JP2021009269A - Image forming apparatus and program - Google Patents

Abstract

To make it possible to accurately detect cleaning performance and prevent a reduction in productivity.SOLUTION: A control unit 10 causes a toner image forming unit to form a patch image on an image carrier, and determines the cleaning performance of a blade member by comparing a first deflection amount that is the amount of deflection of the blade member when the blade member is in contact with a position corresponding to the patch image on the image carrier, with a second deflection amount that is the amount of deflection of the blade member when the blade member is in contact with a position corresponding to the background part of the patch image on the image carrier.SELECTED DRAWING: Figure 2

Description

The present invention relates to an image forming apparatus and a program.

Generally, in the electrophotographic process, the toner remaining on the photoconductor after image formation is cleaned by a blade member, but when a cleaning failure occurs, a phenomenon called filming that causes toner adhesion on the photoconductor occurs and the output image is displayed. Problems that cause noise occur.
Since it is used in various modes, images, and environments in the market, cleaning defects may occur due to local wear, scratches, etc. even before the original life of the blade member.
If a quality problem occurs due to such poor cleaning, the serviceman will replace the unit as a subsequent measure, which will lead to a significant downtime if the time required for the serviceman to arrive is included, which will reduce productivity. The impact is extremely large.

Therefore, in the blade member, paying attention to the fact that cleaning failure occurs when the deformation of the edge portion in contact with the photoconductor becomes large, a strain sensor is provided on the blade member, and control is performed to stop the photoconductor based on the sensor value. A technique has been proposed (see, for example, Patent Document 1).

JP-A-2010-72552

However, Patent Document 1 detects a cleaning defect due to an increase in toner deposited on the blade member, and cannot deal with wear of the blade member.
In addition, the absolute value of the sensor value (strain amount) varies depending on the frictional force between the photoconductor and the blade member (photoreceptor surface roughness, lubricant amount in the case of a lubricant coating system, etc.), so cleaning is performed with just the strain amount. It is insufficient to detect defects.

An object of the present invention is to provide an image forming apparatus and a program capable of accurately detecting cleaning performance and suppressing a decrease in productivity.

In order to solve the above problems, the image forming apparatus of the present invention
A toner image forming portion that forms a toner image on the image carrier,
A blade member that comes into contact with the surface of the image carrier and removes deposits on the surface.
A patch image is formed on the image carrier by the toner image forming portion.
The blade member is located at a position corresponding to the background portion of the patch image on the image carrier and the first deflection amount which is the amount of deflection of the blade member when contacting the position corresponding to the patch image on the image carrier. A control unit that determines the cleaning performance of the blade member by comparing it with the second deflection amount, which is the amount of deflection of the blade member when the blade member comes into contact with the control unit.
It is characterized by having.

In addition, the program of the present invention
A toner image forming portion that forms a toner image on the image carrier,
A blade member that comes into contact with the surface of the image carrier and removes deposits on the surface.
The computer of the image forming apparatus equipped with
A patch image is formed on the image carrier by the toner image forming portion.
The blade member is located at a position corresponding to the background portion of the patch image on the image carrier and the first deflection amount which is the amount of deflection of the blade member when contacting the position corresponding to the patch image on the image carrier. This is a program that functions as a control unit for determining the cleaning performance of the blade member by comparing it with the second amount of deflection, which is the amount of deflection of the blade member when the blade member comes into contact with the blade member.

According to the present invention, the cleaning performance can be detected with high accuracy, and the decrease in productivity can be suppressed.

It is a figure which shows the schematic structure of the image forming apparatus. It is a block diagram which shows the main functional composition of an image forming apparatus. It is a figure which shows the schematic structure of the image forming part. (A) is an enlarged view showing a photoconductor and a blade member, and (b) is a plan view of the blade member of the first embodiment. It is a flowchart which shows the cleaning performance determination process of 1st Embodiment. It is a figure which shows an example of the image formed by the cleaning performance determination process. (A) is an example showing the strain amount data when the cleanability is OK, and (b) is an example showing the strain amount data when the cleanability is NG. It is a figure for demonstrating another structure of a blade member. It is a top view of the blade member of 2nd Embodiment. It is a flowchart which shows the cleaning performance determination process of 2nd Embodiment. It is a figure for demonstrating the cleaning performance determination process of FIG. It is a figure for demonstrating an Example. It is a figure for demonstrating an Example. It is a figure for demonstrating an Example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
[Configuration of image forming apparatus]
First, the configuration of the image forming apparatus 1 according to the present embodiment will be described.
The image forming apparatus 1 is an intermediate transfer type color image forming apparatus using electrophotographic process technology, and as shown in FIGS. 1 and 2, an automatic document conveying unit 2, a scanner unit 3, and an image forming unit 4 A paper feed unit 5, a storage unit 6, an operation display unit 7, a control unit 10, and the like are provided.

The automatic document transporting unit 2 includes a mounting tray on which the document D is placed, a mechanism for transporting the document D, a transport roller, and the like, and transports the document D to a predetermined transport path.
The scanner unit 3 is configured to include an optical system such as a light source and a reflector, irradiates a document D transported along a predetermined transport path or a document D placed on a platen glass with a light source, and receives reflected light. .. Further, the scanner unit 3 converts the received reflected light into an electric signal and outputs it to the control unit 10.

The image forming section 4 includes a yellow image forming section Y, a magenta image forming section M, a cyan image forming section C, a black image forming section K, an intermediate transfer belt T, and a fixing section F. ing.
Each image-forming unit YMCK forms yellow, magenta, cyan, and black toner images on the photoconductor 41, and primary transfers the toner images of each color of YMCK formed on the photoconductor 41 to the intermediate transfer belt T.

