JPS63182679A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent an image carrying body from damage, by driving a driving means by a control means, allowing a developing means to come into contact with the image carrying body only in case of executing a development, and separating the developing means from the image carrying body in other case than the development. CONSTITUTION:In a regular holding state that a copying operation is not being executed, developing devices 121, 122 are separated from a photosensitive drum 10. A selecting command of the developing devices 121, 122 is supplied to a motor driving part 103 from a control part 100, a motor 81 is operated by this motor driving part 103, and the developing device 122 are allowed to contact by pressing on the photosensitive drum 10. Thereafter, an exposing lamp 4 is turned on, and also, motors 51, 52 and 63 are driven, a copying operation by the developing device 122 is executed, and when this copying operation is ended, the developing device 122 is separated from the photosensitive drum 10 again. In such a way, no damage is generated in the photosensitive drum 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an image forming apparatus applied to, for example, an electronic copying machine.

(Prior Art) Recently, for example, in a copying machine capable of performing multi-color copying, a developing device is provided so as to be able to approach and separate from the photosensitive drum, and one of Only the developing device containing developer is brought into contact with the photosensitive drum.

By the way, the surface of the photoreceptor drum is easily damaged. Therefore, if the developing device selected above is in constant contact with the photoreceptor drum, the photoreceptor drum may be damaged, and if copies are made using the photoreceptor drum that is damaged in this way, the photoreceptor drum may be damaged. However, there was a problem in that the quality of the formed image deteriorated.

(Problems to be Solved by the Invention) This invention solves the problem of damage to the image bearing member caused by the developing means, and its purpose is to remove the image bearing member from the developing means outside the image forming apparatus. The present invention aims to provide an image forming arrangement that can prevent damage to the image carrier and prevent deterioration in the quality of the formed image by separating the image bearing member from the image bearing member.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides an image carrier on which an image corresponding to a document image is formed, a developing means for developing the image formed on the image carrier, a driving means for bringing the developing means into contact with and away from the image carrier; and a control means for driving the driving means during development to bring the developing means into contact with the image carrier and separating the developing means from the image carrier after development is completed. It is composed of.

(Function) This invention drives the driving means by the control means, brings the developing means into contact with the image bearing member only when performing development, and separates the developing means from the image bearing member when performing other than development. Trying to prevent body damage.

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

FIGS. 2 and 3 schematically show an image forming apparatus of the present invention, such as a copying machine. That is, 1 is a main body of a copying machine, and an original platen (transparent glass) 2 for holding an original is fixed to the upper surface of this main body 1. This document table 2 is provided with a fixed scale 21 that serves as a reference for setting the document, and furthermore, a document cover 11 that can be opened and closed is provided near the document table 2. The original placed on the original platen 2 is moved back and forth by an optical system consisting of an exposure lamp 4 and mirrors 5, 6, and 7 along the lower surface of the original platen 2 in the direction of arrow a. It is designed to be exposed and scanned.

In this case, mirror 6.7 moves at half the speed of mirror 5 so as to maintain the optical exposure length. The light reflected from the original by the scanning of the optical system, that is, the light reflected from the original by the light irradiation of the exposure lamp 4, is reflected by the mirror 5, 6, 7, passes through the variable magnification lens block 8, and further passes through the mirror 91. .92.9B reflected by photoreceptor drum 1
0, so that an image of the document is formed on the surface of the photosensitive drum 10.

The photosensitive drum 10 rotates in the direction indicated by the arrow in the figure, and the surface is first charged by the charging device 11, and then the image is exposed to slit light at the exposure section Ph, thereby forming an electrostatic latent image on the surface. be done.

This electrostatic latent image is produced by a developing device 12 that contains, for example, red or black toner, and is selectively operated as required.
1.122, the image is visualized by adhering toner.

The developing devices 121 and 122 are detachably attached to the copying machine main body 1, and the color of the toner contained in these developing devices 12 and 122 can be determined by, for example, a It is set by the connection status of multiple pins of the connector.

