JP2009175643A - Image forming apparatus and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus, capable of suppressing disturbance of image on a transfer object resulting from excess of a liquid containing magnetic toner on a magnetic latent image holding body, and a program. <P>SOLUTION: Based on temporal change information showing temporal changes of film thickness of developer on a magnetic drum 12 respectively corresponding to temperature measured by a temperature measurement part 38 and humidity measured by a humidity measurement part 40, control for adjusting the film thickness of developer on the magnetic drum 12 is performed so that the film thickness of developer on the magnetic drum 12 measured by a film thickness measurement part 36 at a point of time when a toner image is transferred to an intermediate transfer body 18 is within a predetermined range. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

In Patent Document 1, an electrostatic latent image is formed on the surface of the image carrier, and a toner image is formed on the surface of the image carrier by applying a liquid containing toner to the surface of the image carrier on which the electrostatic latent image is formed. An image forming apparatus is disclosed in which after the formation, the liquid on the surface of the image carrier is removed, the toner image is dried, and the toner image is transferred onto a recording medium via an intermediate transfer medium.
JP 2004-102316 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus and a program capable of suppressing image disturbance on a transfer target due to an excess of liquid containing magnetic toner on a magnetic latent image holding member.

  In order to achieve the above object, an image forming apparatus according to claim 1 reveals a magnetic latent image holding member having a water-repellent surface and a magnetic latent image formed on the magnetic latent image holding member. For this purpose, a liquid developer supplying means for supplying a liquid developer containing a magnetic toner and an aqueous medium onto the magnetic latent image holding member, and the magnetic latent image is visualized by the liquid developer. A transfer body onto which the developed image formed on the holding body is transferred, and a film of the liquid developer supplied onto the magnetic latent image holding body by the liquid developer supply means on the magnetic latent image holding body. A first measuring means for measuring the thickness, a second measuring means for measuring at least one of temperature and humidity in the vicinity of the magnetic latent image holding member, and the at least one of temperature and humidity measured by the second measuring means. Change in film thickness over time The storage means that stores the temporal change information in advance, and the temporal change information corresponding to at least one of the temperature and the humidity measured by the second measurement means are read from the storage means, and based on the temporal change information, Control means for performing control for adjusting the film thickness so that the film thickness measured by the first measuring means is within a predetermined range when the developed image is transferred to the transfer target; I have.

  According to a second aspect of the present invention, in the first aspect of the present invention, the control means uses the read time-dependent change information to determine the time corresponding to the film thickness measured by the first measurement means. It is determined whether or not the film thickness falls within the range when a predetermined time elapses, and the control is performed only when it is determined that the film thickness does not fall within the range.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the first measuring means has the film thickness in a region where the magnetic latent image is not formed on the magnetic latent image holding member. Is to measure.

  According to a fourth aspect of the invention, in the first aspect of the invention, the liquid developer supplied on the magnetic latent image holding member by the liquid developer supply means instead of the first measurement means. A second storage unit that stores in advance film thickness information indicating a film thickness on the magnetic latent image carrier, and the control unit corresponds to at least one of the temperature and the humidity measured by the second measurement unit. Reading the temporal change information from the storage means, reading the film thickness information from the second storage means, and at the time when the developed image is transferred to the transfer body based on the temporal change information Control for adjusting the film thickness is performed so that the film thickness indicated by the thickness information falls within the above range.

  According to a fifth aspect of the present invention, in the invention of the fourth aspect, the control means uses the read time-dependent change information to determine in advance from a time corresponding to the film thickness indicated by the film thickness information. It is determined whether or not the film thickness falls within the range when the given time has elapsed, and the control is performed only when it is determined that the film thickness does not fall within the range.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, further comprising a blowing means for blowing air on the magnetic latent image holding body, wherein the control means is As control for adjusting the film thickness, control is performed to blow air by the blowing means.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the magnetic latent image holding body and the transfer target are each supported such that both ends thereof are rotatable. The developed image is transferred while the transferred body and the magnetic latent image holding body are rotated, and the control means further comprises: Controlling the magnetic latent image holding member and the transfer target so that the rotation speed of the transfer target is slower than the rotation speed of the magnetic latent image holding member when the developed image is transferred to the transfer target. Is.

  The invention according to claim 8 is the invention according to claim 7, wherein the ratio of the rotational speed of the transferred body to the rotational speed of the magnetic latent image holding body is 0.95 or less. .