FIG. 3 is a diagram showing a schematic configuration of the image forming unit 4. Each image processing unit is composed of a drum-shaped photoconductor 41 (image carrier) that is rotationally driven in the A direction in the drawing, a charging device 42 that uniformly charges the surface of the photoconductor 41, and the charging device 42. An exposure device 43 that exposes the surface of a charged photoconductor 41 to form an electrostatic latent image, and an electrostatic latent image formed by the exposure device 43 are visualized using a developer containing toner. The developing device 44, the primary transfer roller 45 (transfer unit) that transfers the toner image formed on the photoconductor 41 to the intermediate transfer belt T, and the cleaning unit that removes the toner on the photoconductor 41 that has passed through the transfer region. The toner image formed on the photoconductor 41 is primarily transferred to the intermediate transfer belt T that moves in the B direction in the drawing. The toner image transferred to the intermediate transfer belt T is transferred to the paper P by the secondary transfer roller 46, then transferred to the fixing portion F and fixed on the paper P.
The charging device 42, the exposure device 43, the developing device 44, and the primary transfer roller 45 correspond to the toner image forming unit.
Since the configuration and operation of each image forming unit YMCK are the same, a series of image forming operations performed by the image forming unit 4 will be described below by taking the yellow image forming unit Y as an example.

The photoconductor 41 is composed of an organic photoconductor in which a photosensitive layer made of a resin containing an organic photoconductor is formed on an outer peripheral surface of a drum-shaped metal substrate, and is rotationally driven in the direction A in the drawing. Examples of the resin constituting the photosensitive layer include polycarbonate resin, silicone resin, polystyrene resin, acrylic resin, methacrylic resin, epoxy resin, polyurethane resin, vinyl chloride resin, melamine resin and the like.
The photoconductor 41 has an undercoat layer (UCL: Under Coat Layer), a charge generation layer (CGL: Charge Generation Layer), and a charge transport layer (CTL: Charge Transport Layer) on a conductive base tube such as an aluminum tube. It has a layered structure arranged in the order of.

The charging device 42 is, for example, a scorotron type, and uses a charging charger to charge the photoconductor 41 to a constant potential with a negative polarity.

The exposure apparatus 43 exposes the non-image region of the photoconductor 41 based on the image data Dy from the control unit 10 to remove the electric charge of the exposed portion, and forms an electrostatic latent image in the image region of the photoconductor 41. ..
Specifically, the surface of the photoconductor 41 charged negatively by the charging device 42 is removed by the exposure of the exposure device 43, and the charge generation material (CGM: Charge Generation Material) in the CGL is positive or negative. When both charges are generated, the positive charge (hole) passes through the CTL and reaches the surface of the photoconductor 41, and the negative charge passes through the UCL and reaches the substrate, so that an electrostatic latent image is formed on the surface of the photoconductor 41. Is formed.

The developing device 44 includes a developing sleeve 44a arranged so as to face the photoconductor 41 via a developing region. For example, a development bias in which an AC voltage is superimposed on a DC voltage having the same polarity as the charging polarity of the charging device 42, that is, a negative polarity is applied to the developing sleeve 44a, whereby the static electricity formed on the photoconductor 41 is applied. A developer is supplied on the latent image to form a yellow toner image on the photoconductor 41. The developer includes a toner and a carrier for charging the toner.
The toner is not particularly limited, and a commonly used known toner can be used. For example, a binder resin containing a colorant, a charge control agent, a mold release agent, or the like, if necessary, and treated with an external additive can be used. The toner particle size is not particularly limited, but is preferably about 3 to 15 μm.

The primary transfer roller 45 primary transfers the yellow toner image formed on the photoconductor 41 to the intermediate transfer belt T. Similarly, the other image-forming unit MCK also primary-transfers the magenta, cyan, and black toner images to the intermediate transfer belt T. As a result, toner images of each color of YMCK are formed on the intermediate transfer belt T.

The intermediate transfer belt T is a semi-conductive endless belt suspended on a plurality of rollers and rotatably supported, and is rotationally driven in the direction B in the drawing as the rollers rotate. The intermediate transfer belt T is pressure-bonded to the opposing photoconductors 41 by the primary transfer roller 45. A transfer current corresponding to the applied voltage flows through each of the primary transfer rollers 45. As a result, each toner image developed on the surface of each photoconductor 41 is sequentially transferred to the intermediate transfer belt T by each primary transfer roller 45.

The secondary transfer roller 46 is pressed by the intermediate transfer belt T and driven to rotate, so that the toner images of each color of YMCK formed by being transferred to the intermediate transfer belt T are transferred to the paper feed trays 51 to 53 of the paper feed unit 5. Secondary transfer is performed on the paper P transported from. Specifically, the secondary transfer roller 46 is arranged in contact with the secondary transfer opposed roller 461 via the intermediate transfer belt T, and is formed between the secondary transfer roller 46 and the secondary transfer opposed roller 461. When the paper P passes through the transfer nip, the toner image on the intermediate transfer belt T is secondarily transferred to the paper P.

The toner remaining on the photoconductor 41 without being transferred onto the intermediate transfer belt T in the transfer region is conveyed to the cleaning unit 47 and collected by the cleaning unit 47.
Further, the photoconductor 41 whose surface toner has been recovered by the cleaning unit 47 is charged again by the charging device 42, and the next electrostatic latent image is formed to repeat the formation of the toner image.

The cleaning unit 47 includes a blade member 47a, a recovery screw 47b provided substantially below the blade member 47a, and a coating roller 47c provided on the downstream side in the rotational direction of the photoconductor 41 with respect to the blade member 47a. A lubricant rod 47d for supplying a lubricant to the coating roller 47c, a pressing portion 47e for pressing and holding the lubricant rod 47d against the coating roller 47c, and a rotation direction of the photoconductor 41 with respect to the coating roller 47c. It is provided with an immobilization blade 47f provided on the downstream side of the above.

