Patent Application
20160363894
Field of the Invention
The present invention relates to a heating fixing apparatus used in an image forming apparatus.
Description of the Related Art
Conventionally, an electrophotographic process is used in an image forming apparatus, such as an electrophotographic copying machine and an electrophotographic printer, and a fixing unit applies a heat fixing process to a toner image formed on a recording medium. A release wax is often included as a constituent material of electrophotographic toner in recent years. The release wax is included to adjust glossiness of a print image or to provide an effect of dispersibility of a pigment, and the release wax is added to prevent a fixation offset.
There are several types of phenomena of fixation offsets as illustrated below. When heating of a fixing member is insufficient (low temperature) in a fixing process on a recording medium, toner is not sufficiently melted, and fixing strength on the recording medium is small. Therefore, part of the toner is attached to the member. This phenomenon is called a cold offset, and the part of the fixing member with the toner appears as a defect of an image on the recording medium. The fixing strength of the fixed toner is weak, and the toner may be peeled off from the recording medium due to friction or the like. On the other hand, although the toner is sufficiently melted when the temperature of the fixing member is too high, viscosity is reduced. Part of the melted toner is peeled off from the recording medium, and the surface of the fixing member is contaminated. This phenomenon is called a hot offset that causes an image defect on the recording medium as in the cold offset.
Adding a wax component as a release agent to the toner is proposed in order to prevent the fixation offsets (Japanese Patent Application Laid-Open No. H08-184992). The release wax is included in the toner, and the release wax moves to an interface between the melted toner and the fixing member during heating and fixing. In this way, offset resistance can be improved. A technique of adding two or more types of release waxes to the toner is also proposed in order to improve the offset resistance (Japanese Patent Application Laid-Open No. 2000-3070).
Although a toner image is fixed on the recording medium by heating the toner in the fixing apparatuses, ultra-fine particles (UFP) may be generated from the toner or grease due to heat during heating.
The present invention provides a fixing apparatus that fixes a toner image on a recording medium, the apparatus including a heating rotary member configured to heat the toner image, a pressure member configured to come in contact with the heating rotary member to form a nip portion, wherein the recording medium provided with the toner image is conveyed at the nip portion, a cover configured to cover part of an outer surface of the heating rotary member to form a space together with the heating rotary member, the cover extending in a longitudinal direction of the heating rotary member, the cover comprising a partition including a surface, which an extension in the longitudinal direction of the heating rotary member intersects, on an end portion of the cover in the longitudinal direction of the heating rotary member and partitioning the space and outside of the space, and a flange provided on an end portion of the heating rotary member on a same side as the partition in the longitudinal direction of the heating rotary member and comprising an extending portion extending in a direction approaching the cover.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Preferred embodiments of the present invention will now be described in detail in accordance with the accompanying drawings.
Modes for carrying out the invention will be exemplarily described in detail based on embodiments with reference to the drawings. However, dimensions, materials, shapes and relative arrangements of constituent components described in the embodiments should be appropriately changed according to the configuration and various conditions of an apparatus in which the invention is applied. Therefore, the modes are not intended to limit the scope of the invention to the following embodiments.
<Image Forming Apparatus>
The paper feeding cassette 5 stores and houses a recording medium P. The paper feeding cassette 5 includes a paper feeding roller 6 driven based on a paper feeding start signal. In the paper feeding cassette 5, the paper feeding roller 6 separates and feeds each sheet of the recording medium P in the paper feeding cassette 5. The recording medium P passes through registration rollers 7 and a sheet path 8a and is introduced at predetermined timing to a transfer portion R that is a contact nip portion between the photosensitive drum 1 and a transfer roller 9 as a contact rotary transfer member. More specifically, the registration rollers 7 control the conveyance of the recording medium P so that a tip portion of the recording medium P reaches the transfer portion R at the same time when a tip portion of the toner image on the photosensitive drum 1 reaches the transfer portion R. The recording medium P introduced to the transfer portion R is sandwiched and conveyed through the transfer portion R, and meanwhile, a transfer bias power source not illustrated applies a transfer bias with a polarity opposite the toner to the transfer roller 9. As a result, the toner image on the surface side of the photosensitive drum 1 is electrostatically transferred to the surface of the recording medium P at the transfer portion R. A configuration regarding the process of forming an unfixed toner image on the recording medium P corresponds to an image forming unit of the present invention.
