JP5413803B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus in an electrophotographic system such as a color printer or a color copying machine.

  In recent years, electrophotographic image forming apparatuses include apparatuses that form color images, such as color printers and color copiers, and electrophotographic image forming apparatuses that form color images include tandem recording systems. An image forming apparatus has been proposed.

  This image forming apparatus of a tandem type recording system is a color image that is a superposition of toner images by arranging a plurality of photoconductors in parallel and sequentially transferring a single color toner image formed on each photoconductor. An image forming apparatus that forms an image and records the color image on a sheet.

  In the tandem type image forming apparatus, the toner images formed on the respective photosensitive members are once transferred onto the intermediate transfer belt as an intermediate transfer member by the primary transfer device, and then collectively by the secondary transfer device. There is an indirect transfer type image forming apparatus that transfers to a sheet (for example, see Patent Document 1).

  The image forming apparatus of the tandem type indirect transfer method described in Patent Document 1 includes an image forming unit that forms a single color toner image on each photoconductor.

  The image forming unit includes a plurality of image forming means, and each image forming means exposes a drum-shaped photoconductor, a charging device for charging the photoconductor, and the charged photoconductor to form an electrostatic latent image. An optical writing device to be formed, a developing device having a developing roller for forming a toner image on the exposed photosensitive member by attaching toner, and a cleaning device for removing the toner on the photosensitive member after transferring the toner image It is.

  Each of the image forming means is arranged in parallel along the lower side running side of the intermediate transfer belt, and the intermediate transfer belt becomes higher in the height level of the image forming unit as the lower side running side is moved downstream in the running direction. Is arranged so as to be inclined downward. Further, a space having a triangular cross-sectional shape is formed vertically below the exposure means of each image forming means. A power supply unit is disposed in this space, and the power supply unit is covered with an optical writing device and a shielding member of each image forming unit.

  Further, some conventional image forming apparatuses include a blowing unit that cools the image forming unit (see, for example, Patent Document 2).

JP 2006-031054 A Japanese Patent No. 4184170

  In recent years, there has been an increasing demand for higher image forming speed.

Therefore, in the conventional image forming apparatus of the tandem type indirect transfer system, when the image forming speed is increased, the amount of heat generated in the image forming portion increases, thereby causing a chemical change in the developing device of each image forming means and the photosensitive member. Or the like, which may cause image defects, apparatus malfunctions, and the like, so that it is necessary to enhance cooling of the image forming unit.
However, downsizing of the image forming apparatus is also demanded, and there is often no space for providing a fan for supplying air to the image forming unit from vertically below the image forming unit requiring cooling.

  For this reason, the heat generated in the image forming portion accompanying the increase in the image forming speed cannot be efficiently cooled.

  In view of the circumstances described above, it is an object of the present invention to provide an image forming apparatus that efficiently cools heat generated in an image forming unit that occurs with an increase in image forming speed.

In order to achieve the above-described object, an image forming apparatus according to a first aspect of the present invention provides:
An image forming unit comprising a plurality of image forming means for forming an image;
An intermediate transfer member to which each image formed by each image forming means of the image forming unit is sequentially transferred;
First and second air blowing means provided on one end side of the image forming means;
A first guide unit and a second guide unit which are arranged on the vertically lower side of the image forming unit and respectively guide air supplied from the first and second blowing units;
The first guiding means is for guiding air from the vertically lower side to one image forming means among the plurality of image forming means,
The second guide means guides air from the vertically lower side to the image forming means other than the one image forming means among the plurality of image forming means,
When the plurality of image forming units are driven to form an image of a plurality of colors, the first blowing unit and the second blowing unit are driven, and the one image forming unit is driven to obtain a single color image. When forming, the second air blowing means is stopped.

According to a second aspect of the present invention, there is provided an image forming apparatus according to the first aspect of the present invention.
Comprising a third blowing means attached to the other end of the image forming means;
The third air blowing means supplies air collectively to at least a plurality of image forming means excluding the one image forming means among the plurality of image forming means.

According to a third aspect of the present invention, there is provided an image forming apparatus according to the second aspect of the present invention.
A power supply unit provided on a vertically lower side of the image forming unit and configured to supply power to the plurality of image forming units;
At least one of the second blowing unit and the third blowing unit supplies air to the power supply unit.

An image forming apparatus according to a fourth aspect of the present invention is the invention according to any one of the second or third aspects,
A suction unit that is disposed vertically above the image forming unit and sucks air from the other end of the image forming apparatus;
The amount of air supplied to each image forming means is supplied from the third air blowing means located on the other end side, while the air amount supplied from the first air blowing means or the second air blowing means located on the one end side is supplied. It is characterized by being less than the air volume.

An image forming apparatus according to a fifth aspect of the invention is the invention according to any one of the first to fourth aspects.
A support member for supporting the plurality of image forming means;
The support member is formed with a blowout port for blowing at least the air guided by the first guide unit and the second guide unit to the image forming units,
The blower outlet that blows air to the image forming means on the both sides of the adjacent image forming means has an opening area that is larger than the area of the opening of the blowout opening that blows air to the image forming means on the one side. It is large.

An image forming apparatus according to a sixth aspect of the present invention is the invention according to any one of the first to fifth aspects,
A support member for supporting the plurality of image forming means;
The support member is formed with a blowout port for blowing at least the air guided by the first guide unit and the second guide unit to the image forming units,
Each of the image forming means has a developing device for forming an image on a photoconductor,
An L-shaped flexible restraining member that restrains a part of the air blown out from each of the blowout ports is attached to the support member,
The restraining member includes a first portion extending in the axial direction of the developing roll at a peripheral portion near the developing roll of the blowout port, and a shaft at a peripheral portion of the blowing port close to the end of the developing roll. And a second portion extending in a direction perpendicular to the direction.

An image forming apparatus according to a seventh aspect of the invention is the invention according to any one of the first to sixth aspects,
A support member for supporting the plurality of image forming means;
The support member is formed with blowout portions for guiding the air guided to at least the first guide means and the second guide means to the image forming means, respectively.
Each of the image forming means has a developing device attached to the vertical upper side of the blow-out portion,
A flexible restraining member which is attached to the support member and restrains a part of the air blown out from each of the blowout portions;
The restraining member is formed with a contact surface that contacts a lower portion of the developing device.

  According to the first aspect of the present invention, the heat generated in the image forming portion that accompanies an increase in the image forming speed is efficiently cooled as compared with a case where no air is supplied from the vertically lower side of the developing device of each image forming means. In addition, it is possible to eliminate the waste of cooling when performing monochromatic image formation, and to prevent noise when performing monochromatic image formation as much as possible.

Further, the invention of claim 2 can increase the cooling efficiency of the image forming portion in the invention of claim 1 as compared with the case where the third air blowing means is not provided, and can perform image formation of a plurality of colors. When this is done, the number of parts of the image forming apparatus can be reduced as compared with the case where the air blowing means is provided for each image forming means.
According to a third aspect of the present invention, in the second aspect of the present invention, the air supply unit supplies air to the plurality of image forming units excluding one image forming unit, and the air is supplied to the power supply unit. The number of parts of the image forming apparatus can be reduced as compared with the case where the blowing unit is provided separately.

  According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the amount of air supplied from the first air blowing means or the second air blowing means on the one end side is the same as that on the other end side. Compared with the case where the air volume supplied from the third blower is the same as that of the air, it is possible to prevent the possibility of contamination in the machine as much as possible, and in particular, contamination in the machine occurs on the transfer roll or the like as the primary transfer device. As a result, it is possible to prevent as much as possible the possibility of defective transfer of the toner image and loss of image quality on the transferred paper.

  Further, in the invention of claim 5, in the invention of any one of claims 1 to 4, the cooling efficiency is improved as compared with the case where the openings of the respective outlets have the same area.

  According to a sixth aspect of the present invention, in the invention of any one of the first to fifth aspects, contamination in the apparatus due to air blown from the outlet can be prevented as much as possible. It is possible to prevent the possibility of occurrence as much as possible, and thereby to prevent as much as possible the possibility of defective transfer of the toner image and image quality loss on the paper after transfer.

