JPH07253700A - Color unit and image forming device - Google Patents

Abstract

PURPOSE:To correct variance according to the manufacture of each process unit dispensing with user's adjustment by providing a supporting means for integrally supporting the image carrier, the first developing means and the second developing means. CONSTITUTION:With regard to a copying machine 53, a color unit 78 for exclusive color developing of the same size as the size of a unit 60 can be attached for replacing the black and white developing exclusive unit 60. A unit 78 is provided with a color developing unit 79 inside replacing the black and white developing unit 57. Thus, as for the device 53, the unit 60 and the unit 78 is severally provided with the interchangeability with regard to the main body. In the case of replacing the units, at the time of the black and white copying, the copy is obtained by only single process of the latent image forming, the developing, the transfer and the fixing, then at the time of the color copying, the copy is obtained on completing the respective process of the latent image forming, developing and transferring by decomposing for each color. In this way, by attaching the unit with the different process to the main body device, the main body device can be operated corresponding to the intended purpose of the unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and a process unit detachable from the apparatus.

[0002]

2. Description of the Related Art Conventionally, it is known that a process unit having at least an image carrier such as a photoconductor can be attached to and detached from an image forming apparatus such as an electrophotographic apparatus. If maintenance is required in this process unit, it is only necessary to replace this unit with a new unit, which has the advantage of facilitating maintenance.

[0003]

Generally, the chargeability of the photosensitive member varies depending on the manufacturing environment, depending on the manufacturing lot. If the charging ability of the photoconductor varies, a predetermined latent image potential cannot be obtained under a constant charging condition, and the dark part potential becomes too high or, conversely, becomes too low. Therefore, it is preferable to adjust the charging conditions according to the charging ability of the photoconductor, but in the case of the process unit as described above, it is necessary for the user to adjust the adjusting means on the main body side according to the process unit. This is inconvenient because it puts a burden on the operator and makes it easy to forget to adjust.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to correct manufacturing variations of process units without user adjustment.

Another object of the present invention is to make the charging potential of the image carrier constant for each process unit.

[0006]

To achieve the above object, the present invention provides:
A process unit that has an image carrier and is attachable to and detachable from an image forming apparatus has an adjusting unit that can adjust a charging potential of the image carrier, and the adjusting unit is a charging unit that charges the image carrier. The resistance value of a variable resistor connected to the container is changed.

According to another aspect of the present invention, in an image forming apparatus in which a process unit having an image carrier is detachable, a power source for supplying a voltage to a charger for charging the image carrier is provided, and the process unit is provided with It has an adjusting means capable of adjusting the charging potential of the image carrier, and the adjusting means changes the resistance value of a variable resistor connected to a charger for charging the image carrier. Is.

[0008]

EXAMPLES Examples to which the present invention can be suitably applied 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 an electrophotographic method or a magnetic recording method is applied, and a unit detachable from this apparatus.

More specifically, the embodiment described below
A process unit of an image forming apparatus, wherein a process unit that is detachable from a main body of the image forming apparatus has a unit that sets an image forming condition on the apparatus main body side according to an operation mode of the process unit. It is about. Further, the present invention relates to an image forming apparatus having a control unit in which an image forming condition is automatically set by an image forming condition setting unit of a process unit which is detachable from a main body of the image forming apparatus.

In the embodiment described below, a process unit is composed of an image carrier and a characteristic of the image carrier or a purpose of use or a portion for setting an image forming condition on the main body apparatus side in accordance with the purpose and the characteristic. Constitutes the smallest unit of. Therefore, a process unit may include a part for setting image forming conditions, an image carrier, and a part or a plurality of image forming means arranged around the image carrier. The main body device in which the process unit is loaded receives the condition setting unit of this unit, and as a result, an image is formed on the image carrier under the conditions according to the condition setting unit. That is, the condition setting section has a configuration corresponding to the characteristics of the image carrier in the same process unit or the purpose of use of this process unit itself. Therefore, for example, if the process units have the photoconductors having the same characteristics and are used for the same purpose, the condition setting sections of the process units have the same structure. With the above configuration, only by replacing the process unit with respect to the main body device, it becomes possible to automatically set the image forming conditions suitable for this process unit without relying on a specialist.

Now, the present invention will be described below by taking a copying machine to which the electrophotographic method is applied as an example.

