JPH0644180B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the Invention (Field of Industrial Application) The present invention relates to an image forming apparatus utilizing an electrostatic transfer process such as an electrophotographic copying machine and a printer.

(Problems to be solved with the related art) After the transferable toner image formed on the surface of a running image carrier is transferred to a transfer material, an image of repeating the process of cleaning the toner remaining on the surface of the image carrier without contributing to the transfer Forming devices are well known in the art.

In this type of image forming apparatus, in order to remove residual toner, a cleaning blade made of an elastic material such as urethane has a simple structure, is small in size, and is advantageous in terms of cost. ing.

This type of cleaning blade is made slightly wider than the width of the image area on the surface of the image carrier running with a constant width, that is, the developer supply area where the developer is developed by the developing device, and during machining, It is usual that the cleaning blade is constructed so as to surely cover the width of the image area of the image carrier by easily responding to an error in assembling.

As is well known, in a cleaning means using a cleaning blade, many of them make the edge of the blade press-contact with the surface of the running image carrier from a direction that opposes that direction. However, it causes a large friction with the image carrier. However, since a small amount of residual toner is present in the image area on the surface of the image carrier as described above, the cleaning blade originally has an effect of scraping off this toner, but on the contrary, The existence acts as a lubricant at the contact portion between the surface of the image carrier and the blade edge, and the two maintain the desired relative positional relationship to perform the toner removing action.

However, as described above, the length of the cleaning blade is always larger than the width of the image carrier (the length as viewed in the length direction of the blade), and the portions near both ends thereof are outside the image area. However, this portion is always in pressure contact with the surface of the image bearing member where there is no toner, and the friction between the two becomes great, which acts as a brake on the running image bearing member and prevents its running. There is a possibility that the parts may be stabilized, vibrated, or turned over to adversely affect the portion where the original cleaning action should be performed.

The present invention has been made to cope with such a situation as described above, and an appropriate lubricant is supplied to a non-image area (non-developer supply area) on the surface of a running image carrier, particularly near both ends. It is an object of the present invention to provide a cleaning device which avoids the above-mentioned drawbacks and can obtain a stable cleaning action for a long period of time.

(2) Structure of the Invention (Technical Means for Solving Problems and Actions Thereof) In order to achieve the above object, in the present invention, an image carrier and an image carrier by supplying a developer to the image carrier. Image having means for forming a developer image on the body, and a cleaning blade for contacting the image carrier over a region wider than the developer supply region in the longitudinal direction of the image carrier to remove the developer from the image carrier The forming apparatus has a lubricant container and an application roller for applying the lubricant of the container to the image carrier, and the application roller is a region where the developer is not supplied by the developing means in the longitudinal direction of the image carrier. It is characterized in that the cleaning blade is brought into contact only with the vicinity of both ends of the contact area, and is rotated by rotation of the image carrier.

According to this structure, the cleaning blade is pressed against the surface of the image bearing member and is pressed against the image bearing member through some lubricating substance over the entire length, so that vibration is generated due to excessive friction. It is possible to avoid inconveniences such as curling up and local abrasion of the image bearing member, and obtain a stable cleaning action.

(Description of Embodiments) Embodiments in which the present invention is applied to a copying machine will be described below with reference to the accompanying drawings.

FIG. 4 is a side view schematically showing an image carrier (photoreceptor) 1 formed in a cylindrical shape that rotates in the direction of arrow A and a part of the image forming means arranged in the periphery thereof.

Around the photoconductor, of course, a charger for charging the surface photoconductive layer, an exposure section for forming an electrostatic latent image on the charger,
Although a developing device or the like for giving toner to the latent image to visualize the latent image is arranged, these are not directly related to the present invention, and therefore the description thereof will be omitted.

The toner image formed by a developing device (not shown) is the photosensitive member 1.
Along with the rotation of, a transfer portion equipped with the transfer charger 5a is reached.

On the other hand, a transfer material (not shown) separately conveyed from the passage 4 approaches the photoconductor, approaches the toner image on the photoconductor at the transfer portion, and the toner image is transferred by the action of the charger 5a. . After that, the transfer material is separated from the photoconductor by the action of the separation charger 5b, and reaches the next fixing portion (not shown) by the conveying means 6.

