JP4502174B2 - Recording medium conveying apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording medium conveying instrumentation 置及 beauty image forming apparatus, and more particularly, a printing apparatus using an ink jet printer, the ink type label printer or the like, the electrostatic adsorption force of a recording medium such as paper or a postcard to the conveyor belt a recording medium搬装置及 beauty image forming apparatus for adsorbing by.
[0002]
[Prior art]
In an ink jet recording apparatus that performs recording on a recording medium on a conveyance belt by discharging ink from nozzles, a capping member that is arranged to be able to capping the nozzle formation surface of the recording head and a conveyance surface that is wiping the conveyance surface of the conveyance belt A capping / wiping member integrally having a cleaner, and the capping / wiping member can be set to a first position between the nozzle forming surface of the recording head and the conveying belt and a second position which is a standby position apart from the first position. Japanese Patent Application Laid-Open No. H10-228561 is known to have a good operating mechanism, perform good recording, and clean the belt surface of a conveying belt that conveys a recording medium.
[0003]
In addition, when the wiper blade that wipes off the ink adhering to the nozzle surface moves to the ink removal section, it vibrates the wiper blade to reliably remove ink and dust adhering to the wiper blade, and the wiper blade Patent Document 2 discloses a stable use.
[0004]
[Patent Document 1]
JP 2000-263801 A [Patent Document 2]
Japanese Patent Application Laid-Open No. 2002-079681
[Problems to be solved by the invention]
When transporting recording media such as paper and postcards at a high speed, in an image forming apparatus such as a printer that can maintain the flatness of the surface of the recording media with high accuracy, the transporting recording medium is pressed from above with a roller or roller. However, if the ink is not dry, the printed image may be disturbed or the ink attached to the roller may remain and adhere to the recording medium to be printed next. The function of is significantly impaired.
[0006]
Therefore, it has been proposed to transport the recording medium by electrostatic adsorption to the charging belt, but when electrostatic adsorption is used, the recording medium such as paper is electrostatically attracted to the surface of the charging belt and transported. Therefore, the above-mentioned problem is solved. However, there is no problem in a normal use state, but when a paper jam occurs on the charging belt, the paper may be peeled off from the charging belt, and ink may be imprinted on the peeled charging belt by mistake. In addition, since electrostatic adsorption is used, dust in the air, paper dust, and the like adhere to the charging belt, which causes a problem that the conveyance force of the recording medium is reduced. In some cases, the recording medium attached to the charging belt floats due to dirt on the charging belt, and the recording medium that floats contacts the recording head and damages the recording head. Since ink is wasted, there is a considerable impact on the environment.
[0007]
Present invention is to solve the problems, constantly with checking the contamination on the charging belt, by kicking setting a cleaner portion for removing the dirt on the charging belt, dependent on the use and environment of use and aging always can be kept constant, high-speed and recording medium conveying instrumentation 置及 beauty image formation makes it possible to obtain high image quality without dirt on the charging belt to ensure removal, the charge amount of the charged belt that An object is to provide an apparatus.
[0019]
[Means for Solving the Problems]
The recording medium conveying apparatus according to claim 1, wherein the recording medium conveying apparatus is configured to adsorb and convey the recording medium by electrostatic attraction on a charging belt that is sandwiched between a charging roller and an earth roller and travels. When the value from the surface potential sensor is lower than the initial value of the surface potential of the charging belt, the value from the surface potential sensor for measuring the charging belt is compared with the initial value of the surface potential of the charging belt. The charging belt is cleaned by a cleaning device when the value from the surface potential sensor is further lower than the fluctuation range due to the time-dependent change of the surface potential.
[0029]
The image forming apparatus according to claim 2, characterized by a kite comprising a recording medium conveying apparatus according to claim 1.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS. In the following embodiments, an example of an image forming apparatus will be described based on an inkjet printer, but the present invention is not limited to this.
FIG. 1 is an overall configuration explanatory view showing a main part of an ink jet printer according to an embodiment of the present invention.
In the ink jet printer shown in FIG. 1, a transport device that transports a recording medium such as paper or a postcard at a high speed and reliably employs a basic mechanism that attracts the recording medium onto the charging belt 1 functioning as a transport belt by an electrostatic attraction force. Then, a recording medium (not shown) is sucked and conveyed below the print head 8, and the print head 8 discharges ink onto the recording medium to form an image, which is discharged in the paper discharge direction shown in FIG.