  According to a seventh aspect of the present invention, in the invention according to any one of the first to sixth aspects, contamination in the apparatus due to air blown out from the blow-out portion can be prevented as much as possible. It is possible to prevent the possibility of occurrence as much as possible, and thereby to prevent as much as possible the possibility of defective transfer of the toner image and image quality loss on the paper after transfer.

FIG. 1 is a conceptual end view showing a configuration of an image forming apparatus in an electrophotographic system according to Embodiment 1 of the present invention. FIG. 2 is an enlarged perspective view of a main part fracture concept of the image forming apparatus of FIG. FIG. 3 is a conceptual perspective view showing a cross section of the main part of the image forming apparatus of FIG. 1, and particularly a view showing a cross section of the support member. 4 is a conceptual perspective view of a main part of the image forming apparatus of FIG. FIG. 5 is a conceptual cross-sectional view of the main part showing the state of the image forming means supported by the support member of the image forming apparatus of FIG. 1, and in particular, the state of the cross section at each blowing portion on one end side of the image forming means is conceptual. It is the figure shown in. FIG. 6 is a conceptual perspective view of the main part of the image forming apparatus of FIG. 1 and shows the flow of air. FIG. 7 is a conceptual perspective view of the main part of the image forming apparatus of FIG. 1, and particularly shows a state where the support member of FIG. 4 is removed. FIG. 8 is a conceptual plan view schematically showing the configuration, operation, and action of the image forming apparatus in FIG. 4, and particularly in the case of performing image formation of a plurality of colors, the in-machine temperature of the image forming apparatus exceeds a threshold value. It is a figure which shows a mode when there is. FIG. 9 is a conceptual plan view schematically showing the configuration of the image forming apparatus of FIG. FIG. 10 is a conceptual plan view schematically showing the configuration, operation, and action of the image forming apparatus in FIG. 4, and is a view showing a state in particular when monochromatic image formation is performed. FIG. 11 is a conceptual plan view of the main part of the image forming apparatus in FIG. 1 and shows a state in which a part of the image forming means on the support member is removed. 12 is a conceptual cross-sectional view of the main part of FIG. 11. In particular, FIG. 12 (a) is a HH conceptual cross-sectional view of FIG. 11, and FIG. 12 (b) is a GG conceptual cross-sectional view of FIG. . FIG. 13 is a conceptual left side view of the main part of the image forming apparatus in FIG. FIG. 14 is a conceptual perspective view of the main part of the image forming apparatus of FIG. FIG. 15 is a fragmentary enlarged plan view of the main part of the image forming apparatus of FIG. 16 is a conceptual cross-sectional view taken along the line KK of FIG. 17 is a conceptual cross-sectional view of the main part showing a state before the image forming means of FIG. 12 is attached, FIG. 17A is a state in the HH cross section of FIG. 11, and FIG. It is the figure which showed the mode in the GG cross section of 11. FIG. FIG. 18 is a conceptual cross-sectional view showing the flow of air blown from the blowing portion on one end side when no restraining member is attached to the support member of the image forming apparatus of FIG. It is a figure which shows the mode in the done cross section. FIG. 19 is a conceptual perspective view showing a state in which a restraining member is not attached to the support member of the image forming apparatus shown in FIG. 4, and in particular, the flow of air blown from the blowing portion on one end side of the image forming means FIG. FIG. 20 is a diagram conceptually showing the operation and action of the image forming apparatus shown in FIG. FIG. 21 is a conceptual plan view conceptually showing the operation and action of the image forming apparatus of Example 2 of the present application.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a conceptual end view showing a configuration of an image forming apparatus in an electrophotographic system according to Embodiment 1 of the present invention.
As shown in FIG. 1, the image forming apparatus 1 arranges a plurality of photoconductors 3 in parallel with each other, and sequentially transfers the monochromatic toner images formed on the photoconductors 3 to superimpose the toner images. This is a tandem type image forming apparatus that records a color image on a sheet. Further, the image forming apparatus 1 once transfers the toner image formed on each photoconductor 3 onto the intermediate transfer body 12 by the primary transfer apparatus 11 and then collectively forms a sheet of paper (not shown) by the secondary transfer apparatus 15. Indirect transfer type image forming apparatus.
The paper is supplied from the paper supply unit 16 and guided to the secondary transfer device 15. The transferred paper is fixed by the fixing device 17 and then discharged to the discharge unit 19. The paper feed unit 16, the primary transfer device 12, the secondary transfer device 15, and the fixing device 17 are provided in the image forming apparatus 1.

  The image forming apparatus 1 includes an image forming unit 2 that forms a plurality of single-color toner images, and an intermediate transfer member 12 on which a plurality of toner images formed by the image forming unit 2 are sequentially transferred by a primary transfer device 11. And has.

  Among these, the intermediate transfer body 12 is composed of an intermediate transfer belt that is wound around rollers 13 and 14 and travels by rotational driving of the rollers 13 and 14.

In addition, as shown in FIG. 1, the image forming unit 2 forms an image forming unit 2K that forms a black (K) toner image, 2Y that forms a yellow (Y) toner image, and a magenta (M) toner image. 2C for forming, and 2C for forming a cyan (C) toner image.
The black (K) image forming means 2K, the yellow (Y) image forming means 2Y, the magenta (M) image forming means 2M and the cyan (C) image forming means 2C, They are arranged along the lower running side 12 a of the intermediate transfer body 12. The lower running side 12a of the intermediate transfer body 12 is inclined with respect to the horizontal direction, and the cyan (C) image forming means 2C, the magenta (M) image forming means 2M, and the yellow (Y) as it goes downstream in the running direction. The image forming means 2Y and the black (K) image forming means 2K are inclined so that the height level is downward.

  The black (K) image forming means 2K, the yellow (Y) image forming means 2Y, the magenta (M) image forming means 2M and the cyan (C) image forming means 2C have the same structure. The image forming means 2M for magenta (M) will be described as a representative. As shown in FIG. 2, which is an enlarged perspective view of the essential part of the image forming apparatus of FIG. 1, the image forming means 2M for magenta (M) In addition to the drum-shaped photoconductors 3, a charging device 4, an optical writing device 5 having an LED, a developing device 7 having a developing roll 8, and a cleaning device 9 are provided around each photoconductor 3. .

  The developing device 7 also includes a developer transport roll (no symbol) that transports the developer including powdered toner. 2 to FIG. 20 described later, the same parts as those in FIG. 1 are denoted by the same reference numerals.

  When the image forming means 2M of magenta (M) is driven, the photosensitive member 3 rotates, and the charging device 4 and the developing roll 8 rotate following the rotation. When the image forming means 2K of magenta (M) is driven, the developer transport roll rotates, and the optical writing device 5 having an LED irradiates the photoreceptor 3 with light. Therefore, the photosensitive member 3 is charged by the charging device 4, the charged photosensitive member 3 is exposed by the LED of the optical writing device 5 to form an electrostatic latent image, and the exposed photosensitive member is exposed by the developing roll 8 of the developing device 7. A single color magenta (M) toner is attached to the body 3 to form a single color toner image. Further, the monochromatic toner image on the photoconductor 3 is transferred to the intermediate transfer body 12 by the primary transfer device 11, and the toner remaining on the photoconductor 3 after the transfer is transferred to the cleaning device 9 during the rotation of the photoconductor 3. Removed by.

  The primary transfer device 11 is composed of a transfer roll that faces each photoconductor 3 with the intermediate transfer body 12 interposed therebetween.

  As shown in FIG. 1, the image forming unit 2 is disposed on the support member 102. As shown in FIGS. 3 to 4, the support member 102 is formed with a plurality of support portions 102 a whose heights are different from each other in a staircase pattern.

FIG. 3 is a conceptual perspective view showing a cross section of the main part of the image forming apparatus shown in FIG. 1, and particularly a cross section of a support member. 4 is a conceptual perspective view of the main part of the image forming apparatus of FIG. 3 and 4 and FIGS. 6 and 7 to be described later, the image forming units 2K, 2Y, 2M, and 2C supported by the support member 102 are not illustrated.
As shown in FIG. 5, black (K) image forming means 2K, yellow (Y) image forming means 2Y, magenta (M) image forming means 2M, and cyan (C) are formed on each support portion 102a. The image means 2C is supported.
FIG. 5 is a conceptual cross-sectional view of the main part showing the state of the image forming means supported on the support member of the image forming apparatus of FIG. 1, and in particular, the state of the cross section at each outlet on one end side of the image forming means. It is the figure shown conceptually. FIG. 5 represents a state in which the black (K) image forming means 2K and the yellow (Y) image forming means 2Y are arranged among the plurality of image forming means 2K, 2Y, 2M, and 2C. Are shown.