The blade member 47a is provided with, for example, an elastic body obtained by processing polyurethane rubber or the like into a flat plate shape, and is installed so that the tip thereof rubs against the photoconductor 41, and untransferred toner or the like remaining on the surface of the photoconductor 41 is used. It scrapes and removes deposits.
The external additive conveyed together with the toner constantly slips through the blade member 47a and the nip portion of the photoconductor 41, and a part of the slipped external additive is recovered by the coating roller 47c. The charging device 42 and the like may be contaminated by the external additive that has not been recovered.

The recovery screw 47b rotates in one direction, and conveys the toner scraped off by the blade member 47a and dropped to a waste toner box (not shown).

The coating roller 47c is a roll-shaped brush member arranged at a position where the tip portion thereof can come into contact with the photoconductor 41. Under the control of the control unit 10, the coating roller 47c performs counter rotation in which the surface advances in the direction opposite to the traveling direction of the surface of the photoconductor 41 at the contact point with the photoconductor 41, and the linear velocity is slower than that of the photoconductor 41. Rotate so that

The lubricant rod 47d is obtained by melt-shaping and solidifying a lubricant of a powder of a metal soap such as zinc stearate. The lubricant rod 47d is arranged at a position where the tip of the coating roller 47c can come into contact with the lubricant rod 47d, and is scraped off from the tip by the rotation of the coating roller 47c. The scraped lubricant is directly conveyed to the photoconductor 41 and supplied to the surface of the photoconductor 41.

The pressing portion 47e includes, for example, a compression spring that urges the lubricant rod 47d toward the coating roller 47c, and presses and holds the lubricant rod 47d against the coating roller 47c.

As the immobilized blade 47f, similarly to the blade member 47a, for example, an elastic body such as polyurethane rubber processed into a flat plate shape is used. Further, the immobilization blade 47f is installed so as to abut the surface of the photoconductor 41 in a dragging direction (trailing contact) and the tip thereof rubs against the photoconductor 41.
The immobilized blade 47f is for stretching the lubricant powder supplied to the surface of the photoconductor 41 and forming a film on the surface of the photoconductor 41 to form a film (lubricant layer). The lubricant layer formed of zinc stearate is characterized by high releasability (high pure water contact angle) and low friction coefficient, so that it has good transferability and cleanability, and the photoconductor 41 has good transferability. Wearing is also suppressed and the life can be extended.

The image forming unit 4 heats and pressurizes the paper P on which the toner images of each color of YMCK are secondarily transferred by the fixing unit F, and then passes it through a predetermined transport path and discharges it to the outside of the machine.
The above is a series of image forming operations by the image forming unit 4.

The paper feed unit 5 is configured to include a plurality of paper feed trays 51 to 53, and each of the paper feed trays 51 to 53 accommodates a plurality of different types of paper P. The paper feeding unit 5 feeds the paper P accommodated by the predetermined transport path to the image forming unit 4.

The storage unit 6 is composed of an HDD (Hard Disk Drive), a semiconductor memory, and the like, and stores data such as program data and various setting data in a readable and writable manner from the control unit 10.

The operation display unit 7 is composed of, for example, a liquid crystal display (LCD) with a touch panel, and functions as a display unit 71 and an operation unit 72.
The display unit 71 displays various operation screens, operation status of each function, and the like according to the display control signal input from the control unit 10. In addition, it accepts a touch operation by the user and outputs an operation signal to the control unit 10.
The operation unit 72 includes various operation keys such as a numeric keypad and a start key, receives various input operations by the user, and outputs an operation signal to the control unit 10. The user can operate the operation display unit 7 to perform image formation-related settings such as image quality setting, magnification setting, application setting, output setting, and paper setting, paper transport instruction, and stop operation of the device.

The control unit 10 is configured to include a CPU, RAM, ROM, etc., and the CPU expands various programs stored in the ROM into the RAM, and cooperates with the expanded various programs to perform the automatic document transfer unit 2, The operation of each part of the image forming apparatus 1 such as the scanner unit 3, the image forming unit 4, the feeding unit 5, the storage unit 6, the operation display unit 7, and the like is collectively controlled (see FIG. 2).

[Blade member]
Next, the blade member 47a will be described in detail.
FIG. 4A is an enlarged view showing the photoconductor 41 and the blade member 47a, and FIG. 4B is a plan view of the blade member 47a seen from the direction of the arrow in FIG. 4A.

As shown in FIG. 4A, the blade member 47a includes a plate-shaped elastic portion 47a1 formed of polyurethane rubber or the like and a holding portion 47a2 formed of sheet metal.
The tip portion (also referred to as an edge portion) of the elastic portion 47a1 is brought into contact (pressure contact) with the photoconductor 41, and the base end portion is adhesively held by the holding portion 47a2 in the state of a cantilever.

As shown in FIG. 4B, the elastic portion 47a1 is provided with a strain sensor 8 for measuring the degree of bending of the elastic portion 47a1. The strain sensor 8, also referred to as a strain gauge, is provided in a state of being in contact with or embedded in the elastic portion 47a1 by a method such as attaching to the elastic portion 47a1. The strain sensor 8 follows the bending shape of the elastic portion 47a1.

As shown in FIG. 4B, the strain sensor 8 is installed at the center of the blade member 47a in the longitudinal direction (X direction). Further, in the width direction (Y direction) orthogonal to the longitudinal direction of the blade member 47a, the elastic portion 47a1 is on the tip end side of the position (point P) where the elastic portion 47a1 starts protruding from the holding portion 47a2 and comes into contact with the photoconductor 41. It is installed in a position that does not.
The tip side of the elastic portion 47a1 from the protrusion start position (point P) may be expressed as a protrusion portion.

