JPH0391790A - Image forming device - Google Patents

Abstract

PURPOSE:To resuse toner by providing a pattern toner cleaning means which eliminates the toner on a pattern on the photosensitive body between a developing process and a transfer process. CONSTITUTION:The device is constituted by installing the pattern toner cleaning means 10 between the developing means 4 and the transfer means 6. Before the formation of an electrostatic latent image of an original, a latent image of the pattern A is formed on the surface of the photosensitive body 9 by an exposure means 2. The toner 20 by which the pattern A has been visualized is eliminated from the photosensitive body 9 by the pattern toner cleaning means 10 before the formation of the original image. The toner 20 recovered by the pattern toner cleaning means 10 can be reused as developing toner for the original image since three is no deterioration in its characteristic or mixture of impurities such as paper, etc.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an image forming apparatus such as a copying machine.

(Conventional Technique 11r) Conventionally, a latent image pattern or a developed image pattern is formed on a photoconductor through an image forming process such as charging, exposure, development, transfer, and cleaning, and the latent image potential or developed image pattern of this pattern is The image density is detected, and this detection result (detection level) is fed back to each means of the above-mentioned image forming process, and the charging potential, writing light amount, development bias, toner supply, transfer potential, etc. are controlled to ensure proper copying. Various image forming apparatuses configured to obtain images or print images have been proposed.

(Problem to be Solved by the Invention) As described above, in an image forming apparatus that forms a pattern on a photoconductor, toner is delivered to this pattern area, so the amount of toner that is produced by forming this pattern is Toner consumption will increase. Further, this pattern is generally formed in a non-image forming area of the photoreceptor. Therefore, the toner consumed by this pattern is collected as is by a cleaning device located downstream of the transfer device.

Therefore, in this type of image forming apparatus, if a pattern is formed for each image forming process and the original image is corrected in real time, the toner collection tank of the cleaning means becomes unnecessarily full, and the developing means The frequency of replacing waste toner tanks and toner replenishment cartridges is significantly increased. For this reason, this type of image forming apparatus generally
The pattern forming process is executed every time the image forming process is executed a predetermined number of times, and patterns are formed at regular intervals. However, when patterns are formed at regular intervals in this way, it does not have much effect on non-immediate controls such as toner replenishment, but it does not affect immediacy controls such as charging potential and writing light amount. Control that requires this has the disadvantage that the changes during correction become large and the image correction accuracy during image formation deteriorates. In this way, in conventional image forming apparatuses, if a pattern is formed every time one image is formed, it is possible to improve the image correction accuracy during image formation, but on the other hand, wasteful consumption of toner increases. If a pattern is formed using
Although this method can reduce wasteful toner consumption, it also has contradictory drawbacks, such as deteriorating the accuracy of image correction during image formation. On the other hand, in order to eliminate wasteful consumption of toner as described above, the toner collected by the cleaning means is returned to the toner replenishing section of the developing means, and the toner consumed during pattern formation is reused. There are also known image forming devices. However, the toner collected by this cleaning means contains impurities such as paper dust from the transfer paper, and its characteristics have been changed by the transfer and separation charger, so when this toner is reused, There is a problem that causes image deterioration and deterioration of development characteristics. Therefore, in reality, it is extremely difficult to suppress toner consumption due to patterns using such a method.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides charging, exposure,
Through image forming processes such as development, transfer, and cleaning, a latent image pattern or developed image pattern is formed on the photoconductor, and the latent image potential or developed image density of this pattern is detected, and this detection result is used for the above-mentioned image forming process. In an image forming apparatus configured to feed back to each means of the image process to obtain a proper image, the toner on the pattern is removed from the photoreceptor between the means of the development process and the transfer process. The structure is equipped with a pattern toner cleaning means. (Function) According to the present invention, a pattern donor cleaning means for removing toner on the pattern from the photoreceptor is installed between each means of the development process and the transfer process, so that The toner is collected at a site prior to performing the transfer process. (Example) Hereinafter, an example of the present invention will be explained in detail with reference to the drawings. The present invention comprises a charging means 1, an exposing means 2, a latent image potential detecting means 3, a developing means 4, a developed density detecting means 5, a transferring means 6, a separating means 7, and a cleaning means 8, as shown in FIG. The image forming apparatus is configured such that various well-known image forming means for executing the image forming process consisting of the following are arranged around the photoreceptor 9. Here, the charging means, the transfer means 6, and the separation means 7 are composed of scorotron chargers. Further, the latent image potential detection means 3 includes a surface potential sensor that measures the surface potential of the photoreceptor 9. Furthermore, the developing means 4
It consists of a toner replenishment tank 41, a toner replenishment roller 42, a developing sleeve 43, a stirring roller 44, and the like. Further, the developed image density detection means 5 is constituted by a reflective photo sensor that measures the amount of reflected light from the photoreceptor 9. Further, the cleaning means 8 includes a cleaning blade 81, a cleaning roller 82, a housing 83, and the like.