  Further, as shown in FIG. 4, each support portion 102a has a first air outlet 25, a second air outlet 45, or a third air outlet that blows air to the image forming means 2K, 2Y, 2M, and 2C. 65 is formed.

  As shown in FIG. 1, a space S having a triangular cross-sectional shape is formed on the vertically lower side of the image forming unit 2. In this space S, as shown in FIG. 6, a power supply unit 105 having a high voltage power supply device 106 is arranged. FIG. 6 is a conceptual perspective view of the main part of the image forming apparatus of FIG. 1, and shows the flow of air.

FIG. 7 is a conceptual perspective view of the main part of the image forming apparatus of FIG. 1, and particularly shows a state where the support member of FIG. 4 is removed. FIG. 7 also shows the air flow. As shown in FIG. 7, when the support member 102 (FIG. 4) is removed, the power supply unit support member 107 appears. On the power supply unit support member 107, the high voltage power source of the power supply unit 105 (FIG. 6) is displayed. A device 106 is arranged. The power supply unit 105 supplies power to the plurality of image forming units 2K, 2Y, 2M, and 2C.
FIG. 8 is a conceptual plan view schematically showing the configuration, operation, and action of the image forming apparatus in FIG. 4, and particularly in the case of performing image formation of a plurality of colors, the in-machine temperature of the image forming apparatus exceeds a threshold value. It is a figure which shows a mode when there is. FIG. 9 is a conceptual plan view schematically showing the configuration of the image forming apparatus of FIG.

As shown in FIGS. 8 and 7, the image forming apparatus 1 sucks air (outside air) A and B outside the image forming apparatus 1 from one end sides 2a of the image forming units 2K, 2Y, 2M, and 2C, respectively. The first blower P1 and the second blower P2 that are supplied into the image forming apparatus 1 and the air supplied from the first blower P1 and the second blower P2 to the image forming unit 2 respectively. A first guiding means 21 and a second guiding means 41 for guiding are provided.
Among these, the 1st ventilation means P1 and the 2nd ventilation means P2 are provided in the one end side 2a of the image formation means 2K, 2Y, 2M, 2C. The first blower P1 and the second blower P2 are both attached to the surface 1a of the image forming apparatus 1 located on the one end side 2a.

  It should be noted that the surface 1a located on one end side 2a and the surface 1b located on the other end side 2b of the image forming means 2K, 2Y, 2M, and 2C sandwich the high-voltage power supply device 106 from both sides as shown in FIG. Is arranged.

  The one end side 2a of the image forming means 2K, 2Y, 2M, and 2C is the front side in the axial direction of the photoconductor 3, and the other end side 2b is the back side in the axial direction of the photoconductor 3 (FIG. 13). ). The shaft 3a of the photoreceptor 3 is illustrated in FIGS.

  As shown in FIGS. 8 and 9, the first guiding means 21 guides the air supplied from the first blowing means P1 to the black (K) image forming means 2K from the vertically lower side. Yes, the second guide means 41 converts the air supplied from the second blower means P2 into yellow (Y) image forming means 2Y, magenta (M) image forming means 2M, and cyan (C) image forming. They are guided to the means 2C from their respective vertically lower sides.

Further, as shown in FIG. 8, the first guiding means 21 is located between the surface 1a on one end side 2a and the surface 106a on one end side of the high-voltage power supply device 106, or on the surface 1a on one end side 2a and the high-voltage power supply device 106. It is arrange | positioned between the virtual surface 106c which extended the surface 106a of the one end side.
The starting end of the first guiding means 21 is an inlet opening 22 formed on one end side 2a of the image forming means 2K, 2Y, 2M, and 2C, to which the first blowing means P1 is attached. The end of the means 21 is a first outlet 25 formed in the support member 102, and a continuous space for guiding air is formed from the start to the end. The first guide means 21 is arranged on the vertically lower side of the support member 102 except for the terminal end thereof.

The first outlet 21 is formed on the vertical lower side of the developing device 7 (FIG. 5) constituting the black (K) image forming means 2K, and the air guided by the first guide means 21 It blows out to the developing device 7 of the black (K) image forming means 2K.
As shown in FIG. 7, the first guide means 21 has an inlet opening 22 with the first air blowing means P <b> 1 attached at one end, and the inner wall surface of the duct is formed by the power supply support member 107. An intermediate duct portion having one end continuous with the other end of the inlet duct portion, and an inner duct portion having a duct inner wall surface formed by the power supply portion support member 107 and the mounting member 23, An outlet duct having one end continuous with the other end of the intermediate duct portion and a first outlet 25 formed at the other end, the mounting member 23, the power supply portion support member 107, and the support member 102 (FIG. 4). ) And an outlet duct in which the inner wall surface of the duct is formed. The attachment member 23 is a member attached to the power supply unit support member 107.

  Further, as shown in FIG. 8, the second guiding means 41 is provided between the surface 1a on one end side 2b and the surface 106a on one end side of the high-voltage power supply device 106, or on the surface 1a on one end side 2a and the high-voltage power supply device 106. Is disposed between a virtual surface 106c obtained by extending the surface 106a of the one end side 2a.

  The starting end of the second guide means 41 is an inlet opening 42 formed on one end side 2a of the image forming means 2K, 2Y, 2M, and 2C, to which the second air blowing means P2 is attached. The end of the means 41 is each second outlet 45 formed in the support member 102, and a continuous space for guiding air is formed from this start end to each end. The second guide means 41 is disposed on the vertically lower side of the support member 102 except for the respective terminal ends thereof.

  Further, the second outlet 45 is provided with each developing device 7 (FIG. 5) constituting the yellow (Y) image forming means 2Y, the magenta (M) image forming means 2M, and the cyan (C) image forming means 2C. The air formed respectively vertically below and guided by the second guide means 41 is converted into yellow (Y) image forming means 2Y, magenta (M) image forming means 2M, and cyan (C) image forming. It blows out to each developing device of means 2C.

  As shown in FIG. 7, the second guide means 41 is formed with an inlet opening 42 to which the second air blowing means P <b> 2 is attached at one end, and the duct inner wall surface is formed by the attachment member 43. An inlet duct part, an intermediate duct part having one end continuous with the other end of the inlet duct part, an intermediate duct part having a duct inner wall surface formed by a mounting member 44, and one end at the other end of the intermediate duct part Is an outlet duct portion in which a second outlet 45 is formed at the other end, and an outlet duct portion in which the inner wall surface of the duct is formed by the concave portion 44a of the mounting member 44 and the support member 102. It is.

  The attachment member 43 and the attachment member 44 are both attached to the power supply unit support member 107, and the attachment member 44 and the attachment member 43 are connected to each other.

Further, the image forming apparatus 1 sucks air (outside air) C outside the image forming apparatus 1 from the other end side 2b of the image forming units 2K, 2Y, 2M, and 2C, and supplies the air into the image forming apparatus 1. A third blowing unit M and a third guiding unit 61 for guiding the air C supplied from the third blowing unit M to the image forming unit 2 are provided.
Among these, the 3rd ventilation means M is provided in the other end side 2b of the image formation means 2K, 2Y, 2M, 2C. The third blowing means M is attached to the surface 1b of the image forming apparatus located on the other end side 2b.

  The third air blowing means M is configured to convert air C sucked from the other end 2b into black (K) image forming means 2K, yellow (Y) image forming means 2Y, magenta (M) image forming means 2M, and Air is also supplied to the high voltage power supply device 106 of the power supply unit 105 at the same time as it is supplied to the cyan (C) image forming means 2C.

Further, as shown in FIG. 8, the third guide unit 61 includes a surface 1 b on the other end side 2 b of the image forming units 2 K, 2 Y, 2 M, and 2 C and a surface 106 b on the other end side 2 b of the high-voltage power supply device 106. Or a surface 1b on the other end side 2b and a virtual surface 106d obtained by extending the surface 106b on the other end side 2b of the high-voltage power supply device 106.
The third guiding means 61 converts the air supplied by the third blowing means M into black (K) image forming means 2K, yellow (Y) image forming means 2Y, and magenta (M) image forming means 2M. And the cyan (C) image forming means 2C from the respective vertically lower sides.

