JPH01179954A - Detector for photosensitive body fatigue - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Chiya Goko! The present invention relates to a photoreceptor fatigue detection device for electrophotographic image forming apparatuses such as copying machines and facsimile machines.

In conventional electrophotographic image forming apparatuses, the number of times an image is formed on the main body of the image forming apparatus equipped with a photoreceptor is counted, and when the count reaches a predetermined number, the photoreceptor is considered to have reached the end of its lifespan. It's like swapping bodies. However, in such conventional devices, when the photoreceptor is replaced, it is necessary to reset a counter that counts the number of image formations, and there is a problem in that the count reset mechanism complicates the device. Furthermore, there are many photoconductors whose fatigue levels are not known, and if a photoconductor with a certain fatigue level is used, the fatigue of the photoconductor may be uniformly set to a predetermined number of image formations. If a photoreceptor with an unknown degree of fatigue is mounted, a photoreceptor that is already tired may be used or a photoreceptor that is not yet fatigued may be replaced during a predetermined number of image formations.

Therefore, there is a problem that the life count number and the actual lifespan do not match, resulting in a degraded image or wasteful consumption of the photoreceptor.

As a method of grasping the degree of fatigue on each side of the photoconductor, there is a device that detects the charged potential when the photoconductor is charged and determines the life of the photoconductor based on that potential. The drawback is that the peripheral circuitry is complicated and the device is expensive. In addition, in such a device, even if a photoreceptor whose degree of fatigue is unknown is attached, the degree of fatigue is unknown unless it is charged, and the person who checks the degree of fatigue must always perform an action to place an electric potential on the photoreceptor. However, there are problems in that the work is troublesome and the detection lacks immediacy.

The present invention solves the above-mentioned conventional problems and provides a photoconductor fatigue detection device that allows fatigue of the photoconductor to be easily and reliably confirmed whether the photoconductor is alone or attached to an image forming apparatus. It is intended to.

(2) The present invention achieves the above-mentioned object by attaching a support means to a photoreceptor, incorporating an integrated current amount detection member into the support means, and grounding the base of the photoreceptor via the integrated current amount detection member. This is achieved by a photoreceptor fatigue detection device that indicates fatigue.

According to the present invention, the photoreceptor fatigue detection device can be incorporated into an image forming apparatus or used alone, and the amount of fatigue can be easily detected by simply mounting the photoreceptor on a support member. According to the present invention, a current is grounded by a voltage applied from a power source through the base of the photoreceptor and the amount of fatigue, and the amount of fatigue of the photoreceptor is detected from the amount of current applied at that time.

The support frame is formed of an insulating material that is resistant to the charging of the image forming device or the corona discharge of the transfer charger, but if the support frame itself can be supported in an insulating manner, the support frame itself can also be used as a support member, and the support frame itself can be used as a support member. Members can be omitted.

The structure and operation of the present invention will be explained in detail based on the embodiment shown in the drawings.

In FIG. 1, a photoreceptor 1 has a conductive substrate 1a and a photosensitive layer 1b formed on the surface of the substrate 1a.

The photoconductor fatigue detection device 2 includes an insulating support frame 3, a conductive support member 4 supported by the support frame 3, such as a bearing, and a fatigue amount 5 attached to the support frame 3. The amount of fatigue 5 is formed by a device capable of detecting the cumulative amount of energization, such as a cumulative energization time meter, and has a terminal 5a and a ground terminal 5b connected to the support member 4 directly or via a conductor 6.

A grounding piece 7 that is grounded via a conductive wire or directly in contact with the frame of the image forming apparatus is attached to the support frame 3, and a grounding terminal 5b having the fatigue amount 5 is connected to the grounding piece 7.

The support member 4 supports the base 1a of the photoreceptor 1 or the conductive shaft 8 formed on the base 1a. It is convenient that the support member 4 is configured to be able to rotatably support the photoreceptor 1, but depending on the application, it may also be configured to simply allow the base 1a to stand still.

A voltage from a voltage application power source 9 is applied to the photosensitive layer 1b of the photoreceptor 1 using a roller, a brush, or other appropriate means. As a result, the current from the voltage applying power source 9 is applied to the photosensitive layer 1.
b, the base 1a, the support member 4, the conductive wire 6, the terminal 5a, the fatigue amount 5, the ground terminal 5b, and the ground piece 7 to be grounded.

The fatigue of the photoreceptor 1 can be arbitrarily measured independently by the photoreceptor fatigue detection device 2 shown in FIG.