[0031]
The charging belt 1 has an endless shape having a two-layer structure, and is stretched between a driving roller 2 driven by a conveyance motor (not shown) and an earth roller 3 functioning as a driven roller. The grounding roller 3 is set to a ground potential, and the charging belt 1 is sandwiched between the grounding roller 3 and the charging roller 4 provided opposite to the grounding roller 3, and a predetermined voltage is applied from the power supply substrate 5. Is granted.
[0032]
On the downstream side of the print head 8, a surface potential sensor 7 is provided as a means for measuring the surface potential of the charging belt 1, and the surface potential sensor signal output from the surface potential sensor 7 is a control installed in the ink jet printer main body. The control substrate 6 is sent to the substrate 6 and outputs a control signal for controlling the surface potential of the charging belt 1 to the power supply substrate 5.
[0033]
A space for mounting a cleaning cassette 9 for cleaning the charging belt 1 is provided below the charging belt 1 and on the downstream side of the driving roller 2, and the cleaning surface is attached to the charging belt 1 by mounting the cleaning cassette 9. Ink, dust, paper dust and the like adhering to the charging belt 1 are wiped off. Further, the set detection sensor 10 detects that the cleaning cassette 9 is mounted at a predetermined position, and outputs a set detection sensor signal to the control board 6.
[0034]
<Example 1>
The charging belt 1 is stained with ink, dust, paper dust, or the like during use, although it varies depending on use conditions and use environments. The ink stain is caused by the ink mist generated when the print head 8 erroneously prints the ink on the charging belt 1 or by the idle discharge periodically performed by the means for maintaining the state of the print head 8. It becomes.
[0035]
Since a high voltage is applied to the charging belt 1 by the charging roller 4, electric charges remain on the belt after use. For this reason, when paper dust and dust are brought close to each other and not used for a long period of time, not only the conveyance quality is drastically lowered due to the dust adhering to the charging belt 1, but also the paper jam is caused by the degradation of the conveyance quality. Cause frequent occurrence. The present invention provides a system for detecting the state of contamination using a detection means such as a surface potential sensor 7 and determining the state of the charging belt 1.
[0036]
FIG. 2 is a control block diagram for detecting the state (dirt) of the charging belt with a surface potential sensor and determining the state of the charging belt.
In the control block diagram shown in FIG. 2, the surface potential of the charging belt 1 is detected by the surface potential sensor 7, and the detection result is transferred to the control board 6. Since the detection result is an analog value, the AD conversion unit 12 in the control board 6 converts the detection result into a digital value, and transfers the digitally converted value to the CPU 15.
[0037]
Next, since the RAM 13 stores the initial value of the surface potential of the charging belt 1 at the time of shipment of the ink jet printer, the value is read and compared with the value from the surface potential sensor 7. At this time, if the value from the surface potential sensor 7 is higher than the preliminarily stored initial surface potential data, it is considered that the charging belt 1 is dirty, but the charging belt 1 is damaged due to changes over time. Since it is known that the surface potential itself is lowered, the surface potential aging correction data due to the aging change of the charging belt 1 is further read from the ROM 14 and further compared. As a result of the comparison, if it is within the fluctuation range due to the change with time, the print state is shifted as it is, but if not, that is, if the stain is severe, the external interface (I / F) is used to clean the charging belt 1. ) 16 is notified to the display panel 19 including the external connection device 18 and the display substrate 11 through 16.
[0038]
<Example 2> (Hereinafter, Examples 2 to 10 are reference examples)
As described above, the charging belt 1 is stained with ink (including ink mist), dust, paper dust, or the like during use, although it varies depending on use conditions and use environments.
As a method for removing dirt, the charging belt 1 can be cleaned directly. As a direct cleaning method, a rubber blade, bristle brush, sponge or cotton-like material is used. When a rubber blade is used, dirt such as ink can be collected, but the dirt itself cannot be removed. When a bristle brush is used, paper dust or the like accumulates in the bristle brush itself due to electrostatic action, and is not suitable for removing the original dirt. In this regard, a cotton-like material is suitable for removing ink adhering to the charging belt 1 because it sucks ink. In the present invention, it is desirable to employ a cotton-like material as the cleaning means.