  The starting end of the third guiding means 61 is an inlet opening 62 formed on the other end side 2b of the image forming means 2K, 2Y, 2M and 2C, to which the third blowing means M is attached. The end of the guide means 61 is each third outlet 65 formed in the support member 102, and a continuous space for guiding air is formed from the start end to each end. The third guiding means 61 is disposed on the vertically lower side of the support member 102 except for each terminal end.

  The third outlet 21 includes black (K) image forming means 2K, yellow (Y) image forming means 2Y, magenta (M) image forming means 2M and cyan (C) image forming means 2C. The air formed on the vertically lower side of each developing device 7 (see FIG. 5) and guided by the third guide means 61 is made into black (K) image forming means 2K and yellow (Y) image forming. It blows out to each developing device of means 2Y, magenta (M) image forming means 2M, and cyan (C) image forming means 2C.

As shown in FIG. 7, the third guiding means 61 has an inlet duct 62 (FIG. 8) formed at one end and an inner duct wall surface formed by the support member 102 and the mounting member 63. And an outlet duct portion in which one end is continuous with the other end of the inlet duct portion and a third outlet 65 is formed at the other end, and the duct is formed by the concave portion 64a of the mounting member 64 and the support member 102. And an outlet duct portion formed with an inner wall surface.
The attachment member 63 and the attachment member 64 are attached to the power supply unit support member 107, and the attachment member 64 and the attachment member 63 are connected to each other.

  The third guiding means 61 is also for guiding the air supplied by the third blowing means M and the air supplied by the third blowing means M to the high voltage power supply device 106 of the power supply unit 105. .

  The third guide means 61 is a guide means having an inlet opening 62 as a starting end, and a fourth outlet that blows air guided by the third guide means 61 to the power supply section 105 at the end thereof. The third guiding means 61 has a continuous space for guiding air from the start end to the end.

  The fourth outlet 68 is formed by a notch 64 a formed in the attachment member 64 and the support member 102. As shown in FIG. 7, a surface 106 b on the other end side 2 b of the high-voltage power supply device 106 is disposed at a position facing the fourth outlet 68.

  As shown in FIGS. 4 and 9, the first outlet 25 and the second outlets 45 are arranged in a row on one end side 2a of the image forming means 2K, 2Y, 2M, 2C, and each third outlet The outlets 65 are formed in a row on the other end side 2b of the image forming means 2K, 2Y, 2M, 2C. Further, as shown in FIG. 10, on the vertically lower side of the developing device 7 of the black (K) image forming means 2, a first outlet 25 is formed on one end side 2a, and a third outlet 2b is formed on the other end side 2b. An opening 65 is disposed. The yellow (Y) image forming means 2Y, the magenta (M) image forming means 2M, and the cyan (C) image forming means 2C are vertically blown to the one end side 2a on the one side 2a. A mouth 45 is formed, and a third opening 65 is disposed on the other end 2b.

  In the image forming apparatus 1, as shown in FIG. 4, a suction unit 111 that sucks air from the other end side 2b of the image forming units 2K, 2Y, 2M, and 2C is provided vertically above the image forming unit 2. It has. The suction means includes a suction port (not shown) provided on the other end side 2b of the image forming means 2K, 2Y, 2M, and 2C, an exhaust guide means 112 that discharges air sucked from the suction port, And exhaust air blowing means N attached to the guide means. The exhaust air blowing means N is attached to the surface 1a on one end side 2a of the image forming means 2K, 2Y, 2M, 2C.

  Next, the operation and operation of the above-described image forming apparatus 1 will be described, and the configuration will be described in more detail.

In the image forming apparatus 1, it is possible to select a case where one single-color image is formed or a case where a plurality of colors are formed. When forming a single color image, one of the plurality of image forming units 2K, 2Y, 2M, and 2C is driven, and when forming a plurality of color images, the plurality of image forming units The means 2K, 2Y, 2M, and 2C are collectively driven.
In this image forming apparatus 1, a black (K) image is formed and a yellow (Y), magenta (M), cyan (C), and black (K) four-color image is formed. You can choose. When forming a black image, the black (K) image forming means 2K is driven. When forming a four-color image, the black (K) image forming means 2K and yellow (Y) are formed. The image forming unit 2Y, the magenta (M) image forming unit 2M, and the cyan (C) image forming unit 2C are collectively driven.
In this image forming apparatus 1, when image formation of a plurality of colors is performed and the in-machine temperature of the image forming apparatus 1 exceeds a threshold value, at least the first blowing unit P 1 and the second blowing unit P 2 are provided. In this embodiment, the third blowing means M is also driven.

  When the first blower P1 and the second blower P2 are driven, the air (outside air) A outside the image forming apparatus 1 sucked by the first blower P1, as shown in FIGS. The first guide means 21 supplies the developing device 7 of the black (K) image forming means 2K from the vertically lower side thereof through the first outlet 25 located on the one end side 2a. The air (outside air) B outside the image forming apparatus 1 sucked by the second blowing means P2 is yellow (outside) by the second guide means 41 via the second outlets 45 located on the one end side 2a. The image forming means 2Y for Y), the image forming means 2M for magenta (M), and the image forming means 2C for cyan (C) are supplied to the developing devices 7 from the vertically lower side.

Further, the air (outside air) C outside the image forming apparatus 1 sucked by the third blowing means M is passed through the third outlets 65 located on the other end side 2b by the third guiding means 61. Black (K) image forming means 2K, yellow (Y) image forming means 2Y, magenta (M) image forming means 2M, and cyan (C) image forming means 2C. At the same time as being supplied from the lower side, the third guide means 61 supplies the high-voltage power supply device 106 from the other end side 2b through the fourth outlet 68.
Whether or not the in-machine temperature of the image forming apparatus 1 exceeds the threshold value is detected by a temperature measurement sensor provided vertically below the support member 102 and in the vicinity of the high-voltage power supply device 106.

In general, in an image forming apparatus, when the image forming speed is increased, black (K) image forming means 2K, yellow (Y) image forming means 2Y, magenta (M) image forming means 2M, and cyan (C) image forming. The amount of heat generated by the means 2C, in other words, the amount of heat generated by the image forming unit 2 increases.
However, in the image forming apparatus 1 of the first embodiment, the air taken in by the first blower means P1 and the second blower means P2 from the one end side 2a of the image forming means 2K, 2Y, 2M, 2C is the first. By the guide means 21 and the second guide means 41, the developing device 7 of the black (K) image forming means 2K, the developing device 7 of the yellow (Y) image forming means 2Y, and the magenta (M) image forming means 2M. Since the air is supplied to the developing device 7 and the developing device 7 of the cyan (C) image forming means 2C from the vertically lower side thereof, the image forming means 2K, 2Y, 2M, and the developing device 7 of the 2C are vertically below. Compared with the case where air is not supplied from the side, heat generated in the image forming unit 2 can be efficiently cooled.

  In addition, this cooling can prevent as much as possible the possibility of causing image defects and malfunctions of the apparatus due to chemical changes of the developing devices 7 and the photoreceptors 3 of the image forming units 2K, 2Y, 2M, and 2C. .

  In particular, of the heat generated by the image forming means 2K, 2Y, 2M, and 2C, the amount of heat generated in the developing device 7 is large, and the developing device 7 is weak in temperature, so that air is supplied to the developing device 7 from the vertically lower side. This means that the developing device 7 is directly cooled, and the developing device 7 is more efficiently compared to the case where the developing device 7 is not cooled vertically or the developing device 7 is indirectly cooled. Can be cooled. Further, this cooling can prevent as much as possible the possibility of causing a chemical change or the like of each developing device 7 and causing an image defect or a malfunction of the apparatus.