  On the other hand, in order to achieve the above object, the invention described in claim 9 makes the surface of the magnetic latent image holder having water repellency and the magnetic latent image formed on the magnetic latent image holder visible. For this purpose, a liquid developer supplying means for supplying a liquid developer containing a magnetic toner and an aqueous medium onto the magnetic latent image holding member, and the magnetic latent image is visualized by the liquid developer. An image forming apparatus provided with a transferred image onto which a developed image formed on the holding body is transferred, and is supplied to the computer by the liquid developer supplying means on the magnetic latent image holding body. The film thickness information indicating the film thickness is obtained from the first measuring means for measuring the film thickness of the liquid developer on the magnetic latent image holding body, and at least one of temperature and humidity in the vicinity of the magnetic latent image holding body is obtained. From the second measuring means to measure An acquisition step for acquiring environmental information indicating at least one of temperature and humidity; and storage means for preliminarily storing time-dependent change information indicating change with time of the film thickness with respect to at least one of temperature and humidity measured by the second measuring means From the reading step for reading out the time-varying information corresponding to the environmental information acquired in the acquiring step, and the time-varying information read out in the reading step, the developed image is transferred to the transfer body. And a control step for performing control for adjusting the film thickness so that the film thickness indicated by the film thickness information acquired by the acquisition step falls within a predetermined range. .

  According to the first and ninth aspects of the invention, there is an effect that it is possible to suppress image disturbance on the transfer target due to an excess of liquid containing magnetic toner on the magnetic latent image holding member. can get.

  Further, according to the invention described in claim 2, in addition to the effect of the invention described in claim 1, there is an effect that unnecessary execution of control for adjusting the film thickness can be avoided.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, the film thickness is measured without disturbing the developed image formed on the magnetic latent image holding member. The effect that it can be obtained.

  According to the fourth aspect of the present invention, there is no need to provide a means for measuring the film thickness on the magnetic latent image holding member, and as a result, there is an excess of liquid containing developer on the magnetic latent image holding member. An effect is obtained that the disturbance of the image on the transfer medium can be suppressed at a lower cost.

  Further, according to the invention described in claim 5, in addition to the effect of the invention described in claim 4, an effect that unnecessary execution of control for adjusting the film thickness can be avoided.

  Moreover, according to the invention of claim 6, in addition to the effect of the invention of any one of claims 1 to 5, there is an effect that the film thickness can be adjusted more quickly. It is done.

  According to the invention described in claim 7, in addition to the effect of the invention described in any one of claims 1 to 6, the magnetic latent image holder is compared with a case where the present invention is not applied. The effect of improving the transfer efficiency of the developed image formed on the transfer target can be obtained.

  Furthermore, according to the invention described in claim 8, in addition to the effect of the invention described in claim 7, the transfer efficiency of the developed image formed on the magnetic latent image holding member to the transfer target is further improved. The effect that it can be obtained.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic cross-sectional view showing the main configuration of the image forming apparatus 10 according to the first embodiment.

  As shown in the figure, an image forming apparatus 10 is for forming an image on a recording paper P using toner particles described later, and includes a magnetic drum 12, a magnetic head 14, a developing device 16, an intermediate transfer. The body 18, the cleaner 20, the demagnetizer 22, and the transfer fixing roller 24 are configured.

  The magnetic drum 12 is a columnar rotating body whose both ends are rotatably attached to the inner wall of a housing (not shown) of the image forming apparatus 10. A magnetic head 14, a developing device 16, An intermediate transfer member 18, a cleaner 20, and a demagnetizer 22 are sequentially provided. The magnetic drum 12 is rotationally driven in the direction of arrow A in the figure by receiving the rotational driving force of the motor 26.

  In the image forming apparatus 10 according to the present embodiment, the surface of the magnetic drum 12 has water repellency. Here, “water repellency” means the property of repelling water, and specifically means that the contact angle with pure water is 70 degrees or more.

  The magnetic head 14 forms a magnetic latent image on the magnetic drum 12 by emitting magnetic lines of force corresponding to image information input from a terminal device 62 (see FIG. 3) described later to the outer peripheral surface of the magnetic drum 12. To do.

  The developing device 16 supplies a liquid developer containing magnetic toner and an aqueous medium (hereinafter referred to as “developer”) to the magnetic drum 12 in order to make the magnetic latent image formed on the magnetic drum 12 visible. The liquid storage container 30 and the developing roller 32 are included. In the image forming apparatus 10 according to the first embodiment, the yellow magnetic toner is applied. However, the present invention is not limited to this, and it is needless to say that other colors of magnetic toner may be applied.

  The liquid storage container 30 stores a developer. An opening 34 for supplying the developer to the magnetic drum 12 is formed in the liquid storage container 30.

  The developing roller 32 adheres the magnetic toner to the magnetic drum 12. The developing roller 32 is a cylindrical rotating body whose both ends are rotatably attached to the inner wall of the liquid storage container 30, so that a part of the developing roller 32 is immersed in the developer stored in the liquid storage container 30, and the outer peripheral surface. Is provided so as to be in contact with the outer peripheral surface of the magnetic drum 12 through the opening 34 and is driven by the rotation of the magnetic drum 12.

  The intermediate transfer member 18 is a toner image (development image) formed on the magnetic drum 12 by transferring the magnetic latent image with a developing solution. The intermediate transfer member 18 is a columnar rotary member that is rotatably attached at both ends to the inner wall of the housing of the image forming apparatus 10, and is provided so that the outer peripheral surface is in contact with the outer peripheral surface of the magnetic drum 12. In response to the rotational driving force of the motor 28, it is rotationally driven in the direction of arrow B in the figure.

