JP2022001892A - Electrode for electrifying particle filter - Google Patents

Abstract

To provide an image forming system including a device that collects fine particles in a housing.SOLUTION: An image forming system comprises: a negative ion generation unit that generates negative ions that charge particles with electricity to collect electrically charged particles with static electricity; and an electret filter 81 that is positively charged with electricity and collects the electrically charged particles.SELECTED DRAWING: Figure 4

Description

Some image forming systems are equipped with a device that collects fine particles in the housing. The device comprises a negative ion generator that generates negative ions to charge the particles and a positively charged electret filter to capture the charged particles.

FIG. 1 is a schematic representation of an example image forming apparatus that can be used to carry out the various examples disclosed herein. FIG. 2 is a block diagram of an example collection device. FIG. 3 is a schematic diagram of the charging device shown in FIG. FIG. 4 is a schematic diagram of the charging device shown in FIG. FIG. 5 is a schematic view showing a part of the filter charging anode electrode of the example. FIG. 6 is a graph showing an example of the relationship between the total number of printed sheets and the surface potential of the filter. FIG. 7 is a graph showing an example of the relationship between the operating temperature of the fixing device and the charging cycle of the filter. FIG. 8 is a block diagram of a collection device of another example. FIG. 9 is a schematic diagram of the charging device shown in FIG. FIG. 10 is a schematic diagram of the charging device shown in FIG. FIG. 11 is a block diagram of a collection device of another example. FIG. 12 is a schematic diagram of the charging device shown in FIG. FIG. 13 is a block diagram of a collection device of another example. FIG. 14 is a schematic diagram of the charging device shown in FIG. FIG. 15 is a schematic diagram of a charging device of another example. FIG. 16 is a schematic diagram of a charging device of another example. FIG. 17 is a schematic diagram of a charging device of another example. FIG. 18 is a block diagram of a collection device of another example. FIG. 19 is a schematic diagram of the charging device shown in FIG.

In a filter that collects charged particles by static electricity, the static electricity weakens with the passage of time and the like, and the collection rate of charged particles decreases. If the collection rate of charged particles in the filter decreases, the filter needs to be replaced. Therefore, by charging the filter that collects the charged fine particles by static electricity, the replacement cycle of the filter is lengthened and the maintenance cost of the image forming system is reduced.

For example, the image forming system of the example includes a filter configured to collect charged particles by static electricity and a charging device configured to charge the filter. In this image forming system, the charging device may have an electrode that emits filter charging ions to charge the filter.

The image forming system of another example is configured to charge a filter configured to collect charged particles by static electricity, and to charge the filter and charge the particles to form the collected charged particles. It is equipped with a charging device. In this image forming system, the charging device is configured to emit a first ion towards the filter to charge the filter and a second ion to the particles to form the charged particles to be collected. The second ion may have a different polarity from the first ion.

Hereinafter, an example image forming system will be described with reference to the drawings. The image forming system may be an image forming apparatus such as a printer, or may be an apparatus used for an image forming apparatus or the like. In the description based on the drawings, the same elements or similar elements having the same functions are designated by the same reference numerals, and duplicate description will be omitted.

First, a schematic configuration of an example of an image forming apparatus will be described. FIG. 1 is a schematic view of an example image forming apparatus 1. The image forming apparatus 1 shown in FIG. 1 is an apparatus for forming a color image using four colors of magenta, yellow, cyan, and black. The image forming apparatus 1 includes a conveying device 10 for conveying the paper 3 which is a recording medium, image carriers 20M, 20Y, 20C, 20K in which an electrostatic latent image is formed on the surface (peripheral surface), and an electrostatic latent image. 30M, 30Y, 30C, 30K to develop a toner image, a transfer device 40 to transfer the toner image to the paper 3, a fixing device 50 to fix the toner image on the paper 3, and eject the paper 3. The discharge device 60 and the control unit 70 are provided.

The transport device 10 transports the paper 3 as a recording medium on which an image is formed on the transport path 11. The paper 3 is stacked and stored in the cassette 12, and is picked up and conveyed by the paper feed roller 13.

Each of the image carriers 20M, 20Y, 20C, and 20K is also referred to as an electrostatic latent image carrier, a photoconductor drum, or the like. The image carrier 20M forms an electrostatic latent image for forming a magenta toner image. The image carrier 20Y forms an electrostatic latent image for forming a yellow toner image. The image carrier 20C forms an electrostatic latent image for forming a cyan toner image. The image carrier 20K forms an electrostatic latent image for forming a black toner image. The image carriers 20M, 20Y, 20C, and 20K basically have the same configuration. Therefore, the image carrier 20M will be described as a representative unless otherwise specified.

A developing device 30M, a charging roller 22M, an exposure unit 23, and a cleaning unit 24M are provided on the periphery of the image carrier 20M. On the circumferences of the image carriers 20Y, 20C, and 20K, as on the circumferences of the image carrier 20M, the developing devices 30Y, 30C, and 30K, the charging rollers, the exposure unit 23, and cleaning are also performed. A unit and is provided.

The charging roller 22M is a charging means for charging the surface of the image carrier 20M to a predetermined potential. The charging roller 22M moves following the rotation of the image carrier 20M. The exposure unit 23 exposes the surface of the image carrier 20M charged by the charging roller 22M according to the image formed on the paper 3. As a result, the potential of the portion of the surface of the image carrier 20M exposed by the exposure unit 23 changes, and an electrostatic latent image is formed. The cleaning unit 24M collects the toner remaining on the image carrier 20M.

The developing device 30M develops an electrostatic latent image formed on the image carrier 20M with the toner supplied from the toner tank 21M filled with the magenta toner and the carrier, and forms the magenta toner image. The developing device 30Y develops an electrostatic latent image formed on the image carrier 20Y with the toner supplied from the toner tank 21Y filled with the yellow toner and the carrier, and forms the yellow toner image. The developing device 30C develops an electrostatic latent image formed on the image carrier 20C with the toner supplied from the toner tank 21C filled with cyan toner and the carrier, and forms a cyan toner image. The developing device 30K develops an electrostatic latent image formed on the image carrier 20B with the toner supplied from the toner tank 21K filled with black toner and carriers to form a black toner image. The developing devices 30M, 30Y, 30C, and 30K have basically the same configuration. Therefore, unless otherwise specified, the developing apparatus 30M will be described as a representative.

The developing apparatus 30M includes a developing roller 31M for supporting the toner on the image carrier 20M. In the developing apparatus 30M, a two-component developing agent containing a toner and a carrier is used as the developing agent. That is, in the developing apparatus 30M, the toner and the carrier are adjusted to have a desired mixing ratio, and the toner is further mixed and stirred to disperse the toner, whereby the developer to which the optimum charge amount is applied is adjusted. In the developing apparatus 30M, this developing agent is supported on the developing roller 31M. Then, when the developer is conveyed to the region facing the image carrier 20M by the rotation of the developing roller 31M, the toner of the developer supported on the developing roller 31M is formed on the peripheral surface of the image carrier 20M. It moves to the electrostatic latent image and the electrostatic latent image is developed.

The transfer device 40 conveys the toner images formed by each of the developing devices 30M, 30Y, 30C, and 30K and transfers them to the paper 3. The transfer device 40 includes a transfer belt 41 for which a toner image is primarily transferred from each of the image carriers 20M, 20Y, 20C, and 20K, suspension rollers 44, 45, 46, 47 for suspending the transfer belt 41, and an image carrier. Primary transfer rollers 42M, 42Y, 42C, 42K that sandwich the transfer belt 41 together with 20M, 20Y, 20C, 20K and primary transfer the toner image from each of the image carriers 20M, 20Y, 20C, 20K to the transfer belt 41. A secondary transfer roller 43 that sandwiches the transfer belt 41 together with the suspension roller 47 and secondarily transfers each toner image from the transfer belt 41 to the paper 3.

The transfer belt 41 is an endless belt that circulates and moves by suspension rollers 44, 45, 46, 47. Each of the suspension rollers 44, 45, 46, 47 is a roller that can rotate around the axis. The suspension roller 47 is a drive roller that is rotationally driven around the axis, and the suspension rollers 44, 45, and 46 are driven rollers that are driven to rotate by the rotational drive of the suspension roller 47. The primary transfer roller 42M is provided so as to press the image carrier 20M from the inner peripheral side of the transfer belt 41. The primary transfer roller 42Y is provided so as to press the image carrier 20Y from the inner peripheral side of the transfer belt 41. The primary transfer roller 42C is provided so as to press the image carrier 20C from the inner peripheral side of the transfer belt 41. The primary transfer roller 42K is provided so as to press the image carrier 20K from the inner peripheral side of the transfer belt 41. The secondary transfer roller 43 is arranged in parallel with the suspension roller 47 with the transfer belt 41 interposed therebetween, and is provided so as to press the suspension roller 47 from the outer peripheral side of the transfer belt 41. As a result, the secondary transfer roller 43 forms a transfer nip region 14 for transferring the toner image from the transfer belt 41 to the paper 3 between the transfer belt 41 and the transfer belt 41.