On the other hand, sheets of paper (material to be transferred) are taken out one by one from the selected upper paper feed cassette 131 or lower paper feed cassette 132 by a feed roller 141, 142 and a pair of rollers 151, 152, The image is guided through the image to a pair of registration rollers 17, and guided to a transfer section by the pair of registration rollers 17.

Here, the paper feed cassettes 131 and 132 are removably provided at the lower right end of the main body 1, and either one can be selected on the operation panel described later. Further, the cassette size of each of the paper feed cassettes 131 and 132 is detected by a cassette size detection switch 601 and 602, respectively. The cassette size detection switches 601 and 602 are composed of a plurality of microswitches that are turned on and off according to the insertion of cassettes of different sizes.

Furthermore, a manual feed guide 13a is provided on the upper surface of the paper feed cassette 131.
The paper manually inserted through the feed roller 14a
The sheet is guided to the pair of rollers 15 by the roller pair 15, and is then conveyed in the same manner as the sheet fed from the sheet feed cassette 131.

On the other hand, the paper sent to the transfer section comes into close contact with the surface of the photoreceptor drum 10 at the transfer charger 18, so that the toner image on the photoreceptor drum 10 is transferred by the action of the charger 18. . This transferred paper P is transferred to the peeling charger 1
9, the image is electrostatically separated from the photoreceptor drum 10 and conveyed by the conveyor belt 20, and is sent to the fixing roller 521 as a fixing device provided at the end of the conveyor belt 20, where the transferred image is transferred. It will be established. After fixing, the sheet is discharged to a tray 25 outside the main body 1 by a pair of delivery rollers 22. Further, after the photosensitive drum 10 has been transferred, residual toner on the surface is removed by a cleaner 26, and afterimages are erased by a static elimination lamp 27, so that the photosensitive drum 10 returns to its initial state. Note that 29 is a cooling fan for preventing the temperature inside the main body 1 from rising.

Further, the exposure lamp 4 and the mirror 5 are connected to the M1 carriage 4.
11, and the mirror 6.7 is mounted on the second carriage 412.
It is set in.

Further, the first carriage 411 is provided with a spot light source 131 that is movable in a direction orthogonal to the moving direction of the first carriage 411.

Furthermore, an erasing array 15 in which a plurality of light emitting elements are arranged along the longitudinal direction of the photosensitive drum 10 is located between the charging charger 11 of the photosensitive drum 10 and the exposure section Ph.
0 is provided, and when performing partial erasure of a document image, the light emitting elements constituting this erasure array are turned on corresponding to the erasure area designated by the spot light source 131, for example, and the light emitting elements of the photoreceptor drum 10 are illuminated. It is designed to remove static electricity. Therefore, an electrostatic latent image is not formed in the portion from which the charge has been removed even if it is subsequently exposed to light at the exposure portion Ph, so that the document image is erased.

FIG. 4 shows an operation panel 30 provided on the main body 1 of the copying machine. 30a is a copy key for commanding the start of copying;
30b is a numeric keypad for setting the number of copies, etc.; 30c is a display unit for displaying the operating status of each part, paper jams, etc.;
30d is a density setting section for setting copy density; 30e is a count command key for displaying the total number of copies and the number of copies for each color; 30f is an identification code (It) code)
ID count key to display the number of copies corresponding to each ID code when the 10 copy mode is set, which allows copying only when the numbers match. 30G is the part that erases a part of the original image and copies it. Edit keys 30 to be operated when performing deletion, multiple copying, double-sided copying, etc.
h is the magnification key operated when setting the copy magnification, 30
i is a cassette selection key that is operated to select the upper and lower paper feed cassettes 131 and 132; 30J is a color change key that is operated when copying with a different toner color; 30 is, for example, an edit key 30q that is operated In this state, when an erasure range, etc. of the document is specified using the spot light source 131, an operation is performed to store the specified erasure range, etc. in the memory, or to read out information such as the erasure range, etc. stored in the memory in advance. The mode memory key 301 is an information key that is operated when you want to obtain information corresponding to each mode. For example, if you operate this key when a paper jam occurs, the paper jam will be displayed on the display 300 (described later). Information for canceling is now displayed.