In the image forming apparatus according to the present invention, a pattern toner cleaning means 10 is provided between the above-mentioned developing means 4 and transfer means 6.
It can be configured by setting up. The image forming process in this image forming apparatus is executed as follows. That is, in FIG. 1, first, by the charging means 1,
The surface of the photoreceptor 9 is charged. Next, prior to forming an electrostatic latent image on the original, the exposure means 2 forms a latent image of the pattern A described above on the surface of the photoreceptor 9. This pattern A can be formed by writing a pre-formed pattern copy on the contact glass surface on which the original is placed on the photoreceptor 9 using an optical system consisting of mirrors, lenses, etc. Any method may be used, such as directly writing the pattern A onto the photoreceptor 9 using a laser beam.

In addition, if this pattern A is a non-image area of the photoreceptor 9, the image of the side edge of the photoreceptor 9 as shown in FIG. 2 or the center portion of the photoreceptor 9 as shown in FIG. It may be applied to any part between areas B.

Next, the surface potential of the photoreceptor 9 at the portion where the pattern A is formed is measured by the latent image potential detection means 3.

Then, this pattern A is visualized as a toner image by the developing means 4, and then by the developed density detecting means 5.
Its concentration is measured.

As a result, the detection result (detection level) of the latent image potential or developed image density of this pattern A is fed back to each means of the image forming process, and the charging potential, writing light amount, developing bias, toner replenishment, and transfer of each process are fed back. The electric potential and the like are controlled, and the image forming conditions of the original are set in advance so as to obtain an appropriate copy image or print image.

In this way, when the conditions for each image forming means are set,
An original image is formed on the photoreceptor 9 based on a well-known image forming process, and this original image is transferred to a transfer paper (not shown) by the transfer means 6. At this time, the toner remaining on the photoreceptor 9 without being transferred to the transfer paper is removed by the cleaning means 8.
It is removed from the photoreceptor 9 by. On the other hand, the transfer paper is separated from the photoreceptor 9 by the separating means 7, fixed by a fixing means (not shown), and discharged from the apparatus. Incidentally, the toner 20 that has visualized the pattern A is removed from the photoreceptor 9 by the pattern toner cleaning means 10 prior to forming the above-mentioned original image. In the image forming apparatus of this embodiment, as shown in FIG. 2, a pattern A is constantly formed outside the image area B of the photoreceptor 9, and the toner 20 of this pattern A is constantly cleaned by the pattern toner cleaning means 10. It is configured as follows. Therefore, this image forming apparatus constantly detects the pattern A using the latent image potential detecting means 3 or the developed image density detecting means 5, thereby determining the charging potential, writing light amount, developing bias, toner replenishment, etc. of each process.
It is possible to correct and control the transfer potential, etc. in real time, and the image forming conditions of the original can be set so as to always obtain an appropriate copy image or print image.

Here, as shown in FIG.
When applying a method of forming pattern A in the center between the two, it is necessary to control the timing of pattern toner cleaning means 10 so as to remove only the toner 20 of pattern A. For example, when the pattern toner cleaning means 10 is controlled so that the toner 20 is removed by the blade 11 that is in pressure contact with the photoreceptor 9 as in the present embodiment, the blade 11 is moved against the photoreceptor 9. What is necessary is just to control it so that it approaches and separates from it. This type of pattern toner cleaning means 10 is suitable for correcting original images every t sheets. Of course, this method can also be applied to the case where document images are corrected every several sheets.