First, a method for preventing a change in an image due to a difference in characteristics of a photoreceptor, which is 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 an embodiment of the present invention is applied. In this copying machine, the main body can be divided into an upper main body portion 14 and a lower main body portion with one end as a center, and the drawing is a sectional view showing a state in which the upper main body portion is opened with respect to the lower main body portion. .

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 arrow direction. When forming a copy image, 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, the original 5a held on the original cover on the transparent glass original table 5 illuminated by the light source 4 is illuminated by the illumination lamp 4, and the original image by the illumination is recorded on the photosensitive drum 1 by the short focus lens array 6. 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 the developing device 8. The developing device 8 is fixed to the lower main body portion, and the developing roller 8a has fibrous hairs 8b on its surface. Toner 8c is supplied from the toner supply cartridge 7 to the developing roller 8a. In this toner supply, the toner is dropped from the opening of the cartridge 7 in a fixed amount in association with the rotation of the photosensitive drum. The latent image on the photosensitive drum 1 is a developing roller 8a that rotates at a constant peripheral speed with respect to the drum 1.
Thus, the electrostatic latent image is developed 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 onto the transfer paper P conveyed to the surface of the drum 1 by the transfer corona discharger 9. The transfer sheet P is sent out from the cassette C by the feeding roller R1 and reaches the surface of the drum 1 by the transfer sheet guides G1 and G2 and the conveyance / timing roller R2 to transfer the toner. After that, the transfer sheet P is destaticized by the destaticizing roller R3 and separated from the surface of the drum 1. The transport belt R4 reaches the fixing roller R5, the toner image is fixed on the transfer paper P by the fixing roller R5, and then the toner image is discharged onto the paper discharge tray T.

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

In this embodiment, the toner cartridge 7 containing the replenishment toner and the toner collecting container 11 are
The photosensitive drum 1 and the photosensitive drum 1 are integrally held by an arm 12 to form a unit 13. And this unit 1
3 is detachably attached to a predetermined position on the lower main body side by a configuration described later.

Next, a case where the above 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 body portion and the upper body portion are disengaged, the upper body 14 is lifted by the pushing-up means 14c containing the spring, and the apparatus body is opened, as shown in FIG. It becomes a state. So arm 12
When is manually lifted in the direction of arrow A, 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. Note that the alternate long and short dash line in the figure shows the unit 13 in the process of being taken out from the main body device.

Next, a case will be described in which another unit 13a is replaced with the unit 13 and attached to the apparatus main body.

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

In this embodiment, a part of the arm 12a is
There is a condition setting unit for forming an image suitable for the photosensitive drum 1a in consideration of various conditions such as the sensitivity, charging characteristic and residual potential characteristic of the photosensitive drum 1a. This setting unit is composed of a rod-shaped member 15a for driving a member 16 (FIG. 3) for rotating the volume of the image forming adjustment circuit on the main body side. This rod-shaped member 15a is adjusted so as to project from the arm 12a by a predetermined angle or a predetermined length from the arm 12a in accordance with the sensitivity, charging characteristics, etc. of the photosensitive drum at the time of factory shipment, and a screw or an adhesive at an appropriate position. You can fix it with. With this configuration, as will be described in detail later, it becomes possible to rotate the volume according to the angle and length of the rod-shaped member and set the charge amount and image exposure amount that match the characteristics of the photosensitive drum.

When loading the new unit 13a into the main body unit, in this embodiment, the both ends of the drum shaft 1b are slidably fitted to the bearing 14d provided in the lower main body portion, and the shaft 1b is inserted. Is connected to a drive source (not shown) on the main body side, and the drum 1a is rotatably loaded at a predetermined position. At the same time, the arm 12a of the unit 13a is brought into contact with the receiving members 14e and 14f also provided on the lower main body portion to be positioned and held. As a result, the cartridge 7a and the recovery container 11a are loaded in predetermined positions, and the above-mentioned 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 and align with the lower body,
The upper and lower bodies are fixed by engaging a and 14b. Then, the tip of the rod-shaped member 15 a is attached to the shaft 16 provided on the upper body portion 14.
It abuts on the volume rotary member 16 which is rotatable about a. The rod-shaped member 15 rotates the volume rotating member 16 in the clockwise direction by the angle θ corresponding to the installation angle of the rod-shaped member 15 and the protruding length thereof as the upper body descends.

