, and the toner collecting container 11 are integrated can be removed from a predetermined loading position of the apparatus main body. In the drawing, the dashed line indicates the unit 13 in the process of being taken out of the main unit.

Next, a case where another unit 13a is attached to the apparatus main body instead of the above-mentioned unit 13 will be described.

FIG. 2 shows a unit 13a having another photosensitive drum 1a. The toner cartridge 7a and the collecting container 11a are also connected to the photosensitive drum 1a by the arm 1.
2a and are integrally held. 1b is a support shaft of the drum 1, and the drum shaft 1b is a drum 1a
And is rotatable with respect to the arm 12a.

In this embodiment, a part of this arm 12a is
A condition setting unit for forming an image suitable for the photosensitive drum 1a is provided in consideration of various conditions such as the sensitivity, charging characteristics, and residual potential characteristics of the photosensitive drum 1a. The setting section is composed of a rod-like member 15a for driving a member 16 (FIG. 3) for rotating the volume of the image forming adjustment circuit on the main body side. At the time of shipment from a factory, the rod-shaped member 15a is adjusted so as to protrude from the arm 12a by a predetermined angle or a predetermined length from the arm 12a in accordance with the sensitivity and charging characteristics of the photosensitive drum. Should be fixed with. As will be described in detail later, this configuration makes it possible to rotate the volume according to the angle and length of the rod-shaped member, and set the charge amount and the image exposure amount according to the characteristics of the photosensitive drum.

When the new unit 13a is loaded into the main unit, in this embodiment, both ends of the drum shaft 1b are slidably fitted to bearings 14d provided on the lower main body. Is connected to a drive source (not shown) on the main body side, and the drum 1a is rotatably mounted at a predetermined position. At the same time, the arm 12a of the unit 13a comes into contact with the receiving members 14e and 14f also provided on the lower main body, and is positioned and held. As a result, the cartridge 7a and the collection container 11a are loaded at predetermined positions, and the above-described rod-shaped member 15 is also fixed to the main body device at a predetermined angle and a protruding length.

Next, the upper body side is opposite to the arrow A, that is,
Rotate counterclockwise to align with the lower body, and
a and 14b are engaged to fix the upper and lower main bodies. Then, the tip of the rod-shaped member 15 a is connected to the shaft 16 provided on the upper main body 14.
It comes into contact with the volume rotating member 16 that is rotatable about a. Then, as the upper body is lowered, the rod 15 rotates the volume rotating member 16 clockwise by an angle θ according to the installation angle and the protruding length of the rod 15.

FIG. 3 shows a detailed mechanism for setting the volume when the upper body 14 is lowered.

In the figure, reference numeral 14g denotes a fixed side plate of the upper main body 14. The volume rotating member 16 is attached to a fixed side plate 14g of the upper main body 14 so as to be rotatable integrally with the shaft 16a about the shaft 16a. 16b is a compression coil spring, one end of which is connected to the volume rotating member 16,
The other end is attached to the fixed side plate 14g, and the volume rotating member 16 is pressed against the stopper 17 and locked. Therefore, the volume rotating member 16 is
4 is rotated counterclockwise as indicated by an arrow B to close and fix it so as to be aligned with the lower body, and is pushed by a positioning member 15a provided on the arm 12a, and is rotated against the spring force of the spring 16b ( (In this example, the position rotated by the angle θ). Therefore, the volume rotation member 16
When the upper body 14 is opened in the direction of arrow G, that is, when the engagement with the rod-shaped member 15 is released, the upper body 14 returns to the initial position regulated by the stopper 17 by the spring force of the spring 16b. Although the rod-shaped member 15 is fixed to this unit separately from the unit, a part of the unit may be deformed to form a projection.

Next, a method of setting the latent image forming conditions in accordance with the characteristics of the photoreceptor in the unit using the above volume will be described with reference to FIGS. In the case of FIG. 4, the fluctuation of the latent image due to the replacement of the unit is automatically adjusted by changing the exposure amount on the photosensitive drum 1 by the voltage applied to the lamp 4 (FIG. 1). In the case of FIG. Vessel 2
In this example, the applied voltage is changed, and the fluctuation is automatically adjusted.

FIGS. 4 and 5 show the volume rotating member 16.
5 shows an example of a circuit that adjusts a voltage generated by movement of a sliding member 19 that slides on a sliding resistor 18 in conjunction with the rotation of.