Further, since the pattern toner cleaning means 10 only needs to remove the toner 20 of pattern A, it can be constructed in a very small size. Therefore, since the pattern cleaning means 10 occupies a small space, it does not adversely affect other image forming means when installed. Furthermore, in this embodiment, since the developed image density detection means 5 is constituted by a reflection type photo sensor that measures the amount of reflected light from the photoreceptor 9, the toner 2 of pattern A is
is irradiated with light by the light source (LED) of the developed image density detection means 5. Therefore, the potential of the photoreceptor 9 at the portion of pattern A is rapidly lowered at the upstream portion of the patterned toner cleaning means 10, and the electrostatic attraction force of the toner 20 to the photoreceptor 9 is significantly weakened.

As a result, the cleaning effect of the pattern toner cleaning means 1O of this embodiment is greatly enhanced.
Moreover, the toner recovery rate is also greatly increased.

Therefore, this pattern toner cleaning means 10 is as follows:
Even if a brush, roller, or the like is used instead of the blade 11, the toner 20 can be collected very efficiently.

Further, since the pattern toner cleaning means 10 is installed upstream of the transfer means 6, the pattern toner cleaning means 10 is
Pattern A before being affected by corona discharge or transfer paper.
of toner 20 can be collected.

Therefore, the toner 20 collected by the pattern toner cleaning means 1O is free from deterioration of its characteristics and is not contaminated with impurities such as paper dust, so it can be reused as a developing toner for JV draft images.

Therefore, in this embodiment, a toner conveying means 30 is installed to return the toner 20 collected by the pattern toner cleaning means 1o into the toner supply tank 41 of the developing means 4.

As shown in FIG. 1, the toner conveying means 30 includes a toner conveying pipe 31 that communicates the housing 12 of the pattern toner cleaning means 10 and the housing 45 of the toner replenishing tank 41, and a toner conveying pipe 31 that conveys toner within the toner conveying pipe 31. The toner transport coil 32 is rotatably disposed along the path.

Therefore, as shown in FIG. 1, the toner 20 collected by the pattern toner cleaning means 10 is transported along the toner transport path in the toner transport pipe 31 by the rotation of the pattern toner collection square rod 13 and the toner transport coil 32. The toner replenishing tank 4 of the developing means 4
1 and reused as developing toner.

Here, the toner conveying means 30 may be constructed separately from the housing 12 of the pattern toner cleaning means 10 and the housing 45 of the toner supply tank 41, but by integrally constructing each of these means, , each joint can be simplified.

Further, here, the housing 46 of the developing means 4, the latent image potential detecting means 3, and the pattern toner cleaning means 1 are shown.
By integrally constructing the housing 12 and the image density detecting means 5, it is possible to suppress variations in the positional relationship between the respective detecting means 3 and 5, thereby improving their detection stability. I can do it.

(Effects of the Invention) According to the present invention, the toner of a pattern can be recovered without toner deterioration or contamination with impurities, so that the toner can be reused. This makes it possible to prevent image deterioration and development characteristic deterioration when this toner is reused.

In addition, since the remaining toner on the photoreceptor after the transfer process is only for the original image, even if a pattern is formed each time an image is formed and image correction is performed in real time, toner is wasted. can be suppressed.

Therefore, by carrying out the present invention, it is possible to reduce the frequency of replacing the waste toner tank and toner replenishment cartridge of the developing means.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of the present interrogation example, FIG. 2 is a schematic diagram showing the shape of the pattern in the above example, and FIG. 3 is a schematic diagram showing other formation parts of the pattern. . DESCRIPTION OF SYMBOLS 1... Charging means, 2... Exposure means, 3... Latent image potential detection means, 4... Development means, 5... Developed density detection means, 6... Transfer means, 7. ...Separation means, 8...
Cleaning means, 9... Photoreceptor, 10... Pattern toner cleaning means, 11... Blade, 20
...Pattern toner, A...Pattern, B...
image area. %1 Figure%2 Prisoner

Claims (1)

[Scope of Claims] 1. A latent image pattern or a developed image pattern is formed on the photoreceptor by an image forming process such as charging, exposure, development, transfer, and cleaning, and the potential of the latent image or the developed image of this pattern is In an image forming apparatus configured to detect image density and feed back the detection result to each means of the image forming process to obtain an appropriate image, between each means of the developing process and the transfer process, An image forming apparatus further comprising a pattern toner cleaning means for removing toner on the pattern from the photoreceptor. 2. The image forming apparatus according to item 1, wherein the toner removed by the pattern toner cleaning means is returned to the developing means that executes the developing process. 3. The image forming apparatus according to item 1, characterized in that, before the process of the patterned toner cleaning means, a photostatic discharge process of irradiating the pattern with light is executed.