The blade member 47a rotates about the rotation fulcrum R, and the tip portion (point E) is pressed against the photoconductor 41 by the force of a spring (not shown), so that the blade member 47a remains on the photoconductor 41. It is a configuration that removes the toner. By pressure contacting with a spring, the elastic portion 47a1 has a bent shape starting from the protrusion start position (point P) which is the base portion with the holding portion 47a2.

Further, in the present embodiment, as shown in FIG. 4A, with respect to the line EP connecting the contact position (point E) of the elastic portion 47a1 with the photoconductor 41 and the protrusion start position (point P). The rotation fulcrum R is configured to exist on the photoconductor 41 side, and when the photoconductor 41 is driven, a frictional force is applied to the edge portion (point E) of the elastic portion 47a1 in the tangential direction. It is supposed to occur.
The amount of strain of the blade member 47a changes depending on the frictional force between the blade member 47a and the photoconductor 41, and the direction of the change differs depending on the contact method of the blade member 47a.
As shown in FIG. 4A, when the blade member 47a has a spring load and the rotation fulcrum R of the blade member 47a is close to the tangent line between the blade member 47a and the photoconductor 41 as in the present embodiment. As the frictional force increases, the holding portion 47a2 rotates from the solid line to the position of the alternate long and short dash line, and the amount of biting of the blade member 47a into the photoconductor 41 is reduced, so that the amount of distortion of the blade member 47a is reduced. ..

[Operation of image forming apparatus]
Next, the operation of the image forming apparatus 1 will be described.
The image forming apparatus 1 of the present embodiment detects the contact state of the blade member 47a with the photoconductor 41 from the strain amount data obtained from the strain sensor 8 provided on the blade member 47a, and determines the cleaning performance. Executes cleaning performance judgment processing.

FIG. 5 is a flowchart showing a cleaning performance determination process.
It should be noted that such processing is executed at a predetermined timing (for example, at the time of image stabilization operation for every 10K images in A4 horizontal conversion).

First, when the predetermined timing is reached, the control unit 10 starts recording the distortion amount data (step S11), then the image forming unit 4 forms a predetermined patch image G (step S12), and then the distortion amount. Data recording is stopped (step S13).
As the predetermined patch image G, for example, the horizontal band-shaped image shown in FIG. 6 is used.

Next, the control unit 10 distorts the amount of distortion at the timing when the transfer residual toner of the patch image reaches the blade member 47a (that is, the timing when the blade member 47a comes into contact with the position corresponding to the patch image G on the photoconductor 41). Data (hereinafter, distortion amount at the time of image: first deflection amount) and timing when the background portion of the patch image reaches the blade member 47a (that is, at a position corresponding to the background portion of the patch image G in the photoconductor 41). The strain amount data (hereinafter, the strain amount in the background: the second deflection amount) of the blade member 47a contacting timing is compared, and it is determined whether or not the strain amount in the background is larger than the strain amount in the image (hereinafter, the strain amount in the background). Step S14).

When the amount of distortion in the background is larger than the amount of distortion in the image (that is, the amount of distortion in the image <the amount of distortion in the background) (step S14: YES), the control unit 10 has good cleaning performance (OK). (Step S15), and this process is terminated.

On the other hand, when the amount of distortion in the background is less than or equal to the amount of distortion in the image (that is, the amount of distortion in the image ≥ the amount of distortion in the background) (step S14: NO), the control unit 10 has poor cleaning performance (NG). (Step S16), the user is notified by issuing an alarm, displaying a message, or the like (step S17), and this process ends.

Here, the grounds for determining the cleaning performance OK / NG will be described.
As described above, in the configuration in which the rotation fulcrum R of the blade member 47a is close to the tangent line between the blade member 47a and the photoconductor 41 as in the present embodiment, the blade member 47a with respect to the photoconductor 41 as the frictional force increases. The amount of bite is reduced, and the amount of strain of the blade member 47a is reduced.

When the toner reaches the blade member 47a, if the blade member 47a is blocking the toner (that is, if the cleaning performance is OK), the blade member 47a receives a force in a more drawn direction due to the sudden input of the toner. Therefore, the behavior of the blade member 47a changes in the same manner as when the frictional force increases.
On the other hand, when the reached toner slips through the blade member 47a (that is, when the cleaning performance is NG, or when the cleaning performance as a quality is OK but a slight slip-through occurs), the toner that slips through is a lubricant. The frictional force between the blade member 47a and the photoconductor 41 is reduced.

Therefore, when the cleaning performance is OK, the blade behavior is similar to the increase in frictional force at the time of image (toner rushes into the blade member 47a) as compared with the background (toner does not rush into the blade member 47a). It becomes.
Further, when the cleaning performance is NG, the blade behavior is reduced in frictional force at the time of image (toner rushes into the blade member 47a) as compared with the background (toner does not rush into the blade member 47a).

Therefore, in the case of the configuration in which the strain amount of the blade member 47a decreases due to the increase of the frictional force as in the present embodiment, if the cleaning performance is OK, the strain amount of the blade member 47a becomes "at the time of image <at the time of background". If the cleaning performance is NG, the amount of distortion of the blade member 47a is "at the time of image ≥ at the time of background".

FIG. 7A is an example showing the strain amount data obtained when the cleaning performance is OK.
In FIG. 7A, the amount of distortion of the blade member 47a decreases as the frictional force between the blade member 47a and the photoconductor 41 increases. Therefore, the photoconductor 41 is driven from a stop to a blade. The amount of strain of the member 47a is reduced.
Further, when the blade member 47a is in contact with the position corresponding to the patch image G of the photoconductor 41 (at the time of image), the toner that the blade member 47a reaches is blocked, so that the photoconductor is suddenly input by the toner. It behaves in the same manner as when the frictional force with 41 is increased, and the amount of strain is reduced.
Further, when the blade member 47a is in contact with the position corresponding to the background portion of the patch image G of the photoconductor 41 (at the time of the background), the toner that arrives is exhausted or becomes very small. The amount of distortion of the blade member 47a is larger than that at the time of the image, and is substantially the same as the amount of distortion at the time of the original driving.
As described above, the amount of distortion of the blade member 47a is <at the time of image <at the time of background.