  Note that the above-described improvement in cooling efficiency and the effect of preventing the possibility of image defects and apparatus malfunctions as much as possible have at least the first blowing means P1 and the blowing means provided in the image forming apparatus 1. This can be achieved by providing the second air blowing means P2. However, as in the image forming apparatus 1 of the first embodiment, the image forming means 2K, 2Y, 2M, and 2C are connected to the other end 2b of the image forming means. When the third blowing means M for supplying the air C to each developing device 7 is provided, the image forming means 2K, 2Y, 2M, and the like of the image forming unit 2 are compared with the case where the third blowing means M is not provided. 2C, particularly the cooling efficiency of the developing device 7 can be further improved, and this cooling can further prevent the possibility of image defects and device defects.

  Further, in the image forming apparatus 1 according to the first embodiment, the first air blowing unit P1 and the second air blowing unit P2 are provided as the air blowing units for cooling the image forming unit 2. As compared with the case where one large air blowing means is used, the air blowing means having a small air volume per piece can be used.

  Further, according to the image forming apparatus 1, the first guide having a height lower than that of the air blowing unit is provided even if there is no space for providing the air blowing unit between the image forming unit 2 and the high voltage power supply device 106 of the power supply unit 105. The means 21 and the second guide means 41 can be provided, whereby the image forming unit 2 can be cooled by effectively utilizing the space S vertically below the image forming unit 2. Furthermore, according to this image forming apparatus 1, even if there is no space for providing the air blowing means between the image forming unit 2 and the high voltage power supply device 106 of the power supply unit 105, the third guide having a height lower than that of the air blowing means. The means 61 can be provided, whereby the image forming apparatus can be further cooled by effectively utilizing the space S below the image forming unit 2.

Further, in this image forming apparatus 1, the air A, B, or C taken from the outside of the image forming apparatus 1 by the first air blowing means P1, the second air blowing means P2, or the third air blowing means M, respectively, After being guided into the image forming apparatus 1 through the guide means 21, the second guide means 41, and the third guide means 61, the air is sucked from the other end 2b through the suction port (not shown) by the blower means N. Then, it is discharged to the outside of the image forming apparatus 1 through the exhaust guide unit 112.
Therefore, according to the image forming apparatus 1, the air (outside air) A, air B, or air C taken from the outside of the image forming apparatus 1 can be guided from the one end side 2a to the other end side 2b. The cooling effect is higher than when the image forming unit 2 is cooled by the circulation of the air inside. Further, when air (outside air) A, air B, and air C taken from the outside of the image forming apparatus 1 are blown from the one end side 2a and the other end side 2b, compared to the case of blowing outside air from the one end side 2a, The image forming unit 2 can be further cooled with cold outside air.
Further, in the image forming apparatus 1, the second air blowing means P2 is collectively applied to at least the yellow (Y) image forming means 2Y, the magenta (M) image forming means 2M, and the cyan (C) image forming means 2C. Therefore, the number of parts of the image forming apparatus 1 can be reduced compared to the case where the air blowing means is provided for each of the image forming means 2Y, 2M, and 2C when forming images of a plurality of colors.
The effect of reducing the number of parts is that the air blowing means supplies air to at least the yellow (Y) image forming means 2Y, the magenta (M) image forming means 2M and the cyan (C) image forming means 2C. In this embodiment, it can be said that the third air blowing means M is provided as the air blowing means.

In the image forming apparatus 1 of this embodiment, air is supplied at least collectively to the yellow (Y) image forming means 2Y, the magenta (M) image forming means 2M, and the cyan (C) image forming means 2C. The third blowing means M supplies air to the power supply unit 105 simultaneously with the supply of air. Therefore, the number of parts of the image forming apparatus 1 is reduced as compared with the case where the air blowing means for supplying air to the image forming means 2Y, 2M, and 2C and the air blowing means for supplying air to the power supply unit 105 are provided separately. it can.
The component reduction effect of the image forming apparatus 1 is that air is supplied at least collectively to the yellow (Y) image forming means 2Y, the magenta (M) image forming means 2M, and the cyan (C) image forming means 2C. As long as the air blowing means supplies air to the power supply unit 105 simultaneously with the air supply, the air blowing means may be the third air blowing means M as in the first embodiment. For example, the second blowing means P2 may be used.

Further, in this image forming apparatus 1, when image formation of a plurality of colors is performed and the in-machine temperature of the image forming apparatus 1 does not exceed the threshold value, the first blower unit P <b> 1 and the second blower unit P <b> 2 are provided. Do not drive. In this embodiment, the third blowing means M is not driven.
Unless the first blower P1 and the second blower P2 are driven, the air A and the air B from the outside of the image forming apparatus 1 are not taken in, and the first opening 25 on the one end side 2a and each Black (K) image forming means 2K, yellow (Y) image forming means 2Y, magenta (M) image forming means 2M and cyan (C) image forming means 2C vertically above the second opening 45 Air A and Air B are not supplied.

  If the third blower M is not driven, air C from the outside of the image forming apparatus 1 is not taken in, and black (K) vertically above each third opening 65 on the other end 2b. The image forming means 2K of yellow, the image forming means 2Y of yellow (Y), the image forming means 2M of magenta (M), the image forming means 2C of cyan (C), and the high voltage power supply device 106 of the power supply unit 105 are supplied with air C. Not supplied.

  As described above, when image formation of a plurality of colors is performed and the internal temperature of the image forming apparatus 1 exceeds a threshold value, the number of sheets on which image formation is performed and transfer is performed (hereinafter referred to as “output number”). ) Is greater than or equal to a certain number of sheets, and as a result, the amount of heat generated in the image forming unit 2 is larger than that in which the number of output sheets is less than a certain number. Therefore, if the image forming unit 2 is not cooled at this time, black (K) Chemical change of each developing device 7 of each image forming means 2K, yellow (Y) image forming means 2Y, magenta (M) image forming means 2M and cyan (C) image forming means 2C, etc. In this image forming apparatus 1, air A or air B is supplied to each of the image forming means 2K, 2Y, 2M, and 2C. Developing device for image forming means 2K, 2Y, 2M, 2C The or risk of malfunction or the like of the image defects and device invites a chemical change of the photosensitive member 3 is caused can be prevented as much as possible.

  In addition, when image formation of a plurality of colors is performed and the in-machine temperature of the image forming apparatus 1 does not exceed the threshold value, the number of output sheets is less than a certain number. In this case, the image forming means 2K, 2Y, 2M, and 2C have a chemical change in the developing device 7 and the photosensitive member 3 to cause image defects and device defects. The risk of occurrence is as low as possible. Therefore, since it is not necessary to supply air to the image forming units 2K, 2Y, 2M, and 2C, in the image forming apparatus 1, the first blowing unit P1, the second blowing unit P2, and the third blowing unit The air blowing means M was not driven. Thereby, compared with the case where the 1st ventilation means P1, the 2nd ventilation means P2, and the 3rd ventilation means M are driven, the waste of cooling can be prevented as much as possible, and noise is also possible as much as possible. Can be prevented.

  In the image forming apparatus 1, the suction unit 111 sucks air from the other end 2 b. Here, the respective air volumes supplied to the black (K) image forming means 2K, the yellow (Y) image forming means 2Y, the magenta (M) image forming means 2M and the cyan (C) image forming means 2C are: Of these, the amount of air supplied from the first blowing means P1 or the second blowing means P2 located on the one end side 2a is smaller than the amount of air supplied from the third blowing means M located on the other end side 2b. It is trying to become.

  For example, the air volume supplied to the black (K) image forming means 2K will be described as a representative. The air volume supplied to the black (K) image forming means 2K includes the first air volume located on the one end side 2a. The amount of air supplied from the blowing means P1 through the first outlet 25 is smaller than the amount of air supplied from the third blowing means M located at the other end 2b through the third outlet 65. I am doing so.

  Thus, each air volume supplied to each image forming means 2K, 2Y, 2M, 2C is the air volume supplied from the first air blowing means P1 or the second air blowing means P2 located on one end side 2a thereof. If the amount of air supplied from the third air blowing means M located on the other end 2b is reduced, the toner of the image forming means 2K, 2Y, 2M, and 2C is scattered as compared with the case where the air volumes of both are the same. Thus, it is possible to prevent, as much as possible, the possibility that the device adheres to each device in the image forming apparatus 1 and stains it (hereinafter referred to as “in-machine soil”, the same shall apply hereinafter). It is possible to prevent the transfer roller 11 serving as the transfer device 11 from being contaminated in the apparatus, thereby preventing the possibility of image quality defects (defects) from occurring on the paper after transfer.

