JPH02158755A - Electrophotographic process cartridge - Google Patents

Abstract

PURPOSE:To make the cartridge common among different electrophotographic devices and to accomplish the reduction of a production cost and the simplification of management and circulation by providing plural image exposing positions and selecting the image exposing position according to the mounted electrophotographic copying device. CONSTITUTION:The cartridge is constituted by housing a photosensitive drum 3, a developing device 4, a primary electrostatically charger 5 and a cleaner device 6 in an external frame 2 and provides plural image exposing positions P and Q so as to select it according to the mounted electrophotographic copying device. Namely, when it is mounted in an image forming device main body, shutters 7a-7c and a drum shutter 8 are opened and the photosensitive drum 3 is irradiated with image exposure La and Lb from image exposing slits S1 and S2, then the positions of the image exposure La and Lb are changed in the devices having different processing speeds. Thus, the cartridge is made common among the different electrophotographic copying devices, and the reduction of the production cost and the simplification of the management and the circulation are accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrophotographic process cartridge used in an electrophotographic apparatus such as an electrophotographic printer or an electrostatic printer.

(Prior Art) With the recent progress in office automation, there is an increasing need for small and lightweight image forming apparatuses that can be used by individuals. For this reason, in small image forming apparatuses, for the purpose of serviceability, the central part of the single-stroke forming process is unitized as an electrophotographic process cartridge, and this electrophotographic process cartridge is installed and removed from the main body of the image forming apparatus. For example, as shown in FIG. 8, it has been proposed that a photosensitive drum 3 as an image carrier, a cleaner device 6. An electrophotographic process cartridge 1, which is configured by housing a developing device 4, a primary charger 5, and a transfer charger 9 in one frame 2, is attached to and removed from the main body of the image forming apparatus in the direction of the arrow shown in the figure. Furthermore, frame body 2
On the top surface, there is an image exposure slit Sl and a pre-exposure slit S:l.
are formed parallel to the axis of the photoreceptor tram 3.

(Problem to be Solved by the Invention) However, in the past, electrophotographic process cartridges were not compatible between models of electrophotographic devices, so if a user purchased a cartridge by mistake, he or she would be unable to use it. there were.

On the other hand, for manufacturers, manufacturing process cartridges for different models with different process speeds increases the number of parts, increases manufacturing costs, complicates management, and creates multiple distribution routes.

Additionally, technically speaking, in order to use the same cartridge in multiple different models, the layout of the optical system and drive system of the main body of the device must be the same, which limits the degree of freedom in configuring the main body. was there.

Furthermore, as shown in FIG. 9, it takes a certain amount of time for the potential of the photoreceptor drum in the process cartridge to decay after exposure. When irradiated, there is a problem that in devices with high process speeds, the image becomes pale due to insufficient light attenuation.

The present invention has been made in view of the above problems, and its purpose is to simplify the manufacturing cost, management, and distribution of electrophotographic devices by allowing them to be shared among different electrophotographic devices. To provide electrophotographic process cartridges.

Another object of the present invention is to provide an electrophotographic process cartridge that allows various photoreceptors to be used in the same electrophotographic apparatus.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a plurality of light positions in an electrophotographic process cartridge, and sets the image exposure position to the electrophotographic process cartridge installed in the electrophotographic process cartridge. It is characterized by being selectable depending on the device.

Further, the present invention is characterized in that means is provided for causing the electrophotographic apparatus to select the image exposure position in accordance with the light attenuation speed of the photosensitive drum of the electrophotographic process cartridge.

(Function) According to the present invention, it is possible to use a common electrophotographic process cartridge in different electrophotographic apparatuses.

As a result, even if a user mistakenly purchases a cartridge, it will not be impossible to use it, and the manufacturer can also reduce manufacturing costs and simplify management and distribution.

Further, according to the present invention, since the image exposure position can be selected according to the light attenuation speed of the photoreceptor, various photoreceptors can be used in the same electrophotographic apparatus.

(Example) Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a longitudinal sectional view of an electrophotographic process cartridge according to the present invention, FIG. 2 is a longitudinal sectional view showing the electrophotographic process cartridge in a state when it is attached to the main body,
b) is a diagram showing an example of use of the process cartridge, and FIG. 4 is a diagram showing the light attenuation characteristics of the photoreceptor.

The functions of the electrophotographic process cartridge (hereinafter simply referred to as cartridge) will be explained based on FIG.
The cartridge 1 is constructed by housing a photosensitive drum 3, a developing device 4, a primary charger 5, and a cleaner device 6 in an outer frame 2. Further, on the upper surface of the outer frame 2, an image exposure slit Sr,
St and pre-exposure slit S3 are formed, and when the cartridge L is taken out from the main body of the image forming apparatus (not shown) and stored, these slits S□ and S2°83 are closed to the shutter 7a as shown in FIG.

7b and 7c, respectively. Further, a drum shutter 8 having an arcuate cross section is provided below the photosensitive drum 3, and when the cartridge l is removed from the main body of the apparatus and stored, the drum shutter 8 is opened as shown in FIG. As shown, it is closed to protect the photosensitive drum 3. Incidentally, there is toner t in the developing device 4.
is accommodated, and a developing sleeve 4 is located near the photoreceptor drum 3.
A is placed.