[0039]
<Example 3>
As a method for removing the contamination of the charging belt 1, the direct cleaning of the charging belt with a cotton-like material or the like has been described in the second embodiment. However, the cleaning mechanism incorporated in the ink jet printer is not suitable for long-term use because maintenance cannot be performed as mentioned in the above-mentioned problem. In order to solve this problem, the present invention is characterized by providing a unit type cleaning mechanism. If the cleaning mechanism becomes a unit and the cleaning surface is housed in a cassette case, the cleaning effect of the cleaning cassette will begin to deteriorate, or if the cleaning surface of the cleaning cassette becomes dirty, a new cleaning will be performed. Replace with a cassette. As a result, the cleaning effect can be maintained indefinitely, and the deterioration of the cleaning effect can be eliminated.
[0040]
<Example 4>
As described in the first embodiment, the conveyance belt made of the charging belt 1 is contaminated with ink, dust, paper dust, or the like due to various causes. This causes frequent jams.
On the contrary, although the charging belt 1 is dirty due to erroneous detection of the surface potential sensor 7, there is a case where there is no cleaning request from the ink jet printer side, and there is a case where the cleaning cannot be performed. The erroneous detection of the surface potential sensor 7 may be caused when the harness connected to the surface potential sensor 7 is disconnected for some reason or is damaged due to an external impact applied to the surface potential sensor 7.
[0041]
As a means for solving such a situation, a cleaning switch (not shown) is provided in the ink jet printer. If the surface potential sensor 7 cannot detect the expected surface potential due to a defect in the surface potential sensor 7, the ink adheres to the back surface of the paper from which the ink is discharged, or the transport jam frequently occurs due to the influence of dust or the like. When this happens, the cleaning cassette 9 is mounted on the ink jet printer at the user's discretion. In this state, a cleaning switch prepared in advance for the ink jet printer is pressed. As a result, cleaning can be performed manually, and cleaning can be performed not only by a request from the ink jet printer but also by user judgment.
[0042]
<Example 5>
The cleaner surface of the cleaning cassette 9 is exemplified by sponge, cotton-like material, rubber blade, etc. However, when the ink attached to the charging belt 1 is to be wiped off, none of them can be wiped off completely. In order to wipe off the ink, the dirt adhering to the charging belt 1 can be completely removed by absorbing the ink. For that purpose, the cleaner surface is conveniently cotton-like, and if it is cotton-like, ink can be sucked out, which is optimal for the cleaning cassette of the present invention.
[0043]
However, when actually performed, the stain can be removed to a certain extent, but the ink is finally stretched on the charging belt 1 and cannot be completely removed. Therefore, it is necessary to impregnate the cotton-like portion of the cleaner surface with a solution that can float the ink without fixing it to the charging belt. Thereby, since the ink is not fixed on the charging belt 1, almost all of the ink adhering to the charging belt 1 can be removed by the cleaning cassette 9. Here, there are various types of solutions depending on the physical properties of the ink, but a solution containing alcohol is particularly desirable.
[0044]
<Example 6>
As described above, the transport belt made of the charging belt 1 is contaminated with ink, dust, paper dust, or the like due to various causes, so that not only the transport quality is drastically lowered, but also paper jam occurs due to the transport quality degradation. Cause. As a means for solving this problem, the present invention adopts the cleaning cassette method, but there is no means for detecting that the cleaning cassette 9 is mounted.
[0045]
Therefore, in this embodiment, a set detection sensor 10 for detecting that the cleaning cassette 9 is mounted is provided. Examples of the set detection sensor 10 include a light reflection sensor, a light transmission sensor, a switch constituted by a mechanical contact, and a connector connection. By providing the set detection sensor 10 on the ink jet printer main body side in advance, the set detection sensor 10 detects it when the cleaning cassette 9 is mounted, so the problem due to mounting failure can be solved. Conventionally, a trigger for shifting to a cleaning operation by a cleaning switch provided in the ink jet printer is determined by a user judgment. However, when the set detection sensor 10 is provided on the ink jet printer side, when the cleaning cassette 9 is mounted. You can automatically enter the cleaning mode.