  As shown in FIG. 9, the four image forming means are black (K) image forming means 2K, yellow (Y) image forming means 2Y, magenta (M) image forming means 2M and cyan (C). When arranged in the order of the image forming means 2C, a black (K) image forming means 2K and a magenta (M) image forming means 2M are arranged on both sides of the yellow (Y) image forming means 2Y. On both sides of the magenta (M) image forming means 2M, a yellow (Y) image forming means 2Y and a cyan (C) image forming means 2C are arranged. The black (K) image forming means 2K has a yellow (Y) image forming means 2Y arranged on one side, and the cyan (C) image forming means 2C has magenta (M) on one side. Image forming means 2M is arranged.

Therefore, in the yellow (Y) image forming means 2Y and the magenta (M) image forming means 2M, black (K) in which the adjacent image forming means is on one side due to heat generated by the image forming means adjacent to both sides. Compared with the image forming means 2K or cyan (C) image forming means 2C, there is a possibility that a large amount of heat is generated.
Therefore, in this image forming apparatus 1, the yellow (Y) image forming means 2Y having adjacent image forming means on both sides of the first air outlet 25 and the second air outlets 45 formed on the one end side 2a. The second air outlet 45 that blows air to the magenta (M) image forming means 2M has an area S1 of each opening such that the image forming means 2K for black (K) with adjacent image forming means on one side, cyan. The area is larger than the area S2 of each opening of the first outlet 25 and the second outlet 45 for blowing air to the image forming means 2C of (C) (S1> S2).
Then, the amount of air blown from the second blowout port 45 having the area S1 to the yellow (Y) image forming unit 2Y and the magenta (M) image forming unit 2M is set to the first blowout port 25 having the area S2, and the second. More than the amount of air blown from the blowout port 45 to the black (K) image forming means 2K and the cyan (C) image forming means 2C, so that whether adjacent image forming means are on either side or one side. Regardless, the cooling efficiency of the image forming unit can be increased as compared with the case where the areas of the openings of the first outlet 25 and the second outlet 45 are the same.
Here, the width W of each opening of the first outlet 25 and the second outlet 45 is the same, and the area S1 or area S2 of the opening is set depending on the length of each opening along the surface 1a. For example, the yellow (Y) image forming means 2Y has a length L1, and the black (K) image forming means 2K has a length L2 (L2> L1).
In addition, also about each 3rd blowing port 65 of the other end side 2b, it adjoins similarly to having described above about the case of the 1st blowing port 25 and each 2nd blowing port 45 of the front side mentioned above. The third blowing port 65 for blowing air to the yellow (Y) image forming means 2Y and the magenta (M) image forming means 2M on both sides has an area S1 of each opening, and the adjacent image forming means It is designed to be larger than the area S2 of each opening of the third outlet 65 for blowing air to the black (K) image forming means 2K and the cyan (C) image forming means 2C on one side. The areas S1 and S2 are achieved by changing the opening length by making the width W of the opening the same, as in the case of the first outlet 25 and the second outlet 45 on the one end side 2a described above. It is.

FIG. 10 is a conceptual plan view schematically showing the configuration, operation, and action of the image forming apparatus in FIG. 4, and is a view showing a state in particular when performing monochromatic image formation.
As shown in FIG. 10, the image forming apparatus 1 drives the first blower P1 when performing monochrome image formation.
When the first blowing unit P1 is driven, the first air that is sucked from the first blowing unit P1 and outside the image forming apparatus 1 (outside air) A is positioned on the one end side 2a by the first guiding unit 21. Is supplied from the vertically lower side to the developing device 7 of the image forming means 2K for forming a black (K) toner image.
Therefore, compared with the case where air is not supplied from the vertically lower side of the developing device 7 of each image forming means 2K or the case where the developing device 7 is indirectly cooled, the heat generation of the image forming means 2K is efficiently cooled. be able to. In addition, this cooling can prevent as much as possible the possibility of causing image defects, device defects, and the like due to chemical changes in the developing device 7 and the photoreceptor 3 of the image forming means 2K.

  In particular, among the heat generated by the image forming means 2K, the amount of heat generated in the developing device 7 is large, and the developing device 7 is weak in temperature. Therefore, supplying air to the developing device 7 from the vertically lower side is the developing device 7. Therefore, the developing device 7 can be cooled more efficiently than the case where the cooling is not performed from the vertically lower side of the developing device 7 or the case where the developing device 7 is indirectly cooled. Further, this cooling can prevent as much as possible the possibility of causing a chemical change or the like of the developing device 7 and causing an image defect or a malfunction of the apparatus.

Further, in this image forming apparatus 1, after the air A taken in from the outside of the image forming apparatus 1 by the first air blowing means P <b> 1 is guided into the image forming apparatus 1 through the first guiding means 21, it is used for exhausting. The blower N sucks the other end 2b through a suction port (not shown) and discharges it to the outside of the image forming apparatus 1 through the exhaust guide 112.
Therefore, according to this image forming apparatus 1, even when performing monochromatic image formation, the air (outside air) A taken from the outside of the image forming apparatus 1 can be guided from the one end side 2a to the other end side 2b. The cooling effect is higher than when the image forming unit 2 is cooled by circulation of air in the forming apparatus 1.

In addition, when the monochrome image formation is performed, the second blowing unit P2 is not driven. Therefore, no air is supplied to the image forming means 2Y, 2M, and 2C for yellow (Y), magenta (M), and cyan (C).
In addition, when the monochrome image formation is performed, the third blowing unit M is not driven. Therefore, the black (K), yellow (Y), magenta (M), and cyan (C) imaging means 2K, 2Y, 2M, and 2C are not supplied with air through the third outlet 65, Further, air is not supplied to the high-voltage power supply device 106 of the power supply unit 105.
When performing monochrome image formation, the image forming apparatus 1 uses black (K), yellow (Y), magenta (M), and cyan (C) image forming means 2K, 2Y, 2M, and 2C. Since the other image forming means 2Y, 2M, 2C except for the image forming means 2K of K) are not driven, it is not necessary to supply air to the image forming means 2Y, 2M, 2C, and heat generated in the image forming unit 2 The amount is smaller than in the multi-color transfer mode.

  Therefore, when performing monochrome image formation, the first blower P1 of the first blower P1 and the second blower P2 is driven, and the second blower P2 is not driven. Compared with the case where the air blowing means P1 and the air blowing means P2 are driven by the above, or compared with the case where there is only one air blowing means for cooling the image forming unit 2, it is possible to waste the cooling when performing monochrome image formation. It is possible to prevent as much as possible, and to prevent as much noise as possible when performing monochrome image formation.

  Further, in the case of forming a single color image, the amount of heat generated in the image forming unit 2 is smaller than that in the case of forming a plurality of color images. There is no need to supply air to 105 to cool the power supply unit 105, and therefore there is no need to drive the blowing means M. For this reason, the third blower M is not driven when performing monochrome image formation, and compared with the case where the third blower M is driven, there is a waste of cooling when performing monochrome image formation. It is possible to prevent as much as possible, and it is possible to prevent as much noise as possible when performing monochrome image formation.

  Next, the detailed structure of the periphery or vicinity of the 1st blowing outlet 25 and each 2nd blowing outlet 45 which were formed in the front side 101a side of the supporting member 102, and its effect | action are demonstrated.

FIG. 11 is a conceptual plan view of the main part of the image forming apparatus in FIG. 1 and shows a state in which a part of the image forming means on the support member is removed. 12 is a conceptual cross-sectional view of the main part of FIG. 11. In particular, FIG. 12 (a) is a HH conceptual cross-sectional view of FIG. 11, and FIG. 12 (b) is a GG conceptual cross-sectional view of FIG. is there. FIG. 13 is a conceptual left side view of the main part of the image forming apparatus in FIG. 1, and is a diagram conceptually showing an arrangement position of the suppression member.
As shown in FIG. 11 thru | or FIG. 13, in the 1st blowing part 26 which comprises the 1st blowing outlet 25 and the 2nd blowing part 46 which comprises each 2nd blowing opening 45, respectively, A suppression member 81 that suppresses air that suppresses a part of the air A and B supplied from the first outlet 25 and the respective second outlets 45 is attached to a part or the vicinity of the peripheral edge.

