JP2009031660A - Image processing apparatus, control program, and computer-readable recording medium on which control program is recorded - Google Patents

Abstract

An image processing apparatus that controls toner charge amount, suppresses difference in toner adhesion amount, and prevents image density unevenness.
A plurality of patch patterns are formed on an image carrier based on predetermined reference output image density data, an output image density of the patch pattern is detected, and charging, based on the detection result, Controls process execution means including exposure and development means. When the detected variation in the density of the output image is larger than a predetermined standard deviation, the toner charge amount of the developer is increased to suppress image density unevenness.
[Selection] Figure 6

Description

  The present invention relates to an image processing apparatus.

  In the image processing apparatus, a lubricant is applied on the image carrier in order to improve toner cleaning properties, improve image quality, and suppress abrasion of the photosensitive film on the surface layer of the image carrier (photoreceptor).

  However, the image carrier to which the lubricant is applied has less toner adhesion and the image density is lower than that of the image carrier to which the lubricant is not applied. Therefore, an image density difference occurs depending on the application state of the lubricant. There is a case.

For example, the density difference can be made according to the rotation time of the image carrier. In order to solve this problem, in Patent Document 1, the coating amount is controlled according to the rotation time.
Japanese Patent Laid-Open No. 10-247050

  By the way, in the invention described in Patent Document 1, application operation control is performed in order to obtain the set image quality. However, since the application mechanism of the cleaning device is complicated, space saving cannot be achieved. There is.

  In view of the above, the present invention controls image charge amount and suppresses difference in toner adhesion amount, thereby preventing image density unevenness without complicating and increasing the size of a lubricant application mechanism. The purpose is to provide a device.

  To achieve the above object, according to the present invention, patch pattern forming means for forming a plurality of patch patterns on an image carrier based on predetermined reference output image density data, and outputting the plurality of patch patterns Image density detecting means for detecting image density, and process control means for controlling process execution means comprising charging, exposure, and developing means based on the detection result by the image density detecting means, and detected by the image density detecting means Density variation determining means for determining whether or not the density variation of the output image is larger than a predetermined standard deviation, and the process control means is configured such that the density variation of the reference output image has a predetermined standard deviation. Is larger, the charge amount control for increasing the toner charge amount of the developer is performed.

  In the above configuration, when the density variation of the plurality of reference images formed on the image carrier is large, there is non-uniformity in the supply state of the lubricant supplied on the image carrier. There may be non-uniformity in the thickness of the carrier. Therefore, in particular, density unevenness occurs in the halftone image, and dot transfer nonuniformity occurs, resulting in poor image quality.

  Therefore, in the present invention, the patch pattern forming means forms a plurality of patch patterns on the image carrier based on predetermined reference output image density data, and outputs the output image densities of the plurality of patch patterns to the image. It is detected by the concentration detection means. When the detected variation in the density of the output image is larger than a predetermined standard deviation, the toner charge amount of the developer is increased, the amount of toner adhering to the image carrier is increased, and image degradation due to density unevenness is suppressed. To.

  Here, the plurality of patch patterns are created so as to form a plurality of visible images in the longitudinal direction of the image carrier. Similarly, a plurality of density detecting means are arranged in the longitudinal direction of the image carrier.

  According to the above configuration, the process control has been performed by detecting the image density in the circumferential direction of the image carrier. However, by newly performing the reference image density detection in the longitudinal direction, the image quality can be stably maintained.

  By the way, a lubricant is applied on the image carrier for the purpose of cleaning the toner, improving the image quality, and suppressing the abrasion of the photosensitive film on the surface layer of the image carrier (photoreceptor). Further, in various normal image outputs, the untransferred toner is not uniform not only in the circumferential direction on the image carrier but also in the longitudinal direction (axial direction of the photosensitive drum). The supply of the lubricant onto the image bearing member where the non-uniform residual toner exists naturally becomes non-uniform.

  In order to solve this, it is conceivable to increase the supply amount of the lubricant, but this is not practical because the space for storing the lubricant becomes large. Therefore, when a space-saving lubricant is used, it is necessary to cope with not only uniform application of the lubricant but also process control. Therefore, as described above, by newly detecting the reference image density in the longitudinal direction, an attempt is made to maintain stable image quality.