  In the image forming apparatus 10 according to the first embodiment, the diameters of the magnetic drum 12 and the intermediate transfer body 18 are both 150 mm. However, the present invention is not limited to this, and the diameter of the magnetic drum 12 and the diameter of the intermediate transfer body 18 are both. May be determined in accordance with the design specifications and purpose of use of the image forming apparatus 10.

  Further, in the image forming apparatus 10 according to the first embodiment, the magnetic drum 12 is rotated at 10 mm / s by the motor 26 when executing the image forming process. The magnetic drum 12 may be rotated at a rotational speed, and the rotational speed of the magnetic drum 12 may be determined according to the design specifications, purpose of use, etc. of the image forming apparatus 10.

  The transfer fixing roller 24 transfers the toner image conveyed by the intermediate transfer member 18 onto the recording paper P and fixes it at the same time. In the image forming apparatus 10 according to the first embodiment, the recording paper P is sandwiched between the intermediate transfer body 18 and the transfer fixing roller 24, whereby the toner image on the intermediate transfer body 18 is brought into close contact with the recording paper P, As a result, the toner image is transferred to the recording paper P, and at the same time, the toner image is fixed on the recording paper P. However, the present invention is not limited to this, and the fixing of the toner image may be performed only by pressing depending on the characteristics of the toner, or may be performed by pressing and heating by providing a heat generating body on the transfer fixing roller 24.

  The cleaner 20 collects the transfer residual toner on the magnetic drum 12. The demagnetizer 22 erases the magnetic latent image on the magnetic drum 12.

  By the way, in the image forming apparatus 10 configured as described above, when the toner image is conveyed to the contact position with the intermediate transfer member 18 by the magnetic drum 12, the developing solution supplied onto the magnetic drum 12 by the developing device 16 is also used. It will be conveyed to the contact position. The developer on the magnetic drum 12 is pushed out in the direction opposite to the rotation direction of the magnetic drum 12 and the intermediate transfer member 18 at the contact position.

  2, in the image forming apparatus 10, the magnetic drum 12 has a diameter of 150 mm, the intermediate transfer member 18 has a diameter of 20 mm, the outer peripheral surface of the intermediate transfer member 18 is a silicon resin material, and the intermediate transfer member 18 has an outer peripheral surface. When the thickness is 2 mm, the rotation speed of the magnetic drum 12 is 10 mm / s, and the ratio of the rotation speed of the intermediate transfer body 18 to the rotation speed of the magnetic drum 12 is 0.95, the intermediate transfer body 18 is changed from the magnetic drum 12 to the intermediate transfer body 18. An example of the transferred toner image and the surrounding state is shown.

  As shown in the figure, when the amount of the developer on the magnetic drum 12 is too large, the developer is pushed out excessively at the contact position as described above and transferred to the intermediate transfer member 18. A part of the toner image flows.

  Therefore, in the image forming apparatus 10 according to the first embodiment, a film thickness adjustment process for adjusting the film thickness of the developer on the magnetic drum 12 is executed. For this purpose, the image forming apparatus 10 according to the first embodiment includes a film thickness measurement unit 36, a temperature measurement unit 38, a humidity measurement unit 40, and a blower 42.

  The film thickness measuring unit 36 measures the film thickness of the developer on the magnetic drum 12. In the image forming apparatus 10 according to the first embodiment, the CPU 50 to be described later controls the film thickness measurement unit 36 so as to measure the film thickness in the region where the magnetic latent image is not formed on the magnetic drum 12. Yes. Specifically, the film thickness of the developer is measured outside the image forming area of the magnetic drum 12 and at the end of the outer peripheral surface of the magnetic drum 12.

  In the image forming apparatus 10 according to the first embodiment, a light transmission type photosensor (LS7030 manufactured by Keyence Corporation) is applied as the film thickness measurement unit 36. This light transmission type photosensor is provided between the developing device 16 and the intermediate transfer member 18. The light transmission type photosensor includes a light emitting unit that emits light, and a light receiving unit that receives the light and outputs a current corresponding to the received light amount, and an optical axis of the light emitted from the light emitting unit. Is provided close to the outer peripheral surface so as to be in contact with the outer peripheral surface of the magnetic drum 12.

  In the image forming apparatus 10 according to the first embodiment, 10 mm is applied as the distance between the light emitting unit and the light receiving unit of the light transmission type photosensor. What is necessary is just to determine according to a design specification or installation environment.

  In the image forming apparatus 10 according to the first embodiment, the light transmission type photosensor is applied as the film thickness measuring unit 36. However, the present invention is not limited to this, and the film thickness of the developer on the magnetic drum 12 is changed. It goes without saying that other sensors that can be measured may be used.