FIG. 3 shows a detailed mechanism relating to the setting of the volume when the upper main body 14 is lowered.

In the figure, 14g is a fixed side plate of the upper body portion 14. The volume rotating member 16 is attached to the fixed side plate 14g of the upper body 14 so as to be rotatable around the shaft 16a integrally with the shaft 16a. 16b is a compression coil spring, one end of which is attached to the volume rotary member 16,
The other end is attached to the fixed side plate 14g, and the volume rotary member 16 is pressed against the stopper 17 and locked. Therefore, the volume rotating member 16 is the upper body 1
When 4 is rotated counterclockwise as indicated by arrow B so as to be closed and fixed so as to be aligned with the lower body, the position is pushed by the positioning member 15a provided on the arm 12a and rotated against the spring force of the spring 16b ( In this example, it stops at a position rotated by an angle θ). Therefore, the volume rotary member 16 is
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, it is also possible to form a convex portion by deforming a part of the unit.

Next, a method of setting the latent image forming conditions according to the characteristics of the photoconductor in the unit by the above volume will be described with reference to FIGS. 4 and 5. In the case of FIG. 4, the exposure amount to the photosensitive drum 1 is changed by the applied voltage to the lamp 4 (FIG. 1) to automatically adjust the fluctuation of the latent image due to the unit replacement. In the case of FIG. 5, the corona charging is performed. Bowl 2
Similarly, an example is shown in which the applied voltage is changed and the fluctuation is automatically adjusted.

4 and 5 show the volume rotary member 16
An example of a circuit that adjusts the voltage generated by the movement of the sliding member 19 that slides on the sliding resistance 18 in conjunction with the rotation of is shown.

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 rotates on the sliding resistance in association with the amount of rotation of the volume rotating member 16. This circuit is located inside the fixed side plate 14g, that is, the volume rotating member 1
It is fixed to the side opposite to the side where 6 is provided. Therefore, the volume rotating member 16 is a rod-shaped member 15 set according to the characteristics of each photosensitive drum fixed to the loaded unit 13.
If the sliding member 19 is rotated by an angle corresponding to the above, the sliding member 19 is also rotated simultaneously on the sliding resistance 18. A predetermined constant voltage V ₀ is applied to both ends of the sliding resistance 18. Further, the sliding member 19 starts from the initial position 0 when the volume rotating member 16 is in contact with the stopper 17 and is indicated by an arrow C.
It rotates in the direction D according to the shape of the rod-shaped member 15.

Now, 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 photoconductor 1a. Reference numeral 20 is a potentiometer for which the operator adjusts the exposure amount on the main body side according to the document density when actually copying. With the above-mentioned configuration, the sliding member 19 is placed on the sliding resistance 18 and the unit 13 thereof.
The rod 1 is rotated by an angle θ (FIG. 3) corresponding to the rod-shaped member 15a to automatically adjust the voltage of the lamp 4, and the photosensitive member 1a
It is possible to irradiate with an amount of light suitable for.

FIG. 5 shows a circuit in which the voltage applied to the corona wire or grid 3 of the charger 2 is set to a value according to the shape of the rod-shaped member 15 of the unit 13. 2 in the figure
Reference numeral 1 is a transformer and 22 is a rectifier. The input voltage Vi is changed depending on the position of the sliding member 19, and the rod-shaped member 1 is connected from the output terminal 23 to the corona wire of the charger 2 or the grid 3.
The voltage set by 5a is applied. As a result, also in this embodiment, the 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 shows the relationship between the toner density on the photosensitive drum corresponding to the image density of the original, and the second quadrant shows the toner surface potential on the photosensitive drum and the toner density on the photosensitive drum, that is, the developing characteristic.
The third quadrant shows the characteristics of the photoconductor loaded in the unit by the relationship between the image exposure amount and the surface potential of the photoconductor, and the fourth quadrant shows the exposure amount exposed on the photosensitive drum with respect to the image density of the original. Each relationship is shown.

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 charge amount will be described with reference to the above graph.

