JPS63210984A - Image forming device - Google Patents

Abstract

PURPOSE:To decrease the inertial force to be applied to a driving means and to permit sure control of the backward rotating quantity of an image carrier by providing an unidirectional driving power transmission means which can rotate only the image carrier backward when a driving beam is rotated backward. CONSTITUTION:Driving power of a motor 52 is transmitted via a gear 53 and a belt 54 to a gear 55. The undirectional driving power transmission means (one-way clutch) OW is coaxially provided to the gear 55. The one-way clutch OW is so constituted that the clutch is rotated together with the gear 55 in the same direction when the motor 52 is rotated forward and that the clutch is not rotated when the motor 52 is rotated backward. Since only the image carrier is rotated backward when the motor is rotated backward and therefore, the inertial force to be exerted on the driving means is decreased and the sure control of the backward rotating quantity of the image carrier is permitted.

Description

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

(Prior Art) As is well known, in electronic copying machines, after development and transfer are completed, developer remaining on the photosensitive drum is scraped off by a cleaning blade. This blade is brought into contact with the surface of the photoreceptor drum at the beginning of the copying operation, and separated from the photoreceptor drum when the copying operation is completed.

Incidentally, even when the refresh copying operation is completed and the blade is separated from the photoreceptor drum, the photoreceptor drum does not stop instantaneously and rotates somewhat due to inertia. For this reason, the developer remaining on the photosensitive drum may pass through the position where the blade comes into contact during the next copying operation. Since this residual developer is not cleaned by the blade, it appears as so-called black streaks during the next copying operation, causing deterioration in the quality of the copied image.

Therefore, in order to prevent this, after the copying operation is completed and the cleaning blade is separated from the photoreceptor drum, the photoreceptor drum is reversely rotated by a predetermined angle, and the blade is brought into contact with the drum when the next copy is made. By placing the developer in front of the residual developer, the developer can be reliably cleaned.

However, in conventional electronic copying machines, the motor that drives the photoreceptor drum simultaneously drives the developing roller of the developing device, the fixing roller, etc., so the inertial force is large and the amount of reverse rotation of the photoreceptor drum cannot be accurately controlled. It was difficult to do.

(Problems to be Solved by the Invention) This invention solves the problem that it is difficult to control the amount of reverse rotation of the image bearing member because each part of the image forming apparatus is simultaneously driven by the motor that drives the image bearing member. The object of this invention is to provide an image forming apparatus that can reliably control the amount of reverse rotation of an image carrier.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a driving means capable of simultaneously driving at least an image bearing member, a developing means, and a tube means, and a drive means capable of simultaneously driving at least an image bearing member, a developing means, and a tube means, and when the driving means is reversely rotated. The image bearing member is configured with a one-way power transmission means capable of reversely rotating only the image carrier.

(Function) This invention is capable of simultaneously driving the image carrier etc. by the driving means during image construction, and when the driving means is reversely rotated after the image forming operation is completed, the image bearing member etc. is driven by the unidirectional power transmission means. Since only the body is reversely rotated, the inertial force applied to the drive means is reduced, making it possible to reliably control the amount of reverse rotation of the image carrier.

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

4 and 5 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. The document table 2 is provided with an identification 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 document table 2 is moved by an optical system consisting of an exposure lamp 4 and a mirror 5, 6, 7 along the lower surface of the document table 2 in the direction of arrow a. Exposure scanning is performed during reciprocation. In this case, mirror 6.7 moves at the speed of mirror 5, 172, so as to maintain the light 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. .92.9s and guided to the photoreceptor drum 10, so that an image of the document is formed on the surface of the photoreceptor 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 developed by a developer "a1" which contains, for example, red or black toner, and which is selectively operated as required.
21 and 122, a toner is attached to the image to make it visible.

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

On the other hand, the paper (transfer material) is delivered from the selected upper paper feed cassette 131 or lower paper feed cassette 132 to the feed roller 14. ．． 142 and a pair of rollers 151 and 152, the sheet is taken out one by one, guided through a paper guide path 161 and 162 to a pair of registration rollers 17, and guided to a transfer section by this 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 switch 601.6o2 is 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 151 by the roller pair 151, and is then conveyed in the same manner as sheets 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 band Ti 518. The transferred paper P is electrostatically peeled off from the photoreceptor drum 10 by the action of a peeling charger 19 and conveyed by a conveyor belt 20, and then transferred to a fixing roller 21 as a fixing device provided at the end of the conveyor belt 20. The transferred image is fixed by passing through this area. After the paper has been set, it is discharged to a tray 25 outside the main body 1 by a pair of delivery rollers 22. Further, the photosensitive drum 10 after the transfer is removed by a cleaning blade 26 of the cleaner 26.
The residual toner on the surface is removed by step a, and the residual image is erased by the static elimination lamp 27, thereby returning to the 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 mirror 5 are provided in the first carriage 41, and the mirror 6.7 is provided in the second carriage 412.