  Further, in the image forming apparatus 10 according to the first embodiment, as the measurement position of the film thickness measuring unit 36, the developer on the magnetic drum 12 arrives 6 seconds after the developer supply position at the time of image formation. Although the position is applied, the present invention is not limited to this, and the measurement position of the film thickness measurement unit 36 may be determined according to the design specifications, installation environment, and the like of the image forming apparatus 10.

  On the other hand, the temperature measuring unit 38 and the humidity measuring unit 40 are provided between the developing device 16 and the film thickness measuring unit 36 and close to the outer peripheral surface of the magnetic drum 12. The temperature measuring unit 38 measures the temperature near the magnetic drum 12. In the image forming apparatus 10 according to the first embodiment, a thermistor is applied as the temperature measurement unit 38, but the temperature measurement unit 38 is not limited thereto, and other temperature sensors such as a platinum resistance thermometer or a thermocouple are used. Needless to say.

  The humidity measuring unit 40 measures the humidity near the magnetic drum 12. In the image forming apparatus 10 according to the first embodiment, the polymer film humidity sensor is applied as the humidity measuring unit 38. However, the present invention is not limited to this, and other humidity such as a ceramic humidity sensor or an electrolyte humidity sensor is used. Needless to say, a sensor may be used.

  On the other hand, the blower 42 blows air onto the magnetic drum 12 and is provided between the intermediate transfer member 18 and the film thickness measuring unit 36. In the image forming apparatus 10 according to the first embodiment, a sirocco fan is applied as the blower 42. However, the present invention is not limited to this, and other fans such as a turbo fan, a silent fan, and an air foil fan are applied. Needless to say, you can.

  FIG. 3 is a block diagram showing a main configuration of the electrical system of the image forming apparatus 10 according to the first embodiment.

  As shown in the figure, an image forming apparatus 10 includes a CPU (Central Processing Unit) 50, a ROM (Read Only Memory) 52, a RAM (Random Access Memory) 54, an NVM (Non Volatile Memory) 56, a UI (user interface). ) The panel 58 and the communication interface 60 are included.

  The CPU 50 controls the overall operation of the image forming apparatus 10. The ROM 52 functions as a storage unit that stores in advance a control program for controlling the operation of the image forming apparatus 10, a film thickness adjustment processing program to be described later, various parameters, and the like. The RAM 54 is used as a work area when various programs are executed. The NVM 56 stores various types of information that must be retained even when the power switch of the apparatus is turned off.

  The UI panel 58 includes a touch panel display or the like in which a transmissive touch panel is superimposed on a display. Various information is displayed on the display surface of the display, and desired information and instructions are input when the user touches the touch panel. Is done.

  The communication interface 60 is connected to a terminal device 62 such as a personal computer and receives various information such as image information indicating an image formed on the recording paper P from the terminal device 62.

  The CPU 50, ROM 52, RAM 54, NVM 56, UI panel 58, and communication interface 60 are connected to each other via a system bus BUS. Therefore, the CPU 50 accesses the ROM 52, RAM 54, and NVM 56, displays various information on the UI panel 58, grasps the user's operation instruction content on the UI panel 58, and communicates via the communication interface 60 from the terminal device 62. Various types of information can be received.

  The image forming apparatus 10 includes an image forming engine unit 64 that forms an image on the recording paper P by a liquid magnetography method. The image forming engine unit 64 includes the magnetic drum 12, the magnetic head 14, the developing device 16, the intermediate transfer member 18, the cleaner 20, the demagnetizing device 22, the transfer fixing roller 24, and the motors 26 and 28 described above.

  The image forming engine unit 64 is also connected to the system bus BUS. Accordingly, the CPU 50 can control the operation of the image forming engine unit 64.

  Further, the above-described film thickness measurement unit 36, temperature measurement unit 38, humidity measurement unit 40, and blower 42 are also connected to the system bus BUS. Therefore, the CPU 60 acquires film thickness information indicating the film thickness measured by the film thickness measuring unit 36, acquires temperature information (environmental information) indicating the temperature measured by the temperature measuring unit 38, and the humidity measuring unit 40. The humidity information (environmental information) indicating the humidity measured by the above can be obtained, and the operation of the blower 42 can be controlled.

  On the other hand, in the image forming apparatus 10 according to the first embodiment, the temperature and humidity measuring unit 40 measured by the temperature measuring unit 38 is used for executing the above-described film thickness adjustment processing in the ROM 52. The time-dependent change information indicating the time-dependent change in the film thickness of the developer supplied on the magnetic drum 12 corresponding to the combination with the humidity measured by the above is stored in advance.

  FIG. 4 shows a graph illustrating an example of the time-dependent change information stored in the ROM 52.

  As shown in the figure, the time-dependent change information includes the conditions of a temperature of 28 ° C. and a humidity of 80% (28 ° C./80%), a temperature of 22 ° C. and a humidity of 55% (22 ° C. / 55%) and a temperature of 15 ° C. and a humidity of 20% (15 ° C./20%). The developer with respect to the elapsed time when the developer was left on the magnetic drum 12 The result of having measured the change of the film thickness of is shown.