The fixing device 50 passes the paper 3 through the fixing nip region to be heated and pressed, so that the toner image secondarily transferred from the transfer belt 41 to the paper 3 is attached to the paper 3 and fixed. The fixing device 50 includes a heating roller 52 that heats the paper 3 and a pressure roller 54 that presses and rotates the heating roller 52. The heating roller 52 and the pressure roller 54 are formed in a cylindrical shape, and the heating roller 52 has a heat source such as a halogen lamp inside. A fixing nip region, which is a contact region, is provided between the heating roller 52 and the pressure roller 54, and the toner image is melt-fixed to the paper 3 by passing the paper 3 through the fixing nip region.

The ejection device 60 includes ejection rollers 62 and 64 for ejecting the paper 3 on which the toner image is fixed by the fixing device 50 to the outside of the apparatus.

The control unit 70 is an electronic control unit having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The control unit 70 executes various controls by loading the program stored in the ROM into the RAM and executing the program in the CPU. The control unit 70 may be composed of a plurality of electronic control units, or may be composed of a single electronic control unit. The control unit 70 performs various controls on the image forming apparatus 1.

Subsequently, the printing process by the image forming apparatus 1 will be described. When the image signal of the recorded image is input to the image forming apparatus 1, the control unit 70 rotates the paper feed roller 13 to pick up and convey the paper 3 laminated on the cassette 12. Then, the surfaces of the image carriers 20M, 20Y, 20C, and 20K are charged to a predetermined potential by the charging roller 22M (charging step). After that, the control unit 70 irradiates the surfaces of the image carriers 20M, 20Y, 20C, and 20K with laser light by the exposure unit 23 based on the received image signal to form an electrostatic latent image (exposure step). ).

In each of the developing devices 30M, 30Y, 30C, and 30K, the electrostatic latent images formed on the image carriers 20M, 20Y, 20C, and 20K are developed to form a toner image (development step). Each toner image thus formed is primarily transferred to the transfer belt 41 in the region where each of the image carriers 20M, 20Y, 20C, and 20K and the transfer belt 41 face each other (transfer step). Each toner image formed on each of the image carriers 20M, 20Y, 20C, and 20K is sequentially laminated on the transfer belt 41 to form one laminated toner image. Then, the laminated toner image is secondarily transferred to the paper 3 conveyed by the conveying device 10 in the transfer nip region 14 where the suspension roller 47 and the secondary transfer roller 43 face each other.

The paper 3 on which the laminated toner image is secondarily transferred is conveyed to the fixing device 50. Then, when the paper 3 passes through the fixing nip region, the fixing device 50 heats and pressurizes the paper 3 between the heating roller 52 and the pressure roller 54 to melt and fix the laminated toner image to the paper 3. (Fixing process). After that, the paper 3 is discharged to the outside of the image forming apparatus 1 by the ejection rollers 62 and 64.

FIG. 2 is a block diagram of an example collection device 80. As shown in FIGS. 1 and 2, the image forming apparatus 1 includes a collecting apparatus 80.

The collecting device 80 collects particles floating in the housing space 4 defined in the housing 2 of the image forming apparatus 1. The particles collected by the collection device 80 may be, for example, UFP (Ultrafine Particles) having a size of about 5 nm to 300 nm. The particles are generated, for example, from toner, paper, components of the fixing device 50, or other peripheral parts that are heated by the fixing device 50. By arranging the collecting device 80 at a position adjacent to the fixing device 50 in which the amount of particles generated is relatively large, the particles can be collected more effectively. The collecting device 80 includes, for example, a filter 81, an air flow generating device 82, and a charging device 83.

The filter 81 collects charged particles by static electricity. The filter 81 is capable of collecting charged particles by Coulomb force by charging the surface of the filter 81. The surface of the filter 81 may be positively or negatively charged. Further, it is sufficient that at least a part of the surface of the filter 81 is charged with the polarity opposite to that of the charged particles. Hereinafter, as an example, it will be described that the charged particles are positively charged and the surface of the filter 81 is negatively charged.

The filter 81 is, for example, a laminate of a plurality of polymer sheets that have been subjected to an electret treatment. The electret treatment is, for example, a treatment in which a polymer material that has been heated and melted is solidified while applying a high voltage to give the polymer material a structure that retains charge. The filter 81 may have, for example, a simple layer structure, a honeycomb structure, or a corrugated structure. The filter 81 may be charged when collecting charged particles, and may be charged in advance or may be charged after the fact, for example.

The airflow generator 82 generates an airflow for carrying the charged particles to the filter 81. The airflow generator 82 may allow air flow between the housing space 4 and the outside of the housing 2. The airflow generator 82 can be configured by, for example, a fan. The fan may be located inside an opening formed in housing 2.

3 and 4 are schematic views of the charging device 83 shown in FIG. As shown in FIGS. 3 and 4, for example, the charging device 83 charges the particles 5 in order to form the filter charging unit 84 that charges the filter 81 and the charged particles 6 that are collected by the filter 81. It is an ionizer provided with a unit 85 and a power supply 86.

The filter charging unit 84 has, for example, a filter charging anode electrode (first electrode) 91 and a pair of filter charging cathode electrodes 92. The filter charging anode electrode 91 and the pair of filter charging cathode electrodes 92 are made of stainless steel as an example.

FIG. 5 is a schematic view showing a part of the filter charging anode electrode 91 of the example. As shown in FIGS. 3 to 5, the filter charging anode electrode 91 is connected to the power supply 86. A high voltage is applied to the filter charging anode electrode 91 by the power supply 86. The filter charging anode electrode 91 includes a plurality of needle electrodes 95. The plurality of needle electrodes 95 are arranged side by side at equal intervals, for example. The needle electrode 95 is formed so as to project, for example, in the shape of a needle or a saw blade. The pair of filter charging cathode electrodes 92 are grounded and are arranged so as to face each other. The filter charging anode electrode 91 is arranged between the pair of filter charging cathode electrodes 92. The configuration of the filter charging unit 84 is not limited to the examples of FIGS. 3 and 4, and can be appropriately changed.

As shown in FIGS. 3 and 4, in the filter charging unit 84, when the voltage applied to the filter charging anode electrode 91 is smaller than a predetermined value, the filter charging anode electrode 91 and the pair of filter charging cathode electrodes 91 are used. No current flows between the 92 and 92. However, when the voltage applied to the filter charging anode electrode 91 is equal to or higher than a predetermined value, a discharge phenomenon occurs, and a current flows between the filter charging anode electrode 91 and the pair of filter charging cathode electrodes 92. In the filter charging unit 84, the filter charging ions (first ions) are emitted from the plurality of needle electrodes 95 by the current. As the voltage applied to the filter charging anode electrode 91 increases, the amount of current (energization amount) flowing between the filter charging anode electrode 91 and the pair of filter charging cathode electrodes 92 increases, and a plurality of needle electrodes The amount of filter charging ions emitted from 95 also increases.

The filter charging ion is an ion for charging the filter 81 in order to collect the charged particles 6 by static electricity. When the filter 81 collects the charged particles 6 with negative static electricity, the filter charging ions are negative ions. The filter charging ions are emitted from each of the plurality of needle electrodes 95 in the direction pointed to by the needle electrodes 95. The direction pointed to by the needle electrode 95 is the direction in which the needle electrode 95 protrudes, and is the left direction in FIG. That is, the filter charging anode electrode 91 has a first emission direction in which the filter charging ions are discharged, and the first emission direction is the direction pointed to by the needle electrode 95.

The particle charging unit 85 has, for example, a particle charging anode electrode (second electrode) 93 and a pair of particle charging cathode electrodes 94. The particle charging anode electrode 93 and the pair of particle charging cathode electrodes 94 are, for example, made of stainless steel.

FIG. 5 is a schematic view showing a part of the example particle charging anode electrode 93. As shown in FIGS. 3 to 5, the particle charging anode electrode 93 is connected to the power supply 86. A high voltage is applied to the particle charging anode electrode 93 by the power supply 86. The particle charging anode electrode 93 includes a plurality of needle electrodes 96. The plurality of needle electrodes 96 are arranged side by side at equal intervals, for example. The needle electrode 96 is formed so as to project, for example, in the shape of a needle or a saw blade. The pair of particle charging cathode electrodes 94 are grounded and are arranged so as to face each other. The particle charging anode electrode 93 is arranged between the pair of particle charging cathode electrodes 94. The configuration of the particle charging unit 85 is not limited to the examples of FIGS. 3 and 4, and can be appropriately changed.

In the particle charging unit 85, when the voltage applied to the particle charging anode electrode 93 is smaller than a predetermined value, no current flows between the particle charging anode electrode 93 and the pair of particle charging cathode electrodes 94. However, when the voltage applied to the particle charging anode electrode 93 is equal to or higher than a predetermined value, a discharge phenomenon occurs and a current flows between the particle charging anode electrode 93 and the pair of particle charging cathode electrodes 94. In the particle charging unit 85, the particle charging ion (second ion) is emitted from the plurality of needle electrodes 96 by the current. As the voltage applied to the particle charging anode electrode 93 increases, the amount of current (energization amount) flowing between the particle charging anode electrode 93 and the pair of particle charging cathode electrodes 94 increases, and a plurality of needle electrodes The amount of particle charging ions emitted from 96 also increases.