The recording medium P provided with the toner image at the transfer portion R is separated from the surface of the photosensitive drum 1 and is conveyed and introduced to a heating apparatus 11 through a sheet path 8b. A heat/pressure fixing process is applied to the toner image. Meanwhile, a cleaning apparatus 10 removes transfer residual toner and paper powder to clean the surface of the photosensitive drum 1 after the separation of the recording medium (after the transfer of the toner image to the recording medium P), and the photosensitive drum 1 is repeatedly used to create images. After passing through the heating apparatus 11, the recording medium P is guided toward a sheet path 8c and is discharged onto a paper discharge tray 14 from a discharge port 13.
<Heating Apparatus>
The film guide 21 is a heat-resistant rigid member that rotatably supports the heat-resistant film 22 and that serves as a heating element holding member and a guide member (support member) of a film. The reinforcing rigid member 20 is made of, for example, a metal channel member and functions as a rigid member for reinforcing the film guide 21. The ceramic heater 23 is a heating element that heats the film 22 (fixing nip portion) and is installed and held to oppose the inner circumferential surface of the film 22 in the longitudinal direction of the lower surface of the film guide 21. The endless (cylindrical) heat-resistant film 22 is made of a flexible heat-resistant member and is fitted onto the film guide (stay) 21 that is a film guide member including the heating element 23. The inner circumferential length of the endless heat-resistant film 22 is, for example, about 3 mm greater than the outer circumferential length of the film guide 21 including the heating element 23. Therefore, the film 22 is fitted with some room in the circumference.
The film guide 21 is made of a high heat resistance resin, such as polyimide, polyamide imide, PEEK, PPS and liquid crystal polymer, or a composite material of these resins and ceramics, metal or glass. A liquid crystal polymer is used in the present embodiments. A U-shaped sheet metal can be formed by metal, such as SUS and iron. A heat-resistant single-layer film or multi-layer film with a film thickness of 100 μm or less, preferably 40 μm to 90 μm, can be used for the film 22 to reduce the thermal capacity to improve the quick start feature. Examples of the material of the single-layer film include PTFE, PFA and FEP. The multi-layer film can be formed by coating PTFE, PFA, or FEP on the outer circumferential surface of a film made of polyimide, polyamide imide, PEEK, PES or PPS. In the present embodiments, PFA is coated on the outer circumferential surface of a polyimide film with a thickness of about 50 μm. The outside diameter of the film 22 is 18 mm.
The film 22 is rubbed against the heating element and the film guide 21 (heating support), and heat-resistant fixing grease (not illustrated) is applied on the film inner surface to reduce the rubbing resistance. Examples of the heat-resistant fixing grease include a silicone oil, such as dimethylsiloxane, methylphenylsiloxane and methylhydrosiloxane, and a fluorine oil, such as perfluoroether. A mixture of these oils and a heat-resistant fluororesin (such as PFA, PTFA and FEP) fine particles can also be used.
A pressure roller (pressure rotary member) 24 is a film outer surface contact drive unit that places the heat-resistant film 22 between the pressure roller 24 and the heating element 23 to form a nip area N (fixing nip portion) and that rotates and drives the film 22. The pressure roller 24 includes a cored bar, an elastic body layer, and a mold release layer that is an outermost layer. A bearing unit and an energization unit not illustrated cause the pressure roller 24 to sandwich the film 22 with predetermined pressing force, and the pressure roller 24 is pressed against and installed on the surface of the heating element 23. In the present embodiments, plated iron is used for the cored bar, and silicone rubber is used for the elastic body layer. A PFA tube with a thickness of about 30 μm is used for the mold release layer. The outside diameter of the pressure roller 24 is 20 mm, and the thickness of the elastic body layer is 3 mm.