Further, the first carriage 411 is provided with a spot light source 131 that can be moved in a direction perpendicular to the moving direction of the first carriage 411.

Further, between the charging charger 11 of the photoreceptor drum 10 and the exposure section ph, an erasing array 15 in which a plurality of light emitting elements are arranged along the longitudinal direction of the photoreceptor drum 10 is provided.
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. 6 shows an operation panel 30 provided on the main body 1 of the central copying machine. 30a is a trap copying key that commands the start of true 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 the 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 operated when another person makes another copy while copying. 30g is the same magnification key to set the copy magnification to 100%, 30h is the magnification key used to set the copy magnification, 30i is the upper and lower paper feed cassettes 131 and 132. A cassette selection key 30j is operated when making a selection, a color change key 30j is operated when copying with a different toner color, and 30 is operated, for example, the edit key 30n. When an erasing range etc. is specified, a mode memory key 301 is operated to store the specified erasing range etc. in the memory or to read out information such as the erasing range etc. stored in the memory in advance, and 301 is information corresponding to each mode. This is an information key that is operated when you want to obtain a paper jam.For example, when this key is operated when a paper jam occurs, information for clearing the paper jam is displayed on a display 30o, which will be described later.

30m is a function check key, and by operating this function check key 30m, it is possible to display on the display 30o what kind of function is set. Reference numeral 30n denotes an editing key that is operated when performing partial deletion, multiple copying, double-sided copying, etc. in which a part of the original image is deleted and copied. 300 is a display device consisting of, for example, a liquid crystal dot matrix panel;
For example, the setting status of the copying machine is displayed in the form of characters at .degree., and when the various cows 30e, 30f, 30g to 30m are operated, the corresponding characters are displayed. Furthermore, if a paper jam occurs during a copying operation, for example, the display 30o displays the location of the paper jam and countermeasures for the jam using text and graphics. Operation keys 301 to 304 and 305 to 308 for selecting various functions displayed on the display 30o are arranged on both sides of the display 30o. Moreover, 30p is the spot light source 13 mentioned above.
This movement key 30p can be tilted in all directions as shown by arrows 30q to 30t, and when these arrows 30q to 30t are operated, the spot light source 131 moves in the same direction. It is supposed to be done. 30u is a position designation key for inputting the coordinate position indicated by the spot light source 131.

1 and 2 schematically show a drive system of a copying machine. The motor 51 drives the first carriage 411 and the second carriage 412. motor 52
The cooling fan 29 is directly connected to the cooling fan 29 . The power of this motor 52 is transmitted to the gear 5 through a gear 53 and a belt 54.
5. This gear 55 is coaxially provided with a gear 56 and a one-way power transmission means (hereinafter referred to as a one-way clutch) 0W. This one-way clutch OW
is rotated in the same direction together with the gear 55 when the motor 52 is rotated in the forward direction (direction of arrow F in the figure), and -
When the motor 52 is rotated in the opposite direction (direction of arrow R in the figure), it is prevented from rotating. A photosensitive drum driving gear 57 is meshed with a gear 56 provided on the gear 55 . This gear 57 has a gear 58 coaxially connected thereto.
A gear 59 is meshed with the gear 58. A gear 60 is provided coaxially with the gear 59, and a timing belt 62 is stretched between the gear 60 and a gear 61 provided on the photosensitive drum 10.

On the other hand, a double-toothed timing belt 63 is applied to the gear of the one-way clutch 56, and a developing unit driving wheel 64 is driven by this timing belt 63. A gear 65 is provided coaxially with this gear 64.

This gear 65 is currently @! It drives the developing rollers 66 and 67 of the developing devices 121 and 122, and when the developing device 122 is selected, the gear 6 provided on the developing roller 67
8 and the developing device 121 is selected,
A gear 71 is provided on the developing roller 66 via an idle gear 69 and a gear 7o provided coaxially with this gear 69.
It is now connected to.

Further, the motor 52 drives the registration roller pair 17, the conveyance belt 20, the fixing roller pair 21, and the delivery roller pair 22. That is, the timing belt 63 includes:
Gear 73 is meshed with gear 73 and gear 74.7.
The registration roller pair 17 is driven sequentially through 5, 76, and 77.