30m is a function check key, and when this function check key 30m is operated, the display 30o can display what kind of function is set. 30n is a dial for adjusting the contrast of the display 30o. Reference numeral 30o denotes a display device consisting of, for example, a liquid crystal dot matrix panel, and on this display device 30o, for example, the setting status of the copying machine is displayed in characters, and the various keys 30e130f, aoa to 30
When m is operated, the corresponding characters are displayed. Furthermore, if a paper jam occurs during a copying operation, for example, the display 30° displays the location of the paper jam and countermeasures for the jam using text and graphics.

On both sides of the display 30o are operation keys 301 to 304.3 for selecting various functions displayed on the display 300.
0! i to 30a are arranged. Further, 30p is a movement key for moving the aforementioned spot light source 131,
This movement key 30p is as shown by arrows 30q to 30t.
It is said that it can be tilted in all directions, and these arrows 30q to 30
When t is operated, the spot light source 131 is moved in the same direction. 30u is a position designation key for inputting the coordinate position indicated by the spotlight WA131.

FIG. 5 schematically shows the drive system of the copying machine.

The motor 51 drives the first carriage 411 and the second carriage 412. The motor 52 drives the cooling fan 29, and the power of the motor 52 is transmitted via a gear 53, a belt 54, and a gear 55 to a gear 56 provided coaxially. This gear 56 drives the developing rollers 57 and 58 of the developing device 121 and 122, and when the developing device 122 is selected, it meshes with the gear 59 provided on the developing roller 58, and drives the developing device 121. is selected, the idle gear 60
, is connected to a gear 62 provided on the developing roller 57 via a gear 61 provided coaxially with this gear 60 .

Further, the motor 63 drives the photosensitive drum 10 and the fixing roller pair 20. That is, the power of the motor 63 is transmitted via a gear 64, a chain 65, gears 66 to 69, and a belt 70 to a gear 71 coaxially provided on the photoreceptor drum 10. Furthermore, the power of the motor 63 is transmitted via the chain 65 and gears 72 to 78 to a gear 79 provided coaxially with the pair of fixing rollers 21 .

FIG. 6 shows the driving means for the developing units 121 and 122.

The motor 81 selectively drives the developing devices 121 and 122, and the power of the motor 81 is transmitted to a gear 88 via a gear 82, a belt 83, and gears 84-87. A cam 89.90 is mounted coaxially on this gear 88. One end of an L-shaped lever 91,92 is abutted on each of these cams 89,90. The intermediate portions of these levers 91, 92 are rotatably held, and the other ends are connected to the intermediate portions of arms 93, 94, each of which has one end connected to a developing device 121, 122.

The other ends of these arms 93, 94, and lever 91.
A spring 95.96 is stretched between the other ends of the lever 92, and the spring 95.96 presses one end of the lever 91.92 against the cam 89.90.

Further, an operator 98 of a switch 97 is in contact with the cam 89, and this switch 97 causes the developing device 12 to
1.122 operating positions are detected.

In FIG. 6, the developing device 122 is selected, and this developing device 122
This shows the state in which development is possible. In this state, when the developing device 121 is selected, the motor 81 is driven and the cams 89.90 are rotated in the direction shown by arrow A in the figure, and the arms 93.94 are moved toward the lever 91.
．． 92, they are moved in the directions of arrows B and C, respectively.

Therefore, the developing device 122 is separated from the photosensitive drum 10, and the developing device 121 is brought into contact with the photosensitive drum 10. The state in which the developing unit 12 is in contact with the photosensitive drum 10 is detected by a switch 97, and the operation of the motor 81 is stopped in accordance with this detection output.

In this state, if the developing device 122 is selected,
In response to the rotation of the motor 81, an operation opposite to that described above is performed, and the developing device 122 is brought into contact with the photosensitive drum 10 as shown in the figure.