A driving system not illustrated rotates and drives the pressure roller 24 at a predetermined peripheral speed in a direction of an arrow. As a result of the rotation and drive of the pressure roller 24, rotation force acts on the film 22 due to frictional force between the outer circumferential surface of the pressure roller 24 and the outer surface (outer circumferential surface) of the film 22 at the nip portion N, and the film 22 also rotates. The inner surface (inner circumferential surface) side of the film 22 comes in close contact with and slides over the surface of the heating element 23 at the nip portion N, and the film 22 follows the pressure roller 24 and rotates at substantially the same peripheral speed as the rotation peripheral speed of the pressure roller 24 in a direction of an arrow on the circumference of the film guide 21.
Silver, palladium, glass powder (inorganic binding agent) and an organic binding agent are mixed and blended to obtain a paste, and the paste is formed in a linear belt-like shape on the substrate 27 by screen printing to obtain the resistance heating member 26 of the present embodiments. Other than silver palladium (Ag/Pd), an electric resistance material, such as RuO2 and Ta2N, can be used for the material of the resistance heating member. A resistance value of the resistance heating member is 20Ω at room temperature. A ceramics material, such as alumina and aluminum nitride, is used for the substrate 27 as a heat-resistant insulating substrate. In the present embodiments, an alumina substrate with a width of 7 mm, a length of 270 mm, and a thickness of 1 mm is used. A screen printing pattern of silver palladium is used for the power feeding electrodes 29 and 30. The overcoat layer 28 of the resistance heating member 26 is mainly intended to secure electrical insulation between the resistance heating member 26 and the surface of the heating element 23 as well as slidability of the film 22. In the present embodiments, a heat-resistant glass layer with a thickness of about 50 μm is used for the overcoat layer 28.
An alternating current power source AC feeds power to the power feeding electrodes 29 and 30 at longitudinal end portions of the resistance heating member, and the resistance heating member 26 generates heat throughout the entire length in the longitudinal direction to raise the temperature of the heating element 23. The external contact-type thermistor 25 detects the rise in temperature. The CPU 31 imports the output of the external contact-type thermistor 25 after A/D conversion, and based on the information, the power applied to the resistance heating member 26 by a triac 32 is controlled by phase control or wave number control. In this way, the temperature of the heating element 23 is controlled. More specifically, the temperature of the heating element 23 is raised if the temperature detected by the external contact-type thermistor 25 is lower than a predetermined set temperature, and the temperature is lowered if the temperature is higher than the set temperature. In this way, the electrification is controlled to maintain the heating element 23 at a certain temperature during the fixation. In the present embodiments, the output is changed by the phase control in 21 levels from 0 to 100% in increments of 5%. The output of 100% indicates an output when the heating element 23 is fully electrified.
In a state that the heating element 23 is activated at a predetermined temperature and the rotation peripheral speed of the film 22 by the rotation of the pressure roller 24 is steady and, a transfer unit introduces, to the nip portion N, the recording medium P as a material to be heated for which the image is to be fixed. The recording medium P is sandwiched and conveyed through the pressure welding nip portion N along with the film 22, and the heat of the heating element 23 is provided to the recording medium P through the film 22 to heat and fix an unfixed image (unfixed toner image) on the recording medium P to the surface of the recording medium P. The recording medium P passing through the nip portion N is separated from the surface of the film 22 and conveyed.
<Generation Mechanism of UFP>
A wax in the toner is liquefied by the heat and the pressure when the toner image passes through the nip N and is permeated to the surface of the toner from the inside of the toner. In this case, part of the wax is vaporized and released into the air. A small amount of part of the wax remains on the surface of the film 22 after passing through the nip N, and the wax is continuously heated by the film 22 and vaporized. The vaporized wax enters a liquid-phase or solid-phase fine particle state (UFP) due to the ambient temperature, and the wax floats on an air flow around the heating apparatus 11. The UFP is also generated from the sliding grease around the ceramic heater 23 that is a heating element, during heating by the heater 23. Although the sliding grease is heat-resistant, a small amount of the sliding grease is vaporized during heating by the heater and comes out from both end portions of the film 22. The sliding grease becomes liquid-phase UFP due to the ambient temperature and floats on an air flow around the heating apparatus 11.