Here, the characteristic curve of the most standard photoconductor is curve a, and an original is exposed to this photoconductor at an exposure amount b, and toner development is performed with a developing device of development characteristic c. A toner image of curve d was obtained. Here, the unit having the photosensitive drum having the above characteristics is removed from the main body device, and another unit is loaded into the main body. At this time, when the photosensitive drum having the characteristic of the curve e is used for another unit, if an image is formed under the same exposure condition as the above, the halftone has too strong contrast as shown by the curve f. Obtain a toner image.

Therefore, by the method described in FIG.
The maximum exposure amount is moved from the point I to the point II so that the exposure amount is as shown by the line g only by mounting the unit on the main body. The exposure amount is changed by setting a rod-shaped member fixed to the unit. As a result, it is possible to reproduce a toner image having characteristics that substantially match the curve d obtained by the standard photoconductor.

Next, when a unit using a photosensitive drum having the characteristic of the curve h was loaded in the main body apparatus and an image was formed on the line b, which is a standard light amount, and the corona charge amount was not changed, the curve A toner image such as i that is light and has low contrast is obtained. Here, when the corona charge amount was increased by the rod-shaped member of the unit without changing the exposure amount so that the maximum surface potential of the photosensitive drum was substantially changed from the point III to the point IV, the characteristic was very close to the curve d. Could be obtained.

With the above structure, the rod-shaped member provided in the unit for setting the process conditions makes it possible to always form a stable image.

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

Whereas the photosensitive drum held by the arm 12 and the peripheral means are unitized in the above embodiment, this embodiment is unitized by the photosensitive drum and the image forming condition setting unit. In this embodiment, the drum bearing 24 is provided on the lower body. The photosensitive drum 25 has its shaft 25a.
Is rotatably attached to the pair via a pairing 25b. Further, a projection member 25c, which is a member different from the arched shaft 25a corresponding to the rod-shaped 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 other properties 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 is always fitted in a fixed direction. Therefore, when an arbitrary photosensitive drum 25 is loaded into the main body device, the shaft 25
The protrusion member 25c fixed to the main body is fixed in a fixed direction with respect to the main body device. Further, the drum 25 is the bearing 2
In the state of being fitted with 4, a drive source (not shown) on the main body side can be connected to rotate freely with respect to the shaft 25a.
Therefore, as described with reference to FIG. 1, when the upper main body 14 is rotated downward as indicated by the arrow E and the upper and lower main bodies are closed together to close the upper and lower main bodies, the projecting member 25c of the volume rotating member 1 described in FIG.
6, and the rotating member 16 corresponding to the size of the protruding member 25c is rotated clockwise. Therefore, if the sliding member 19 (FIGS. 4 and 5) interlocked with the rotation of the rotating member 16 is rotated as in the above-described example, a preferable latent image forming condition corresponding to the characteristics of the drum is automatically obtained. Can be done.

Still another embodiment will be described with reference to FIGS. 8 and 9.

The present embodiment shows an example of a copying apparatus which is not of the vertically dividable type like the apparatus shown in FIG. Further, in contrast to the case where the condition is set by the mechanical connection such as the cam in the above-mentioned embodiment, this embodiment shows an example in which a predetermined electric circuit is formed by connecting the connectors.

The main body 26 of the copying apparatus 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 by the unit 32,
This unit is attachable to and detachable from the apparatus body 26.
That is, the guide 33 provided on the main body 26 side is engaged and slid with the rail 34 provided on a part of the unit 32, and the unit 32 is inserted into the main body apparatus along the guide 33 and loaded. To do. Further, in order to set the positions of the main body device and the unit, the pin 35 of the main body is fitted into the opening 36 on the unit side.

Therefore, in this 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 leading end in the loading direction of the unit) is fixed so as to face the pin 37. 38 on the back 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, the volume resistor 39 is attached to the unit 32 side, and the photosensitive drum 2
The sliding resistance 41 of the resistor 39 is set so that an image forming condition suitable for the photosensitive drum is set according to the characteristics of No. 7.
A slider 42 for determining the resistance value is set on the upper side, and the slider 42 is fixed with an adhesive or the like. Such fixing of the slider may be performed before the photosensitive drum is made into a drum and the photosensitive drum is shipped from the factory.