  By the way, the inventors changed the ratio of the rotational speed of the intermediate transfer body 18 to the rotational speed of the magnetic drum 12 (hereinafter referred to as “speed ratio”) using the image forming apparatus 10 according to the first embodiment. As a result, an experiment was conducted to examine the transfer rate, and the experimental results shown in Table 1 and FIG. 5 were obtained. The transfer rate here is the ratio of the amount of magnetic toner contained in the toner image on the intermediate transfer body 18 after transfer to the amount of toner particles contained in the toner image on the magnetic drum 12 before transfer. It is.

According to this experiment, as shown in Table 1 and FIG. 5, the transfer rate increases as the speed ratio decreases from 1.05 to 0.95, and the transfer rate peaks at a speed ratio of 0.95. Thus, it was found that the transfer rate is stable when the speed ratio is 0.95 or less.

  Therefore, in the image forming apparatus 10 according to the first embodiment, when the toner image formed on the magnetic drum 12 is transferred to the intermediate transfer body 18, the rotation speed of the intermediate transfer body 18 is the rotation speed of the magnetic drum 12. The magnetic drum 12 and the intermediate transfer member 18 are controlled so as to be slower. That is, when the CPU 50 transfers the toner image formed on the magnetic drum 12 to the intermediate transfer body 18, the motors 26 and 28 are set so that the rotation speed of the intermediate transfer body 18 is slower than the rotation speed of the magnetic drum 12. I have control.

  Needless to say, the frictional force generated between the magnetic drum 12 and the intermediate transfer member 18 increases as the speed ratio increases from 1, and the frictional force decreases as the speed ratio approaches 1.

  Therefore, in the image forming apparatus 10 according to the first embodiment, the CPU 50 controls the motors 26 and 28 so that the speed ratio becomes 0.95 in order to increase the transfer rate as much as possible while suppressing the frictional force as much as possible. is doing.

  Next, the operation of the image forming apparatus 10 according to the first embodiment will be described. First, the processing flow of the image forming engine unit 64 will be briefly described.

  When the rotational driving of the magnetic drum 12 and the intermediate transfer member 18 is started, a magnetic latent image is formed on the magnetic drum 12 by the magnetic head 14. Then, the developer stored in the liquid storage container 30 is transported by the developing roller 32 that rotates in the direction of arrow C (see FIG. 1) as the magnetic drum 12 rotates, and is formed on the magnetic drum 12. Supplied to the magnetic latent image. As a result, the magnetic latent image is visualized and becomes a toner image. The toner image is transferred to the intermediate transfer member 18 with the magnetic drum 12 and the intermediate transfer member 18 being rotated. That is, the toner image is conveyed by the magnetic drum 12 rotating in the direction of arrow A in the figure, and transferred to the outer peripheral surface of the intermediate transfer member 18. The toner image conveyed in the direction of arrow B by the intermediate transfer body 18 is transferred to the recording paper P at a position where it is in contact with the transfer and fixing roller 24 and simultaneously fixed.

  In the magnetic drum 12 on which the toner image is transferred to the intermediate transfer member 18, the transfer residual toner is conveyed to a contact position with the cleaner 20 and collected by the cleaner 20. After the transfer residual toner is collected by the cleaner 20, the magnetic drum 12 rotates and moves to the position of the demagnetizer 22 while holding the magnetic latent image, and the magnetic latent image on the magnetic drum 12 is erased by the demagnetizer 22. . As a result, the magnetic drum 12 is returned to the magnetic state before image formation.

  Next, with reference to FIG. 6, the operation of the image forming apparatus 10 when the above-described film thickness adjustment processing is executed during image formation will be described. 6 shows a film thickness adjustment processing program executed by the CPU 50 of the image forming apparatus 10 at predetermined time intervals (here, 0.1 seconds) when the image forming engine unit 64 is executing the image forming processing. The program is stored in advance in a predetermined area of the ROM 52.

  In step 100 of the figure, the film thickness information indicating the film thickness measured by the film thickness measuring unit 36 is acquired from the film thickness measuring unit 36 and the temperature information indicating the temperature measured by the temperature measuring unit 38 is measured. The humidity information acquired from the unit 38 and indicating the humidity measured by the humidity measuring unit 40 is acquired from the humidity measuring unit 40.

  In the next step 102, as described above, the temporal change information corresponding to each of the temperature indicated by the temperature information acquired in step 100 and the humidity indicated by the humidity information acquired in step 100 is read from the ROM 52.