FIG. 7B is an example showing the strain amount data obtained when the cleaning performance is NG.
In FIG. 7B, at the time of the image, the toner reaching the blade member 47a has slipped through the blade member 47a. Since the toner that passes through the blade member 47a functions as a lubricant between the blade member 47a and the photoconductor 41, the frictional force between the blade member 47a and the photoconductor 41 is reduced, whereby the amount of distortion of the blade member 47a is reduced. Is more than the original amount of distortion during driving.
Further, when the change from the image time to the background time, the amount of toner that arrives disappears or becomes very small, so that the amount of distortion of the blade member 47a decreases and becomes substantially the same as the original amount of distortion during driving. ..
As described above, the amount of distortion of the blade member 47a is ≧ background at the time of image.

As a configuration of the blade member 47a, for example, as shown in FIG. 8A, a line connecting the contact position (point E) of the elastic portion 47a1 with the photoconductor 41 and the protrusion start position (point P). The rotation fulcrum R may be present on the opposite side of the photoconductor 41 with respect to the EP.
In such a configuration, as shown in FIG. 8A, the holding portion 47a2 rotates from the solid line to the position of the alternate long and short dash line as the frictional force increases, and the biting amount of the blade member 47a increases. The amount of distortion of 47a increases.
Further, as shown in FIG. 8B, when the blade member 47a has a fixed load, the blade member 47a is in the contact state indicated by the alternate long and short dash line as the frictional force increases, and the biting amount of the blade member 47a is increased. As the number increases, the amount of strain of the blade member 47a increases.

In this way, in the case where the amount of distortion of the blade member 47a increases due to the increase in frictional force, if the cleaning performance is OK, the amount of distortion of the blade member 47a is "at the time of image> at the time of background", and the cleaning performance is NG. If there is, the amount of distortion of the blade member 47a is "at the time of image ≤ at the time of background". Therefore, in the cleaning performance determination process, the determinations in steps S15 and S16 may be changed according to the configuration.

[Effect of the embodiment]
As described above, according to the present embodiment, the control unit 10 of the image forming apparatus 1 forms the patch image G on the photoconductor 41 by the image forming unit 4, and corresponds to the patch image G in the photoconductor 41. The amount of strain when the blade member 47a comes into contact with the position (first amount of deflection) and the amount of strain when the blade member 47a comes into contact with the position corresponding to the background portion of the patch image G on the photoconductor 41 (the amount of second deflection). ) To determine the cleaning performance of the blade member 47a.
Specifically, the blade member 47a is installed so that the amount of strain decreases as the frictional force with the photoconductor 41 increases, and the control unit 10 has a case where the first amount of bending is smaller than the second amount of bending. , Judge that the cleaning performance is good.
Therefore, since the cleaning performance is determined by comparing the two values, it is possible to detect the cleaning performance with high accuracy, and it is possible to grasp the deterioration of the cleaning performance before the quality problem occurs. Therefore, the decrease in productivity can be suppressed.

Since the frictional force between the photoconductor 41 and the blade member 47a can be measured with respect to the photoconductor torque, the same relationship as described above can be seen, but it is affected by other elements, and is usually driven by the photoconductor. Since the torque is measured by detecting the current of the motor, the accuracy is low, and because it is an indirect detection of the blade state, the sensitivity is low, so it is difficult to detect minute slip-through, and cleaning before quality problems occur. It is very difficult to grasp the performance.
On the other hand, if the strain sensor 8 provided on the blade member 47a is used as in the present embodiment, the behavior of the blade member 47a can be directly detected, so that the sensitivity and accuracy are high and quality problems occur. It is possible to grasp the deterioration of cleaning performance before the occurrence of. Then, if a notification is given by an alarm or the like before the quality problem occurs, the service can be provided before the quality problem occurs, and the influence on the productivity can be suppressed.

In the above embodiment, the cleaning performance determination process is executed during the image stabilization operation, but a cleaning performance determination mode for executing the cleaning performance determination process may be separately provided.
When the cleaning performance judgment mode is provided, the image forming conditions are changed so that the load applied to the blade member 47a increases in the mode as compared with the image forming time based on the image forming job (normal image forming time). Is preferable.
For example, the image formation speed can be made faster than the set speed at the time of normal image formation.
Alternatively, the transfer conditions can be adjusted so that the amount of residual toner transferred increases as compared with the case of normal image formation.
Further, by separating the primary transfer rollers, the amount of residual transfer toner may be increased as compared with the case of normal image formation.
By doing so, the cleaning load increases as compared with the case of normal image formation, and the detection sensitivity of the cleaning performance can be further improved.

<Second Embodiment>
Next, the second embodiment of the present invention will be described focusing on the differences from the first embodiment. In the following description, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 9 is a plan view of the blade member 47a according to the present embodiment.
As shown in FIG. 9, the blade member 47a is provided with a plurality of (7 in this case) strain sensors 8 (8a to 8 g).
The strain sensors 8 are arranged side by side along the longitudinal direction (X direction) of the blade member 47a, and the intervals are set so that the detection ranges (predetermined design values) of the adjacent strain sensors 8 overlap. By doing so, it is possible to detect the amount of strain by dividing it in the longitudinal direction of the blade member 47a.

FIG. 10 is a flowchart showing a cleaning performance determination process executed by an image forming apparatus including the blade member 47a.

First, the control unit 10 acquires the results of determining OK / NG of the cleaning performance from all the distortion sensors 8 (step S21).
Specifically, the control unit 10 executes steps S11 to S16 in the cleaning performance determination process of the first embodiment for each of the plurality of strain sensors 8.