When the cartridge L configured as described above is loaded into the main body of the image forming apparatus, the shutters 7a, 7b, 7c and the drum shutter 8 are opened, and the image exposures La and Lb are exposed, as shown in FIG. The light is irradiated onto the photosensitive drum 3 from the slits S1 and S2. Note that in Figure 2, 9 is a transfer charger provided on the main body side of the apparatus.

In such a cartridge 1, one image formation is performed through the following process.

That is, first, the photoreceptor tram 3 is uniformly and uniformly charged by the primary charging member 5, and then image exposure La or Lb is irradiated onto the photoreceptor drum 3 through the slit S1 or S. An electrostatic latent image is formed on the photoreceptor drum 3. This electrostatic latent image is visualized as a toner image in the developing device 4, and the toner image is transferred by pressing a transfer paper (not shown) against the toner image and applying corona discharge by the transfer charger 9. transferred onto paper.

Thereafter, this toner image is fixed onto the transfer paper by a fixing device (not shown) provided on the main body side of the apparatus, and the transfer paper on which the toner image has been fixed is discharged to the outside of the machine by a discharging means (not shown).

On the other hand, the toner T and paper powder remaining on the photoreceptor drum 3 are removed by the cleaner 6, and the uneven potential remaining on the photoreceptor drum 3 is removed from the photoreceptor drum 3 through the slit S3. It is attenuated by the overlying pre-exposure.

The above is a series of image forming processes, and this series of image forming processes is repeated in the image forming apparatus.

In the above configuration, the cartridge 1 is two electrophotographic devices! ! It can be used for AB. Also, outfit! t
The process speed of A is 47 mm/see, that of WB is 94 mm/sec, and the photoreceptor drum 3 has a diameter of 3.
0 mm and has the optical attenuation characteristics shown in FIG. 4 for one hour.

In the case of the photoreceptor tram 3, it takes 200 m5ec from image exposure to development.
It is sufficient to perform image exposure Lb at a position Q upstream of the position R facing the developing sleeve 4a (see Fig. 2) by sec = 9.4 mm, and for apparatus B, 94 mm/5e
Image exposure La may be performed at a position P upstream by cxO, 2 sec = 18.8 mm.

As described above, since the positions of the image exposure La and Lb are changed in the apparatuses A and H having different process speeds,
Appropriate latent image potential can be obtained, a decrease in image density can be prevented, and the cartridge l can be used with the device! It can be shared by A and B.

Another advantage is that the position of the optical system (laser optical system in the illustrated example) can be easily changed depending on the design of the apparatus, as shown in FIGS. 3(a) and 3(b). That is, in FIG. 3, 1
Reference numeral 1 denotes an interface controller which processes an input image signal and sends a signal to the laser drive circuit 12 to cause the laser 13 to emit light. Then, the laser drive circuit 12 changes the current flowing through the laser 13 in response to this signal, causing it to blink. The light emitted from the laser 13 is directed to the polygon mirror 1 by the collimator lens 14.
After the light is focused on the photoreceptor drum 3, the fθ lens 16 corrects the scanning speed difference between the center and the end of the photoreceptor tram 3, and the light is reflected by a mirror 17 to scan the photoreceptor drum 3.

In FIGS. 3(a) and 3(b), depending on the arrangement of the optical system, the slits s,,S! , S:l, a convenient one is selected. When the cartridge L is attached to the main body of the apparatus, it is better to open the unused slits (slits Ss and Ss in Fig. 3(a), and slits S1 and S3 in Fig. 3(b)). is 0. around the primary charger 5. This is to prevent o3 and NOx from accumulating, and since this o3 and NOx cause deterioration of the photoconductor tram 3, it is recommended to open the slit in this way to ventilate the inside of the cartridge l with fresh air. desirable.

Incidentally, in the above embodiment, two slits for image exposure were provided, but it goes without saying that three or more slits may be provided. or,
Even one slit is sufficient as long as it has a sufficient width and the image exposure position can be changed.

However, in this case, it is necessary that the outer frame of the cartridge has sufficient strength.

In the above embodiment, the cartridge can be shared by changing the image exposure position for devices with different process speeds, but conversely, various photoreceptor drums can be used in one type of electrophotographic device. It is also available for use.

For example, assume that there is a photosensitive drum having light attenuation characteristics represented by curves T and S in FIG.

Then, at the development position, the potential of the exposed part of the photoreceptor is 1
If 50V is sufficient, in a photoreceptor drum having characteristic S, it will take 25V to reach the developing position.
Image exposure may be applied as early as 0 m5ec, and for a photoreceptor drum with characteristic T, image exposure may be applied as early as 100 m5ec. If a time of 100 m5 ec or more elapses after exposure, the potential drops to 150 V or less, and when toner is applied to the exposed area using the one-inversion developing force method, the toner image becomes thick and dark.