With the above structure, when the pin 37 used for electrical connection on the unit 32 side is inserted into the jack 38, the exposure lamp 43 is connected to the unit 3 mounted in the main body apparatus.
According to the set value of the volume resistor 39 of No. 2, the optimum voltage can be applied to the lamp 43 for any arbitrary unit. Therefore, the operator simply sets another unit in the copying apparatus main body to replace the unit, and the optimum exposure amount or pre-exposure amount can be automatically set for the loaded unit. As described above, the lamp to be adjusted is, for example, the image exposure source (4 in FIG. 1),
Alternatively, it may be a pre-exposure lamp that exposes the photosensitive drum 27 before it is charged by the charger 2.

In the above-mentioned embodiments, the case where a stable image is always obtained without changing the image quality depending on the unit used even when the characteristics of the photoconductor in the unit are not constant has been described. That is, since the image forming condition corresponding to the unit is automatically determined according to the characteristics of the photoconductor loaded in the unit, the operator only needs to load the unit in the main body device to adjust the image. It is possible to set the image forming conditions according to the characteristics of the photoconductor without adding.

Here, in each of the above-described embodiments, only the case where the single condition is automatically set by the rod-shaped member or the pin on the unit side which is the condition setting unit for image formation is shown, but the present invention is not limited to this. Instead, for example, by using a plurality of volume members and a plurality of rod-shaped members corresponding thereto or a plurality of pairs of connectors, it is 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 the present embodiment, the condition setting member provided in the unit for setting the image forming condition may be mechanical means such as the above-mentioned cam.
Alternatively, it may be an electric means such as an electric connector. Further, by reading an information signal mark which is a command signal for adjusting the characteristics or adjustment of the photoconductor written on the unit surface with a bright and dark image signal by an optical reading means of a known technique, or by a magnetic reading means. The image forming condition on the main body side may be adjusted by reading the information signal written in the kit. In this case, the condition setting section provided on the unit side serves as 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. 3 described above. In the figure, reference numeral 44 denotes a side plate fixed to the upper body portion, and push button switches 45a, 45b, 45c such as micro switches are fixed to the side plate at equal intervals. On the other hand, reference numeral 46 is an arm that constitutes a unit, and a protruding member 47 is fixed to this arm with an adhesive or the like corresponding to the position of the switch 45. The position of the convex portion of the projecting member 47 is fixed at a position predetermined by the characteristics of the photosensitive drum in the unit. With the above configuration, by pushing down the upper body in the direction of arrow F, the side plate 44 is also lowered, and as a result,
One of the buttons 45 is pressed to select a predetermined latent image forming condition.

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 loaded in a predetermined position on the lower main body of the main body device 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 ends of the DC power source 50 is connected to the back electrode of the photosensitive drum and is grounded. The other output terminal for this terminal has three terminals showing different DC voltages and is connected to one terminal of the switch 45. The other terminal of the switch 45 has a high frequency power source 51 (2000 Vp
(p, 1500 Hz), and the other output terminal of the high frequency power source 51 is connected to the developing roller 52 of the developing device. Therefore, an alternating voltage waveform in which a desired DC voltage is superimposed is applied between the developing roller and the back electrode of the photosensitive drum by the switch pressed by the convex portion of the protruding member 47, and the latent image on the photosensitive drum is developed. To be done. Depending on the position of the convex portion of the projecting member 47, an appropriate developing bias voltage is applied between the developing roller and the back surface electrode of the photosensitive drum so as to always compensate for the photosensitive member of each unit 48 having different characteristics. Therefore, it is possible to obtain a stable image even when the photoconductor characteristics of the unit are different from those of the previously used unit.

[0053]

[Table 1]

The above-mentioned Table 1 is a table showing the numerical values of the above-mentioned examples, and a drum using an organic optical semiconductor was used as the photosensitive drum. Further, in this example, the photosensitive drums A, B, and C of different types having different bright portion potentials with respect to a constant reference exposure amount are provided.
One unit 48 was used. The three output terminals except the ground terminal of the DC power supply 50 are -250V, -200 in advance.
V and -150V, and these terminals are
The switch 45 was connected to one terminal as shown in FIG.
For the photosensitive drums A, B, C with different characteristics,
It was possible to apply appropriate developing bias voltage to the developing roller by pressing and connecting the microswitches 45c, 45b and 45a in accordance with the position of the convex portion of the protruding member 47.
From this, it was 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 described in FIG. 8 is pushed into the main body and loaded. In this case,
It is also possible to arrange the switch group at the back side of the main body device or at a position along the pushing path of the unit.