  Further, a lubricant supply means for supplying a lubricant to the image carrier is provided, and a brush roller of a cleaning device for cleaning toner remaining on the image carrier is used as the lubricant supply means. And

  According to the above configuration, since the brush roller of the cleaning device is used as one component of the lubricant supply unit, the number of parts can be reduced compared to the case where the lubricant supply unit and the component of the cleaning device are configured as separate members. And space saving.

  Further, by using the brush roller, it is possible to supply the lubricant more smoothly than using other members.

  The cleaning device includes a cleaning blade and a brush roller arranged to contact the image carrier upstream of the cleaning blade in the rotational direction of the image carrier, and the lubricant of the lubricant supply means The lubricant is disposed in contact with the brush roller so as to be supplied onto the image carrier via a brush roller. The brush roller rotates in the reverse direction to the rotation direction of the image carrier and is controlled to rotate at a peripheral speed ratio of 1.02 to 1.10 with respect to the image carrier.

  According to the above configuration, in order to improve the cleaning property of the brush roller, the toner has been removed by rotating at the high peripheral speed ratio by rotating in the same direction as the image carrier or rotating in the reverse direction (driven direction). By supplying the agent onto the image carrier, the toner cleaning property can be improved, and high-speed rotation of the brush roller is not necessary.

  In addition, there is a problem that toner scattering is large and contamination inside the machine is severely caused by rotating the brush roller at high speed and in the same direction. However, the brush roller rotates in the reverse direction (driven direction) with the image carrier and rotates at a low peripheral speed ratio. By doing so, a clean image processing apparatus without toner scattering can be provided.

  Here, the amount of lubricant supplied onto the image carrier is preferably 10 to 60 μg per A4 size sheet calculated from the number of rotations of the image carrier. When the supply amount of the lubricant is 10 μg or less, the effect of the lubricant is hardly exhibited. On the other hand, if it exceeds 60 μg, the supply amount of the lubricant increases, and a large-sized lubricant is installed, which causes a problem in space saving.

  In addition, in the charge amount control mode for increasing the toner charge amount of the developer, when the toner charge amount is controlled by toner concentration control in the developing means, the numerical value from the toner concentration sensor for detecting the toner concentration and / or the charge amount The toner charge amount is calculated based on the prediction based on the printing rate indicating the printing state of the image in the control mode.

  According to the above configuration, it is known that the adhesion force of the toner to the image carrier comprises a mechanical adhesion force and an electrostatic adhesion force. By supplying the lubricant onto the image carrier, the mechanical adhesive force of the toner is reduced and the total adhesive force is reduced. When the toner has a low charge amount, the contribution of the mechanical adhesion force is large. Therefore, if there is uneven supply of the lubricant on the image carrier, the toner adhesion amount decreases, and the density unevenness occurs in the halftone image. Therefore, it is necessary to increase electrostatic charge by increasing the charge amount of the toner.

  Therefore, a mode for increasing the charge amount of the toner is operated. In this case, the toner concentration in the developer is measured by a magnetic permeability sensor, but varies depending on the state of the developer in the developing device. In order to increase the toner charge amount, the amount of toner in the developer is lowered by attaching toner on the image carrier. It is possible to control the toner concentration in the developer with high accuracy.

  In addition, in the charge amount control mode in which the toner charge amount of the developer is increased, when the toner charge amount is controlled by toner density control in the developing means, the image forming conditions for securing the image density vary depending on the environment and life cycle. Is calculated using a correction table for correcting.

  According to the above configuration, the charge amount of the toner is affected by the deterioration of the developer and the toner, and changes in the ambient temperature, humidity, and the like, which are external factors, so correction is necessary. Image quality can be improved if the toner charge amount is determined by correcting variations due to this environment and life cycle.

  Here, the image forming condition is at least one of the voltage applied to the charging unit, the intensity of the light source to be exposed, and the adjustment value of the bias power source of the developing device.

  According to the above configuration, since it is affected by the deterioration of the toner and the photoconductor in the electrophotographic process and changes in the ambient temperature, humidity, and the like, which are external factors, correction is necessary. Therefore, the image forming conditions are corrected based on these environments and life cycles. As the image forming condition, a good image quality can be obtained by adjusting at least one of the voltage applied to the charging unit, the intensity of the light source to be exposed, and the adjustment value of the bias power source of the developing device.