Here, examples of the air flow around the heating apparatus 11 include an air flow caused by a cooling fan in the image forming apparatus, an air flow generated along with the conveyance of the recording medium P and an air flow generated by heating of the recording medium P by the heating apparatus 11. As for the direction of the air flow, an air flow blowing into the heating apparatus 11 from the upstream side in the recording medium conveyance direction sends the UFP to the outside of the device through the conveyance path (sheet path 8c of
The UFP in the floating state is easily condensed if the floating state is long and is easily adsorbed to surrounding members. Therefore, condensing of the UFP in the floating state can be induced from the viewpoint of reducing the release of the UFP to the outside of the device. The UFP tends to be condensed when the temperature is high and when the UFP is floating at a high concentration. Therefore, to progress the condensing, the air flow carrying the UFP can be reduced as much as possible around the generation source to stagnate the UFP (hereinafter, written as “retain the UFP”).
On that account, a greater retention space Z of the detention member 41 is better. It is also desirable that the retention space Z is a space long in the direction away from the film 22 as in the present embodiment. Due to a reason described later, the position of the wall tip of the detention member 41 can be close to the recording medium conveyance surface to weaken the air flow flowing into the retention space Z, and the time that the UFP is retained inside of the detention member 41 can be increased. Therefore, it is necessary that the detention member 41 covers around the film 22 that is a generation source of the UFP to retain the UFP just after the generation in the retention space Z. More specifically, (1) the path of the air flow for carrying the UFP from the generation source to the outside of the device can be elongated, and (2) the speed of the air flow carrying the UFP from the generation source to the outside of the device can be reduced. These can promote the condensing of the UFP and the adsorption to the surrounding members to reduce the release of the UFP to the outside of the device.
<Detention Member>
In this case, a height X of the detention member 41 from the recording medium conveyance surface at the tip of the upstream wall in the conveyance direction of the recording medium is lower than V. The distance ka between the upstream wall of the detention member 41 in the conveyance direction of the recording medium and the film 22 is equal to or smaller than 5 mm. This can reduce the speed of the air flow carrying the UFP. The reason will be described below.
As illustrated in
As illustrated in
To reduce the release of the UFP to the outside of the device, the time that the UFP is retained in the retention space Z can be increased as much as possible, and the wind flowing in the retention space Z from the upstream to the downstream in the paper conveyance direction can be weakened. In this regard, it is desirable that the direct inflow air Ks is not generated, that is, the tip height X of the upstream wall in the paper conveyance direction of the detention member 41 is equal to or smaller than V.
To further weaken the air flowing into the detention member 41, the clearance ka between the upstream wall in the recording medium conveyance direction of the detention member 41 and the film 22 can be as small as possible to cause the inflow air to hit the laminar flow Rw to weaken the inflow air. As a result of intensive studies, the present inventor has found that the laminar flow Rw exists within a range of 5 mm from the surface of the film 22. Therefore, it is desirable that the value of ka is within a range of 5 mm or less.
A larger retention space Z is better, and it is particularly effective to increase Y in
Although the air flow in the circumferential direction of the film 21 inside of the detention member 41 has been described, an air flow in the longitudinal direction also exists particularly near both ends of the detention member 41. The air flow in the longitudinal direction can also be weakened to further increase the effect of retaining the UFP. To weaken the air flow in the longitudinal direction, it is effective to provide side walls 44 for blocking the air flow in the longitudinal direction in a retention space 43 near both ends of the detention member as illustrated in
The present embodiment is characterized by using a configuration combining the side walls (partitions) 44 as first wall portions near both ends inside of the detention member 41 and the collar portions 34 as second wall portions included in the flanges in order to weaken the air flowing in the longitudinal direction of the detention member 41. Effects of the present embodiment will be described below.
In this way, an air flow bent by providing the side wall and the collar portion can be formed in upper and lower parts of the space between the film 22 and the detention member 41 to slow down the air flow. However, the following configuration can further slow down the air flow.
The gap G is provided between the side wall 44 of the detention member 41 and the film 22 to prevent the side wall 44 from coming in contact with the rotating film 22. When the gap G is greater than the length (height) K from the film surface of the collar portion 34, an air flow Fw remains that directly goes out of the detention member 41 (without hitting the collar portion 34) from the gap G as illustrated in
Therefore, as illustrated in
In
Other main dimensions of the heating apparatus of the embodiment 1 (main dimensions defined in
Based on the configuration, the shapes of the detention member 41 and the side wall 44 and the shape of the collar portion 34 (dk and hk of
As illustrated in the projection view of
As illustrated in the projection view of
As illustrated in the projection view of
As illustrated in the projection view of
The following Table 1 illustrates results of actual measurement of the UFP in the embodiments and the comparative examples.