As described above, depending on the number of combinations of push buttons and protrusions, it is possible to simultaneously correct a plurality of conditions such as charging and exposure amount. 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. In order to finely adjust the charging potential depending on the difference in the characteristics of the photoconductor, it is preferable to adjust the resistance value with the variable resistor 41 shown in FIG.

By the way, the image forming conditions for correcting different photoreceptor characteristics and forming a stable image are the charging conditions of the charger such as the grid voltage value or the corona applied voltage, or the image is transferred. The voltage of the transfer discharger, the voltage of the charge removal discharger in the latent image forming means, or the current value applied to these corona dischargers may be used. Further, when the light quantity of the lamp is changed, the pre-exposure quantity or the image exposure quantity may be used. Further, as long as the effects of the above-described embodiment can be obtained, the rotation time condition of the photosensitive drum before the start of image formation or the exposure amount and the pre-charging condition at this pre-rotation may be used. Further, it may be a developing bias voltage condition, a rotation time condition of the photosensitive drum after the transfer of the visible image, or an exposure static elimination condition at the time of the subsequent rotation, and further, a temperature of the photosensitive drum for keeping the characteristics of the photosensitive drum constant. It may be a control condition.

By the way, in the above embodiment, the characteristics of the photoconductor differ from unit to unit due to the image forming condition setting unit, and the difference prevents the finished image from changing. However, as another usage of the condition setting section, it is possible to automatically set the sequence corresponding to the purpose of use of the unit and the whole process adapted to this unit.

For example, a unit dedicated to monochrome copying and a unit dedicated to color copying are prepared for a common main unit,
It is also possible to set the main body device to perform an operation for black-and-white or color copying according to the unit loaded in the main body device. As a matter of course, the automatic setting of the sequence and the compensation accompanying the characteristic change of the photosensitive drum can be performed at the same time.

In the following, the former color / electrophotographic copying machine will be described as an example for setting the entire sequence of process conditions according to units.

An apparatus 53 shown in FIG. 12 is a black-and-white copying machine using electrophotography, which also serves as a color, and a photosensitive drum 54 having a photoconductive layer provided on a conductive drum substrate is rotatably supported in a direction of an arrow. Has been done. 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 according to the rotating direction of the drum. In this device, the discharger 55, the developing device 57, and the cleaning device 59 are integrally supported together with the photosensitive drum by a unit 60 that is detachable from the main body device. The unit 60 includes guide rails 61, 6 fixed to the main body side.
It is guided and supported by 2, and is attached to and detached from the main body device.
The transfer corona discharger 58 is provided inside the transfer drum 63 provided on the main body side and having an insulating mesh, and the transfer drum is provided with a gripper 65 for holding the tip of the transfer material 64. A corona discharger 66 for charging the drum to attract the transfer material 64 is provided near the outer periphery of the transfer drum 63.

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 the original on the original table 67 that reciprocates in the upper part of the main body with a lamp 68. Drum 5 through element array 56
4 is exposed to form a latent image. The formed latent image is developed by the developing device 57, and the developed image is transferred to the transfer material by the transfer corona discharger 58.

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

By the way, for the copying machine 53, a color unit 7 dedicated to color development shown in FIG.
8 can be loaded. This unit 78 is shown in FIG.
A color developing device 79 is contained in place 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 sequentially arranged.

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

When the units are exchanged in this way, the processes for forming a copy image are different between the two units. That is, in 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, after the latent image formation by each color separation, development and transfer, the fixing process is completed to obtain a copy. According to the present invention, such a unit having a different process is loaded into the main body device,
The unit can be operated depending on the purpose of use of this unit, which 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 0 is loaded, and FIG. 15 is a plan view when the color copying unit 78 is loaded. As shown in the figure, each unit is provided with projections 80a and 78a at predetermined positions. Then, each convex portion selects one of the specific switches 81a or 81b in order to select a process that matches the purpose of use of the loaded unit among the switches 81a and 81b provided for this convex portion on the main device side. 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 in the drawing is a control unit for operating or driving each unit of the main body apparatus. In the control unit, a power supply circuit 83, 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. In this way, the effect of providing an independent circuit according to the process is that it is a dedicated circuit, so high-level control is possible, and even if one circuit becomes unusable, the main unit can be operated by another circuit. Can operate.

