JPH01167879A - Cleaning device for photosensitive body - Google Patents

Abstract

PURPOSE:To form an image with high quality extending over a long period of time by setting a load of a cleaning blade so as to go to the minimum value required for eliminating a toner on a photosensitive body in accordance with the environmental temperature. CONSTITUTION:Immediately before a transferred residual toner reaches an opposed position of a cleaning blade 2 of a cleaning device 11, a cam 30 is turned and by energizing force of a spring 24, the blade 2 is pressed against a photosensitive body 1. In such a case, by a temperature detecting sensor, an environmental temperature is converted to an electric signal and by a microcomputer, a turning angle of a cam 32 is calculated, and a prescribed load is applied to the blade 2. This load goes to the minimum value required in an environmental temperature at that time. In such a way, when a temperature is low, and when it is high, a small blade load, and a large blade load are applied, respectively, therefore, an image having a high quality can be obtained extending over a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cleaning device for a photoconductor of an electrophotographic apparatus, and more particularly to a photoconductor cleaning device of a type in which a cleaning blade is brought into pressure contact with a rotating photoconductor.

[Prior Art] Image forming apparatuses such as transfer-type electrophotographic copying machines generally use a rotating drum-type image bearing member, that is, a photoreceptor, having a photoconductive photosensitive layer on the outer surface. An electrostatic latent film is formed on the photosensitive layer and developed with toner, and the resulting toner image is transferred to recording paper. After the transfer is completed, residual toner on the outer peripheral surface of the photoreceptor is peeled off and cleaned by a cleaning device, an electrostatic latent image is formed again, and a new image is transferred. It is well known that in general image forming apparatuses, the residual toner is removed by pressure contact with a blade member which has a simple structure and has a high cleaning effect.

In the conventional blade pressure welding method, the blade load is set, for example, as shown in FIG. 4, the holding member 3 that holds the cleaning blade 2 is integrated with the lever 5, is pivoted to the lever 4, is biased by the spring 6, and the cleaning blade is 2 to the photoreceptor 1, and as shown in FIG. 2 to the photoconductor 1, or by holding a holding member that holds the cleaning blade in a fixed position so that the cleaning blade is pressed against the photoconductor by the elasticity of the cleaning blade. In all of these cases, the load on the cleaning blade is set to be constant.

[Problems to be Solved by the Invention] In the cleaning blade load setting method described above, the blade load value required at the environmental temperature at which the cleaning performance deteriorates the most is selected as the multiple value. However, the required blade load value changes as the environmental temperature changes, and the above-mentioned cleaning blade load value is generally excessive as a load value under normal use.

Applying an excessive load to the cleaning blade during normal use will accelerate wear and damage to the blade edge and deteriorate its durability. Furthermore, if the load on the cleaning blade is increased and a blade pressure release mechanism is used, uneven rotation of the drum will occur, which may cause misalignment during latent image formation, toner image formation, transfer, etc. (The larger the set load on the blade, the greater the uneven rotation of the drum when crimping and releasing pressure. The disadvantage is that no conditions are set, which increases the frequency of parts replacement.

The present invention has been made to solve the above problems,
It is an object of the present invention to provide a photoconductor cleaning device in an electrophotographic apparatus, which has a long life for a cleaning blade and a photoconductor, and does not cause image distortion due to uneven rotation of the photoconductor.

Means for Solving Problem E] In order to achieve the above object, the apparatus of the present invention is a photoreceptor cleaning apparatus having a cleaning blade formed in a drum shape and pressed against the circular surface of a rotating photoreceptor, in which the environmental temperature is lowered. It is characterized in that the load of the Kooning blade is set according to.

In order to determine the load value of the cleaning blade, the ring IN temperature is converted into an electrical signal by a temperature detection sensor,
Based on that signal, the plow microcomputer determines the operation of the blade load control mechanism and the optimum blade load value is applied.

[Function] The blade load value required to clean the toner on the photoreceptor of an electrophotographic copying machine is determined by the environmental temperature.
When the environmental temperature is low, the blade load value may also be small.

In the present invention, the blade load value is determined based on the environmental temperature information, so a blade load value that is unnecessarily excessive is not used.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the main parts of a color copying machine to which the present invention is applied, and FIG. 2 is an enlarged sectional view showing the drive section of the cleaning device in FIG. 1.

In the figure, reference numeral 1 denotes a photoreceptor made of an organic optical semiconductor (OPC) laminated on a cylindrical conductive drum, which forms a color toner image while rotating in the direction of the arrow shown in the figure. The surface of the photoreceptor 1 is uniformly charged by a charger 8, and laser exposure 9 is irradiated to form a charged latent image corresponding to a toner image of each color, and the toner of that color is transferred to a developing device 12 (13, 14). )
attached by. The charging exposure and development described above is repeated once for each color, thus three times for three colors. The above laser exposure is main scanned in the direction perpendicular to the paper surface and combined with sub-scanning by the rotation of the drum to form charged latent images corresponding to yellow, magenta, and cyan images on the surface of the photoreceptor. The image information is provided by a conventionally known color separation image reading device and image processing device. In this way, a color toner image is formed on the photoreceptor 1. To explain the time course, during the first rotation of the photoreceptor 1, a charged latent image corresponding to the yellow toner created by the laser exposure 9 is removed. 〇-,'-rt7 image mounting @
The developing row 512 is
' to form a yellow toner image on the surface of the photoreceptor 1. During the second rotation of the photoreceptor 1, magenta toner is similarly applied to the surface of the photoreceptor 10 by the magenta toner I/O roller 13- of the magenta toner I& device 13. Further, during the third rotation of the photoreceptor, cyan toner is adhered by the developing roller 14- of the cyan toner developing device 14.