To evaluate the UFP, a sealed chamber of 3 cubic meters is filled with purified air, and an image forming apparatus is installed in the chamber. The UFP concentration in the chamber just after five minutes of continuous printing of an image with a printing rate of 5% is measured. A nanoparticle size distribution measurement device FMPS 3091 (TSI Inc.) is used for the measurement. A monochrome LPB with a process speed of about 230 mm/second and 40 ppm is used as the image forming apparatus. Here, the unit of the UFP concentration is parts/cm3·second, and a reduction rate denotes a value indicating a ratio of reduction in the UFP concentration relative to the UFP concentration of the comparative example 1 (Ref) without the detention member.
It can be understood from the results of the embodiment 1-4 and the comparative example 2 of Table 1 that the arrangement of just the side walls 44 on the detention member 41 is more effective than the comparative example. It can also be understood that the concentration of the generated UFP can be effectively reduced by forming the flanges around the end portions of the fixing roller (fixing film) of the image fixing apparatus and the detention member in desired shapes. More specifically, the UFP concentration can be more effectively reduced by forming an area with hk≧dk (area where the side walls 44 and the collar portions 34 oppose each other in the longitudinal direction). It can also be understood that the generated UFP concentration can be more effectively reduced by making hk greater than dk and further increasing the area where the collar portions 34 and the detention member side walls 44 overlap in the side surface projection view.
In the description above, the effects of the present embodiment have been described by illustrating an example of the air flow from the inside to the outside of the detention member at the detention member end portion with reference to
Although the example of the heating apparatus of the film heating system has been described in the present embodiment, the present invention can also be applied to a heating fixing apparatus of a heat roller system and to an image forming apparatus including the heating fixing apparatus. Although the wall portions of the detention member and the collar portions are formed as in the configuration described above at both sides of the retention space in the longitudinal direction in the present embodiment, the configuration may be adopted only on one side.
According to the present embodiment, the detention member and flange configuration can be used to effectively retain the UFP generated by the wax and the fixing grease inside of the detention member (retention space). Therefore, the number of UFPs released to the outside of the image forming apparatus can be reduced by condensing the UFPs through the retention or by progressing the adsorption of the UFPs inside of the detention member.
In an embodiment 2 of the present invention, the configuration of the detention member of the embodiment 1 is improved to obtain an effect of further reducing the UFP concentration. In the embodiment 2, differences from the embodiment 1 will be mainly described. Matters not described here in the embodiment 2 are the same as in the embodiment 1.
Although the wax in the toner is a main and large contributor as a generation source of the UFP, the UFP is also generated from the fixing grease for reducing the friction between the film and the heater in some cases. The UFP caused by the fixing grease is discharged outside from both ends of the film 22, that is, from between the film 22 and the collar portions 234. Therefore, it is desirable that the collar portions 234 are also inside of the detention member 241 in order to reduce the discharge of the UFP caused by the fixing grease to the outside of the device. As a result, the UFP discharged from between the end portions of the film 22 and the collar portions 234 can be retained inside of the detention member 241 (retention space Z).
The following Table 2 illustrates results of actual measurement of the UFP based on the configuration described above. For comparison, the results of the comparative example 1 of the embodiment 1 without the detention member are also provided.
The UFP concentration is evaluated by the same method as in the embodiment 1. More specifically, a sealed chamber of 3 cubic meters is filled with purified air, and an image forming apparatus is installed in the chamber. The UFP concentration after five minutes of continuous printing of an image with a printing rate of 5% is measured. A nanoparticle size distribution measurement device FMPS 3091 (TSI Inc.) is used for the measurement as in the embodiment 1.
As can be understood from the results of Table 2, the UFP concentration of the embodiment 2 is lower than in the comparative example 1. It can also be understood that the reduction rate of the UFP concentration is large in the embodiment 2 compared to the results of the embodiment 1 (Table 1). This is because the UFP caused by the grease generated from both ends of the film 22 that is easily discharged to the outside in the detention member 41 of the embodiment 1 can be imported inside (retention space) of the detention member 241 in the detention member 241 of the embodiment 2.