  According to the present invention, there is also provided a control program for controlling an image processing apparatus using a computer, wherein a patch pattern forming unit forms a plurality of patch patterns on an image carrier based on predetermined reference output image density data. A process control step for controlling a process execution means including charging, exposure, and development means based on the detection result of the image density detection process, and an image density detection process for detecting an output image density of the plurality of patch patterns. A density variation determination step for determining whether or not the density variation of the output image detected in the image density detection step is larger than a predetermined standard deviation. In the process control step, the reference output Perform charge amount control to increase the toner charge amount of the developer when the density variation of the image is larger than a predetermined standard deviation. It is possible to provide a control program of an image processing apparatus according to claim. Furthermore, a computer-readable recording medium in which such a control program is recorded can be provided.

    As described above, according to the present invention, when the density variation of the detected output image is larger than a predetermined standard deviation, the toner charge amount of the developer in the developing unit is increased, and the amount of toner adhering to the image carrier is increased. In addition, it is possible to provide an image processing apparatus that suppresses image deterioration due to density unevenness and has good image quality.

  FIG. 1 is a block diagram of an image processing apparatus cleaning apparatus according to the present invention, and FIG. 2 is a schematic block diagram of the image processing apparatus. As shown in FIG. 2, the image processing apparatus 10 forms an image (here, a monochrome image) corresponding to image data on a sheet. The image processing apparatus 10 includes a photoconductor (image carrier) 1, and a charging unit (charging unit) 2, an exposure unit (exposure unit) 3, and the like around which a well-known Carlson process is performed. A development unit (development unit) 4, a transfer unit (transfer unit) 5, a fixing unit 6, a cleaning unit (cleaning device) 7, and a plurality of optical sensors 8 (image density detection unit) are provided.

  The photosensitive member 1 has a drum shape and is rotatably supported by a housing (not shown). The surface of the photoreceptor 1 is uniformly charged to a predetermined potential by the charging unit 2, and an electrostatic latent image corresponding to the image data is written by the exposure unit 3. Thereafter, the electrostatic latent image is visualized with toner by the developing unit 4 to form a toner image. The formed toner image is transferred by the transfer unit 5 onto the recording sheet S fed from a paper feed tray (not shown), sent together with the recording sheet S to the fixing unit 6, where it is melted and fixed on the paper. Is done. Thereafter, the recording sheet S on which the toner image is fixed is discharged onto a discharge tray.

  The transfer unit 5 includes a first transfer roller 5a, a second transfer roller 5b, and an intermediate transfer belt 5c. The toner image on the photoreceptor 1 is transferred to the intermediate transfer belt 5c using the first transfer roller 5a. The toner image on the intermediate transfer belt 5c is transferred to the recording sheet S between the second transfer roller 5b and the backup roller 5d. After the transfer, the recording sheet S is guided and fixed between the fixing roller 6a and the pressure roller 6b of the fixing unit 6 and then discharged from a paper discharge tray (not shown).

On the other hand, after the toner image is transferred to the recording sheet S, the toner 1 remaining on the surface is removed by a cleaning unit 7 to be described later, and the charge remaining on the surface is removed by a neutralizing unit (not shown). At the same time, the charging unit 2 is charged again.
The cleaning unit 7 will be described in detail with reference to FIG. FIG. 1 is an enlarged cross-sectional view showing the configuration of the cleaning unit 7. The cleaning unit 7 includes a blade 11, a brush roller 12, a solid lubricant 13, a toner recovery screw 15, and a flicker 16, and these members are covered with a case 18.

  The blade 11 is for collecting toner remaining on the surface of the photoconductor 1 and is formed of a long rubber member whose longitudinal direction is the axial direction of the photoconductor 1. The blade 11 is arranged so that one long side is attached to the downstream side in the rotation direction of the photoconductor 1 in the opening provided in the case 18, and the edge (corner) of the other long side is in contact with the surface of the photoconductor 1. Has been.

  The blade 11 dams off the transfer residual toner remaining on the surface of the photoreceptor 1 after the toner image is transferred, and scrapes it off while performing a stick-slip operation. The stick-slip operation is based on the operation in which the contact portion of the blade 11 with the photosensitive member 1 moves in the rotation direction of the photosensitive member 1 according to the movement of the surface of the photosensitive member 1 and the elastic force of the blade 11 itself. The movement of returning to the position is repeated, and the edge of the blade 11 slides on the surface of the photoreceptor 1.