The particle charging ion is an ion for charging the particle 5 in order to form the charged particle 6. When the filter 81 collects the charged particles 6 with negative static electricity, the particle charging ions are positive ions, and the positively charged charged particles 6 are formed by the particle charging ions. Particle charging ions are emitted from each of the plurality of needle electrodes 96 in the direction pointed to by the needle electrodes 96. The direction pointed to by the needle electrode 96 is the direction in which the needle electrode 96 protrudes, and is the left direction in FIG. That is, the particle charging anode electrode 93 has a second emission direction in which the particle charging ions are emitted, and the second emission direction is the direction pointed to by the needle electrode 96.

As shown in FIGS. 1, 2 and 4, an air flow path 8 through which the air flow 7 generated by the air flow generator 82 flows is formed in the housing space 4. The air flow path 8 is an air flow path formed at an arbitrary position in the housing space 4 by the air flow generator 82, and the air in the housing space 4 is discharged to the outside of the housing 2 and floats in the housing space 4. This is a path for carrying the particles 5 to the filter 81. That is, the air flow path 8 may be any flow path of air formed in the housing space 4 by the air flow generator 82, and may be, for example, a flow path defined by a flow path forming member such as a duct. , A flow path that is not defined by such a flow path forming member and is naturally formed in the housing space 4 may be used. When the air flow path 8 is defined by a flow path forming member such as a duct, the air flow 7 can be efficiently generated. A plurality of air flow paths 8 may be formed in the housing space 4, or may be branched and merged into a plurality of air flow paths 8. In the figure, the line indicating the outer edge of the air flow path 8 may be a flow path forming member such as a duct, and is a line virtually indicating the boundary of the air flow path 8 naturally formed in the housing space 4. May be.

In the air flow path 8, the particle charging unit 85, the filter charging unit 84, and the filter 81 are arranged in this order along the direction of the air flow 7. That is, in the direction of the air flow 7, the filter charging unit 84 having the filter charging anode electrode 91 is arranged upstream of the filter 81, and the particle charging unit 85 having the particle charging anode electrode 93 is the filter charging anode. It is arranged upstream of the filter charging unit 84 having the electrode 91. The airflow generator 82 may be arranged at any position in the air flow path 8, and may be arranged downstream of the filter 81 in the direction of the airflow 7, for example.

The filter charging unit 84 is arranged so that the plurality of needle electrodes 95 of the filter charging anode electrode 91 point toward the filter 81. That is, the plurality of needle electrodes 95 point toward the filter 81 (downstream side in the direction of the air flow 7), and the first discharge direction in which the filter charging ions of the filter charging anode electrode 91 are discharged is the filter 81. Is aimed at. Therefore, when a voltage is applied to the filter charging anode electrode 91, filter charging ions are emitted from the plurality of needle electrodes 95 toward the filter 81. As a result, the surface of the filter 81 is charged by the filter charging ions. The filter charging ions may be those that charge the surface of the filter 81 that is not charged at all, or may further charge the surface of the filter 81 that is already charged.

Further, the particle charging unit 85 is arranged so that the plurality of needle electrodes 96 of the particle charging anode electrode 93 point away from the filter 81. That is, the plurality of needle electrodes 96 point toward the direction away from the filter 81, and the second emission direction in which the particle charging ions of the particle charging anode electrode 93 are discharged is directed toward the direction away from the filter 81. .. For example, the plurality of needle electrodes 96 point in the direction opposite to the filter 81 (upstream side in the direction of the air flow 7), and the second emission direction in which the particle charging ions of the particle charging anode electrode 93 are discharged is , Is directed in the opposite direction of the filter 81. Therefore, when a voltage is applied to the particle charging anode electrode 93, the particle charging ions are emitted from the plurality of needle electrodes 96 toward the side away from the filter 81, for example, in the direction opposite to the filter 81. .. As a result, the particles 5 contained in the air flow 7 of the air flow path 8 are charged by the particle charging ions to become charged particles 6, and the charged particles 6 are collected by the filter 81 charged by the filter charging ions. ..

As shown in FIGS. 2 to 4, the control unit 70 is charged so as to selectively switch between applying a voltage to the filter charging anode electrode 91 and applying a voltage to the particle charging anode electrode 93. It controls the power supply of the device 83. That is, the control unit 70 does not apply a voltage from the power supply 86 to the particle charging anode electrode 93 while the voltage is being applied from the power supply 86 to the filter charging anode electrode 91. On the other hand, the control unit 70 does not apply a voltage from the power supply 86 to the filter charging anode electrode 91 while the voltage is being applied from the power supply 86 to the particle charging anode electrode 93.

It is not always necessary to apply the voltage to the filter charging anode electrode 91 or the particle charging anode electrode 93, and it may be performed at any timing. For example, the control unit 70 may apply a voltage to the particle charging anode electrode 93 only when it is desired to collect the particles 5 floating in the housing space 4. Further, the control unit 70 may apply a voltage to the filter charging anode electrode 91 only when it is desired to charge the filter 81. The control unit 70 operates the airflow generator 82 when a voltage is applied to the filter charging anode electrode 91 or the particle charging anode electrode 93. The control unit 70 may operate the airflow generator 82 when no voltage is applied to the filter charging anode electrode 91 or the particle charging anode electrode 93.

By the way, as the number of integrated prints of the image forming apparatus 1 increases, the surface potential of the filter 81 becomes smaller. As the surface potential of the filter 81 decreases, the collection rate of the filter 81 also decreases. Therefore, the control unit 70 may determine the timing of applying the voltage to the filter charging anode electrode 91 based on at least one of the surface potential of the filter 81 and the total number of printed sheets of the image forming apparatus 1. That is, as shown in FIG. 6, when the surface potential of the filter 81 becomes smaller than a predetermined threshold potential, the control unit 70 may apply a voltage to the filter charging anode electrode 91 to charge the filter 81. The surface potential of the filter 81 can be obtained, for example, from the measured value of the measuring instrument attached to the filter 81. Further, when the cumulative number of prints of the image forming apparatus 1 exceeds a predetermined threshold value, the control unit 70 may apply a voltage to the filter charging anode electrode 91 to charge the filter 81. The total number of prints of the image forming apparatus 1 can be obtained from, for example, the log information of the image forming apparatus 1.

In the fixing device 50, when the temperature of the fixing device 50 rises, the vaporized substance that is the source of the particles evaporates, and the particles are generated. That is, the higher the operating temperature of the fixing device 50, the more the generation of particles is promoted, and the lower the operating temperature of the fixing device 50, the more the generation of particles is suppressed. The operating temperature of the fixing device 50 may be the maximum temperature of the fixing device 50. The surface potential of the filter 81 becomes smaller as the charged particles 6 are captured by the filter 81. Therefore, as the number of generated particles increases, the surface potential of the filter 81 becomes smaller. Therefore, the control unit 70 may determine the charging cycle in which the voltage is applied to the filter charging anode electrode 91 based on the operating temperature of the fixing device 50. The charging cycle is, for example, the charging timing interval (number of prints) shown in FIG. That is, as shown in FIG. 7, the control unit 70 may shorten the charging cycle as the operating temperature of the fixing device 50 is higher, and may lengthen the charging cycle as the operating temperature of the fixing device 50 is lower.

In the filter charging unit 84, the larger the voltage value (voltage value) applied to the filter charging anode electrode 91, the larger the charging amount of the filter 81. Further, in the filter charging unit 84, the longer the application time of the voltage applied to the filter charging anode electrode 91, the larger the charging amount of the filter 81. On the other hand, as described above, the surface potential of the filter 81 becomes smaller as the cumulative number of printed sheets of the image forming apparatus 1 increases. Further, the higher the operating temperature of the fixing device 50, the smaller the surface potential of the filter 81. Therefore, the control unit 70 is applied to the voltage value applied to the filter charging anode electrode 91 and the filter charging anode electrode 91 based on at least one of the integrated number of prints of the image forming apparatus 1 and the operating temperature of the fixing device 50. At least one of the applied times of the voltage may be determined. For example, the control unit 70 may increase the voltage value applied to the filter charging anode electrode 91 as the number of integrated prints of the image forming apparatus 1 increases, and applies the voltage applied to the filter charging anode electrode 91. You may lengthen the time. Further, the control unit 70 may lengthen the marking time of the voltage applied to the filter charging anode electrode 91 as the operating temperature of the fixing device 50 becomes higher.

As described above, in the collecting device 80 shown in FIG. 2, the charging device 83 is configured to charge the filter 81. The static electricity of the filter 81 becomes weaker with the passage of time, and the collection rate of charged particles decreases. However, by charging the filter 81 with the charging device 83, the filter 81 can be used for a long period of time. can. Thereby, for example, the replacement cycle of the filter 81 can be lengthened, and the maintenance cost of the image forming apparatus 1 can be reduced.

Further, by discharging the filter charging ions from the filter charging anode electrode 91 of the charging device 83, the filter 81 can be easily charged by the filter charging ions.

Further, since the plurality of needle electrodes 95 of the filter charging anode electrode 91 point toward the filter 81, the filter charging ions can be discharged to the filter 81 from each of the plurality of needle electrodes 95. As a result, the filter 81 can be appropriately charged.