Next, the control unit 10 determines whether or not there is a distortion sensor 8 determined to be cleaning performance NG as a result of step S21 (step S22), and if not (step S22: NO), determines that there is no problem with cleaning performance. (Step S23), this process is terminated.

On the other hand, when there is a distortion sensor 8 determined to be cleaning performance NG (step S22: YES), the control unit 10 determines whether or not all the distortion sensors 8 are determined to be cleaning performance NG (step S24). If it is determined that all the distortion sensors 8 are NG in cleaning performance (step S24: YES), it is determined that there is a problem in cleaning performance (step S25), and notifications such as alarm output and message display are performed (step S26). This process ends.

Then, when not all the distortion sensors 8 have determined that the cleaning performance is NG (step S24: NO), the control unit 10 shifts to the refresh mode for adjusting the cleaning performance of the blade member 47a (step S27). ..
Specifically, in the refresh mode, for example, as shown in FIG. 11, a patch image G is formed only in a portion corresponding to the detection range of the distortion sensor 8 (8d) determined to be cleaning performance NG, and the distortion sensor 8 is formed. In this mode, a process for promoting wear in a region other than the detection range of (8d) is executed.
That is, since the amount of the toner external additive that passes through the blade member 47a is smaller in the region without the patch image, the frictional force between the photoconductor 41 and the blade member 47a is large, and by doing so, the blade member 47a Wear at the desired position will be promoted.

In the refresh mode, the amount of lubricant applied may be increased to promote blade wear on the background portion. To increase the amount of lubricant applied, a general method such as increasing the rotation speed of the application brush can be applied.
Further, here, if there is even one sensor judged to be cleaning performance NG, the refresh mode is executed. However, when carrying out the refresh mode, the number of sensors judged to be cleaning performance NG is reduced to, for example, half or less. You may set it to.

Next, as described above, the control unit 10 forms a patch image at a position corresponding to the distortion sensor 8 determined by the image forming unit 4 to be cleaning performance NG (step S28), and the control unit 10 is outside the detection range of the distortion sensor 8. Accelerates area wear.

Next, the control unit 10 determines whether the cleaning performance is OK / NG in the same manner as in step S21 (step S29), and determines whether or not there is a distortion sensor 8 having cleaning performance NG in the same manner as in step S22 (step). S30).

Then, when there is no distortion sensor 8 having a cleaning performance of NG (step S30: NO), the control unit 10 shifts to the above step S23. On the other hand, when there is a distortion sensor 8 having a cleaning performance of NG (step S30: YES), the control unit 10 shifts to the above step S25.

As described above, according to the present embodiment, the blade member 47a includes a plurality of strain sensors 8 arranged side by side along the longitudinal direction thereof, and the detection ranges of the strain amounts of the adjacent strain sensors 8 are mutual. overlapping.
Therefore, the blade member 47a can be divided in the longitudinal direction to detect the cleaning performance. Therefore, in the single sensor 8, when the wear progresses partially, the retracted state of the blade member becomes non-uniform even if the amount of wear of the wear progressing portion is light (partially the wear progresses). It is possible to detect such partial wear where there is a possibility that toner may slip through the portion due to (the amount of pulling in of the blade member is reduced).
In the case of photoconductor torque, it can be detected only by the total width of the blade member, but when a strain sensor is adopted, a plurality of strain sensors may be provided along the longitudinal direction of the blade member as in the present embodiment. Since it can be performed, it becomes possible to detect the cleaning performance more accurately. Therefore, it is possible to suppress a decrease in productivity by detecting minute toner slip-through before a quality problem occurs due to poor cleaning with high accuracy.

Further, according to the present embodiment, the control unit 10 notifies the user when it is determined that all the distortion sensors 8 have poor cleaning performance as a result of determining the cleaning performance of the blade member 47a by the plurality of distortion sensors 8. When there is a strain sensor 8 determined to have good cleaning performance and a strain sensor 8 determined to have poor cleaning performance, a refresh mode for adjusting the cleaning performance of the blade member 47a is executed.
For this reason, the refresh mode enables continuous operation if the cleaning performance is restored in the case of slight partial wear, and if it does not recover, it is judged to be a factor such as severe partial wear, scratches, or photoconductor filming. Will be notified.
Further, the refresh mode makes it possible to grasp in advance whether or not the factor is the blade member 47a when some quality problem occurs, and it can be used as a factor analysis means at a service site or the like.

Further, according to the present embodiment, the control unit 10 has a portion corresponding to the detection range of the distortion sensor 8 which is determined to have good cleaning performance on the photoconductor 41 in the refresh mode, and a cleaning performance on the photoconductor 41. A patch image with a different amount of toner is formed at the portion corresponding to the detection range of the distortion sensor determined to be defective.
As a result, the wear of the blade member 47a in the region other than the detection range of the strain sensor 8 determined to be cleaning performance NG can be efficiently promoted.

Specific details such as the configuration, structure, control content, and order shown in the above embodiment can be appropriately changed without departing from the spirit of the present invention.

For example, in the first and second embodiments, the strain sensor 8 detects the amount of deflection of the blade member 47a, but if the amount of deflection of the blade member 47a can be detected, the strain sensor 8 is not used. You may use the means of.

Further, in the first and second embodiments, the photoconductor 41 as the image carrier has been described as an example, but the image carrier may be the intermediate transfer belt T. In this case, the blade member is the blade member 48a (see FIG. 1) of the cleaning unit 48 that removes the toner on the intermediate transfer belt T.

[Example]
Hereinafter, examples of the present invention will be described.