[0046]
<Example 7>
As described above, the transport belt made of the charging belt 1 is contaminated with ink, dust, paper dust, or the like due to various causes, so that not only the transport quality is drastically lowered, but also paper jam occurs due to the transport quality degradation. Cause. As a means for solving this problem, a system in which the cleaning cassette 9 is mounted when necessary is adopted. However, after cleaning, the charging belt 1 is moistened by the effect of the solution soaked in the cleaner surface, so that the transport system is used. It can cause serious problems.
[0047]
As a means for solving such a problem, an internal time counter 17 that counts the time until the charging belt 1 dries after the cleaning is completed is provided in the control substrate 6 and counted. With respect to the time until drying, the time until drying is measured in advance in all the operating environment ranges where the ink jet printer is installed, and the maximum time until drying is taken as the count time. In addition, during counting, the inkjet printer notifies the external connection device (for example, personal computer (PC)) 18 that it is drying. At that time, the inkjet printer side performs control so as not to accept a print command input from the external connection device 18. Then, after the count is finished, the inkjet printer notifies the external connection device 18 that printing is possible.
[0048]
FIG. 3 is a control sequence diagram illustrating a process for cleaning the charging belt.
When the power of the inkjet printer is turned on, the initial operation is performed, the charging belt rotates, and the carriage mounted with the print head is operated. During this time, the surface potential of the charging belt is measured n times by the surface potential sensor. To do. Based on the measured value of the surface potential sensor, it is checked whether or not the charging belt is dirty. If it is determined that there is no dirt, the sequence operation is shifted to the normal operation.
When the contamination is higher than a predetermined level, a cleaning request is output, an LED on the operation panel of the ink jet printer is turned on to display an error, and a cleaning request command is output to the externally connected device.
[0049]
When a cleaning request is output, it is checked whether or not a cleaning cassette is mounted. When the user mounts the cleaning cassette and when it is detected that the cleaning cassette is mounted, cleaning of the charging belt is started. At this time, the externally connected device is notified that cleaning is to be performed.
Next, the charging belt is rotated by a predetermined amount, cleaning is performed with the cleaning cassette, and when the cleaning is completed, this is notified to the externally connected device, and a request notification is given to take out the cleaning cassette.
It is checked whether or not the cleaning cassette has been taken out. If it is detected that the cleaning cassette has been taken out, a charging belt drying waiting timer is set to notify the externally connected device that the charging belt is waiting to be dried.
[0050]
When the charging belt drying waiting timer finishes counting the time, the notification of drying waiting for the externally connected device is canceled, and it is checked whether or not cleaning has been performed three times in succession. If the cleaning is performed three times in succession, an error notification is sent to the externally connected device, the fact that the charging belt is still contaminated is displayed, and the process is terminated.
If the charging belt has not been cleaned three times in succession, the process returns to the initial operation and the cleaning process is repeated.
In the normal operation sequence, if a paper jam occurs during the printing operation, a notification requesting the removal of jammed paper is sent to the external device to check whether the jammed paper has been removed. When the removal of the jammed paper is completed, the operation moves to the initial operation.
[0051]
<Example 8>
As a means for solving the problems of the conventional cleaning mechanism, in this embodiment, the cleaning cassette 9 is provided with a cap for protecting the cleaner surface of the cleaning cassette. The function and effect of the cap are not only used for protecting the cleaner surface of the cleaning cassette 9 from dust and dirt, but also effective for long-term storage. The cap may have any shape as long as it satisfies the function of protecting the cleaner surface from dust and dirt. However, if the cap is removed during storage, the cleaner surface cannot be maintained, so at least the structure must not be easily removed. Examples of the structure that cannot be easily removed include a lock type and a packing type.
[0052]
<Example 9>
The problem of losing the cap due to forgetting to remove the cap or removing the cap poses a problem in the configuration itself in which the cap must be removed. In order to solve this problem, the present embodiment proposes an integrated cap and cleaning cassette. Since the cleaning cassette 9 itself has a cap and is in a locked state, the structure is such that the user cannot normally open the cap and touch the cleaner surface inside.