Further, in the direction of the air flow 7, the particle charging anode electrode 93 (particle charging unit 85), the filter charging anode electrode 91 (filter charging unit 84), and the filter 81 are arranged in this order. Therefore, the particles 5 contained in the air flow of the air flow path 8 can be made into charged particles 6 charged by the particles charging ions and collected by the filter 81 charged by the filter charging ions.

Further, by pointing the direction in which the plurality of needle electrodes 96 of the particle charging anode electrode 93 are separated from the filter 81, the particle charging ions can be emitted from each of the plurality of needle electrodes 96 in the direction away from the filter 81. As a result, it is possible to suppress the static elimination of the filter 81 by the particle charging ions emitted from each of the plurality of needle electrodes 96.

FIG. 8 is a block diagram of the collection device 80A of another example. The collection device 80A is used in place of the collection device 80, for example, in the image forming device 1 shown in FIG. As shown in FIG. 8, the collecting device 80A includes, for example, a filter 81, an air flow generating device 82, and a charging device 83A.

9 and 10 are schematic views of the charging device 83A shown in FIG. As shown in FIGS. 9 and 10, for example, the charging device 83A includes a filter charging portion 84A for charging the filter 81 and a particle charging portion for charging the particles in order to form the charged particles collected by the filter 81. It is an ionizer equipped with 85A and a power supply 86A.

The filter charging portion 84A has, for example, a part of the anode electrode 111 and a pair of filter charging cathode electrodes (first counter electrode) 112. The particle charging portion 85A has, for example, a part of the anode electrode 111 and a pair of particle charging cathode electrodes (second counter electrodes) 114. The anode electrode 111 is used for particle charging for forming filter charging ions (first ions) for charging the filter 81 and collected charged particles by changing the polarity of the voltage applied to the anode electrode 111. Any ion (second ion) can be released. That is, the anode electrode 111 is one electrode that emits filter charging ions and particle charging ions. The anode electrode 111 is arranged over both the filter charging portion 84A and the particle charging portion 85A. The anode electrode 111 is connected to the power supply 86A. A high voltage is applied to the anode electrode 111 by the power supply 86A. The anode electrode 111, the pair of filter charging cathode electrodes 112, and the pair of particle charging cathode electrodes 114 are, for example, made of stainless steel.

In the filter charging portion 84A, the anode electrode 111 includes a plurality of needle electrodes 115 (first electrode portion). The plurality of needle electrodes 115 are arranged side by side at equal intervals, for example. The needle electrode 115 is formed so as to project, for example, in the shape of a needle or a saw blade. The pair of filter charging cathode electrodes 112 are grounded via a switch 117 and are arranged so as to face each other. The plurality of needle electrodes 115 are arranged between the pair of filter charging cathode electrodes 112. The configuration of the filter charging portion 84A is not limited to the examples of FIGS. 9 and 10, and can be appropriately changed.

In the particle charging portion 85A, the anode electrode 111 includes a plurality of needle electrodes 116 (second electrode portions). The plurality of needle electrodes 116 are arranged side by side at equal intervals, for example. The needle electrode 116 is formed so as to project, for example, in the shape of a needle or a saw blade. The pair of particle charging cathode electrodes 114 are grounded via a switch 117 and are arranged so as to face each other. The plurality of needle electrodes 116 are arranged between the pair of particle charging cathode electrodes 114. The configuration of the particle charging portion 85A is not limited to the examples of FIGS. 9 and 10, and can be appropriately changed.

The filter charging ions are emitted from each of the plurality of needle electrodes 115 in the direction pointed to by the needle electrodes 115. The direction pointed to by the needle electrode 115 is the direction in which the needle electrode 115 protrudes. That is, the anode electrode 111 has a first discharge direction in which the filter charging ions are discharged, and this first discharge direction is the direction pointed to by the needle electrode 115. Particle charging ions are emitted from each of the plurality of needle electrodes 116 in the direction pointed to by the needle electrodes 116. The direction pointed to by the needle electrode 116 is the direction in which the needle electrode 116 protrudes. That is, the anode electrode 111 has a second emission direction in which particles charging ions are emitted, and this second emission direction is the direction pointed to by the needle electrode 116.

The switch 117 is an electric circuit component that selectively grounds a pair of filter charging cathode electrodes 112 and a pair of particle charging cathode electrodes 114. That is, the switch 117 does not ground the pair of particle charging cathode electrodes 114 while the pair of filter charging cathode electrodes 112 are grounded. On the other hand, the switch 117 does not ground the pair of filter charging cathode electrodes 112 while the pair of particle charging cathode electrodes 114 are grounded.

In the filter charging portion 84A, when the pair of filter charging cathode electrodes 112 are grounded by the switch 117 and a voltage equal to or higher than a predetermined value is applied to the anode electrode 111, a discharge phenomenon occurs and the pair of filters with the anode electrode 111 occurs. A current flows between the charging cathode electrode 112 and the charging cathode electrode 112. Then, the filter charging ions are emitted from the plurality of needle electrodes 115 by the current. As the voltage applied to the anode electrode 111 increases, the amount of current flowing between the anode electrode 111 and the pair of filter charging cathode electrodes 112 increases, and the filter charging ions emitted from the plurality of needle electrodes 115 The amount released will also increase. The filter charging ions are emitted from each of the plurality of needle electrodes 115 in the direction pointed to by the needle electrodes 115. The direction pointed to by the needle electrode 115 is the direction in which the needle electrode protrudes.

In the particle charging portion 85A, when a pair of particle charging cathode electrodes 114 are grounded by the switch 117 and a voltage equal to or higher than a predetermined value is applied to the anode electrode 111, a discharge phenomenon occurs and a pair of particles with the anode electrode 111. A current flows between the charging cathode electrode 114 and the charging cathode electrode 114. In the particle charging portion 85A, the particle charging ions are emitted from the plurality of needle electrodes 116 by the current. As the voltage applied to the anode electrode 111 increases, the amount of current flowing between the anode electrode 111 and the pair of particle charging cathode electrodes 114 increases, and the particle charging ions emitted from the plurality of needle electrodes 116 increase. The amount released will also increase. Particle charging ions are emitted from each of the plurality of needle electrodes 116 in the direction pointed to by the needle electrodes 116. The direction pointed to by the needle electrode 116 is the direction in which the needle electrode 116 protrudes.

An insulator 118 may be arranged between each of the pair of filter charging cathode electrodes 112 and the pair of particle charging cathode electrodes 114. The insulator 118 insulates a pair of filter charging cathode electrodes 112 and a pair of particle charging cathode electrodes 114. The insulator 118 prevents current from flowing between the anode electrode 111 and the pair of particle charging cathode electrodes 114 when the pair of filter charging cathode electrodes 112 is grounded by the switch 117. Further, the insulator 118 prevents a current from flowing between the anode electrode 111 and the pair of filter charging cathode electrodes 112 when the pair of particle charging cathode electrodes 114 are grounded by the switch 117. As the insulator 118, for example, a resin-based material such as rubber is used.

As shown in FIGS. 1, 9 and 10, an air flow path 8A through which the airflow 7A generated by the airflow generator 82 flows is formed in the housing space 4. The air flow path 8A is an air flow path formed at an arbitrary position in the housing space 4 by the air flow generator 82, and the air in the housing space 4 is discharged to the outside of the housing 2 and floats in the housing space 4. This is a path for carrying the particles 5 to the filter 81. In the air flow path 8A, the particle charging portion 85A, the filter charging portion 84A, and the filter 81 are arranged in this order along the direction of the air flow 7A. That is, in the direction of the air flow 7A, the filter charging portion 84A having the plurality of needle electrodes 115 is arranged upstream of the filter 81, and the particle charging portion 85A having the plurality of needle electrodes 116 has the plurality of needle electrodes 115. It is arranged upstream of the filter charging portion 84A having. The airflow generator 82 may be arranged at any position in the air flow path 8A, and may be arranged downstream of the filter 81 in the direction of the airflow 7, for example.

The anode electrode 111 is arranged so that the plurality of needle electrodes 115 of the filter charging portion 84A point toward the filter 81, and the plurality of needle electrodes 116 of the particle charging portion 85A point toward the filter 81. .. That is, the plurality of needle electrodes 115 point toward the filter 81 (downstream side in the direction of the air flow 7), and the first discharge direction in which the filter charging ions of the anode electrode 111 are discharged is directed toward the filter 81. ing. Further, the plurality of needle electrodes 116 point toward the direction away from the filter 81, and the second emission direction in which the particle charging ions of the anode electrode 111 are discharged is directed toward the direction away from the filter 81. For example, the plurality of needle electrodes 116 point in the direction opposite to the filter 81 (upstream side in the direction of the air flow 7A), and the second emission direction in which the particle charging ions of the anode electrode 111 are emitted is the filter 81. It is directed in the opposite direction. Therefore, the pair of filter charging cathode electrodes 112 are grounded by the switch 117, and a voltage is applied to the anode electrodes 111 to release filter charging ions from the plurality of needle electrodes 115 toward the filter 81. .. As a result, the surface of the filter 81 is charged by the filter charging ions. Further, the pair of particle charging cathode electrodes 114 are grounded by the switch 117, and a voltage is applied to the anode electrodes 111 to move away from the plurality of needle electrodes 116 from the filter 81, for example, the opposite of the filter 81. Particle charging ions are emitted toward the direction. As a result, the particles 5 contained in the air flow 7A of the air flow path 8A are charged by the particle charging ions to become charged particles 6, and the charged particles 6 are collected by the filter 81 charged by the filter charging ions. ..