(System configuration)
The image forming unit shown in FIG. 3 was operated under the following conditions.
Process speed: 400 mm / s
Lubricating brush material: Acrylic, Fineness: 3d, Density: 150KF / inch2, Outer diameter: 14mm, Photoreceptor bite amount: 1mm,
θ ・ ・ ・ 0.5, counter rotation Lubricant material ・ ・ ・ ZnSt, pressing pressure: 5N
Immobilized BL material: Polyurethane, rubber hardness: 70 °, photoconductor bite amount: 0.5 mm, contact angle: 50 °, thickness: 1.5 mm

(Example 1)
In Example 1, the blade members shown in FIGS. 4 (a) and 4 (b) were used. The details are as follows.
Blade member material: Polyurethane, rubber hardness: 70 °, thickness: 2mm, contact force: 30N / m, contact angle: 20 °
The strain sensor uses KFGS-2-120-C1-11L3M3R (manufactured by Kyowa Electric Co., Ltd.), and in the protruding part of the blade member, cyano is applied to the photoconductor contact surface side in the substantially central part in the longitudinal direction (X direction). It was adhered with an acrylate adhesive.

The durable image g11 (chart (1)) shown in FIG. 12 was created on paper in an environment of a temperature of 10 ° C. and a humidity of 20% by an image forming apparatus having the above configuration.
Then, the patch image G shown in FIG. 6 was formed during the image stabilization operation for every 10 kp image in A4 horizontal conversion, and the cleaning performance was determined by the cleaning performance determination process shown in FIG.

(Example 2)
The mode was changed to the cleaning performance judgment mode every 10 kp sheets in A4 horizontal conversion, and the same procedure as in Example 1 was performed except that the cleaning performance was judged.
In the cleaning performance judgment mode, the system speed was increased to 600 mm / s.

(Example 3)
The mode was changed to the cleaning performance judgment mode every 10 kp sheets in A4 horizontal conversion, and the same procedure as in Example 1 was performed except that the cleaning performance was judged.
Cleaning performance determination mode, adjusts the transfer conditions were set to the blade member reaches the toner amount assumed maximum value of the normal image formation of (0.5g / m ²⁾ Ryakubai (1g / m ^2).

(Example 4)
The same procedure as in Example 1 was carried out except that the cleaning performance determination mode was entered every 10 kp sheets in A4 horizontal conversion and the cleanability was determined.
In the cleaning performance judgment mode, the development conditions are such that the transfer means is separated and the toner amount is developed to be approximately twice (1 g / m ² ) of the assumed maximum value (0.5 g / m ² ) at the time of normal image formation. I set it up.

(Example 5)
In Example 5, the same as in Example 1 except that the blade member shown in FIG. 9 was used.
As the strain sensor, the same strain sensor as that used in Example 1 was used, and it was adhered to the photoconductor contact surface side of the protruding portion of the blade member with a cyanoacrylate adhesive. In addition, the detection range of each distortion sensor was set to overlap each other.

(Comparative Example 1)
A durable image g11 (chart (1)) was created on paper in the same manner as in Example 1 using a blade member having the same configuration as that of the blade member of Example 1 except that the distortion sensor was not provided.
Further, after printing 100 kp sheets of the chart (1) as a whole, 2 kp sheets of the image g12 shown in FIG. 13 were printed, and the generation of image noise due to poor cleaning was evaluated as the performance evaluation after durability.

(Example 6)
In the sixth embodiment, the durable image g13 (chart (2)) shown in FIG. 14 is created on paper in an environment of a temperature of 10 ° C. and a humidity of 20% by an image forming apparatus provided with a blade member similar to that of the fifth embodiment. did.
Then, the patch image G shown in FIG. 6 was formed during the image stabilization operation for every 10 kp image in A4 horizontal conversion, and the cleaning performance was determined by the cleaning performance determination process shown in FIG.
Further, after printing 100 kp sheets of the chart (2) as a whole, 2 kp sheets of the image g12 shown in FIG. 13 were printed, and the generation of image noise due to poor cleaning was evaluated as a performance evaluation after durability.
In the chart (2), since low coverage and high coverage are mixed, it is assumed that the wear of the blade member progresses unevenly.

(Comparative Example 2)
A durable image g13 (chart (2)) was created on paper in the same manner as in Example 6 by using a blade member having the same configuration as the blade member of Example 6 except that the distortion sensor was not provided.
Further, the performance was evaluated after durability in the same manner as in Example 6.

(Evaluation)
Table I shows the results of Examples 1 to 5 and Comparative Example 1.
Table II shows the results of Example 6 and Comparative Example 2.
In each of Examples 1 to 6, the cleaning performance was good (◯) up to the number of printed sheets of 60 kp, so Table I shows the results after the number of printed sheets of 70 kp.

In the case of Example 1, since it was determined that the cleaning performance was poor (x) after 90 kp, it was possible to grasp the deterioration of the cleaning performance before the quality problem occurred.

In the case of Example 2, since the speed was increased in the cleaning performance judgment mode and the cleaning load was increased, the cleaning property detection sensitivity was improved, and it could be judged that the cleaning performance was poor (x) after 80 kp durability, which was earlier than that of Example 1. It became possible to grasp the deterioration of cleaning performance.

In the case of Example 3, since the amount of toner reached by the blade member was increased and the cleaning load was increased in the cleaning performance judgment mode, the cleanability detection sensitivity was improved, and it was judged that the cleaning performance was poor (x) after 70 kp durability. It has become possible to grasp the deterioration of cleaning performance at an earlier stage than 2.

In the case of Example 4, since the amount of toner reached by the blade member was increased and the cleaning load was increased in the cleaning performance judgment mode, the cleanability detection sensitivity was improved, and it could be judged that the cleaning performance was poor (x) after 70 kp durability. It became possible to grasp the deterioration of the cleaning performance at the same stage as in 3.

In the case of Example 5, it was determined that the cleaning performance was poor (x) after 90 kp durability as in Example 1.