  The solid lubricant 13 is applied to the surface of the photoreceptor 1 by the brush roller 12 and has a rectangular parallelepiped shape having the same length (width) as the length of the photoreceptor 1 in the longitudinal direction. The solid lubricant 13 is held by a lubricant holding member 14 and can be replaced when worn out and the remaining amount is reduced.

  The lubricant holding member 14 is designed to be slightly larger than the solid lubricant 13, and the solid lubricant 13 having a rectangular parallelepiped shape is adhered and fixed to the lubricant holding member 14 with a double-sided tape (not shown), or the solid lubricant 13 is fixed. The lubricant holding member 14 can be fitted and fixed.

  Further, the lubricant holding member 14 may contact the brush with the solid lubricant 13 by its own weight instead of fixedly installing the solid lubricant 13. Further, both ends of the lubricant holding member 14 are supported by the case 18 so as to be movable in the brush direction so that the amount of shaving does not decrease as the solid lubricant 13 is consumed. It may be configured to move to.

  In FIG. 1, the lubricant holding member 14 is supported by the case 18 with a compression coil spring 14 a interposed between the top surface of the case 18.

  The brush roller 12 is a cylindrical roller having a large number of brush hairs planted outward in the radial direction of the peripheral surface and having substantially the same length (width) as the photoconductor 1. The photosensitive member 1 and the axis of each other are arranged in parallel so that the tip of the brush bristles hits.

  The brush roller 12 is rotationally driven in a direction opposite to the rotational direction of the photosensitive member 1, and thereby both slide in the same direction at the contact portion.

  Further, the brush roller 12 has a peripheral speed ratio with respect to the photoreceptor 1 of 1.02 to 1.10. The brush roller 12 rotates in the reverse direction (driven direction) with respect to the photosensitive member 1 and rotates at a low peripheral speed ratio, so that a clean image processing apparatus without toner scattering can be obtained.

  The amount of lubricant supplied on the image carrier is 10 to 60 μg per A4 size calculated from the number of rotations of the photoreceptor 1. When the supply amount of the lubricant is 10 μg or less, the effect of the lubricant is hardly exhibited. If it exceeds 60 μg, the amount of lubricant supplied will increase, and a large-sized lubricant will be installed, so there is a problem in space saving.

  The contact portion of the photosensitive member 1 with the brush roller 12 is downstream of the transfer portion of the photosensitive member 1 in the rotation direction of the photosensitive member 1, and the surface of the photosensitive member 1 after the toner image is transferred and the brush roller. 12 abuts. The brush roller 12 scrapes off the solid lubricant 13 disposed on the upstream side of the brush rotation direction with respect to the contact portion with the photoreceptor 1 and applies the scraped lubricant to the surface of the photoreceptor 1.

  As described above, the brush roller 12 applies the fine particles of the solid lubricant 13 to the surface of the photoreceptor 1, thereby reducing the frictional force between the blade 11 and the surface of the photoreceptor 1, and Since the adhesion force of the toner to the surface is weakened, the residual toner can be efficiently removed by the blade 11.

  At the same time, the brush roller 12 also has a function of scattering the toner adhering to the surface of the photosensitive member 1 by contacting with the photosensitive member 1, and as a result, the removal by the blade 11 is efficiently performed. Yes. Further, the brush roller 12 is arranged at a position where the toner scraped off and scraped by the blade 11 can be collected, and the toner scraped off by the blade 11 can be removed by the scraping force of the brush tip. While removing mechanically from the surface, it also has a function of collecting in the case 18.

  The flicker 16 is in contact with the brush roller 12. The flicker 16 is a rectangular plate-like member having substantially the same width as the brush roller 12, and its long side (edge) is set so that its longitudinal direction is parallel to the axis of the brush roller 12. It arrange | positions so that the brush roller 12 may contact uniformly. The flicker 16 has a function of dropping the toner adhering to the hair of the brush roller 12 into the case 18.