In this embodiment, the electrophotographic apparatus main body has a plurality of optical systems or is capable of changing the optical path using a mirror or the like. An example of this is shown in FIG. 5, or the electrophotographic apparatus shown in FIG. 5 has two optical systems x and Y.

In such an electrophotographic apparatus, when the photosensitive drum 3 has the light attenuation characteristic shown by the curve T in FIG.
The time between the image exposure process and the development process is shortened to prevent the photoreceptor potential from attenuating too much.

Therefore, the exposure optical system and image exposure position selection as described above were installed for each cartridge as shown in FIG. Frames 18a and 19a are microswitches 1 of the electrophotographic device
This is done by selecting and pressing 8b and 19b. In FIG. 6, 20.degree. 21 is a terminal for supplying voltage to the primary charger or developing device.

By adopting such a configuration, it becomes possible to use photoreceptor drums with different light attenuation characteristics.
The number of optical systems and slits may be arbitrary, and the number of frames and microswitches may be increased according to the number.

Further, another embodiment of the present invention is shown in FIG. 7, and this embodiment
The image exposure position is made variable by rotating the mirror 17 according to the light attenuation speed of the photosensitive tram 3. In this case, the distances P'V and Q'V connecting the point V on the mirror 17 and the image exposure points P', Q'' on the photoreceptor tram 3 are set equal to maintain the focal length. For a cartridge containing a photoreceptor tram 3 having the characteristics shown by the curve S in FIG. 4, the top 18a shown in FIG. If it is tilted as shown by the solid line in the figure, a point P' on the photoreceptor drum 3 will be image-exposed.

Further, for a cartridge containing a photoconductor tram 3 having the characteristics shown by the curve T in FIG. 4, the top 19a shown in FIG. If it is tilted as shown by the broken line in the figure, a point Q' on the photoreceptor drum 3 will be image-exposed.

For example, at a process speed of 47 mm/see, the diameter is 30 mm.
When the above method is applied to an electrophotographic apparatus using a photoreceptor drum of mm, the phenomenon position on the photoreceptor drum 3 is 47mm/5ecxO, 25mm=11.
It is sufficient to set the image exposure point P' 75 mm upstream, and
For a photoconductor having the characteristics shown by the curve T in FIG.
It is sufficient to set the image exposure point Q' upstream by 5ec
The relationship between R and the phenomenon position R is the same as that in the previous embodiment.

In this way, even for photosensitive drums having two characteristics, the potential at the phenomenon position R can be made the same by changing the image exposure position, and there is no difference in image density due to cartridge replacement.

(Effects of the Invention) As is clear from the above description, according to the present invention, the electrophotographic process cartridge is provided with a plurality of image exposure positions, and the image exposure positions are set according to the electrophotographic apparatus in which the electrophotographic process cartridge is installed. This makes it possible to standardize electrophotographic process cartridges between different electrophotographic devices, and as a result, users do not have to worry about not being able to use the cartridge even if they purchase it by mistake. This also has the effect of reducing manufacturing costs and simplifying management and distribution.

Further, according to the present invention, since the image exposure position can be selected according to the light attenuation speed of the photoreceptor, it is possible to use various photoreceptors in the same electrophotographic apparatus. It will be done.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an electrophotographic process cartridge according to the present invention, FIG. 2 is a longitudinal sectional view showing the state of the electrophotographic process cartridge when it is attached to the main body, and FIGS. 3(a) and (b)
) is a diagram showing an example of how a process cartridge is used, FIG. 4 is a diagram showing the light attenuation characteristics of a photoreceptor, FIG. 5 is a configuration diagram of an electrophotographic apparatus showing a modified embodiment of the present invention, and FIG. 6 is a diagram showing the same modification. Perspective view of the electrophotographic process cartridge according to the embodiment, No. 7
The figure is a configuration diagram of an electrophotographic apparatus showing another embodiment of the present invention.
FIG. 8 is a perspective view showing a conventional electrophotographic apparatus and an electrophotographic process cartridge, and FIG. 9 is a diagram showing the light attenuation characteristics of a photoreceptor. l... Electrophotographic process cartridge, 2... Outer frame (frame body), 3... Photosensitive drum, 4... Developer, 5
...Primary charger, 6...Cleaner device, S,,S,. S...slit. Figure 3 (b) Figure 4 → Gin) X4CmS) Figure S Figure 9 1 hour (ms)

Claims (3)

[Claims] (1) An electrophotographic process cartridge that is removably attached to the main body of an electrophotographic apparatus and that houses a photosensitive drum and other process equipment in a single frame, which has a plurality of image exposure positions and is installed. An electrophotographic process cartridge characterized in that an image exposure position can be selected depending on the electrophotographic apparatus used. (2) The electrophotographic process cartridge according to claim 1, wherein the frame has a plurality of image exposure slits. (3) In an electrophotographic process cartridge that is detachable from the main body of an electrophotographic apparatus and that houses a photoreceptor drum and other process equipment in a single frame, the cartridge corresponds to the light attenuation speed of the photoreceptor drum. 1. An electrophotographic process cartridge, comprising means for causing an electrophotographic apparatus to select an image exposure position.