In the case of Comparative Example 1, the cleaning performance could not be determined, and the result of the performance evaluation after durability confirmed that image noise was generated (x).
That is, in Comparative Example 1, since the deterioration of the cleaning performance cannot be grasped, a quality problem occurs in the performance evaluation after durability.
In addition, in Examples 1 to 5, it is determined that the cleaning performance is judged as described above due to the configuration, and it can be grasped in advance that the cleaning performance has deteriorated, so that it is not necessary to evaluate the performance after durability. However, it has not been implemented here.

In the chart (2), since low coverage and high coverage are mixed, it is assumed that the wear of the blade member progresses unevenly. However, in the case of the sixth embodiment, a plurality of strain sensors are provided in the longitudinal direction of the blade member. By providing it, the cleaning property could detect "x" after the durability of 70K sheets.
After that, the mode was changed to the refresh mode, and the cleaning performance after the refresh mode was good (◯) up to 100 kp, and then the cleanability detection result was good until the end of the durability of 100 K sheets. In addition, the result of the performance evaluation after durability was that no image noise was generated (〇).
Therefore, it can be seen that it is possible to detect minute toner slip-through before the quality problem occurs due to poor cleaning with high accuracy, and it is possible to suppress a decrease in productivity.

In the case of Comparative Example 2, the cleaning performance could not be determined, and the result of the performance evaluation after durability confirmed that image noise was generated (x).

1 Image forming device 2 Automatic document transfer unit 3 Scanner unit 4 Image forming unit 41 Photoreceptor (image carrier)
42 Charging device (toner image forming unit)
43 Exposure device (toner image forming unit)
44 Developing device (toner image forming unit)
45 Primary transfer roller (toner image forming part, transfer part)
46 Secondary transfer roller 47 Cleaning unit 47a Blade member 47a1 Elastic unit 47a2 Holding unit 48 Cleaning unit 48a Blade member T Intermediate transfer belt 5 Paper feed unit 6 Storage unit 7 Operation display unit 8 (8a to 8g) Distortion sensor 10 Control unit

Claims (14)

A toner image forming portion that forms a toner image on the image carrier,
A blade member that comes into contact with the surface of the image carrier and removes deposits on the surface.
A patch image is formed on the image carrier by the toner image forming portion.
The blade member is located at a position corresponding to the background portion of the patch image on the image carrier and the first deflection amount which is the amount of deflection of the blade member when contacting the position corresponding to the patch image on the image carrier. A control unit that determines the cleaning performance of the blade member by comparing it with the second amount of deflection, which is the amount of deflection of the blade member when the blade member comes into contact with the control unit.
An image forming apparatus comprising. The blade member includes a strain sensor and
The image forming apparatus according to claim 1, wherein the control unit detects the amount of deflection of the blade member as the amount of strain by the strain sensor. The blade member is installed so that the amount of strain decreases as the frictional force with the image carrier increases.
The image forming apparatus according to claim 2, wherein the control unit determines that the cleaning performance is good when the first bending amount is smaller than the second bending amount. The blade member is installed so that the amount of strain increases as the frictional force with the image carrier increases.
The image forming apparatus according to claim 2, wherein the control unit determines that the cleaning performance is good when the first bending amount is larger than the second bending amount. When the control unit determines the cleaning performance of the blade member,
2. The method of claim 2 is characterized in that the mode shifts to a cleaning performance determination mode for changing the image forming conditions in the toner image forming portion so that the load applied to the blade member increases as compared with the time of forming an image based on the image forming job. The image forming apparatus according to any one of 4 to 4. The image forming apparatus according to claim 5, wherein the control unit makes the image forming speed faster than the set speed at the time of image forming based on the image forming job in the cleaning performance determination mode. The toner image forming unit includes a transfer unit that transfers a toner image formed on the image carrier to a transfer target.
In the cleaning performance determination mode, the control unit uses the residual toner on the image carrier after the toner image on the image carrier is transferred to the transfer target from the time of image formation based on the image forming job. The image forming apparatus according to claim 5, wherein the transfer conditions of the transfer unit are changed so as to increase the number of images. The toner image forming unit includes a transfer unit that transfers a toner image formed on the image carrier to a transfer target.
The image forming apparatus according to claim 5, wherein the control unit separates the transfer unit and the image carrier in the cleaning performance determination mode. The image forming apparatus according to any one of claims 2 to 8, wherein the blade member includes a plurality of strain sensors arranged side by side along the longitudinal direction thereof. The image forming apparatus according to claim 9, wherein the detection ranges of the amount of distortion of adjacent distortion sensors overlap each other. The claim is characterized in that the control unit notifies the user when the cleaning performance of the blade member is determined by the plurality of strain sensors and the cleaning performance is determined to be poor by all the strain sensors. The image forming apparatus according to 9 or 10. When the control unit has a strain sensor determined to have good cleaning performance and a strain sensor determined to have poor cleaning performance as a result of determining the cleaning performance of the blade member by the plurality of strain sensors. The image forming apparatus according to claim 11, wherein the image forming apparatus shifts to a refresh mode for adjusting the cleaning performance of the blade member. In the refresh mode, the control unit includes a portion corresponding to the detection range of the distortion sensor determined to have good cleaning performance on the image carrier and distortion determined to have poor cleaning performance on the image carrier. The image forming apparatus according to claim 12, wherein the patch image having a different amount of toner is formed from the portion corresponding to the detection range of the sensor. A toner image forming portion that forms a toner image on the image carrier,
A blade member that comes into contact with the surface of the image carrier and removes deposits on the surface.
The computer of the image forming apparatus equipped with
A patch image is formed on the image carrier by the toner image forming portion.
The blade member is located at a position corresponding to the background portion of the patch image on the image carrier and the first deflection amount which is the amount of deflection of the blade member when contacting the position corresponding to the patch image on the image carrier. A program that functions as a control unit that determines the cleaning performance of the blade member by comparing it with the second amount of deflection, which is the amount of deflection of the blade member when the blade member comes into contact with the blade member.

Images