The toner collecting screw 15 is arranged on the bottom surface side of the case 18 and sends out the toner collected by the brush roller 12 to a waste toner box (not shown) outside the case 18. A seal material is attached to the upstream side of the opening of the case 18 in the rotation direction of the photosensitive member 1 so as to prevent the collected toner from leaking out of the case 18 again.
Here, when the lubricant cannot be uniformly applied to the surface of the photosensitive member 1 and a coated portion and a non-coated portion are generated, the toner adhesion amount is different and image density unevenness occurs. In this embodiment, the process unit is controlled by a plurality of optical sensors 8 (image density detection means) to improve the image quality.

  As shown in FIG. 3, the plurality of optical sensors 8 are arranged in the longitudinal direction that is the axial direction of the photoreceptor 1. When the halftone patch pattern is written on the photoreceptor 1 by the exposure unit 3 and the developing device 4, the optical sensor 8 detects the toner density of the patch pattern. By controlling the amount of charge by the charging unit 2 in accordance with the toner density detected here, image density unevenness is suppressed.

  The potential sensor 9 detects the potential of the electrostatic latent image on the photoreceptor 1. From the detected potential and the toner density of the patch pattern, the potential potential required to ensure the toner density is calculated, and process control is performed.

  As the charging unit 2, any one of a contact charging method and a non-contact charging method such as a scorotron charger may be selected.

  As shown in FIG. 2, the transfer unit 5 temporarily transfers the toner image visualized on the surface of the photosensitive member 1 to a belt-like intermediate transfer member and then transfers it to the recording sheet S. The toner image of the photosensitive member 1 may be directly transferred onto a recording sheet.

  Although not described further, the image processing apparatus 10 can form images on both the front and back sides of the recording sheet by switchback conveyance of the recording sheet (paper).

  FIG. 4 is an electrical block diagram for controlling the toner charge amount based on the patch pattern. The image forming unit 50 is a process unit that forms image data on the recording sheet S as shown in FIG. The control unit 40 includes a microcomputer and controls each component included in the image processing apparatus. In addition to a general image forming control unit, the control unit 40 includes a halftone patch pattern writing control unit 401, a patch pattern density variation determination unit 402, a toner density control unit 403, and a charge amount control unit. 404, a grid potential / laser intensity / development bias adjustment unit 405 is provided.

  The halftone patch pattern writing control unit 401 reads the halftone patch pattern stored in the storage unit 41 and instructs image formation on the photoreceptor 1 based on the patch density reference value. Here, the density of the written patch pattern is detected by the optical sensor 8.

  The patch pattern density variation determination unit 402 calculates the density variation detected by the plurality of optical sensors 8 and compares it with the patch density reference value 412 of the storage unit 41. The definition of the density reference value will be described later.

  The toner density control unit 403 and the charge amount control unit 404 control the toner density in the developing device 4 and the charge amount in the charging unit 2 based on the determination result of the patch pattern density variation determination unit 402.

  Further, in accordance with the control of the charge amount, the process control is performed by the adjustment unit 405 of the developing bias power source connected to the grid potential / laser intensity / developing device 4 that is the light source of the exposure unit 3.

  FIG. 5 shows the overall operation flow of the present invention. FIG. 6 shows a detailed flow of “control based on checked density”. First, as shown in FIG. 5, a halftone patch pattern is written on the photoreceptor 1. A plurality of patch patterns are formed along the length direction (axial direction) of the photoreceptor 1. Since the toner density of the patch pattern is detected on the downstream side of the developing device 4 of the photoreceptor 1, it is detected by the optical sensor 8. Since a plurality of optical sensors 8 are arranged in the length direction (axial direction) of the photosensitive member 1, the density is detected from each optical sensor 8.

  The density detected by each optical sensor 8 is compared with the reference output density data stored in the storage unit 41. The reference output density data may be a different value depending on the length direction of the photoconductor 1, or the same value may be used.

  The surface potential of the photoconductor 1 may vary in the length direction of the photoconductor 1 due to manufacturing variations of the photoconductor 1 and the like. For this reason, the surface potential of the photoreceptor 1 charged by the charging unit 2 is not uniform in the length direction and may show different values. In such a case, the value measured by the plurality of optical sensors 8 in the length direction of the photosensitive member 1 is compared with individual reference output density data calculated and stored in accordance with the characteristics of the surface potential, and the degree of variation ( Difference). Alternatively, for example, a value to be compared is stored in the storage unit 41 as an arithmetic average value of a plurality of reference output density data, and this value is compared with each detected density to calculate a variation degree (difference). May be.