Although the example of the heating apparatus of the film heating system has been described in the present embodiment, the present invention can also be applied to, for example, a pressure film side end portion configuration using a heat roller system fixing roller and a pressure film internally using grease for reducing the friction.
In an embodiment 3 of the present invention, the detention member and the flanges of the embodiment 2 are improved to obtain an effect of further reducing the UFP concentration. In the embodiment 3, differences from the embodiments 1 and 2 will be mainly described. Matters not described here in the embodiment 3 are the same as in the embodiments 1 and 2.
In the embodiment 3, collar portions and side walls of a detention member can be engaged to more thoroughly retain the UFP inside of the detention member than in the embodiment 2, and the detention member and the flange portions are integrated. In the embodiment 2, the side walls of the detention member are arranged outside of the collar portion to easily import the UFP caused by the fixing grease discharged from both end portions of the fixing film to the inside of the detention member. As a result, the UFP concentration can be reduced more than in the embodiment 1. However, there is still a gap between the side wall 244 of the detention member and the collar portion 234 in the embodiment 2, and there is an air flow path going through the gap. Therefore, a small amount of air flowing to the outside of the detention member or air flowing to the inside from the outside of the detention member may be inevitably generated. In this regard, the collar portions and the detention member are integrated to eliminate the gap in the embodiment 3.
The following Table 3 illustrates results of actual measurement of the UFP using the embodiments 3-1 and 3-2. For comparison, the results of the comparative example 1 of the embodiment 1 without the detention member are also provided.
The UFP concentration is evaluated by the same method as in the embodiment 1. More specifically, a sealed chamber of 3 cubic meters is filled with purified air, and an image forming apparatus is installed in the chamber. The UFP concentration after five minutes of continuous printing of an image with a printing rate of 5% is measured. A nanoparticle size distribution measurement device FMPS 3091 (TSI Inc.) is used for the measurement as in the embodiment 1.
As can be understood from the results of Table 3, the UFP concentration in the configurations of the embodiments 3-1 and 3-2 is reduced compared to the comparative example 1. It can also be understood that the reduction rate of the UFP concentration is higher compared to the results of the embodiment 2. In the embodiment 2, a small amount of UFP caused by the grease generated from both ends of the film is discharged to the outside from the gap between the first collar portion 234 and the side wall 244. In the embodiment 3, the side walls 344 are engaged and integrated between the first collar portions 334 and the second collar portions 335, and the gap is eliminated (retention space is closed in the longitudinal direction). Therefore, the UFP caused by the grease can be effectively imported to the retention space. It can also be understood that the reduction rate of the UFP concentration of the embodiment 3-2 of the embodiment 3 is larger than that of the embodiment 3-1. The reason will be described with reference to
In this way, the UFP can be retained in the detention member in the embodiment 3 more effectively than in the embodiment 2, and the UFP concentration can be more effectively reduced. In the embodiment 3-2, the extension portions 446 are provided at both end portions in the longitudinal direction of both upstream and downstream walls positioned in the recording medium conveyance direction of the detention member 441. The extension portion 446 may be provided only on one of the upstream wall and the downstream wall, and even in that case, the UFP concentration can be reduced more than in the embodiment 3-1. However, the effect of reducing the UFP concentration is the highest when the extension portions 446 are provided on both of the upstream and downstream walls as in the embodiment 3-2.
The present invention has been described in the embodiments based on the heating apparatus of the film system. However, a fluorine oil or a silicone oil is used on the heat roller inner surface in some cases when an induction heating system is used as a heating system of the heat roller or when a radiation type heater, such as a halogen heater, is used in place of the ceramics substrate heater. The present invention can also be applied to such a configuration, and it is obvious that the concentration of the generated UFP can be effectively reduced in the same way in the configuration.
The configurations of the embodiments can be combined with each other as much as possible. For example, the configuration of the embodiment 1 may be adopted for the configuration of the side wall (first wall portion) of the detention member and the collar portion (second wall portion) at one of the end portions, and the configuration of the embodiment 3 may be adopted at the other end portion.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2015-119552, filed Jun. 12, 2015, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-119552 | Jun 2015 | JP | national |