  In the image forming apparatus 10 according to the first embodiment, as the process of step 102, the time-dependent change most suitable for each of the temperature measured by the temperature measuring unit 38 and the humidity measured by the humidity measuring unit 40 is performed. A process of reading information from the ROM 52 is applied. That is, among the above-mentioned three-time condition change information, the change information corresponding to the temperature closest to the temperature measured by the temperature measurement unit 38 and the humidity closest to the humidity measured by the humidity measurement unit 40 are obtained. A process of reading the corresponding time-dependent change information and the ROM 52 is applied. For example, when the temperature measured by the temperature measuring unit 38 is 30 ° C. and the humidity measured by the humidity measuring unit 40 is 50%, the change with time corresponding to the condition of 28 ° C./80%, 22 ° C. The time-dependent change information corresponding to the condition of / 55% is read from the ROM 52.

  In the image forming apparatus 10 according to the first embodiment, as the processing of step 102, the temperature measured by the temperature measurement unit 38 is a median value between 28 ° C. and 22 ° C. or 22 ° C. and 28 ° C. When it is the median value, the time-dependent change information corresponding to the higher temperature is read from the ROM 52, and the humidity measured by the humidity measuring unit 40 is the median of 80% and 55% or the median of 55% and 20%. When the value is a value, the process of reading the time-dependent change information corresponding to the higher humidity from the ROM 52 is applied.

  In the next step 104, the time change information corresponding to the temperature indicated by the temperature information acquired in step 100 and the time change information corresponding to the humidity indicated by the humidity information acquired in step 100, read in step 102. And the average value is calculated.

  In the next step 106, when the predetermined time has elapsed from the time corresponding to the film thickness indicated by the film thickness information acquired in step 100, using the average value calculated in step 104, the film thickness is determined. Is determined to be within a predetermined range. If the determination is negative, the process proceeds to step 108. If the determination is affirmative, the film thickness adjustment processing program is terminated.

  In the image forming apparatus 10 according to the first embodiment, the average value calculated in step 104 is used to determine in advance from the time corresponding to the film thickness indicated by the film thickness information acquired in step 100. A process is applied to determine whether or not the film thickness is in a predetermined range when a predetermined time has elapsed.

  The predetermined time here is the time from when the toner image passes over the film thickness measuring unit 36 until it reaches the contact position with the intermediate transfer member 18.

  Further, in the image forming apparatus 10 according to the first embodiment, when the film thickness of the developer on the magnetic drum 12 is within the predetermined range, the magnetic transfer from the magnetic drum 12 to the intermediate transfer member 18 is performed. When the toner image is transferred, it is impossible to visually confirm that a part of the toner image on the intermediate transfer body 18 is flowing. A value or the like obtained by computer simulation based on the design specification of the apparatus 10 can be applied. The predetermined range may be input by the user according to the application and required accuracy of the image forming apparatus 10 and this value may be applied.

  In the image forming apparatus 10 according to the first embodiment, 0.5 μm to 3 μm is applied as the predetermined range.

  On the other hand, in step 108, the film thickness indicated by the film thickness information acquired in step 100 is within the predetermined range when the toner image formed on the magnetic drum 12 is transferred to the intermediate transfer body 18. Thus, the control for adjusting the film thickness is performed, and then the film thickness adjustment processing program is terminated.

  Note that in the image forming apparatus 10 according to the first embodiment, the control for blowing air by the blower 42 is applied as the control for adjusting the film thickness in step 108.

  When the air blower 42 blows air over the magnetic drum 12 in this way, as shown in FIG. 7 as an example, the film thickness of the developer on the magnetic drum 12 is transferred from the magnetic drum 12 to the intermediate transfer member 18. When the developer on the magnetic drum 12 is simply left (the blower), the speed becomes a film thickness α (3 μm in the first embodiment) that does not cause the disturbance of the toner image on the intermediate transfer member 18 at this time. 42 when there is no ventilation by 42). The said speed changes according to the ventilation volume of the air blower 42. FIG.

  Therefore, in the image forming apparatus 10 according to the first embodiment, the air flow rate is determined according to the film thickness indicated by the film thickness information acquired in step 100.

  As the air flow rate, the film thickness measured by the film thickness measuring unit 36 after the toner image passes over the film thickness measuring unit 36 and reaches the contact position with the intermediate transfer member 18 is determined in advance. As a value that can fall within the specified range, a value obtained in advance by an experiment with an actual apparatus of the image forming apparatus 10 or a computer simulation based on a design specification of the image forming apparatus 10 can be applied.

  In the first embodiment, step 100 corresponds to an acquisition step of the present invention, step 102 corresponds to a reading step of the present invention, and steps 104 to 108 correspond to control steps of the present invention.

[Second Embodiment]
In the first embodiment, the film thickness measurement unit 36 measures the film thickness of the developing solution on the magnetic drum 12 by way of example. However, in the second embodiment, the film thickness measurement unit is described. An example of a case where measurement by 36 is not performed will be described.

  In the image forming apparatus according to the second embodiment, the ROM 52 stores in advance film thickness information indicating the film thickness of the liquid supplied onto the magnetic drum 12 by the developing device 16. The only difference is the image forming apparatus 10 according to the first embodiment, and the other configuration is the same as that of the image forming apparatus 10 according to the first embodiment. To do.