In both examples, the sliding member 19 is integrally mounted coaxially with the shaft 16a of the volume rotating member 16. Therefore, the sliding member 19 turns on the sliding resistance in conjunction with the turning amount of the volume turning member 16. This circuit is located inside the fixed side plate 14g, that is, the volume rotating member 1
6 is fixed to the opposite side. Therefore, the volume rotating member 16 is a rod-shaped member 15 set in accordance with the characteristics of each photosensitive drum fixed to the loaded unit 13.
, The sliding member 19 also rotates on the sliding resistance 18 in conjunction with the rotation. A fixed constant voltage V ₀ is applied to both ends of the sliding resistor 18. The sliding member 19 is moved from the initial position 0 where the volume rotating member 16 is in contact with the stopper 17 with an arrow C.
It rotates in the direction of D according to the shape of the rod-shaped member 15.

FIG. 4 shows a circuit for automatically adjusting the voltage applied to the exposure lamp 4 to a voltage value which is the standard light amount of the photosensitive member 1a. Reference numeral 20 denotes a potentiometer that allows the operator to adjust the amount of exposure on the main unit according to the density of the document when actually copying. With the above configuration, the sliding member 19 moves on the sliding resistance 18 to the unit 13.
Is automatically rotated by an angle θ (FIG. 3) corresponding to the rod member 15a of FIG.
It is possible to irradiate with an amount of light suitable for.

FIG. 5 is a circuit for setting the voltage applied to the corona wire or grid 3 of the charger 2 to a value corresponding to the shape of the rod 15 of the unit 13. In the figure, 2
1 is a transformer and 22 is a rectifier. The input voltage Vi changes according to the position of the sliding member 19, and the rod-shaped member 1 is connected to the corona wire or the grid 3 of the charger 2 from the output terminal 23.
The voltage set by 5a is applied. Thus, also in the present embodiment, a voltage automatically adjusted according to the characteristics of the photosensitive drum of the unit 13a can be applied to the corona wire or the grid.

FIG. 6 is a quaternary chart for each step showing the tone reproduction characteristics of the photosensitive drum-copy.

The first quadrant represents the relationship between the toner density on the photosensitive drum corresponding to the image density of the document, and the second quadrant represents the toner potential on the photosensitive drum and the toner density on the photosensitive drum, that is, development characteristics.
The third quadrant shows the characteristics of the photoreceptor loaded in the unit by the relationship between the image exposure amount and the surface potential of the photoreceptor, and the fourth quadrant shows the exposure amount exposed to the photosensitive drum with respect to the image density of the original. The relationships are shown respectively.

An example in which the difference in the image formation result due to the difference in the characteristics of the photosensitive drum is stabilized by changing the exposure amount or the charging amount will be described with reference to the above graph.

Here, the most standard characteristic curve of the photosensitive member is designated as curve a, and the original is exposed to the photosensitive member with an exposure amount b, and the toner is developed with a developing device having a developing characteristic c. A toner image with a curve d was obtained. Here, the unit having the photosensitive drum having the above characteristics is detached from the main unit, and another unit is mounted on the main unit. At this time, when a photosensitive drum having the characteristic of curve e is used in another unit, if an image is formed under the same exposure conditions as described above, the contrast is too strong with a halftone as shown by curve f. Obtain a toner image.

Therefore, the method described with reference to FIG.
The maximum exposure is moved from the point I to the point II so that the exposure becomes like the line g just by loading the unit into the main body. The change of the exposure amount is performed by setting a rod-shaped member fixed to the unit. As a result, it is possible to reproduce a toner image having characteristics substantially matching the curve d obtained by the standard photoconductor.

Next, a unit using the photosensitive drum having the characteristic of the curve h was mounted on the main body, and an image was formed on the line b, which is a standard light amount, without changing the corona charge amount. A light and low-contrast toner image such as i is obtained. Here, the corona charging amount was increased by the rod member of the unit without changing the exposure amount, and the maximum surface potential of the photosensitive drum was substantially changed from the point III to the point IV. Was obtained.

With the above-described structure, a stable image can be always formed by the rod-like member provided for setting the process conditions in the unit.

Next, another embodiment will be described with reference to FIG.