Further, a gear 78 is meshed with the timing belt 63, and the conveyor belt 2o is driven sequentially through this gear 78 and gears 79.8, 181, and 82. Furthermore, the pair of fixing rollers 21 is driven via gears 83 and 84 which are sequentially meshed with the gear 81, and the gear 8 which is sequentially meshed with the gear 84.
The pair of delivery rollers 22 is driven via the rollers 5, 86, and 87.

FIG. 3 shows the main parts of the control circuit. Control unit 10
0 controls the operation of the entire photocopier, and this control unit 100 includes the aforementioned operation panel 30, a solenoid 26b1 that drives the cleaning blade 26a, a static elimination lamp 27, and a lamp regulator that controls the lighting of the exposure lamp 4. 101, the switch 60. ．． A switch sensor 102 consisting of a switch sensor 602, etc., and a motor drive circuit 103 for driving and controlling the motors 51, 52, etc. are connected.

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

When the copy key 30 is operated, the solenoid 26b is energized and the cleaning blade 26a is brought into contact with the surface of the photoreceptor drum. In this state, the motor 51 is rotated in a predetermined direction, and the motor 52 is rotated in the forward direction (direction of arrow F shown in FIG. 1) to rotate the photosensitive drum 10. and the selected developing device 121 or 122, registration roller pair 17, conveyor belt 20. Fixing roller pair 2
1. The paper ejection roller pair 22 is rotated. At the same time, the static elimination lamp 27, the exposure lamp 4, various chargers, etc. are operated as appropriate to perform the copying operation.

On the other hand, when the copying operation is completed, the motor 52 is stopped, the solenoid 26b is deenergized, and the cleaning blade 26a is separated from the surface of the photoreceptor drum 10. Thereafter, the motor 52 is rotated in the opposite direction (in the direction of arrow R shown in FIG. 1).

At this time, the timing belt 63 is not operated due to the action of the one-way clutch OW, so the registration roller pair 17 and the like are not operated, and only the photosensitive drum 10 is rotated in the reverse direction. Then, while the photosensitive drum 10 is rotated in the opposite direction by a predetermined rotation angle, the motor 52 is stopped and placed in a standby state.

According to the above embodiment, the photosensitive drum 10 is driven by the motor 52, and the power of the motor 52 is transmitted to the developing device 121, 122, the pair of fixing rollers 21, etc. via the one-way clutch OW, and all of these components are used during copying. The motor 5
2, and when the copying operation is completed, the motor 52 is reversely rotated to reversely rotate only the photoreceptor drum 10 to control the stop position of the photoreceptor drum. Therefore, when the photoreceptor drum 10 is rotated in the reverse direction, only the photoreceptor drum 10 is operated by the action of the one-way clutch OW, so the inertial force applied to the motor 52 is smaller than in the past, and the operation of the motor 52 is controlled. can be easily carried out.

Therefore, it is possible to reliably remove the developer remaining on the photoreceptor drum 10, and it is possible to prevent image quality deterioration of the copied image due to the residual developer.

Note that this invention is not limited to the above embodiments,
Of course, various modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As described in detail in L1 below, according to the present invention, during image formation, the image carrier etc. are simultaneously driven by the driving means, and when the driving means is reversely rotated after the image forming operation is completed, Since only the image carrier is reversely rotated by the one-way power transmission means, the inertial force applied to the drive means is reduced, and an image forming apparatus that can reliably control the amount of reverse rotation of the image carrier can be provided.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the present invention, and Fig. 2 is a side view schematically showing the drive system, Fig. 2 is a schematic diagram showing only the drive system shown in Fig. 1, and Fig. 3 is a control system. 4 and 5 respectively show the configuration of the image forming apparatus, FIG. 4 is an external perspective view, and FIG. 5 is a side sectional view.
FIG. 6 is a plan view showing the configuration of the operation panel. 1... Film copying machine body, 121.122... Developing device, 2
6...Cleaner, 26a...Cleaning blade, 30...Operation panel, 51.52...Motor, 1
00...Control unit, 103...Motor drive unit, OW・
...One-way clutch.

Claims (1)

[Claims] In an image forming apparatus that has a driving means capable of simultaneously driving at least an image bearing member, a developing means, and a fixing means, and rotates the image bearing member in reverse after the image forming operation is completed, when the driving means is reversely rotated, the An image forming apparatus comprising a one-way power transmission means that allows only the image carrier to rotate in reverse.