  Then, the density variation determination unit 402 of the control unit 40 determines whether the calculated density variation is outside the range of the density reference value. Here, the density reference value is a standard deviation value σ of density. If it is within the density reference value, the density unevenness is small, and normal processing is performed.

  In normal processing, an average value of each detected concentration is calculated, and process control is performed according to the calculated average value. For example, when the arithmetic average value is lower than a certain reference concentration, the concentration is low, and when the arithmetic average value is higher than the reference concentration, the concentration is high. Therefore, the process control (grid potential, laser intensity, Adjust development bias).

  On the other hand, if the density variation of the patch pattern is outside the range of the density reference value (standard deviation value σ), density unevenness has occurred, and the following processing is performed. The toner charge amount is increased corresponding to the density unevenness. As the toner charge amount is increased, the toner density of the developing device 4 is decreased. The developing device 4 confirms the current toner concentration by a toner concentration sensor (magnetic permeability sensor) and calculates a toner concentration to be lowered. If only the toner density sensor is used, variations occur depending on the state of the developer in the developing device 4.

  In addition, to increase the toner charge amount, the toner amount in the developer is decreased. Therefore, the toner concentration in the developer can be accurately controlled in a short time by grasping the toner consumption during image formation. There is a need to. Therefore, not only using the toner density sensor but also making a prediction based on the image printing rate representing the image printing situation at the time of toner density adjustment.

  Further, since it is affected by the life cycle such as deterioration of the developer and toner and the environmental change such as ambient temperature and humidity which are external factors, it is necessary to correct. The correction data is read from the correction table 411 of the storage unit 41, and the toner density is calculated including the correction data from these environmental conditions and life cycle. The correction data is, for example, a correction coefficient stored in accordance with the life cycle and environmental conditions, and the coefficient value is stored in the correction table. By doing so, it is possible to obtain an appropriate toner concentration according to environmental conditions and changes in the life cycle.

  Further, since the density of the patch pattern cannot be secured due to the change in the toner charge amount, process control is performed. The process control reads the potential of the electrostatic latent image detected by the potential sensor 9, calculates the potential potential necessary to ensure the toner density from the potential of the electrostatic latent image and the density of the patch pattern, and The adjustment value of the applied voltage (grid potential), laser intensity, and developing bias of 2 is calculated. Then, the image processing apparatus is controlled to operate with the value calculated above.

  Thus, in this embodiment, when the density variation of the detected output image is larger than the predetermined standard deviation value, the toner charge amount of the developer in the developing unit is increased, and the toner adhering to the image carrier is removed. The image quality can be improved by suppressing the image deterioration due to density unevenness.

  In this embodiment, the writing control unit 401, the density variation determination unit 402, the toner density control unit 403, the charge amount control unit 404, and the charging unit applied voltage / laser intensity / development bias adjustment unit 405 are included in the control unit 40. A ROM (read only memory) storing a control program to be realized, a RAM (random access memory) expanding the program, a storage device (recording medium) such as a memory storing the program and various data, and the like are provided.

  An object of the present invention is to supply the control unit 40 with a recording medium in which the program code (execution format program, intermediate code program, source program) of the control program described above is recorded so as to be readable by the computer, This can also be achieved by the CPU and MPU) reading and executing the program code recorded on the recording medium.

  Examples of the recording medium include a tape system such as a magnetic tape and a cassette tape, a magnetic disk such as a floppy (registered trademark) disk / hard disk, and an optical disk such as a CD-ROM / MO / MD / DVD / CD-R. Card system such as IC card, IC card (including memory card) / optical card, or semiconductor memory system such as mask ROM / EPROM / EEPROM / flash ROM.

  The control device 40 may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited. For example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication. A net or the like is available.

  Also, the transmission medium constituting the communication network is not particularly limited. For example, even in the case of wired such as IEEE 1394, USB, power line carrier, cable TV line, telephone line, ADSL line, etc., infrared rays such as IrDA and remote control, Bluetooth ( (Registered trademark), 802.11 wireless, HDR, mobile phone network, satellite line, terrestrial digital network, and the like can also be used.