In contrast to the above-mentioned embodiment in which the photosensitive drum held by the arm 12 and the peripheral means are unitized, in this embodiment, the photosensitive drum and an image forming condition setting unit are unitized. In this embodiment, the drum bearing 24 is provided on the lower main body. The photosensitive drum 25 has a shaft 25a.
Is rotatably mounted via a pairing 25b. Further, a projecting member 25c, which is a member different from the arcuate shaft 25a corresponding to the bar-like member 15a in FIG. 3, is fitted and fixed to the end of the drum shaft 25a.
The size of the protruding portion of the protruding member 25c is determined according to the sensitivity and the like of the photosensitive drum 25.
Further, a cutout portion is provided in a portion of the drum shaft 25a that fits with the bearing 24, so that the drum shaft 25a always fits in the bearing 24 in a fixed direction. Therefore, when an arbitrary photosensitive drum 25 is loaded into the main unit, the shaft 25
Is fixed in a fixed direction with respect to the main body device. The drum 25 is a bearing 2
4 and connected to a drive source (not shown) on the main body side in a state of being fitted to the main body 4 so as to be rotatable with respect to the shaft 25a.
Therefore, as described in FIG. 1, when the upper main body 14 is rotated downward as shown by the arrow E to be combined with the lower main body and the upper and lower main bodies are closed, the projection member 25c is moved to the volume rotating member 1 shown in FIG.
6 and rotates the rotation member 16 clockwise according to the size of the projection member 25c. Therefore, by rotating the sliding member 19 (FIGS. 4 and 5) in conjunction with the rotation of the rotating member 16 as in the above-described example, it is possible to automatically obtain a preferable latent image forming condition according to the characteristics of the drum. Can be done.

Still another embodiment will be described with reference to FIGS.

This embodiment shows an example of a copying apparatus which is not of the type which can be divided in the vertical direction as in the apparatus of FIG. Further, while the above-described embodiment sets the conditions by mechanical connection such as a cam, the present embodiment shows an example in which a predetermined electric circuit is formed by connecting connectors.

The main body of the copying apparatus 26 shown in FIG. 8 is substantially the same as the copying apparatus shown in FIG. 1 except that the main body is not divided and opened. However, the photosensitive drum 27, the developing device 28, the cleaning device 29, the toner collecting container 30, and the charging device 31 are integrally held in the unit 32,
This unit is detachable from the apparatus main body 26.
That is, a rail 34 provided on a part of the unit 32 is engaged and slid on a guide 33 provided on the main body 26 side, and the unit 32 is inserted into the main body device along the guide 33 and loaded. I do. Furthermore, in order to set the positions of the main unit and the unit, the pins 35 of the main unit are fitted into the openings 36 on the unit side.

Therefore, in the present embodiment, when the unit 32 is loaded into the main body 26, the insertion pin 37 provided on the back side of the unit (that is, the front end in the loading direction of the unit) is fixed to face the pin 37. Jack 38 on the back side of the main unit
The electric circuit is configured so that the conditions necessary for the unit 27 are automatically set on the main body side. That is, in this embodiment, as shown in FIG. 9, a volume resistor 39 is mounted on the unit 32 side, and the photosensitive drum 2
The sliding resistance 41 of the resistor 39 is set such that image forming conditions suitable for the photosensitive drum are set according to the characteristics of the photosensitive drum 7.
A slider 42 for determining a resistance value is set above, and the slider 42 is fixed with an adhesive or the like. Such a fixing of the slider may be performed before the photosensitive drum is shipped from a factory after the photosensitive member is formed into a drum.

When the pin 37 used for electrical connection on the unit 32 side is inserted into the jack 38 by the above configuration, the exposure lamp 43 causes the unit 3 loaded in the main unit to be mounted.
According to the set value of the volume resistor 39 of 2, the optimum voltage can be applied to the lamp 43 for any arbitrary unit. Therefore, the operator can automatically set the optimum exposure amount or pre-exposure amount for the loaded unit simply by loading another unit into the copying apparatus main body to replace the unit. The lamp to be adjusted is, for example, the image exposure source (4 in FIG. 1) as described above.
Alternatively, a pre-exposure lamp that exposes the photosensitive drum 27 before charging the photosensitive drum 27 with the charger 2 may be used.