In addition, in FIG. 11, although the suppression member 81 with respect to the 1st blower opening 25 is attached and the mode that the suppression member 81 with respect to the 2nd opening part 45 is not attached yet is illustrated, each 2nd opening part is illustrated. The restraining member 81 is attached to 45 as well.
Here, the structure in which the suppressing member 81 is attached to the outlet and the operation when the suppressing member 81 is attached are the same in the first outlet 25 and the respective second outlets 45. As shown in FIG. 20, the manner in which the suppression member 81 is attached to the outlet 25 will be described as a representative.

As shown in FIGS. 14 and 15, the restraining member 81 is composed of a flexible member attached to the support portion 102 a of the support member 102. For example, the flexible member is a sponge-like member, and the material thereof is, for example, urethane foam.
FIG. 14 is a conceptual perspective view of the main part of the image forming apparatus shown in FIG. FIG. 15 is a fragmentary enlarged plan view of the main part of the image forming apparatus of FIG. FIG. 14 and FIG. 15 show the peripheral portion of the outlet 25 on the one end side 2a and the vicinity thereof. 14 and 15 show a state where the black (K) image forming means 2K is removed.
The suppression member 81 is an L-shaped member and includes a first portion 81a and a second portion 81b.
Among these, as shown in FIGS. 11, 12A, and 13 to 15, the first portion 81a is a shaft of the developing roll 8 at the peripheral edge portion 102b on the side near the developing roll 8 of the first outlet 25. It is formed by extending in the axial direction of 8a.

Further, as shown in FIGS. 11, 12 (b), 14, and 15, the second portion 81 b has a peripheral edge on the side near the end 8 b (FIG. 11) of the developing roll 8 of the first outlet 25. The portion 102c is formed by extending in a direction perpendicular to the axial direction of the shaft 8a.
The first portion 81a and the second portion 81b are formed continuously.
In addition, as shown in FIG. 16 which is KK conceptual sectional drawing of FIG. 11, it suppresses between the 1st blower outlet 25 of the one end side 2a, and the 3rd blower outlet 65 of the other end side 2b. The member 81 is not disposed. In FIG. 11, a third blowing portion 66 including the first blowing portion 26, the second blowing portion 46, and the third blowing port 65 is illustrated.

17 is a conceptual cross-sectional view of the main part showing a state before the image forming means of FIG. 12 is attached, FIG. 17A is a state in the HH cross section of FIG. 11, and FIG. It is the figure which showed the mode in the GG cross section of 11. FIG.
When the image forming means 2K is arranged on the support portion 102a of the support member 102 shown in FIGS. 17 (a) and 17 (b), the image forming means 2K of the image forming means 2K is shown in FIGS. 12 (a) and 12 (b). The lower portion 7a of the developing device 7 is in contact with a contact surface 81c formed on the suppressing member 81, whereby the black (K) image forming means 2K is supported by the support portion 102a via the suppressing member 81. . The first outlet 25 is disposed on the vertical lower side of the developing device 7 of the black (K) image forming means 2K.

  FIG. 18 is a conceptual cross-sectional view showing the flow of air blown from the blow-out portion on the front side when no restraining member is attached to the support member of the image forming apparatus of FIG. 4, and is particularly represented by FIG. It is a figure which shows the mode in the done cross section. FIG. 19 is a conceptual perspective view showing a state in which the suppressing member is not attached to the support member of the image forming apparatus shown in FIG. 4, and particularly shows the flow of air blown out from the blowing portion on one end side. FIG.

As shown in FIG. 18, the air A (FIGS. 8 and 10) blown from the blowout port 25 on the front side 101a is blown from the vertically lower side to the casing 7b of the developing device 7 of the image forming means 2K to develop the air. Along the housing 7 b of the apparatus 7, the first outlet 25 is branched into a side where the developing roll 8 is disposed and a side where the developing roll 8 is not disposed.
On the side where the developing roll 8 is disposed, the photoreceptor 3 of the image forming means including the developing roll 8 is present. Therefore, the air F1 branched to the side where the developing roll 8 is disposed It goes in the direction of the tangent line (development nip) N with the photoreceptor 3. On the other hand, the air flow F2 branched to the side where the developing roll 8 is not disposed flows along the housing 7b of the developing device 7, and the image forming means adjacent to the side where the developing roll 8 is not disposed is provided. When there is, it goes to the photoreceptor 3.

In this way, of the air flows F1 and F2, which are branched into two, the flow F1 is attached between the developer head where the developer rises in a spike shape or between the photoreceptor 3 and the developing roll 8 in the development nip portion. A flow F3 (FIG. 20) along the axial direction of the shaft 8a of the developing roll 8 is formed in the vicinity of the developing nip N along the film seal 70 and the like, and the end portion of the shaft 8a of the developing roll 8 as shown by the flow F4. It is released at 8b.
At this time, the air released at the end 8 b of the shaft 8 a entrains the scattered toner (toner cloud) at the end 8 b near the developing nip N, and this toner reaches the inside of the image forming apparatus 1. Therefore, there is a risk that the conveyed toner adheres to each device in the image forming apparatus 1 and contaminates it (hereinafter, this contamination is referred to as “in-machine contamination”). In particular, when internal contamination occurs on the transfer roll, which is the primary transfer device 11, there is a possibility that a transfer failure of the toner image may occur and an image quality defect (defect) may occur on the paper after transfer.

  Therefore, as shown in FIG. 20, the air flow F <b> 1 flowing to the side where the developing roll 8 is disposed is sealed by the suppressing member 81. In this way, when the restraining member 81 restricts the blowing direction from the first outlet 25, it is possible to prevent contamination in the machine as much as possible, and in particular, it is possible to prevent as much as possible the possibility of contamination in the machine from the primary transfer device. Therefore, it is possible to prevent as much as possible the possibility of defective transfer of the toner image and image quality defects (defects) on the paper after the transfer. FIG. 20 is a diagram conceptually showing the operation and action of the image forming apparatus shown in FIG. 12A. For the sake of understanding of the present invention, the flow F1 is shown.

  FIG. 21 is a conceptual plan view conceptually showing the operation and action of the image forming apparatus of Example 2 of the present application. In FIG. 21, the same parts as those in FIG. 1 are denoted by the same reference numerals.

  The image forming apparatus 101 according to the second embodiment is the same as the first embodiment in that the first guide unit 21 guides air from the vertically lower side to the black (Y) image forming unit 2K. However, unlike the first embodiment, the first guide means 21 has two terminations, the first outlet 25 on the one end side 2 a and the first outlet 25 on the other end side 2.

  The third guiding means 41 does not have a third outlet 65 for guiding air from the vertically lower side of the black (Y) image forming means 2K as in the first embodiment, at the end thereof.

  In the image forming apparatus 101 according to the second embodiment, the air A supplied from the first blower unit P1 is supplied by the first guide unit 21 to the first opening 25 on the one end side 2a and the air on the other end side 2b. Since air A is supplied to the black (K) image forming means 2K through the first air outlet 25, the black (K) image forming means 2K is supplied from the first air outlet 25 on the front side 101a side. Compared with the first embodiment in which air is supplied, the wind force for cooling the image forming means K in the case of performing monochromatic image formation increases, and the cooling effect can be enhanced.

  The air C supplied from the third blowing means M is not guided to the black (K) image forming means 2K by the third guide means 31, and the air C is yellow (Y) image forming means. 2Y and magenta (M) image forming means 2M and cyan (C) image forming means 2C are supplied from their respective vertically lower sides, and at the same time, as in the first embodiment, the high voltage power supply device of power supply section 105 Air is supplied to 106.

  In the image forming apparatuses 1 and 101 according to the first and second embodiments, air is supplied to the power supply unit 105 by the third blowing unit M. However, instead of the third blowing unit M, the second blowing unit M is used. Air may be supplied to the power supply unit 105 by the means P2, and in that case, the air can be supplied to the image forming unit 2 and the power supply unit 105 without providing the third blower unit M.