The support frame 3 is formed of an insulating material, but if it can be installed through an insulating material, it can be formed of a conductive material.

In this case, the support frame 3 itself may also be structured to serve as the support member 4, for example, a bearing.

When the photoreceptor fatigue detection device is incorporated into an image forming apparatus, such as an electrophotographic copying machine, it can be configured as shown in FIG. Since the configuration of the image forming apparatus is well known, only the names of the parts will be listed and detailed explanations of the functions will be omitted.

A charger 11 , an exposure position 25 for optical information, a developing device 12 , a transfer charger 13 , a cleaning device 14 , and a static eliminator 15 are arranged around the photoreceptor 1 .
2 includes a toner supply tank 16 and a developing roller 17,
The cleaning device 14 includes a cleaning blade 18, a waste toner tank 19, a cleaning seal 20, and a collection roller 21, the charger 11 includes a shield case lla and a charge wire llb, and the transfer charger 13 includes a shield case 13a and a charge wire. 1
3b.

The developing device 12 is supported by a developing unit frame 22,
The cleaning device 14 and the static eliminator 15 are supported by a cleaning unit frame 23. The developing unit frame 22 and the cleaning unit frame 23 are attached to the support shaft 2.
4 are pivotally connected to each other. Further, the developing unit frame 22 and the cleaning unit frame 23 are connected to the spring 2.
6, the developing roller 17 and the cleaning blade 18
are biased toward each other so as to be pressurized against the photoreceptor 1 when set against the photoreceptor 1.

The developing device 12 and the cleaning device 14 can be attached to and detached from the photoreceptor 1 as a unit, and the developing unit frame 22 and the cleaning unit frame 23 are opened around the support shaft 24 against the force of the spring 26 during attaching and detaching operations. Make it. When set, the photoreceptor 1 is sandwiched between the developing unit frame 22 and the cleaning unit frame 23 by the spring 26. This sets the positional relationship of the developing roller 17, cleaning blade 18, and cleaning seal 20 with respect to the photoreceptor 1 with respect to the photoreceptor 1.

A paper feeder 27, a lower registration roller 28, an upper registration roller 29, a lower registration guide 30a, and an upper registration guide 3 are used to supply copy paper for transfer to the photoreceptor 1.
0b, and a transfer paper conveyance guide 2 that conveys the copy paper after transfer.
5 is provided.

A predetermined distance between the transfer charger 13 and the photoreceptor 1 is maintained by the push-up force of the push-up spring 32 . In this case, when the support frame 3 that supports the photoreceptor is attached to the frame of the image forming apparatus, for example, the lower surface of the support frame 3 and the shield case 13a of the transfer charger 13 are in contact with each other, so that a predetermined distance is obtained. You can also.

The support frame 3 can function to position the photoreceptor 1 when attached to the device frame. When the support frame 3 is attached, the grounding piece 7 comes into contact with the resist upper guide 30b (for example, as shown in FIG. 1), so that the support frame 3 can be grounded.

The opposite end of the photoreceptor (not shown) is rotatably supported and driven by a gear train or the like.

In this case, the support structure may be similar to that of the support frame 3 and the support member 4. The support frame 3 holds the photoreceptor 1, the developing unit frame 22, and the cleaning sheet 23.
It is common to configure the device so that it remains fixed to the machine frame when it is removed.

In an image forming apparatus, generally, as shown in FIG. 3, a high voltage power source VC for corona discharge is connected to the charge wire llb of the electrification charger 11, a shield case lla is grounded, and a charge wire 1 of the transfer charger 13 is connected to the charge wire 1b of the charger 11.
3b is connected to a corona discharge voltage power source (2), and the shield case 13a is grounded. Further, a bias voltage RVB is connected to the developing roller 17. ■This high voltage power supply. , 7 and the bias power supply (2) can be used also as the voltage application power supply 9.

In the charger 11, the charging current IC is separated into a current ICZ flowing through the shield case lla and a current Ll flowing through the base 1a, which are joined by a common ground to form a circuit. Similarly, in the transfer charger 13, the current I is separated into a current IT2 flowing through the shield case 13a and a current ITI flowing through the base la of the photoreceptor, which are combined at a common ground to form a circuit. Due to the bias voltage of the developing roller 17, a current (2) flows through the photoreceptor base 1a due to toner charging. As a result, a current (2) flows through the base 1a of the photoreceptor.

becomes 10-[c++ Ir+-Is.