In the above-described embodiment, a case has been described in which even when the characteristics of the photoconductor in the unit are not constant, a stable image is always obtained without a change in image quality depending on the unit used. That is, since the image forming conditions corresponding to the unit are automatically determined in accordance with the characteristics of the photoreceptor loaded in the unit, the operator only needs to load the unit into the main body device and the hand for adjustment is required. Without this, it is possible to set image forming conditions according to the characteristics of the photoconductor.

Here, in each of the above-described embodiments, only the case where a single condition is automatically set by the rod member or the pin on the unit side serving as the image forming condition setting unit has been described. However, the present invention is not limited to this. Instead, for example, by using a plurality of volume members and a plurality of bar-shaped members or a plurality of pairs of connectors, it is also possible to automatically adjust a plurality of image forming conditions such as a charge amount and an exposure amount at the same time.

Further, in this embodiment, the condition setting member provided in the unit for setting the image forming conditions may be a mechanical means such as a cam as described above.
Alternatively, electrical means such as an electric connector may be used. Also, by reading an information signal mark, which is a command signal for the characteristics or adjustment of the photoreceptor, written on the unit surface with a light and dark image signal by optical reading means of a known technique, or by magnetic reading means The image forming conditions on the main body side may be adjusted by reading the information signal written in the kit. In this case, the condition setting unit provided on the unit side is a magnetic storage means such as an information mark or a magnetic plate.

FIG. 10 shows another example of the condition setting section, and corresponds to FIG. In the figure, reference numeral 44 denotes a side plate fixed to the upper main body, and push button switches 45a, 45b, 45c such as micro switches are fixed to this side plate at equal intervals. On the other hand, reference numeral 46 denotes an arm which constitutes a unit, and a projecting member 47 is fixed to this arm by an adhesive or the like corresponding to the position of the switch 45. The position of the convex portion of the projection member 47 is fixed at a position predetermined for the characteristics of the photosensitive drum in the unit. With the above configuration, the side plate 44 is also lowered by pressing the upper body in the direction of arrow F, and as a result,
One of the buttons 45 is pressed, and a predetermined latent image forming condition is selected.

FIG. 11 shows a control circuit for changing the developing bias voltage by selecting the push button.

As shown in the figure, when the unit 48 is mounted at a predetermined position on the lower main body and the upper main body 49 is lowered to a predetermined position with respect to the lower main body, the switch 45b is turned on. One of the output terminals of the DC power supply 50 is connected to the back electrode of the photosensitive drum and is grounded. The other output terminal to this terminal has three terminals indicating different DC voltages, and is connected to one terminal of the switch 45. The other terminal of the switch 45 is connected to a high frequency power supply 51 (2000 Vp
p, 1500 Hz), and the other output terminal of the high-frequency power supply 51 is connected to a developing roller 52 of a developing device. Therefore, an alternating voltage waveform on which a desired DC voltage is superimposed is applied between the developing roller and the back electrode of the photosensitive drum by a switch pressed by the convex portion of the projection member 47, and the latent image on the photosensitive drum is developed. Is done. Depending on the position of the projection of the projection member 47, an appropriate developing bias voltage is always applied between the developing roller and the back electrode of the photosensitive drum to compensate for the different characteristics of the photosensitive members of each unit 48. Therefore, a stable image can be obtained even when the photoconductor characteristics of the unit are different from those of the previously used unit.

[0054]

[Table 1]

The above Table 1 shows the numerical values of the above embodiments, and a drum using an organic optical semiconductor was used as the photosensitive drum. In this case, there are three types of photosensitive drums A, B, and C having different bright portion potentials with respect to a fixed reference exposure amount.
One unit 48 was used. The three output terminals of the DC power supply 50 except for the ground terminal are previously set to -250 V and -200 V.
V and -150 V, and this terminal is
As shown in the figure, the switch 45 was connected to one terminal.
For photosensitive drums A, B, and C having different characteristics,
The microswitches 45c, 45b, and 45a were pressed and connected in accordance with the positions of the projections of the projection members 47, respectively, so that an appropriate developing bias voltage could be applied to the developing roller.
This proved that stable image formation was always possible even on photosensitive drums having different characteristics.

Of course, the present invention can also be applied to a device in which the unit as shown in FIG. 8 is pushed into the main body and loaded. In this case,
The switch group can be arranged at the back of the main unit or at a position along the pushing passage of the unit.