As shown in FIGS. 8 to 10, the control unit 70 controls the power supply of the charging device 83A so that the polarity of the voltage applied to the anode electrode 111 is selectively switched. Further, the control unit 70 controls the switch 117 so that the filter charging cathode electrode 112 or the particle charging cathode electrode 114 is selectively grounded. That is, in the control unit 70, the first state in which the switch 117 grounds the pair of filter charging cathode electrodes 112 and the power supply 86A applies a negative voltage to the anode electrode 111, and the switch 117 has a pair of particle charging cathodes. The electrode 114 is grounded, and the power supply 86A selectively switches between a second state in which a positive voltage is applied to the anode electrode 111. The first state is a state in which filter charging ions are emitted from the plurality of needle electrodes 115. The second state is a state in which particles charging ions are emitted from the plurality of needle electrodes 116.

The control unit 70 does not have to be in either the first state or the second state at all times, but may be in the first state or the second state at an arbitrary timing. For example, the control unit 70 may control the power supply 86A and the switch 117 so as to be in the second state only when it is desired to collect the particles 5 floating in the housing space 4. Further, the control unit 70 may control the power supply 86A and the switch 117 so as to be in the first state only when the filter 81 is desired to be charged. The control unit 70 operates the airflow generator 82 when the first state or the second state is set. The control unit 70 may operate the airflow generator 82 when the first state or the second state is not set.

As described above, in the collecting device 80A shown in FIG. 8, the charging device 83A is configured to charge the filter 81. The static electricity of the filter 81 becomes weaker with the passage of time, and the collection rate of charged particles decreases. However, the charging device 83A charges the filter 81 so that the filter 81 can be used for a long period of time. can. Thereby, for example, the replacement cycle of the filter 81 can be lengthened, and the maintenance cost of the image forming apparatus 1 can be reduced.

Further, by discharging the filter charging ions from the anode electrode 111 of the charging device 83A, the filter 81 can be easily charged by the filter charging ions.

Further, since the plurality of needle electrodes 115 of the filter charging portion 84A point toward the filter 81, the filter charging ions can be discharged to the filter 81 from each of the plurality of needle electrodes 115. As a result, the filter 81 can be appropriately charged.

Further, by pointing the direction away from the filter 81 by the plurality of needle electrodes 116 of the particle charging portion 85A, the particle charging ions can be emitted from each of the plurality of needle electrodes 116 toward the direction away from the filter 81. As a result, it is possible to suppress the static elimination of the filter 81 by the particle charging ions emitted from each of the plurality of needle electrodes 116.

FIG. 11 is a block diagram of the collection device 80B of another example. The collection device 80B is used in place of the collection device 80, for example, in the image forming device 1 shown in FIG. As shown in FIG. 11, the collecting device 80B includes, for example, a filter 81, an air flow generating device 82, and a charging device 83B.

FIG. 12 is a schematic view of the charging device 83B shown in FIG. As shown in FIG. 12, the charging device 83B includes, for example, a charging unit 84B that charges the filter 81 and charges the particles in order to form charged particles to be collected by the filter 81, a power supply 86B, and a rotary actuator 87B. It is an ionizer equipped with.

The charging unit 84B has, for example, an anode electrode 121 and a pair of cathode electrodes 122. The anode electrode 121 and the pair of cathode electrodes 122 are made of stainless steel as an example.

The anode electrode 121 is connected to the power supply 86B. A high voltage is applied to the anode electrode 121 by the power supply 86B. The anode electrode 121 is used for charging particles by changing the polarity of the voltage applied to the anode electrode 121 to form filter charging ions (first ions) for charging the filter 81 and charged particles to be collected. Any ion (second ion) can be released. That is, the anode electrode 121 is one electrode that emits filter charging ions and particle charging ions.

The anode electrode 121 includes a plurality of needle electrodes 123. The plurality of needle electrodes 123 are arranged side by side at equal intervals, for example. The needle electrode 123 is formed so as to project, for example, in the shape of a needle or a saw blade. The pair of cathode electrodes 122 are grounded and are arranged so as to face each other. The anode electrode 121 is arranged between the pair of cathode electrodes 122. The configuration of the charging unit 84B is not limited to the example of FIG. 12, and can be appropriately changed.

In the charging unit 84B, when a voltage equal to or higher than a predetermined value is applied to the anode electrode 121, a discharge phenomenon occurs and a current flows between the anode electrode 121 and the pair of cathode electrodes 122. Then, the current causes ions to be emitted from the plurality of needle electrodes 123. As the voltage applied to the anode electrode 121 increases, the amount of current (energization amount) flowing between the anode electrode 121 and the pair of cathode electrodes 122 increases, and the amount of ions emitted from the plurality of needle electrodes 123 increases. Will also increase. Ions are emitted from each of the plurality of needle electrodes 123 in the direction pointed to by the needle electrode 123. The direction pointed to by the needle electrode 123 is the direction in which the needle electrode 123 protrudes. That is, the anode electrode 121 has a discharge direction in which ions are discharged, and this discharge direction is the direction pointed to by the needle electrode 123. Then, in the charging unit 84B, by changing the polarity of the voltage applied to the anode electrode 121, any ion of the filter charging ion and the particle charging ion can be emitted from the plurality of needle electrodes 123.

The rotary actuator 87B rotates the charging unit 84B between the first position and the second position. The first position is a position where the plurality of needle electrodes 123 point toward the filter 81, that is, a position where the ion emission direction of the anode electrode 121 faces the filter 81. The second position is a position where the plurality of needle electrodes 123 point away from the filter 81, that is, a position where the emission direction in which ions are emitted faces away from the filter 81. For example, the second position is a position where the plurality of needle electrodes 123 point in the direction opposite to the filter 81, that is, a position in which the emission direction of the ions of the anode electrode 121 is directed in the direction opposite to the filter 81. .. The rotary actuator 87B can be configured by, for example, a rotary shaft (not shown) for holding the charging unit 84B and a motor (not shown) for rotating the rotary shaft.

As shown in FIGS. 1, 11 and 12, an air flow path 8B through which the airflow 7B generated by the airflow generator 82 flows is formed in the housing space 4. The air flow path 8B is an air flow path formed at an arbitrary position in the housing space 4 by the air flow generator 82, and the air in the housing space 4 is discharged to the outside of the housing 2 and floats in the housing space 4. This is a path for carrying the particles 5 to the filter 81. In the air flow path 8B, the charging unit 84B and the filter 81 are arranged in this order along the direction of the air flow 7B. That is, in the direction of the air flow 7B, the charging unit 84B having the plurality of needle electrodes 123 is arranged upstream of the filter 81. The airflow generator 82 may be arranged at any position in the air flow path 8B, and may be arranged downstream of the filter 81 in the direction of the airflow 7B, for example.

As shown in FIGS. 1, 11 and 12, the control unit 70 controls the rotary actuator 87B so that the charging unit 84B can be switched between the first position and the second position. Further, the control unit 70 controls the power supply of the charging device 83B so that the polarity of the voltage applied to the anode electrode 121 can be selectively switched. That is, in the control unit 70, the rotary actuator 87B sets the charging unit 84B in the first position so that the plurality of needle electrodes 123 point toward the filter 81, and the power supply 86B applies a negative voltage to the anode electrode 121. In the first state, the rotary actuator 87B positions the charging unit 84B in the second position so that the plurality of needle electrodes 123 point away from the filter 81, and the power supply 86B applies a positive voltage to the anode electrode 121. Selectively switch between the two states. The first state is a state in which filter charging ions are emitted from the plurality of needle electrodes 123. The second state is a state in which particles charging ions are emitted from the plurality of needle electrodes 123.

Therefore, in the first state, the filter charging ions are emitted from the plurality of needle electrodes 123 toward the filter 81. As a result, the surface of the filter 81 is charged by the filter charging ions. Further, in the second state, the particle charging ions are emitted from the plurality of needle electrodes 123 toward the direction away from the filter 81, for example, the direction opposite to the filter 81. As a result, the particles 5 contained in the air flow 7B of the air flow path 8B are charged by the particle charging ions to become charged particles 6, and the charged particles 6 are collected by the filter 81 charged by the filter charging ions. ..

The control unit 70 does not have to be in either the first state or the second state at all times, but may be in the first state or the second state at an arbitrary timing. For example, the control unit 70 may control the rotary actuator 87B and the power supply 86B so as to be in the second state only when it is desired to collect the particles 5 floating in the housing space 4. Further, the control unit 70 may control the rotary actuator 87B and the power supply 86B so as to be in the first state only when the filter 81 is desired to be charged. The control unit 70 operates the airflow generator 82 when the first state or the second state is set. The control unit 70 may operate the airflow generator 82 when the first state or the second state is not set.

As described above, in the collecting device 80B shown in FIG. 11, the charging device 83B is configured to charge the filter 81. The static electricity of the filter 81 becomes weaker with the passage of time, and the collection rate of charged particles decreases. However, the charging device 83B charges the filter 81 so that the filter 81 can be used for a long period of time. can. Thereby, for example, the replacement cycle of the filter 81 can be lengthened, and the maintenance cost of the image forming apparatus 1 can be reduced.