  The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

1 is a configuration diagram of a cleaning device of an image forming apparatus according to the present invention. Schematic configuration diagram of an image processing device The perspective view which shows arrangement | positioning of the optical sensor on an image carrier Control block diagram for controlling toner charge amount based on patch pattern FIG. 1 is a flowchart illustrating the overall operation of an image processing apparatus according to the present invention. Control flowchart based on checked concentration

Explanation of symbols

1 Photoconductor (image carrier)
2 Charging unit (charging means)
3 Exposure unit (exposure means)
4 Development unit (development means)
5 Transfer unit (transfer means)
6 Fixing unit 7 Cleaning unit (cleaning device)
8 Optical sensor (Image density detection means)
DESCRIPTION OF SYMBOLS 10 Image processing apparatus 40 Control part 41 Storage part 50 Image formation part 401 Patch pattern writing control part 402 Density variation judgment part 403 Toner density control part 404 Charge amount control part 405 Adjustment part

Claims (10)

  On the image carrier, based on predetermined reference output image density data, patch pattern forming means for forming a plurality of patch patterns, image density detecting means for detecting output image densities of the plurality of patch patterns, And a process control means for controlling a process execution means comprising charging, exposure and developing means based on the detection result by the image density detection means, and the density variation of the output image detected by the image density detection means is predetermined. A density variation determination unit that determines whether or not the standard deviation is larger than the standard deviation is provided, and the process control unit is configured such that when the density variation of the reference output image is larger than a predetermined standard deviation, the toner charge amount of the developer An image processing apparatus that performs charge amount control to increase the value.   The plurality of patch patterns are created so as to form a plurality of visible images in the longitudinal direction of the image carrier, and a plurality of the image density detection means are arranged in the longitudinal direction of the image carrier. The image processing apparatus according to claim 1, wherein:   Lubricant supply means for supplying a lubricant is provided on the image carrier, and a brush roller of a cleaning device for cleaning toner remaining on the image carrier is used as the lubricant supply means. The image processing apparatus according to claim 1.   The cleaning device includes a cleaning blade and a brush roller arranged to contact the image carrier upstream of the cleaning blade in the rotation direction of the image carrier, and the lubricant of the lubricant supply means is a brush. The lubricant is disposed in contact with the brush roller so as to be supplied onto the image carrier through a roller, and the brush roller rotates in the reverse direction to the rotation direction of the image carrier, so that the peripheral speed with respect to the image carrier is increased. The image processing apparatus according to claim 3, wherein the rotation is controlled at a ratio of 1.02 to 1.10.   5. The image processing apparatus according to claim 4, wherein the amount of the lubricant supplied onto the image carrier is 10 to 60 [mu] g per A4 size calculated from the number of rotations of the image carrier. . In the charge amount control mode in which the toner charge amount of the developer is increased, the process control unit is configured to detect a toner concentration by a numerical value from a toner concentration sensor when the toner charge amount is controlled by toner concentration control in the developing unit, and / or 2. The image processing apparatus according to claim 1, wherein the image processing apparatus is controlled by a toner charge amount calculated based on a prediction based on a printing rate indicating an image printing state in the charge amount control mode. In the charge amount control mode for increasing the toner charge amount of the developer, when the toner charge amount is controlled by toner density control in the developer unit, the process control unit determines the image forming condition for securing the image density as an environmental condition. The image processing apparatus according to claim 1, wherein the calculation is performed using a correction table for correcting fluctuations due to the life cycle.   The image processing apparatus according to claim 7, wherein the image forming condition is at least one of an applied voltage to a charging unit, an intensity of a light source to be exposed, and an adjustment value of a bias power source of a developing device. A control program for controlling an image processing apparatus using a computer,
On the image carrier, based on predetermined reference output image density data, a patch pattern forming step for forming a plurality of patch patterns, an image density detection step for detecting an output image density of the plurality of patch patterns, Based on the detection result of the image density detection process, it comprises a process control process for controlling the process execution means comprising charging, exposure, and development means, and the density variation of the output image detected in the image density detection process is predetermined. A density variation determination step for determining whether or not the deviation is larger than a standard deviation, and in the process control step, when the density variation of the reference output image is larger than a predetermined standard deviation, the toner charge amount of the developer A control program for an image processing apparatus, wherein charge amount control for increasing the charge amount is performed. A computer-readable recording medium on which the control program according to claim 9 is recorded.

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