As described above, a plurality of conditions such as charging and exposure can be simultaneously corrected by the number of combinations of the push buttons and the projections, and subtle latent image forming conditions can be set. Becomes Of course, this method can be used not only for changing the exposure amount but also for setting other conditions such as charging and developing bias.

The image forming conditions for forming a stable image by correcting different photoreceptor characteristics may be a charging condition of a charger such as a grid voltage value or a corona applied voltage, or transfer an image. May be a voltage of a transfer discharger, a voltage of a discharging discharger in the latent image forming means, or a current value applied to these corona dischargers. When the light amount of the lamp is changed, it may be a pre-exposure amount or an image exposure amount. Further, if the effects of the above-described embodiment can be obtained, the rotation time condition of the photosensitive drum before the start of the image formation, or the exposure amount and the pre-charge condition during the pre-rotation may be used. Further, it may be a condition of a developing bias voltage, a condition of a rotation time of the photosensitive drum after the transfer of a visible image, or a condition of a static electricity removal during the subsequent rotation. Control conditions may be used.

In the above-described embodiment, the characteristics of the photosensitive member differ from unit to unit depending on the image forming condition setting unit, and the difference prevents the finished image from changing. However, as another use of this condition setting unit, corresponding to the purpose of use of the unit, it is also possible to automatically set a sequence as a whole process adapted to this unit. It is also possible to prepare a unit dedicated to black and white copying and a unit dedicated to color copying, and set the main unit to perform black and white or color copying operations according to the unit loaded into the main unit. Needless to say, compensation can be performed simultaneously with the automatic setting of the sequence due to a change in the characteristics of the photosensitive drum.

In the following, a description will be given of the former color-shared electrophotographic copying machine as an example in which the entire sequence of process conditions according to the unit is set.

An apparatus 53 shown in FIG. 12 is a monochrome black-and-white copying machine using electrophotography. The photosensitive drum 54 provided with a photoconductive layer on a conductive drum base is rotatably supported in a direction indicated by an arrow. Have been. Around the drum 54, a corona discharger 55, a short-focus optical element array 56, a developing device 57, a transfer corona discharger 58, and a cleaning device 59 are arranged in accordance with the rotation direction of the drum. In this apparatus, the discharger 55, the developing unit 57, and the cleaning unit 59 are integrally supported by a unit 60 detachable from the main unit together with the photosensitive drum. The unit 60 includes guide rails 61 and 6 fixedly provided on the main body side.
It is guided and supported by 2 and is attached to and detached from the main unit.
Further, the transfer corona discharger 58 is provided in a transfer drum 63 provided on the main body side and having an insulating net. The transfer drum is provided with a gripper 65 for holding a leading end of a transfer material 64. A corona discharger 66 is provided near the outer periphery of the transfer drum 63 to charge the drum and attract the transfer material 64.

In the above copying machine, the corona discharger 55
To uniformly charge the surface of the photosensitive drum 54 with a predetermined polarity, and then illuminate a document on a reciprocating platen 67 in the upper part of the main unit with a lamp 68. In the case of color copying, reflected light is passed through a color separation filter 69. Drum 5 through element array 56
4 to form a latent image. The formed latent image is developed by a developing device 57, and the developed image is transferred to a transfer material by a transfer corona discharger 58.

The transfer material is supplied from a transfer material supply tray 70 by a feed roller 71, and is conveyed to a transfer drum 63 via a timing roller 72. The transfer material having completed the transfer is released by the gripper 65 and separated by the separating means 73, sent to the fixing device 75 via the moving path 74 and fixed, and further sent out onto the paper output tray 77 via the discharge roller 76. .

In the meantime, the color machine 7 for exclusive use for color development shown in FIG.
8 can be loaded. This unit 78 is shown in FIG.
A color developing device 79 is provided instead of the black and white developing device 57 of the unit. The developing device 79 includes a yellow developing device 79a and a magenta developing device 79 in the rotation direction of the photosensitive drum 54.
b, and a cyan developing device 79c are arranged in this order.

In the apparatus 53 of this embodiment, as described above, the black and white copying unit 60 and the color copying unit 7
8 is compatible with this body. The replacement of this unit is performed as described with reference to FIG.
This unit in the direction of the rotation axis of the guide rails 62 and 63
It is performed by moving along.