  Next, with reference to FIG. 8, the operation of the image forming apparatus 10 according to the second embodiment when the film thickness adjustment process described above is executed during image formation will be described. Note that FIG. 8 illustrates a film thickness adjustment processing program executed by the CPU 50 of the image forming apparatus 10 at predetermined time intervals (here, 0.1 seconds) when the image forming engine unit 64 is executing image forming processing. The program is stored in advance in a predetermined area of the ROM 52.

  In step 200 of the figure, temperature information indicating the temperature measured by the temperature measuring unit 38 is acquired from the temperature measuring unit 38, and humidity information indicating the humidity measured by the humidity measuring unit 40 is acquired from the humidity measuring unit 40. To do.

  In the next step 202, the time-dependent change information corresponding to the combination of the temperature indicated by the temperature information acquired in step 200 and the humidity indicated by the humidity information acquired in step 200 is read from the ROM 52, and the film thickness information is updated. Read from ROM 52.

  In the next step 204, the temporal change information corresponding to the temperature indicated by the temperature information acquired in step 200 and the humidity indicated in the humidity information acquired in step 200, read out in step 202, And the average value is calculated.

  In step 206, using the average value calculated in step 204, the film thickness is determined in advance when a predetermined time elapses from the time corresponding to the film thickness indicated by the film thickness information read in step 202. It is determined whether or not it is within a predetermined range. If a negative determination is made here, the process proceeds to step 206. If an affirmative determination is made, the film thickness adjustment processing program ends.

  In the next step 208, when the toner image formed on the magnetic drum 12 is transferred to the intermediate transfer body 18, the film thickness indicated by the film thickness information read in step 202 falls within the predetermined range. Thus, the control for adjusting the film thickness is performed, and then the film thickness adjustment processing program is terminated.

  As mentioned above, although this invention was demonstrated using said each embodiment, the technical scope of this invention is not limited to the range as described in each said embodiment. Various modifications or improvements can be added to the above-described embodiments without departing from the spirit of the invention, and embodiments to which the modifications or improvements are added are also included in the technical scope of the present invention.

  In addition, each of the above embodiments does not limit the invention described in the claims, and all combinations of features described in each of the above embodiments are indispensable for solving means of the invention. Not always. Each of the above embodiments includes inventions at various stages, and various inventions can be extracted by a combination according to the situation in a plurality of disclosed constituent requirements. Even if some constituent elements are deleted from all the constituent elements shown in each of the above embodiments, as long as an effect is obtained, a configuration in which these some constituent elements are deleted can be extracted as an invention.

  For example, in each said embodiment, although the example in the case of adjusting a film thickness with the air blower 42 was mentioned and demonstrated, this invention is not limited to this, It seems to adjust a film thickness using a heater. Alternatively, the film thickness may be adjusted by using the blower 42 and the heater together.

  Further, in each of the embodiments described above, an example of the case where the film thickness is adjusted using magnetic change information corresponding to a combination of temperature and humidity has been described, but the present invention is not limited to this, The film thickness may be adjusted using magnetic change information corresponding to one of temperature and humidity.

  Further, in each of the above-described embodiments, the description has been given by taking the form example in the case where three types of time-varying information are stored in advance in the ROM 52, but the present invention is not limited to this and is stored in the ROM 52. There may be any number of changes over time. However, in order to perform highly accurate control, a certain kind is required.

  In each of the above embodiments, the magnetic drum 12 and the intermediate transfer body 18 are rotating bodies. However, the present invention is not limited to this, and the magnetic drum 12 and the intermediate transfer body 18 may be belts.

  In addition, the configuration (see FIGS. 1 and 3) of the image forming apparatus 10 described in the above embodiments is merely an example, and it is needless to say that the configuration can be changed according to the situation without departing from the gist of the present invention. Yes.

  The flow of the film thickness adjustment processing program described in each of the above embodiments (see FIGS. 6 and 8) is also an example, and unnecessary steps can be deleted without departing from the gist of the present invention. It goes without saying that new steps can be added and the processing order can be changed.

1 is a schematic cross-sectional view illustrating a main configuration of an image forming apparatus according to an embodiment. FIG. 6 is a diagram illustrating an example of a toner image transferred from a magnetic drum to an intermediate transfer member and a peripheral state thereof. 1 is a block diagram illustrating a main configuration of an electrical system of an image forming apparatus according to an embodiment. 6 is a graph showing an example of temporal change information stored in a ROM of the image forming apparatus according to the embodiment. 6 is a graph illustrating an example of a relationship between a transfer rate and a ratio of a rotation speed of an intermediate transfer member to a rotation speed of a magnetic drum in the image forming apparatus according to the first embodiment. It is a flowchart which shows the flow of a process of the film thickness adjustment process program which concerns on 1st Embodiment. In the image forming apparatus according to the embodiment, the change with time of the film thickness of the developer on the magnetic drum when air is blown by the blower and the change with time of the film thickness of the developer on the magnetic drum when no air is blown by the fan It is a graph which shows. It is a flowchart which shows the flow of a process of the film thickness adjustment process program which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Magnetic drum (magnetic latent image holding body)
16 Developing device (liquid developer supply means)
18 Intermediate transfer member (transfer target)
36 Film thickness measuring section (first measuring means)
38 Temperature measuring part (second measuring means)
40 Humidity measuring unit (second measuring means)
42 Blower (Blowing means)
50 CPU (control means)
52 ROM (storage means, second storage means)