[0053]
When cleaning, the cap of the cleaning cassette 9 is unlocked by a mechanism on the ink jet printer side in the process of inserting the cleaning cassette 9 into a predetermined position of the ink jet printer. When the cleaning cassette 9 is further inserted deeply, there is a mechanism for opening the unlocked cap so that the cleaner surface of the cleaning cassette 9 is exposed. By inserting the cleaning cassette 9 to the end, the cleaner surface comes into contact with the charging belt 1 and is ready for cleaning.
[0054]
Conversely, when removing the cleaning cassette 9, when the cleaning cassette 9 is grasped and removed, the cap is first closed and the cleaning cassette 9 is capped. As it is further pulled out, the cap lock changes from the unlocked state to the locked state, and is completely locked. That is, when the cleaning cassette 9 is pulled out from the ink jet printer, the cap is locked, so that the user will not forget to close the cap.
[0055]
<Example 10>
When the charging belt 1 is severely soiled, the ink wiped off from the cleaner surface adheres, so that the effect of removing the stain is reduced. As a means for solving these problems, it is necessary that the cleaning surface of the cleaning cassette is always clean. As a means for realizing this, in this embodiment, the cleaner surface of the cleaning cassette is made movable without being fixed, and the cleaner itself is changed to a continuous configuration (endless shape).
[0056]
4A and 4B are diagrams showing an example of the cleaning cassette. FIG. 4A is a side view showing the appearance of the cleaning cassette, and FIG. 4B is a perspective view showing the internal configuration of the cleaning cassette.
In the cassette case 20 of the cleaning cassette 9, an endless cleaner surface 21 spanned between the rollers 22 and 23 is accommodated. One roller 22 is provided with a gear 24 that meshes with a drive gear in the ink jet printer and drives the cleaner surface 21 when the cleaning cassette 9 is mounted at a predetermined position of the ink jet printer.
When the cleaner surface 21 is made movable, the uncontaminated part comes into contact with the charging belt 1, so that further dirt can be removed.
[0057]
【The invention's effect】
A recording medium conveying apparatus according to claim 1, by automatically detecting the cleanliness of the strip conductive belt, the cleaning timing of the charging belt device determines automatically, it is possible to clean the best timing for the user .
[0067]
The image forming apparatus according to claim 2, by reliably remove the soil on a static-belt, the charge amount of the charged belt always can be kept constant, so it is possible to obtain a high speed and high image quality is there.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an overall configuration showing a main part of an ink jet printer according to an embodiment of the present invention.
FIG. 2 is a control block diagram for determining the state of the charging belt by detecting the state of the charging belt with a surface potential sensor.
FIG. 3 is a control sequence diagram illustrating a process for cleaning a charging belt.
4A and 4B are diagrams illustrating an example of a cleaning cassette. FIG. 4A is a side view illustrating the appearance of the cleaning cassette, and FIG. 4B is a perspective view illustrating the internal configuration of the cleaning cassette.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Charging belt, 2 ... Drive roller, 3 ... Ground roller, 4 ... Charging roller, 5 ... Power supply board, 6 ... Control board, 7 ... Surface potential sensor, 8 ... Print head, 9 ... Cleaning cassette, 10 ... Set detection Sensor 11, display board, 12 A / D converter, 13 RAM, 14 ROM, 15 CPU, 16 external I / F, 17 internal time counter, 18 externally connected device, 19 display panel , 20 ... cassette case, 21 ... cleaner surface, 22 ... driving roller, 23 ... driven roller, 24 ... gear.

Claims (2)

In a recording medium conveying apparatus that adsorbs and conveys a recording medium by an electrostatic attraction force on a charging belt that is sandwiched between a charging roller and an earth roller.
Compare the value from the surface potential sensor that measures the surface potential of the charging belt and the initial value of the surface potential of the charging belt;
When the value from the surface potential sensor is lower than the initial value of the surface potential of the charging belt, compared with data indicating the variation range due to the change in the surface potential of the charging belt with time,
A recording medium conveying apparatus, wherein the charging belt is cleaned by a cleaning device when a value from the surface potential sensor is further lower than the fluctuation range.   An image forming apparatus comprising the recording medium conveying device according to claim 1.

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