When the units are exchanged in this way, the processes for forming a copied image differ between the two units. That is, in the case of black-and-white copying, only one latent image formation,
A copy is obtained by the steps of development, transfer and fixing. But,
In the case of color copying, a fixing process is completed after formation of a latent image by each color separation, development, and transfer to obtain a copy. The present invention loads such a unit having a different process into the main unit,
The main unit can be operated according to the purpose of use of this unit, and will be described in detail below.

FIG. 14 shows a black-and-white copying unit 6 in the main unit.
FIG. 15 is a plan view when the color copying unit 78 is loaded. As shown in the figure, each unit is provided with convex portions 80a and 78a at predetermined positions. Each of the protrusions is selected from among the switches 81a and 81b provided for the protrusion on the main body device side, by selecting one of the specific switches 81a or 81b in order to select a process that matches the purpose of use of the loaded unit. Push.

FIG. 16 shows a specific example in which the process is changed by selecting the switch 81. In this embodiment, the control circuit itself is selected by the switch. Reference numeral 82 denotes a control unit for operating or driving each unit of the main unit. The control unit includes a power supply circuit 83 and a black-and-white circuit 84 for driving the device 53 to obtain a black-and-white copy, and a color copy. A color circuit 85 for obtaining the color image is provided independently. The effect of providing an independent circuit according to the process in this way is that since the dedicated circuit is used, advanced control is possible, and even if one of the circuits becomes unusable, the main unit can be controlled by another circuit. Can operate.

Here, when the unit 60 is loaded into the main unit, the first circuit 84 is selected, and a control signal for monochrome copying is generated at the output terminal 86. As shown in FIG. 17, the control at this time is such that the transfer material gripper 65 transfers the toner image on the photosensitive drum 54, that is, the transfer drum 63.
Is only to sandwich the transfer material for one rotation.

On the other hand, when the color unit 78 is loaded, as shown in FIG. 15, the convex portion 78a of the unit 78 selects the switch 81b, and the circuit 85 of FIG. 16 is selected. In this case, as shown in FIG.
And the developing devices 79a, 79b, 79c of the respective colors are driven. That is, to obtain one color copy, the original image is formed with a latent image by a blue filter and development with a yellow toner, and toner transfer to a transfer material, and then a latent image with a green filter and development with a magenta toner, And toner transfer to the same transfer material, and finally red
Latent image formation by filter and development by cyan toner,
Then, the toner is transferred to the same transfer material. After the above steps are completed, the gripper 65 is released, and the transfer material reaches the fixing device 75.

As described above, the image forming condition setting section provided in the unit can automatically set not only the exposure amount and the charge amount as a part of the image forming conditions but also the entire process, that is, the sequence. Becomes In particular, when a plurality of independent control circuits are provided, it is easy to select a sequence after performing the above correction.

Next, as an example in which a unit having the same shape is loaded with a different action, an example in which the unit selects positive development or negative development will be described.

More specifically, the unit 60 shown in FIG. 12 is used for negative, and the same unit (not shown) is used for positive.
When a negative unit having toner of the same polarity as the latent image is loaded in the main body, the bias to the developing device is determined by selecting the specific circuit described with reference to FIG. On the other hand, when a positive unit having a positive toner having a toner having a polarity opposite to that of the latent image is loaded in the main body, a bias for preventing toner from adhering to the non-latent image portion by selecting another circuit is applied to the developing device. Applied. As a specific control circuit, the circuit as described with reference to FIG. 11 can be used, and a bias output that promotes one of the developments may be obtained by a pressed switch.

In the case where a plurality of circuits are selected by the image formation setting unit of the unit in this manner, by increasing the number of circuit combinations, not only the sequence selection but also the image carrier as described above is simultaneously performed. Variations in characteristics can be corrected.

As described above, according to the above-described embodiment, even if the unit is replaced with an arbitrary unit, the optimum image forming conditions and process for the loaded unit can be automatically obtained, and the main body can be always stably obtained. It can be operated in conjunction with. Further, according to the present embodiment, for example, it is possible to switch from black image formation to image formation of another color or to use an image using a two-component developer without replacing the unit and requiring complicated adjustment on the main unit side. It is possible to switch from the formation to the image formation using the one-component developer, and the function of the main body device can be enhanced.

Further, in each of the above-described embodiments, an example in which an image is formed by an electrostatic latent image using a photosensitive member has been described. However, the present invention is not limited to this. The invention can also be applied to a known image forming method such as that disclosed in JP-A-56-106253.