  In the image forming apparatuses 1 and 101 according to the first and second embodiments, the order in which the black (K), yellow (Y), magenta (M), and cyan (C) are arranged is determined based on the lower running side of the intermediate transfer body 12. 12a, the cyan image forming means 2C, the magenta (M) image forming means 2M, the yellow (Y) image forming means 2Y, and the black (K) image forming means 2K increase in the downstream direction. However, the order of arrangement of the image forming means is not limited to this, and driving is performed when a single color image is formed among the image forming means 2K, 2Y, 2M, and 2C of a plurality of colors. The image forming means to be performed and the image forming means of other colors other than that may be arranged separately.

  The image forming apparatuses 1 and 101 of the first and second embodiments are printers that perform four-color transfer of black (K), yellow (Y), magenta (M), and cyan (C), and perform black image formation. The image forming apparatus that can select between the case of performing the image formation and the case of performing the four-color image formation has been described. However, in the present invention, the color of the image formation when the single-color image formation is performed is not limited to black (K). In the present invention, the color of image formation in the case of forming a plurality of color images is not limited to black (K), yellow (Y), magenta (M), and cyan (C), and may be different from these. In addition, the image forming colors in the case of forming a plurality of colors of images are not limited to four colors, and a plurality of colors may be used.

  In the image forming apparatuses 1 and 101 of the first and second embodiments, an example of application to a printer capable of selecting a black image formation and a four-color image formation has been described. The present invention is not limited to this, and the present invention can be applied to all image forming apparatuses that can select and perform single-color image formation and multi-color image formation.

  In addition, the present invention is not limited to the above-described embodiment, and can be appropriately modified and implemented within a range not changing the gist thereof.

  The present invention can be applied to all types of image forming apparatuses capable of selecting and performing single-color image formation and multiple-color image formation.

DESCRIPTION OF SYMBOLS 1, 101 ... Image forming apparatus 2 ... Image forming part 2a ... One end side 2b ... Other end side 2K, 2Y, 2M, 2C ... Image forming means 2K ... One image forming means,
2Y, 2M, 2C ... Image forming means 2Y, 2M, 2C ... except for one image forming means At least three image forming means 2Y, 2M ... Image forming means 2K, 2C ... adjacent to each other on both sides Image forming means 7 on one side Image forming means 7 ... developing device 8 ... developing roll 8a ... developing roll shaft 8b ... developing roll end 21 ... first guiding means 25, 45, 65 ... outlet (first Air outlet, 2nd air outlet, 3rd air outlet)
26, 46, 66 ... blowing part (first blowing part, second blowing part, third blowing part)
41 ... 2nd guide means 61 ... 3rd guide means 81 ... suppression member 81a ... 1st part 81b ... 2nd part 81c ... contact surface 102 ... support member 102b ... peripheral edge part 102c of the side close to the developing roll of the outlet ... periphery 105 near the end of the developing roll at the outlet ... Power supply 111 ... Suction means P1 ... First blowing means P2 ... Second blowing means M ... Third blowing means M, P2 ... One Air blowing means

Claims (9)

An image forming unit comprising a plurality of image forming means for forming an image;
An intermediate transfer member to which each image formed by each image forming means of the image forming unit is sequentially transferred;
First and second air blowing means provided on one end side of the image forming means;
A first guide unit and a second guide unit, which are arranged vertically below the image forming unit and guide air supplied from the first and second blowing units, respectively;
A support member for supporting the plurality of image forming means ,
The first guiding means guides air from one of the plurality of image forming means to the image forming means from the vertically lower side,
The second guide means guides air from the vertically lower side to the image forming means other than the one image forming means among the plurality of image forming means,
When the plurality of image forming units are driven to form an image of a plurality of colors, the first blowing unit and the second blowing unit are driven, and the one image forming unit is driven to obtain a single color image. When forming, stop the second blowing means,
The support member is formed with blowout ports for blowing air guided to at least the first guide means and the second guide means to the image forming means,
The blowout port that blows air to the image forming means on the both sides of the adjacent image forming means has an opening area larger than the area of the opening of the blowout port that blows air to the image forming means on one side. An image forming apparatus. An image forming unit comprising a plurality of image forming means for forming an image;
An intermediate transfer member to which each image formed by each image forming means of the image forming unit is sequentially transferred;
First and second air blowing means provided on one end side of the image forming means;
A first guide unit and a second guide unit, which are arranged vertically below the image forming unit and guide air supplied from the first and second blowing units, respectively;
A support member for supporting the plurality of image forming means;
With
The support member is formed with a blow-out port for blowing at least the air guided by the first guide means and the second guide means to the image forming means,
Each of the image forming means
Developing device for forming an image on a photoreceptor
Have
An L-shaped flexible restraining member that restrains a part of the air blown out from each of the blowout ports is attached to the support member,
The suppression member is
A first portion extending in the axial direction of the developing roll at the peripheral edge of the outlet near the developing roll;
A second portion extending in a direction perpendicular to the axial direction at the peripheral edge of the outlet near the end of the developing roll;
Having
An image forming apparatus. An image forming unit comprising a plurality of image forming means for forming an image;
An intermediate transfer member to which each image formed by each image forming means of the image forming unit is sequentially transferred;
First and second air blowing means provided on one end side of the image forming means;
A first unit that is attached to the other end of the image forming apparatus and is located on the one end side of the plurality of image forming units at least in a plurality of image forming units excluding the one image forming unit. A third blowing means for supplying air having a larger air volume than that supplied from the second blowing means or the second blowing means;
A first guide unit and a second guide unit which are arranged on the vertically lower side of the image forming unit and respectively guide air supplied from the first and second blowing units ;
The first guiding means guides air from one of the plurality of image forming means to the image forming means from the vertically lower side ,
The second guide means guides air from the vertically lower side to the image forming means other than the one image forming means among the plurality of image forming means ,
When the plurality of image forming units are driven to form an image of a plurality of colors, the first blowing unit and the second blowing unit are driven, and the one image forming unit is driven to obtain a single color image. The image forming apparatus is characterized in that the second blower is stopped when forming. A third blower attached to the other end of the image forming apparatus;
Said third sending means, among the plurality of image forming means, at least, according to claim 1 or, wherein the supply air collectively to a plurality of image forming means excluding the one of the image forming means the image forming apparatus according to 2. A power supply unit provided on a vertically lower side of the image forming unit and configured to supply power to the plurality of image forming units;
The image forming apparatus according to claim 1 , wherein at least one of the second blowing unit and the third blowing unit supplies air to the power supply unit. A suction unit that is disposed vertically above the image forming unit and sucks air from the other end of the image forming apparatus;
The amount of air supplied to each image forming means is supplied from the third air blowing means located on the other end side, while the air amount supplied from the first air blowing means or the second air blowing means located on the one end side is supplied. the image forming apparatus according to claim 1 or 2, characterized in that it is less than Rukazeryou. A support member for supporting the plurality of image forming means;
The support member is formed with a blowout port for blowing at least the air guided by the first guide unit and the second guide unit to the image forming units,
The blower outlet that blows air to the image forming means on the both sides of the adjacent image forming means has an opening area that is larger than the area of the opening of the blowout opening that blows air to the image forming means on the one side. The image forming apparatus according to claim 2, wherein the image forming apparatus is large. A support member for supporting the plurality of image forming means;
The support member is formed with a blowout port for blowing at least the air guided by the first guide unit and the second guide unit to the image forming units,
Each of the image forming means
It has a developing device that forms an image on the photoreceptor,
An L-shaped flexible restraining member that restrains a part of the air blown out from each of the blowout ports is attached to the support member,
The suppression member is
A first portion extending in the axial direction of the developing roll at the peripheral edge of the outlet near the developing roll;
A second portion extending in a direction perpendicular to the axial direction at the peripheral edge of the outlet near the end of the developing roll.
The image forming apparatus according to claim 1 or 3, characterized in. A support member for supporting the plurality of image forming means;
The support member is formed with blowout portions for guiding the air guided to at least the first guide means and the second guide means to the image forming means, respectively.
Each of the image forming means
A developing device attached to a vertical upper side of the blowing portion;
A flexible restraining member that is attached to the support member and restrains a part of the air blown out from each of the blowout portions;
The The inhibitory member, an image forming apparatus according to claim 1 or 3, characterized in that the contact surface in contact with the bottom of the developing device is formed.