Further, by discharging the filter charging ions from the anode electrode 121 of the charging device 83B, the filter 81 can be easily charged by the filter charging ions.

Further, the control unit 70 controls the rotary actuator 87B and the power supply 86B to put them in the first state, so that the filter charging ions can be discharged to the filter 81 from the plurality of needle electrodes 123 pointing in the direction of the filter 81. .. As a result, the filter 81 can be appropriately charged.

Further, the control unit 70 controls the rotary actuator 87B and the power supply 86B to bring them into the second state, so that the particles charging ions are discharged from the plurality of needle electrodes 123 pointing in the direction away from the filter 81 in the direction away from the filter 81. can do. As a result, it is possible to suppress the static elimination of the filter 81 by the particle charging ions emitted from each of the plurality of needle electrodes 123.

FIG. 13 is a block diagram of the collection device 80C of another example. The collection device 80C is used in place of the collection device 80, for example, in the image forming device 1 shown in FIG. As shown in FIG. 13, the collecting device 80C includes, for example, a filter 81, an air flow generating device 82, and a charging device 83C.

FIG. 14 is a schematic diagram of the charging device 83C shown in FIG. As shown in FIG. 14, the charging device 83C includes, for example, a filter charging unit 84C that charges the filter 81, and a particle charging unit 85C that charges the particles to form the charged particles collected by the filter 81. It is an ionizer including a power supply 86C and a power supply 87C.

The filter charging unit 84C has, for example, a filter charging anode electrode (first electrode) 131 and a pair of filter charging cathode electrodes 132. The filter charging anode electrode 131 and the pair of filter charging cathode electrodes 132 are made of stainless steel as an example.

The filter charging anode electrode 131 is connected to the power supply 86C. A high voltage is applied to the filter charging anode electrode 131 by the power supply 86C. The filter charging anode electrode 131 includes a plurality of needle electrodes 135. The plurality of needle electrodes 135 are arranged side by side at equal intervals, for example. The needle electrode 135 is formed so as to project, for example, in the shape of a needle or a saw blade. The pair of filter charging cathode electrodes 132 are grounded and are arranged so as to face each other. The plurality of needle electrodes 135 are arranged between the pair of filter charging cathode electrodes 132. The configuration of the filter charging unit 84C is not limited to the example of FIG. 14, and can be appropriately changed.

In the filter charging unit 84C, when a voltage equal to or higher than a predetermined value is applied to the filter charging anode electrode 131, a discharge phenomenon occurs, and a current occurs between the filter charging anode electrode 131 and the pair of filter charging cathode electrodes 132. Flows. Then, the filter charging ions are emitted from the plurality of needle electrodes 135 by the current. As the voltage applied to the filter charging anode electrode 131 increases, the amount of current flowing between the filter charging anode electrode 131 and the pair of filter charging cathode electrodes 132 increases, and the current flows from the plurality of needle electrodes 135. The amount of light emitted from the filter for charging is also increased. The filter charging ions are emitted from each of the plurality of needle electrodes 135 in the direction pointed to by the needle electrodes 135. The direction pointed to by the needle electrode 135 is the direction in which the needle electrode protrudes. That is, the filter charging anode electrode 131 has a first emission direction in which the filter charging ions are discharged, and the first emission direction is the direction pointed to by the needle electrode 135.

The particle charging unit 85C has, for example, a particle charging anode electrode (second electrode) 133 and a pair of particle charging cathode electrodes 134. The particle charging anode electrode 133 and the pair of particle charging cathode electrodes 134 are, for example, made of stainless steel.

The particle charging anode electrode 133 is connected to the power supply 87C. A high voltage is applied to the particle charging anode electrode 133 by the power supply 87C. The particle charging anode electrode 133 includes a plurality of needle electrodes 136. The plurality of needle electrodes 136 are arranged side by side at equal intervals, for example. The needle electrode 136 is formed so as to project, for example, in the shape of a needle or a saw blade. The pair of particle charging cathode electrodes 134 are grounded and are arranged so as to face each other. The plurality of needle electrodes 136 are arranged between the pair of particle charging cathode electrodes 134. The configuration of the particle charging unit 85C is not limited to the example shown in FIG. 14, and can be appropriately changed.

In the particle charging unit 85C, when a voltage equal to or higher than a predetermined value is applied to the particle charging anode electrode 133, a discharge phenomenon occurs, and a current occurs between the particle charging anode electrode 133 and the pair of particle charging cathode electrodes 134. Flows. Then, the current causes the particles charging ions to be emitted from the plurality of needle electrodes 136. As the voltage applied to the particle charging anode electrode 133 increases, the amount of current flowing between the particle charging anode electrode 133 and the pair of particle charging cathode electrodes 134 increases, and the current flows from the plurality of needle electrodes 136. The amount of particles charging ions released also increases. Particle charging ions are emitted from each of the plurality of needle electrodes 136 in the direction pointed to by the needle electrode 136. The direction pointed to by the needle electrode 136 is the direction in which the needle electrode 136 protrudes. That is, the particle charging anode electrode 133 has a second emission direction in which the particle charging ions are discharged, and the second emission direction is the direction pointed to by the needle electrode 136.

As shown in FIGS. 1, 13 and 14, an air flow path 8C through which the airflow 7C generated by the airflow generator 82 flows is formed in the housing space 4. The air flow path 8C is an air flow path formed at an arbitrary position in the housing space 4 by the airflow generator 82, and the air in the housing space 4 is discharged to the outside of the housing 2 and floats in the housing space 4. This is a path for carrying the particles 5 to the filter 81. In the air flow path 8C, the particle charging unit 85C, the filter 81, and the filter charging unit 84C are arranged in this order along the direction of the air flow 7C. That is, in the direction of the air flow 7C, the particle charging unit 85C having the plurality of needle electrodes 136 is arranged upstream of the filter 81, and the filter charging unit 84C having the plurality of needle electrodes 135 is arranged downstream of the filter 81. Has been done. The airflow generator 82 may be arranged at any position in the air flow path 8C, and may be arranged downstream of the filter charging unit 84C in the direction of the airflow 7C, for example.

The filter charging unit 84C is arranged so that the plurality of needle electrodes 135 of the filter charging anode electrode 131 point toward the filter 81, and the filter charging ions of the filter charging anode electrode 131 are discharged. The first emission direction is directed to the filter 81. That is, the plurality of needle electrodes 135 point toward the filter 81 (upstream side in the direction of the air flow 7C). Therefore, when a voltage is applied to the filter charging anode electrode 131, filter charging ions are emitted from the plurality of needle electrodes 135 toward the filter 81. As a result, the surface of the filter 81 is charged by the filter charging ions.

Further, the particle charging unit 85C is arranged so that the plurality of needle electrodes 136 of the particle charging anode electrode 133 point away from the filter 81, and the particle charging ions of the particle charging anode electrode 133 are discharged. The second emission direction is directed away from the filter 81. For example, the plurality of needle electrodes 136 point in the direction opposite to the filter 81 (upstream side in the direction of the air flow 7C), and the second emission direction in which the particle charging ions of the particle charging anode electrode 133 are discharged is , Is directed in the opposite direction of the filter 81. Therefore, when a voltage is applied to the particle charging anode electrode 133, the particle charging ions are emitted from the plurality of needle electrodes 136 toward the side away from the filter 81, for example, in the direction opposite to the filter 81. .. As a result, the particles 5 contained in the air flow 7C of the air flow path 8C are charged by the particle charging ions to become charged particles 6, and the charged particles 6 are collected by the filter 81 charged by the filter charging ions. ..

As shown in FIGS. 1, 13 and 14, the control unit 70 powers the charging device 83C so that the voltage is applied to the filter charging anode electrode 131 and the particle charging anode electrode 133 at an arbitrary timing. Control the supply. The control unit 70 operates the airflow generator 82 when a voltage is applied to the filter charging anode electrode 131 or the particle charging anode electrode 133. The control unit 70 may operate the airflow generator 82 when no voltage is applied to the filter charging anode electrode 131 or the particle charging anode electrode 133.

Here, since the filter charging unit 84C is arranged downstream of the filter 81 in the direction of the air flow 7C, even if the filter charging ions are emitted from the plurality of needle electrodes 135 toward the filter 81, the charged particles 6 The charged particles 6 are suppressed from being statically eliminated by the filter charging ions before they are collected by the filter 81.

Therefore, the control unit 70 may control the power supply of the charging device 83C so that the voltage is applied to the filter charging anode electrode 131 and the particle charging anode electrode 133 at the same time, for example. That is, the control unit 70 applies the voltage from the power supply 86C to the filter charging anode electrode 131 and the voltage from the power supply 87C to the particle charging anode electrode 133 at the same time. 87C may be controlled.

As described above, in the collecting device 80C shown in FIG. 13, the charging device 83C is configured to charge the filter 81. The static electricity of the filter 81 becomes weaker with the passage of time, and the collection rate of charged particles decreases. However, the charging device 83C charges the filter 81 so that the filter 81 can be used for a long period of time. can. Thereby, for example, the replacement cycle of the filter 81 can be lengthened, and the maintenance cost of the image forming apparatus 1 can be reduced.