[0077]

As described above, according to the present invention, 1
Since images of a plurality of colors can be formed by a single image forming apparatus, an economical and efficient image forming system can be provided. Furthermore, according to the present invention,
Instead of mounting units for a plurality of colors at the same time, the units can be replaced as needed, so that an image forming system that can reduce the size of the image forming apparatus main body can be provided. . In addition, according to the present invention, it is determined whether the unit attached to the image forming apparatus main body is the first unit or the second unit,
Since the image conditions can be automatically determined so that the image is formed under the image forming conditions according to the determination result, the operator has to manually set the image forming conditions even though the units can be exchanged freely. Can be omitted.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electrophotographic copying machine using an embodiment to which the background art of the present invention is applied.

FIG. 2 is a perspective view of a unit holding a drum.

FIG. 3 is a perspective view of the vicinity of attachment of a positioning member.

FIG. 4 is an electric circuit diagram showing an example of automatically adjusting the voltage of an exposure source.

FIG. 5 is an electric circuit diagram showing an example of automatically adjusting the voltage of the charger.

FIG. 6 is a quaternary chart for each step showing a tone reproduction characteristic of a photosensitive drum-copy.

FIG. 7 is a perspective view of a condition setting unit showing another example of performing automatic adjustment by loading a drum.

FIG. 8 is a perspective view of a copying machine to which another embodiment is applied.

FIG. 9 is an electric circuit diagram showing still another example of performing automatic adjustment.

FIG. 10 is a perspective view of another embodiment of the condition setting unit.

11 is a control circuit diagram by the mechanism shown in FIG.

FIG. 12 is a sectional view of a color and multifunction copying machine to which a preferred embodiment of the present invention is applied.

FIG. 13 is a sectional view of a unit to which the embodiment shown in FIG.

FIG. 14 is a plan view showing a relationship between a unit and a main body side switch.

FIG. 15 is a plan view showing a relationship between a unit and a main body side switch.

FIG. 16 is an electric circuit diagram showing an example of selecting a circuit by a condition setting unit.

FIG. 17 is a timing chart showing a difference in process between units.

FIG. 18 is a timing chart showing a difference in process between units.

[Explanation of symbols]

1, 1a, 25, 40, 54 Image carrier (photosensitive drum) 15, 15a, 25c, 37, 45a, 45b, 45
c, 60a, 78a Image forming condition setting unit 13, 13a, 32, 60, 78 Unit 53 Color / monochrome copying machine 79 Color developing device 79a Yellow developing device 79b Magenta developing device 79c Cyan developing device

Claims (6)

(57) [Claims] 1. An image forming system for forming an image on a recording medium, comprising: a. An image forming apparatus main body; b. A first unit having a first photoconductor, first developing means for developing a latent image formed on the first photoconductor, and a first photoconductor and first developing means; A second photoconductor, a second developing unit for developing a latent image formed on the second photoconductor with a color different from the first developing unit, and the second photoconductor. A second unit having a body and a second developing unit; and a mounting unit provided on the image forming apparatus main body, which can be mounted with compatibility. C. The stomach loaded unit to the mounting means is whether the first unit determines whether the second unit, the determination
Control means for automatically determining image conditions so as to form an image under image formation conditions according to the result ; d. An image forming system, comprising: a conveyance unit for conveying the recording medium. 2. The apparatus according to claim 1, wherein the control unit automatically determines a charge amount for charging the first photoconductor or the second photoconductor according to the determination result. Image forming system. 3. The apparatus according to claim 1, wherein the control unit automatically determines an exposure amount for exposing the first photoconductor or the second photoconductor according to the determination result. Image forming system. 4. The apparatus according to claim 1, wherein said control means automatically determines a bias voltage value to be applied to said first developing means or said second developing means in accordance with said determination result. Image forming system. 5. The control device according to claim 1, wherein the control unit is configured to apply a voltage applied to a transfer unit for transferring the toner image formed on the first photoconductor or the second photoconductor to the recording medium in accordance with the determination result. The image forming system according to claim 1, wherein the value is automatically determined. 6. The controller according to claim 1, wherein the controller applies a current applied to a transfer unit for transferring the toner image formed on the first photoconductor or the second photoconductor to the recording medium in accordance with the determination result. The image forming system according to claim 1, wherein the value is automatically determined.