FIG. 1 shows the main parts of the control circuit. Control unit 10
0 controls the operation of the entire copying machine according to the program stored in the memory 101, and this control unit 10
0 has the operation panel 30.0 described above. A motor 51 that drives the exposure lamp 4, various sensors 102 such as the switch 97, the first carriage 411, and the second carriage 412.
, a motor 52 that drives the developing devices 121, 122, etc., a motor 63 that drives the photosensitive drum 10@, a developing device 121 .
a motor control unit 103 that controls the operation of the motor 81 and the like for selecting 122; the spot light source 131 (not shown);
An erase array 150 and the like are connected.

In the above configuration, the gist of the invention will be explained.

The developing units 12x and 122 are spaced apart from the photosensitive drum 10 in a normal standby state in which no copying operation is performed. Both developing devices 121 and 122 are the photosensitive drum 1.
The state away from 0 is detected by switch 97.

In this state, it is assumed that, for example, the developer 122 is selected, and when the copy key 30a of the operation panel 30 is operated, a selection command for the developer 121 and 122 is supplied from the control unit 100 to the motor drive unit 103. The motor 81 is operated by the motor driving section 103 to drive the developing device 122.
is brought into contact with the photosensitive drum 10. When the developing device 122 comes into contact with the photosensitive drum 10, this is detected by the switch 97, and the motor 81 is stopped via the control section 100 and the motor drive section 103. After that, in the control section 100, the exposure lamp 4 is turned on, and the motor 51.5 is turned on.
2.63 is driven, and the developing device 122 performs a copying operation.

When this copying operation is completed, the motor 81 is driven again via the control section 100 and the motor drive section 103. When the developing device 122 is moved to a predetermined position, this is detected by the switch 97, the motor 81 is stopped, and the developing device 12 is moved to a predetermined position.
1.122 is returned to the standby state in which it is separated from the photoreceptor drum 10.

According to the above embodiment, in the standby state where no copying operation is being performed, the developing devices 121 and 122 are connected to the photosensitive drum 10.
I try to stay away from it. Therefore, it is possible to prevent damage to the photoreceptor drum 10, and thus it is possible to prevent the quality of the formed image from deteriorating.

Furthermore, since damage to the photoreceptor drum 10 can be prevented, the life of the photoreceptor drum 10 itself can be extended.

In the above embodiment, the present invention is applied to an electronic copying machine equipped with a plurality of developing devices, but the present invention is not limited to this. For example, the present invention can be applied to an electronic copying machine with a single developing device. It is also possible to apply

It goes without saying that various other modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As described in detail above, according to the present invention, the developing means is separated from the image carrier in cases other than development, thereby preventing damage to the image carrier and improving the quality of the formed image. An image forming apparatus that can prevent image quality deterioration can be provided.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram showing one embodiment of an image forming apparatus according to the present invention, FIGS. 2 and 3 respectively show the configuration of the image forming apparatus, and FIG. 2 is an external perspective view, and FIG. Figure 3 is a side sectional view, Figure 4 is a plan view showing the configuration of the operation panel,
Figure 5 is a side view schematically showing the configuration of the drive system;
The figure is a configuration diagram showing the driving means of the developing device. 1...Copying machine main body, 121.122...Developer, 3
0...Operation panel, 51.52.63.81...Motor, 100...Control unit. Applicant's agent Patent attorney Takehiko Suzue Figure 1

Claims (2)

[Claims] (1) an image carrier on which an image corresponding to the original image is formed; a developing means for developing the image formed on the image carrier;
a driving means for moving the developing means toward and away from the image carrier;
An image forming apparatus comprising: a control means for driving the driving means to bring the developing means into contact with the image carrier during development, and for separating the developing means from the image carrier after completion of development. (2) The scope of the claim characterized in that the image carrier is provided with a plurality of developing means, and the developing means are selectively operated with respect to the image carrier by the driving means according to the control of the control means. The image forming apparatus according to item 1.