Further, by discharging the filter charging ions from the filter charging anode electrode 131 of the charging device 83C, the filter 81 can be easily charged by the filter charging ions.

Further, since the plurality of needle electrodes 135 of the filter charging unit 84C point toward the filter 81, the filter charging ions can be discharged to the filter 81 from each of the plurality of needle electrodes 135. As a result, the filter 81 can be appropriately charged.

Further, by pointing the direction away from the filter 81 by the plurality of needle electrodes 136 of the particle charging unit 85C, the particle charging ions can be discharged from each of the plurality of needle electrodes 136 toward the direction away from the filter 81. As a result, it is possible to suppress the static elimination of the filter 81 by the particle charging ions emitted from each of the plurality of needle electrodes 136.

Further, by arranging the filter charging unit 84C downstream of the filter 81 in the direction of the air flow 7C, even if a voltage is applied to the filter charging anode electrode 131 and the particle charging anode electrode 133 at the same time, the particles 5 can be generated. It can be charged and collected in the filter 81. Further, by applying a voltage to the filter charging anode electrode 131 and the particle charging anode electrode 133 at the same time, for example, the charge amount of the filter 81 decreases or the charge amount of the filter 81 decreases even if the time elapses or the number of printed sheets increases. It is possible to suppress a large decrease.

FIG. 18 is a block diagram of another example collection device 80G. The collection device 80G is used in place of the collection device 80, for example, in the image forming device 1 shown in FIG. As shown in FIG. 18, the collecting device 80G includes, for example, a filter 81, an air flow generating device 82, and a charging device 83G.

FIG. 19 is a schematic view of the charging device 83G shown in FIG. As shown in FIG. 19, the charging device 83G includes, for example, a filter charging unit 84G that charges the filter 81, and a particle charging unit 85G that charges the particles to form the charged particles collected by the filter 81. An ionizer equipped with a power supply (not shown).

The filter charging unit 84G has, for example, a filter charging anode electrode (first electrode) 141 and a pair of filter charging cathode electrodes 142. The filter charging anode electrode 141 and the pair of filter charging cathode electrodes 142 are, for example, made of stainless steel.

The filter charging anode electrode 141 is connected to a power source. A high voltage is applied to the filter charging anode electrode 141 by a power source. The filter charging anode electrode 141 includes a plurality of needle electrodes 145. The plurality of needle electrodes 145 are arranged side by side at equal intervals, for example. The needle electrode 145 is formed so as to project in the shape of a needle or a saw blade, for example. The pair of filter charging cathode electrodes 142 are grounded and are arranged so as to face each other. The plurality of needle electrodes 145 are arranged between the pair of filter charging cathode electrodes 142. The configuration of the filter charging unit 84G is not limited to the example of FIG. 19, and can be appropriately changed.

In the filter charging unit 84G, when a voltage equal to or higher than a predetermined value is applied to the filter charging anode electrode 141, a discharge phenomenon occurs, and a current occurs between the filter charging anode electrode 141 and the pair of filter charging cathode electrodes 142. Flows. Then, the filter charging ions are emitted from the plurality of needle electrodes 145 by the current. As the voltage applied to the filter charging anode electrode 141 increases, the amount of current flowing between the filter charging anode electrode 141 and the pair of filter charging cathode electrodes 142 increases, and the current flows from the plurality of needle electrodes 145. The amount of light emitted from the filter for charging is also increased. The filter charging ions are emitted from each of the plurality of needle electrodes 145 in the direction pointed to by the needle electrodes 145. The direction pointed to by the needle electrode 145 is the direction in which the needle electrode protrudes. That is, the filter charging anode electrode 141 has a first emission direction in which the filter charging ions are discharged, and the first emission direction is the direction pointed to by the needle electrode 145.

The particle charging unit 85G has, for example, a particle charging anode electrode (second electrode) 143 and a pair of particle charging cathode electrodes 144. The particle charging anode electrode 143 and the pair of particle charging cathode electrodes 144 are, for example, made of stainless steel.

The particle charging anode electrode 143 is connected to a power source. A high voltage is applied to the particle charging anode electrode 143 by a power source. The particle charging anode electrode 143 includes a plurality of needle electrodes 146. The plurality of needle electrodes 146 are arranged side by side at equal intervals, for example. The needle electrode 146 is formed so as to project, for example, in the shape of a needle or a saw blade. The pair of particle charging cathode electrodes 144 are grounded and are arranged so as to face each other. The plurality of needle electrodes 146 are arranged between the pair of particle charging cathode electrodes 144. The configuration of the particle charging unit 85G is not limited to the example of FIG. 19, and can be appropriately changed.

In the particle charging unit 85G, when a voltage equal to or higher than a predetermined value is applied to the particle charging anode electrode 143, a discharge phenomenon occurs, and a current occurs between the particle charging anode electrode 143 and the pair of particle charging cathode electrodes 144. Flows. Then, the current causes the particles charging ions to be emitted from the plurality of needle electrodes 146. As the voltage applied to the particle charging anode electrode 143 increases, the amount of current flowing between the particle charging anode electrode 143 and the pair of particle charging cathode electrodes 144 increases, and the current flows from the plurality of needle electrodes 146. The amount of particles charging ions released also increases. Particle charging ions are emitted from each of the plurality of needle electrodes 146 in the direction pointed to by the needle electrode 146. The direction pointed to by the needle electrode 146 is the direction in which the needle electrode 146 protrudes. That is, the particle charging anode electrode 143 has a second emission direction in which the particle charging ions are discharged, and the second emission direction is the direction pointed to by the needle electrode 146.

As shown in FIGS. 1, 18 and 19, the housing space 4 is formed with an air flow path 8G through which the airflow 7G generated by the airflow generator 82 flows, and a filter charging unit region 147. .. The air flow path 8G is an air flow path formed at an arbitrary position in the housing space 4 by the air flow generator 82, and the air in the housing space 4 is discharged to the outside of the housing 2 and floats in the housing space 4. This is a path for carrying the particles 5 to the filter 81. The filter charging unit region 147 is a region arranged adjacent to the air flow path 8G.

In the air flow path 8G, the particle charging unit 85G and the filter 81 are arranged in this order along the direction of the air flow 7G. That is, in the direction of the air flow 7G, the particle charging unit 85G having the plurality of needle electrodes 146 is arranged upstream of the filter 81. The airflow generator 82 may be arranged at any position in the air flow path 8G, and may be arranged downstream of the filter 81 in the direction of the airflow 7G, for example.

The filter charging unit region 147 is arranged at a position adjacent to the filter 81. The filter charging unit 84G is arranged in the filter charging unit region 147. That is, the filter charging unit 84G is arranged at a position adjacent to the filter 81 outside the air flow path 8G. The filter charging unit 84G may be arranged at the same position as the filter 81 in the direction of the air flow 7G, may be arranged on the upstream side of the filter 81, or may be arranged on the downstream side of the filter 81. good.

For example, the air flow path 8G is defined by a flow path forming member 148 such as a duct, and the filter charging unit region 147 is formed by a shielding housing 149 arranged so as to cover a part of the flow path forming member 148. It may be imaged. In this case, the flow path forming member 148 has an opening, and the filter charging unit region 147 may be communicated with the air flow path 8G through the opening of the flow path forming member 148. However, the air flow path 8G may not be defined by the flow path forming member 148, and the filter charging unit region 147 may not be defined by the shielding housing 149.

The filter charging unit 84G is arranged in the filter charging unit region 147 so that the plurality of needle electrodes 145 of the filter charging anode electrode 141 point toward the filter 81, and the filter charging anode electrode 141 The first emission direction in which the filter charging ions are emitted is directed toward the filter 81. That is, the plurality of needle electrodes 145 point toward the filter 81. Therefore, when a voltage is applied to the filter charging anode electrode 141, filter charging ions are emitted from the plurality of needle electrodes 145 toward the filter 81. As a result, the surface of the filter 81 is charged by the filter charging ions.

Further, the particle charging unit 85G is arranged so that the plurality of needle electrodes 146 of the particle charging anode electrode 143 point away from the filter 81, and the particle charging ions of the particle charging anode electrode 143 are discharged. The second emission direction is directed away from the filter 81. For example, the plurality of needle electrodes 146 point in the direction opposite to the filter 81 (upstream side in the direction of the air flow 7G), and the second emission direction in which the particle charging ions of the particle charging anode electrode 143 are emitted is , Is directed in the opposite direction of the filter 81. Therefore, when a voltage is applied to the particle charging anode electrode 143, the particle charging ions are emitted from the plurality of needle electrodes 146 toward the side away from the filter 81, for example, in the direction opposite to the filter 81. .. As a result, the particles 5 contained in the air flow 7G of the air flow path 8G are charged by the particle charging ions to become charged particles 6, and the charged particles 6 are collected by the filter 81 charged by the filter charging ions. ..