The residual toner remaining on the surface of the photoconductor without contributing to the transfer at the transfer portion reaches the cleaning device 2 as the photoconductor rotates, and is scraped off and cleaned by the cleaning blade 3 attached thereto. The photoconductive surface again reaches the above-mentioned position of the charger and the process is repeated in the same manner as above.

In the case of such a constitution, as described above, the edge of the cleaning blade which is in pressure contact with the surface of the photosensitive member 1 is wider than the width of the image forming area on the surface (developer supply in the longitudinal direction of the image carrier). It is in contact with the image carrier over a wider area than the area). That is, as partially shown in FIG. 2, a non-image area on both sides of the image area (developer supply area) D on the surface of the cylindrical photoreceptor 1 (only one of which is shown in the drawing). (Non-developer supply area) ND exists, and the edge of the cleaning blade extends to the non-image area on such a surface as indicated by a dotted line E in FIG.

In such a case, in the present embodiment, the lubricant applying device 7 is provided near the boundary line between the image area D and the non-image area ND in the vicinity of the non-image area. Photoreceptor 1 not shown
Needless to say, a similar device may be arranged at the opposite end of the.

The lubricant applying device 7 has a container 7b and a roller 7a rotatably arranged on the container 7b and made of an appropriate material such as rubber, felt or metal. A liquid or viscous lubricant 8 such as silicon oil, molybdenum disulfide and general-purpose machine oil is stored in the container, and a part of the roller 7a is immersed therein.

The roller 7a is in contact with the photoconductor in the non-image area of the photoconductor, as can be seen from FIGS. 1 and 2, and its length is preferably determined so as to reach both ends of the cleaning blade.

With this structure, the roller 7a also rotates with the rotation of the photoconductor 1, and the lubricant in the container adheres to the roller and further adheres to the surface of the photoconductor. Therefore, the contact edge E of the cleaning blade, especially the part of the contact edge E that comes into pressure contact with the non-image area of the photoconductor, is also rubbed under pressure in the presence of the lubricant, so that it is possible to prevent the occurrence of vibration and curling.

According to the experiment, when the cleaning blade made of urethane rubber was pressed against the photoconductor having the organic semiconductor, the friction coefficient of the non-image area was about 2.0 without the lubricant. When the above silicone oil was used, the friction coefficient remained at 0.4 or less, and the above-mentioned inconvenience did not occur.

Reference numeral 7C in FIG. 1 is a scraper for controlling the lubricant, which is controlled by the type of the lubricant and the pressure contact force of the roller 7a to the photoconductor 1 so that the lubricant does not enter the image area. The position shall be set appropriately.

The above is a description of the case where the present invention is applied to a copying machine.
It will be easily understood that the present invention can be applied to other image forming apparatuses, and the image carrier can be applied to other than the cylindrical shape, such as an endless belt shape.

(3) Effect of the invention Since the present invention has the above-described configuration, the cleaning blade is pressed against the image carrier through some lubricating substance over its entire length, so that the cleaning blade is turned over due to excessive friction. The generation prevention function can be maintained for a long period of time until the lubricant in the lubricant storage container is used up, and it contributes to the formation of a high-quality image over a long period of time.

[Brief description of drawings]

FIG. 1 is a side view of the essential parts of an embodiment in which the present invention is applied to a copying machine, FIG. 2 is a perspective view of the essential parts of the same, and FIG. 3 is an explanatory view showing the operation of the cleaning device of the copying machine. 1 ... Photoconductor, 2 ... Cleaning device, 3 ... Cleaning blade, 7 ... Lubricant supply device, 8, 9 ... Lubricant.

Claims (1)

[Claims] 1. An image carrier, a developing means for supplying a developer to the image carrier to form a developer image on the image carrier, and an area wider than a developer supplying area in a longitudinal direction of the image carrier. In an image forming apparatus having a cleaning blade that contacts the image carrier and removes the developer from the image carrier, a lubricant container and a coating roller that coats the lubricant of the container on the image carrier are provided. Then, the coating roller is contacted only in the longitudinal direction of the image bearing member where the developer is not supplied by the developing means and in the vicinity of both ends of the cleaning blade contacting region, and the image bearing member is rotated. An image forming apparatus characterized in that it is driven to rotate together with it.