Generally, the current I3 is often within the error range, so it can be ignored.Also, electric charge is stored in the photosensitive member 11b by the charging charger 11 and the transfer charger 13;
This charge is moved by the optical information and the charge removal light from the charge removal device 15, and as a result, the area irradiated with light is electrically neutralized, and eventually becomes an initial neutralized state before being charged.
It can be considered that the fatigue caused by work on the photoreceptor 1 is mainly caused by charge transfer, and it can be determined that the fatigue of the photoreceptor 1 is accumulated depending on the amount of current when the surface of the photoreceptor is charged. Therefore, fatigue can be confirmed by setting up an integrated energization time meter based on Faraday's law as the fatigue meter 5, and displaying the movement of the electrolyte by the integrated energization, so-called electric quantity.

1 and 2 show an example in which the current passing through the base 1a of the photoreceptor 1 is taken out through the shaft 8, but the photoreceptor layer lb is not formed on the peripheral surface of the photoreceptor 1 other than the paper passing area. , substrate 1
a and use a conductive brush etc. to connect the terminal 5 of the fatigue meter 5.
A structure that connects to a can also be used. The terminal 5a of the fatigue meter 5 is connected by clipping the conductor 6 and the grounding piece 7.
The ground terminal 5b is inverted and removable so that it can be connected to the conductor 6 and the grounding piece 7, making reuse possible; however, the fatigue meter 5 cannot be removed in order to reliably indicate the photoconductor that has reached the end of its service life. Alternatively, the photoconductor fatigue detection device 2 may be replaced together with the photoconductor.

By considering the inclined position of the scale plate 5c of the fatigue meter 5, the scale can be observed from the top surface of FIG. become.

The image forming apparatus main body 50 is attached to the upper structure 5 as shown in FIG.
1 is configured to be vertically tiltable with respect to the lower structure 52, the developing unit frame 22 and the cleaning unit 23
is pivotally connected to the upper structure 51 by the support shaft 24, and the upper structure 51
Developing unit frame 2 is opened by tilting upward.
2 and the cleaning unit frame 23 can be configured to be separated from the photoreceptor 1. Naturally, both unit frames 22 and 23 are not limited to being supported by the upper structure 51. In such an image forming apparatus main body 50, if an observation window 53 for the scale 5a of the fatigue meter 5 is provided at the front, the unit frames 22 and 23 can be always viewed from the front. The degree of fatigue of the photoreceptor can be monitored. Furthermore, when the upper structure 51 is flipped upward and opened, monitoring can also be performed from above.

In order to enable monitoring from both directions, the scale plate 5c is arranged at an angle, but if a reflective mirror or the like is used, the direction in which the scale plate 5c is arranged is not limited, and the monitoring direction can also be vertical or horizontal. It becomes possible to monitor at any location and in any direction without being limited to the following. It is also possible to open the upper structure 51 and observe the fatigue meter from any direction while the developing unit frame 22 and cleaning unit frame 23 are assembled to the lower structure 52.

The movement of the electrolyte in the fatigue meter 5 is detected by a sensor such as a CCD,
By electrically processing this, various controls are possible.For example, if the amount of electrolyte movement is approaching the end of its lifespan, the operation display section of the image forming apparatus will indicate that the lifespan of the photoconductor is approaching its end. Other designs can be made as necessary, such as displaying a message indicating that the photoconductor cannot be copied and prompting the photoconductor to be replaced when the photoconductor reaches the end of its service life, or displaying this when the photoconductor is not securely installed. becomes.

1) According to the present invention, fatigue of the photoreceptor can be easily confirmed whether the photoreceptor is alone or incorporated into an image forming apparatus. In addition, the rotating photoconductor can be checked with a simple structure, and there is no need for a complicated structure. This also makes it easier to adjust the relative positions of each member.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a photoconductor fatigue detection device according to the present invention, and FIG. 2 is a partial sectional view showing the relationship between the photoconductor fatigue detection device and various parts of an image forming apparatus when incorporated into an image detection device. FIG. 3 is a schematic diagram showing the relationship between the photoreceptor and various power sources, and FIG. 4 is a schematic front view of an example of the main body of the image forming apparatus. l...Photoconductor 1a...Base 1b...Photosensitive N 2...Photoconductor fatigue detection device 3
...Support frame 4...Support member 5...Fatigue meter
5a...Terminal 5b...Grounding terminal 9...Voltage application power supply (other 1
Figure 3

Claims (1)

[Claims] A photoconductor fatigue detection device that includes a support means attached to a photoconductor, a cumulative current amount detection member is incorporated into the support device, and a base of the photoconductor is grounded via the cumulative current amount detection member to indicate photoconductor fatigue. .