When the unit 60 is loaded in the main unit, the first circuit 84 is selected and a control signal for black-and-white copying is generated at the output terminal 86. As shown in FIG. 17, the control at this time is performed while the transfer material gripper 65 transfers the toner image on the photosensitive drum 54, that is, the transfer drum 63.
The transfer material is only sandwiched during one rotation of.

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, the color separation filter 69 as shown in FIG.
And the developing devices 79a, 79b, 79c for the respective colors are driven. That is, in order to obtain one color copy, the original image is formed with a latent image by a blue filter and developed with a yellow toner, and toner is transferred to a transfer material, and then a latent image is formed with a green filter and developed with a magenta toner. And toner transfer to the same transfer material, and finally red
Latent image formation with a filter and development with cyan toner,
And toner transfer to the same transfer material. After the above steps are completed, the gripper 65 is opened and the transfer material reaches the fixing device 75.

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

Next, as an example in which even units having the same shape are loaded with different actions, an example in which the unit selects positive development or negative development will be described.

Specifically, the unit 60 shown in FIG. 12 is used for the negative, and the same unit (not shown) is used for the positive.
When a negative unit having toner having the same polarity as the latent image is loaded in the main body, the bias to the developing device is determined by the selection of 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 the toner from adhering to the non-latent image portion is applied to the developing device by selecting another circuit. Is applied. As a concrete control circuit, the circuit as shown in FIG. 11 can be used, and it is sufficient to obtain a bias output which promotes one development by pressing a switch.

When a plurality of circuits are selected by the image forming setting section of the unit as described above, the number of combinations of circuits is increased, so that not only the selection of the sequence but also the above-mentioned image carrier can be performed simultaneously. It is also possible to correct variations in characteristics.

As described above, according to the above-described embodiment, even if the unit is replaced with an arbitrary unit, the optimum image forming condition and process for the loaded unit can be automatically obtained, and the main body is always stable. It became possible to operate in conjunction with. Further, according to the present embodiment, for example, switching from black image formation to image formation of another color or an image using a two-component developer without requiring complicated adjustments on the main body side only by replacing units. The formation can be switched 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 photoconductor is shown, but the present invention is not limited to this, and an image is formed by a magnetic latent image or the like. It can also be applied to a well-known image forming method as disclosed in Japanese Patent Laid-Open No. 56-106253.

[0077]

As described above, according to the present invention, the advantages of the process unit that can be easily maintained can be exhibited, and the manufacturing variations among the process units can be corrected without the need for the user to adjust. Further, the charge potential of the image carrier can be made constant for each process unit.

[Brief description of drawings]

FIG. 1 is a 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 near the position where a positioning member is attached.

FIG. 4 is an electric circuit diagram showing an example of automatically adjusting a 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 the tone reproduction characteristics of the photosensitive drum-copy.

FIG. 7 is a perspective view of a condition setting unit showing another example in which automatic adjustment is performed 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 according to the mechanism shown in FIG.

FIG. 12 is a cross-sectional view of a color combined copying machine to which a preferred embodiment of the present invention is applied.

FIG. 13 is a cross-sectional view of a unit to which the device shown in FIG. 12 can be loaded, to which an embodiment of the present invention is applied.

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

FIG. 15 is a plan view showing the relationship between the unit and the 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 diagram showing a difference in processes depending on units.

FIG. 18 is a timing chart showing the difference in the process depending on the unit.

[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 (2)

[Claims] 1. A color unit attachable to a main body of an image forming apparatus, comprising: an image carrier, a first developing unit for developing a latent image formed on the image carrier, and a image forming unit formed on the image carrier. Second developing means for developing the latent image with a color different from that of the first developing means, the image carrier, the first developing means, and the second developing means are integrally supported. And a supporting unit for controlling the color unit. 2. An image forming apparatus for forming an image on a recording medium, an image carrier, a first developing unit for developing a latent image formed on the image carrier, and an image carrier formed on the image carrier. Second developing means for developing the latent image with a color different from that of the first developing means, the image carrier, the first developing means, and the second developing means are integrally supported. An image forming apparatus comprising: a mounting unit having a supporting unit for mounting a color unit, and a transport unit for transporting a recording medium.