Claims (9)

A magnetic latent image carrier having a water-repellent surface;
Liquid developer supply means for supplying a liquid developer containing magnetic toner and an aqueous medium onto the magnetic latent image holding member in order to make the magnetic latent image formed on the magnetic latent image holding member visible.
A transfer target onto which a developed image formed on the magnetic latent image holding member is transferred by revealing the magnetic latent image with the liquid developer;
First measuring means for measuring a film thickness of the liquid developer supplied on the magnetic latent image holding body by the liquid developer supplying means on the magnetic latent image holding body;
Second measuring means for measuring at least one of temperature and humidity in the vicinity of the magnetic latent image holder;
Storage means for storing in advance time-varying information indicating a time-dependent change in the film thickness with respect to at least one of temperature and humidity measured by the second measuring means;
The time point change information corresponding to at least one of temperature and humidity measured by the second measurement unit is read from the storage unit, and the developed image is transferred to the transfer medium based on the time change information. Control means for performing control for adjusting the film thickness so that the film thickness measured by the first measurement means falls within a predetermined range;
An image forming apparatus.   The control means uses the read time-dependent change information to determine whether the film thickness falls within the range when a predetermined time elapses from the time corresponding to the film thickness measured by the first measurement means. The image forming apparatus according to claim 1, wherein the control is performed only when it is determined whether or not the film thickness is out of the range.   3. The image forming apparatus according to claim 1, wherein the first measuring unit measures the film thickness in a region where the magnetic latent image is not formed on the magnetic latent image holding member. Instead of the first measuring means, film thickness information indicating the film thickness of the liquid developer supplied on the magnetic latent image holding body by the liquid developer supplying means on the magnetic latent image holding body is stored in advance. A second storage means,
The control means reads out the temporal change information corresponding to at least one of temperature and humidity measured by the second measurement means from the storage means, and reads out the film thickness information from the second storage means, 2. Control for adjusting the film thickness based on change information so that the film thickness indicated by the film thickness information falls within the range when the developed image is transferred to the transfer target. The image forming apparatus described.   The control means uses the read time-dependent change information to determine whether the film thickness falls within the range when a predetermined time has elapsed from the time corresponding to the film thickness indicated by the film thickness information. The image forming apparatus according to claim 4, wherein the control is performed only when it is determined that the film thickness does not fall within the range. Further comprising air blowing means for blowing air onto the magnetic latent image holding body,
The image forming apparatus according to any one of claims 1 to 5, wherein the control unit performs control to blow air by the blower unit as control for adjusting the film thickness. The magnetic latent image holding body and the transferred body are each a rotating body or a belt that is rotatably supported at both ends,
The transferred body is a transfer of the developed image in a state where the transferred body and the magnetic latent image holding body are rotated.
The control means further includes the magnetic latent image holding body and the magnetic latent image holding body so that a rotation speed of the transfer body is slower than a rotation speed of the magnetic latent image holding body when the developed image is transferred to the transfer body. The image forming apparatus according to claim 1, wherein the image receiving member is controlled.   The image forming apparatus according to claim 7, wherein a ratio of a rotational speed of the transfer body to a rotational speed of the magnetic latent image holding member is 0.95 or less. A magnetic latent image holding body having water repellency on the surface and a liquid developer containing magnetic toner and an aqueous medium are held in the magnetic latent image holding for revealing the magnetic latent image formed on the magnetic latent image holding body. A liquid developer supply means for supplying onto the body; and a transfer body onto which the developed image formed on the magnetic latent image holding body is transferred by revealing the magnetic latent image with the liquid developer. Corresponding to the provided image forming device,
On the computer,
Film thickness information indicating the film thickness is obtained from a first measuring unit that measures the film thickness of the liquid developer supplied onto the magnetic latent image holding member by the liquid developer supplying unit. An acquisition step of acquiring environmental information indicating at least one of the temperature and humidity from a second measurement unit that measures at least one of temperature and humidity in the vicinity of the magnetic latent image holder,
Temporal change information corresponding to the environmental information acquired by the acquisition step from storage means that stores in advance time-dependent change information indicating the temporal change of the film thickness with respect to at least one of temperature and humidity measured by the second measurement unit A reading step of reading
A predetermined range of film thickness indicated by the film thickness information acquired by the acquisition step at the time when the developed image is transferred to the transfer target based on the temporal change information read by the reading step. A control step for performing control for adjusting the film thickness so as to fit in
A program for running