The control unit 70 controls the power supply of the charging device 83G so that the voltage is applied to the filter charging anode electrode 141 and the particle charging anode electrode 143 at an arbitrary timing. The control unit 70 operates the airflow generator 82 when a voltage is applied to the filter charging anode electrode 141 or the particle charging anode electrode 143. The control unit 70 may operate the airflow generator 82 when no voltage is applied to the filter charging anode electrode 141 or the particle charging anode electrode 143, and the filter charging anode electrode 141 and the particle charging anode electrode 142 may be operated. The power supply of the charging device 83G may be controlled so that the voltage is applied to the electrodes 143 at the same time. Since the filter charging unit 84G is arranged at a position adjacent to the filter 81 outside the air flow path 8G, even if the filter charging ions are emitted from the plurality of needle electrodes 145 toward the filter 81, the charged particles 6 The charged particles 6 are suppressed from being statically eliminated by the filter charging ions before they are collected by the filter 81.

As described above, in the collecting device 80G shown in FIG. 18, the charging device 83G is configured to charge the filter 81. The static electricity of the filter 81 becomes weaker with the passage of time, and the collection rate of charged particles decreases. However, the charging device 83G charges the filter 81 so that the filter 81 can be used for a long period of time. can. Thereby, for example, the replacement cycle of the filter 81 can be lengthened, and the maintenance cost of the image forming apparatus 1 can be reduced.

Further, by discharging the filter charging ions from the filter charging anode electrode 141 of the charging device 83G, the filter 81 can be easily charged by the filter charging ions.

Further, since the plurality of needle electrodes 145 of the filter charging unit 84G point toward the filter 81, the filter charging ions can be discharged to the filter 81 from each of the plurality of needle electrodes 145. As a result, the filter 81 can be appropriately charged.

Further, by pointing the direction away from the filter 81 by the plurality of needle electrodes 146 of the particle charging unit 85G, the particle charging ions can be discharged from each of the plurality of needle electrodes 146 toward the direction away from the filter 81. As a result, it is possible to suppress the static elimination of the filter 81 by the particle charging ions emitted from each of the plurality of needle electrodes 146.

Further, since the filter charging unit 84G is arranged at a position adjacent to the filter 81 outside the air flow path 8G, even if a voltage is applied to the filter charging anode electrode 141 and the particle charging anode electrode 143 at the same time, the voltage may be applied. The particles 5 can be charged and collected by the filter 81. By applying a voltage to the filter charging anode electrode 141 and the particle charging anode electrode 143 at the same time, for example, even if time elapses or the number of printed sheets increases, the charging amount of the filter 81 decreases or greatly decreases. Can be suppressed.

Further, since the filter charging unit 84G is arranged outside the air flow path 8G, it is possible to suppress the air flow 7G from being obstructed by the filter charging unit 84G. As a result, the pressure loss of the airflow 7G is suppressed, so that the flow rate of the airflow 7G can be secured.

It should be understood that all aspects, advantages and features described herein are not necessarily achieved or included by any one particular example and embodiment. In fact, although various examples have been described and shown herein, it should be clear that other examples can be modified in their arrangement and details. All modifications and modifications contained within the spirit and scope of the protected subject matter claimed herein are claimed.

For example, when the particles are charged in advance, or when the particles are charged by another device, as shown in FIG. 15, the charging device does not have a function or a device for emitting particles for charging particles. good. Further, if the air flow can be generated in the air flow path by another device, the collecting device may not be provided with the air flow generating device. The charging device 83D shown in FIG. 15 includes a filter charging unit 84D corresponding to the filter charging unit 84 shown in FIGS. 3 and 4, and a power supply (not shown). Similar to the filter charging unit 84 shown in FIGS. 3 and 4, the filter charging unit 84D includes a filter charging anode electrode 91D having a plurality of needle electrodes 95D and a pair of filter charging cathode electrodes 92D. Have. The voltage is not always applied to the filter charging anode electrode 91D, and may be applied at any timing. The charging device 83D does not have a configuration corresponding to the particle charging unit 85 shown in FIGS. 3 and 4.

In such a case, the charging device 83D can charge the filter 81 by discharging the filter charging ions, and the charged particles 6 contained in the air flow 7D of the air flow path 8D can be used for filter charging. It can be collected by the filter 81 charged with ions. That is, the static electricity of the filter 81 becomes weaker with the passage of time and the collection rate of charged particles decreases, but the charging device 83D charges the filter 81 so that the filter 81 can be used for a long period of time. be able to. Thereby, for example, the replacement cycle of the filter 81 can be lengthened, and the maintenance cost of the image forming apparatus 1 can be reduced.

Further, as another configuration of the charging device for discharging ions in a predetermined emission direction, for example, a charging device 83E as shown in FIG. 16 can be used. The charging device 83E shown in FIG. 16 includes an anode electrode 91E extending in a wire shape and a cathode electrode 92E arranged so as to surround the anode electrode 91E. The anode electrode 91E extends in a direction intersecting the air flow, for example, in a direction orthogonal to the air flow. The cathode electrode 92E surrounds the anode electrode 91E around the axis of the anode electrode 91E, and is shaped so that a part of the anode electrode 91E around the axis is open. Therefore, when a voltage is applied to the anode electrode 91E while the cathode electrode 92E is grounded, ions are emitted from the anode electrode 91E and the ions are emitted in the direction of the opening of the cathode electrode 92E with respect to the anode electrode 91E. Is released to. That is, the direction of the opening of the cathode electrode 92E with respect to the anode electrode 91E is the emission direction in which ions are emitted. Each electrode of each of the above charging devices may be replaced with an electrode of such a charging device 83E.

Further, as another configuration of the charging device for charging the filter, for example, the charging device 83F as shown in FIG. 17 can be used. The charging device 83F shown in FIG. 17 is a device that charges the filter 81 by friction or charge injection. The charging device 83F may be triboelectrically charged, for example, by rubbing the surface of the filter 81 with a resin brush. Further, the charging device 83F may charge the filter 81 by injecting electric charge by applying a voltage to the magnetic brush in contact with the surface of the filter 81. Each of the above charging devices may be replaced with such a charging device 83F.

Claims (15)

A filter configured to collect charged particles by static electricity,
A charging device configured to charge the filter.
Image formation system. The charging device has an electrode that emits filter charging ions to charge the filter.
The image forming system according to claim 1. The electrode has an emission direction in which the filter charging ions are discharged, and is configured to emit the filter charging ions when the emission direction is directed toward the filter.
The image forming system according to claim 2. A rotary actuator configured to rotate the electrode between a first position in which the emission direction faces the filter and a second position in which the emission direction faces away from the filter is provided.
At the first position, the electrode emits the filter charging ion, and at the second position, the particle charging ion for forming the collected charged particles is emitted.
The particle charging ion has a different polarity from the filter charging ion.
The image forming system according to claim 3. The electrode corresponds to the first electrode and corresponds to the first electrode.
The charging device has a second electrode that emits particles charging ions to form the charged particles that are collected.
The second electrode has a different polarity from that of the first electrode.
The image forming system according to claim 2. The second electrode has a discharge direction in which the particle charging ions are discharged, and is configured to discharge the particle charging ions when the discharge direction points away from the filter.
The image forming system according to claim 5. The filter, the first electrode, and the air flow path in which the second electrode is arranged,
An airflow generator configured to generate an airflow in the air flow path is provided.
In the direction of the airflow, the first electrode is located upstream of the filter and the second electrode is located upstream of the first electrode.
The image forming system according to claim 5. The first electrode has a first discharge direction in which the filter charging ions are discharged, and the first discharge direction is directed downstream in the direction of the air flow.
The second electrode has a second emission direction in which the particles charging ions are emitted, and the second emission direction faces upstream in the direction of the air flow.
The image forming system according to claim 7. A control unit configured to control the power supply of the charging device so as to selectively switch between application of a voltage to the first electrode and application of a voltage to the second electrode is provided.
The image forming system according to claim 7. The filter, the first electrode, and the air flow path in which the second electrode is arranged,
An airflow generator configured to generate an airflow in the air flow path is provided.
In the direction of the airflow, the first electrode is located downstream of the filter and the second electrode is located upstream of the filter.
The image forming system according to claim 5. A control unit configured to control the power supply of the charging device and apply a voltage to the first electrode and the second electrode at the same time is provided.
The image forming system according to claim 10. A filter configured to collect charged particles by static electricity,
It comprises a charging device configured to charge the filter and charge the particles to form the charged particles to be collected.
Image formation system. The charging device is configured to emit a first ion towards the filter to charge the filter and a second ion to the particles to form the charged particles to be collected. Ori,
The second ion has a different polarity from the first ion.
The image forming system according to claim 12. The charging device has one electrode configured to release the first ion and the second ion to the filter.
The electrode has a first emission direction in which the first ion is released, a first electrode portion in which the first emission direction faces the filter, and a second emission direction in which the second ion is emitted. It also has a second electrode portion whose second emission direction is directed away from the filter.
The charging device has a first counter electrode facing the first electrode portion and a second counter electrode facing the second electrode portion.
The image forming system according to claim 13. The charging device has a first electrode configured to emit the first ion to the filter and a second electrode configured to emit the second ion to the charged particles. ,
The image forming system includes an air flow path in which the filter, the first electrode, and the second electrode are arranged, and an air flow generator configured to generate an air flow in the air flow path. ,
In the direction of the airflow, the second electrode is located upstream of the filter and the first electrode is located downstream of the filter.
The image forming system according to claim 13.

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