The color image thus formed on the surface of the photoreceptor is transferred by a transfer device 16 onto recording paper fed from a paper feeder 15. The transferred recording paper is sent to a rear chamber 18 where it is separated by a separator 17, and the three-color images are fixed on the recording paper. Since the three-color images are combined on the photoreceptor 1 and transferred onto the recording paper at once, a good image quality without color shift can be obtained. In the above process, the photoreceptor first passes through the cleaning device 11 while carrying a yellow toner image, and then passes through the cleaning device 11 while carrying yellow toner and magenta toner images. In this way, when an untransferred image passes, the cleaning device 11 is deactivated, and the cleaning device 11 is activated at other times. The cleaning device will be explained below with reference to FIGS. 2 and 3. FIG. 2 is a sectional view of a cleaning device showing an embodiment of the present invention. A cleaning blade 2 constituting the main cleaning means is held by a holding member 3, and the holding member 3 is also fixed to a lever 5. Lever 5 is shaft 4
It is pivoted to and is urged by a spring 24 to rotate counterclockwise at all times. The cam 30 disposed on the left side of the lever 5 is for releasing the operation of the cleaning device, and is rotated around a shaft 31. When the lever 5 is pushed, the lever 5 is rotated clockwise around the shaft 4. Remove the cleaning blade 2 from the photoreceptor 1 by 1!1it. The cam 32 is rotated around a shaft 33, and by changing the rotation angle of the shaft 33, the lever 5 can be rotated counterclockwise by different rotation angles to apply an arbitrary load to the cleaning blade 2.

The rotation angle of the cam 32 will be described later.

The toner receiver 25 is arranged with a gab of about 0.2 to 0.3M between the toner collecting row and the photoreceptor 1, which is a component of the toner receiver, and is rotated in the direction of the arrow. Approximately 500 V is applied. 26 is a toner guide that transports the toner from above the toner collection roller 3 to the casing 2.
Lead to the lower groove of No.8. 27 is rotated by a screw so that a spiral blade sends toner into a toner reservoir.

Next, to explain the operation of the cleaning device, as mentioned above, when the untransferred toner passes, the cleaning device does not operate, so the cam 30 pushes the lever 5, and the cleaning blade 2 is moved to a position away from the photoreceptor 1. is held in Immediately before the residual toner on the transfer device reaches the position facing the cleaning blade 2 of the cleaning device, the cam 30 is rotated to the position shown in FIG. Ru. At this time, a load determined by the environmental temperature information is applied to the cleaning blade 2.

That is, as shown in FIG.
The environmental temperature is converted into an electrical signal, and based on the electrical signal, the plow control computer 51 calculates the rotation angle of the cam 32 and drives the pulse motor drive device 52 and the pulse motor 5.
3 to rotate the cam 32.

In this way, the load on the cleaning blade is the minimum value required at the current environmental temperature. This state is maintained throughout the passage of the imaged portion. In this way, the residual toner is peeled off from the surface of the photoreceptor by the cleaning blade 2 and guided into the lower groove of the casing along the path shown by the arrow. That is, the toner collection roller 2
5 has a voltage of opposite polarity applied to it, so it attracts toner and does not create a crowd of people below. Toner collection roller 25
The upper toner is sent onto the toner guide 26 as the toner collection roller rotates.

In this way, when the environmental temperature is low, a small blade load is applied, and conversely, when the environmental temperature is high, a large blade load is applied.

[Effects of the Invention] As explained above, in the cleaning device of the present invention, the 'R weight of the cleaning blade is set to the minimum value necessary to remove the toner on the photoreceptor according to the environmental temperature. Therefore, the load on the cleaning blade during normal use is reduced. Therefore, there is less wear on the cleaning blade and the photoreceptor, and their lifespan is extended.

Further, in the type in which the cleaning blade is brought into and out of pressure contact with the photoreceptor, uneven rotation of the photoreceptor due to contact and release of pressure contact is reduced, and the problem of image distortion due to uneven rotation of the photoreceptor is improved.

In this manner, the present invention provides a cleaning device that can produce high-quality images over a long period of time using the conventional blade cleaning method that is simple, highly stable, and has good cleaning efficiency.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main parts of a color copying machine to which the present invention is applied, FIG. 2 is an enlarged sectional view showing the cleaning device 11 in FIG. 1 excluding the drive section, and FIG. Book diagrams of the blade load operating mechanism, Figures 4 and 5
The figure is a sectional view showing a conventional cleaning device U. 1... Photoreceptor, 2... Cleaning blade, 3...
...Holding member, 4...Shaft, 5...Lever, 6...
Spring, 7... Weight, 8... Charger, 9... Laser exposure, 11... Cleaning device, 12... Developing device, 15... Paper feeding device, 16... Transfer Vessel, 17...
・Separator, 18... Fixing device, 24... Spring, 25.
... Toner collection roller, 26 ... Toner guide, 27
...Screw, 28...Casing, 30.32
,...Cam, 31.33,...Axis, 50...Temperature detection sensor, 51...Microcomputer, 52
... Pulse motor drive device, 53... Pulse motor. Applicant's agent Hiroshi Fujimoto Mitsugei 1 Sona 2 Mego 3 Figure 4 - Verse 5 Figure

Claims (1)

[Claims] A photoconductor cleaning device having a cleaning blade formed in the shape of a drum and pressed against the peripheral surface of a rotating photoconductor, characterized in that the load of the cleaning blade is set according to environmental temperature.