JP7413792B2 - Image forming unit and image forming device - Google Patents

Description

The present invention relates to an image forming unit and an image forming apparatus, and is suitable for application to image forming apparatuses such as copying machines and printers, for example.

Conventionally, image forming apparatuses emit light onto the surface of a photoreceptor drum in an image forming unit from a head unit having an exposure head that emits exposure light emitted from an LED (Light Emitting Diode) chip, which is a light emitting element. irradiation to form an electrostatic latent image on the surface of the photoreceptor drum, and then develop the developer image by attaching a developer to the electrostatic latent image, and then transfer the developer image to a medium such as paper. , devices in which an image is printed by fixing the developer image on a medium in a fixing section are widely used.

In such an image forming apparatus, an opening is formed in a flow path forming wall provided between adjacent image forming units, and air is caused to flow from above the flow path forming wall toward the charger through the opening. (For example, see Patent Document 1).

Japanese Patent Application Publication No. 2012-98378

In such an image forming apparatus, it is desired to maintain image quality by keeping each member inside the image forming apparatus at an appropriate temperature.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose an image forming unit and an image forming apparatus that can maintain each member inside the image forming apparatus at an appropriate temperature and maintain image quality.

In order to solve this problem, the image forming unit of the present invention includes a main body, an image carrier having an electrostatic latent image and at least a part of which is provided inside the main body, and an image carrier, at least a part of which is provided inside the main body. a supply roller that is provided and supplies developer to the image bearing member; a layer regulating member that is at least partially provided inside the main body and that regulates the developer layer adhering to the supply roller ; and a layer regulating member that is at least partially provided inside the main body. and a cleaning section for removing developer attached to the image bearing member , and the main body section has a first opening provided near the layer regulating member and a second opening provided near the cleaning section . The first opening and the second opening communicate with each other.

As a result, the present invention allows the air taken into the main body through the first opening to pass through the vicinity of various members inside the main body, and then to be discharged to the outside of the main body through the second opening. The cooling efficiency of the image forming unit by the cooling member can be improved.

Further, in the image forming unit of the present invention, there is provided a main body, an image carrier at least partially provided inside the main body, and carrying an electrostatic latent image; a supply roller that supplies developer to the body; and a layer regulating member, at least a portion of which is provided inside the body and which regulates the developer layer adhering to the supply roller. It has an opening that exposes it to the outside.

As a result, according to the present invention, the air taken into the main body through the opening can be applied to the layer regulating member, and the cooling efficiency of the image forming unit by the cooling member can be improved.

Further, in the image forming apparatus of the present invention, the above-described image forming unit, a fixing unit that fixes the image formed by the image forming unit onto a medium, and a fixing unit provided between the fixing unit and the image forming unit in the conveying direction of the medium. a cooling member that cools the image forming unit; and a duct portion provided between the image forming unit and the fixing unit in the conveying direction, and the duct portion is connected to a first partition wall provided on the cooling member side. , a second partition wall facing the first partition wall and provided closer to the fixing unit than the first partition wall, and the first partition wall and the second partition wall are configured to cool the image forming unit by a cooling member. A flow path is formed through which the air flows between the fixing unit and the cooling member.

As a result, in the present invention, the first partition wall prevents the air discharged from the image forming unit from leaking to the fixing unit and cooling the fixing unit, and the first partition wall and the second partition wall prevent the air discharged from the fixing unit from leaking to the fixing unit. It is possible to prevent the heat from being transmitted to the image forming unit and heating the image forming unit, thereby improving printing quality.

According to the present invention, it is possible to realize an image forming unit and an image forming apparatus that can keep each member inside the image forming apparatus at an appropriate temperature and maintain image quality.

FIG. 1 is a perspective view showing an external configuration (1) of an image forming apparatus. FIG. 2 is a plan view showing the external configuration (2) of the image forming apparatus. FIG. 2 is a left side view showing the internal configuration (1) of the image forming apparatus. FIG. 3 is a left side view showing the internal configuration of the image forming apparatus when the top cover and front cover are open. FIG. 2 is a perspective view showing the internal configuration (2) of the image forming apparatus. FIG. 3 is a perspective view showing the configuration of a fixing unit, a duct section, a head unit, and an image forming unit. 7 is a sectional view taken along the line AA in FIG. 6, showing the configuration of a fixing unit, a duct section, a head unit, and an image forming unit according to the first embodiment; FIG. 7 is a partial cross-sectional view taken along the line AA in FIG. 6, showing the configuration of a duct portion, a head unit, and an image forming unit according to the first embodiment. 7 is a partial cross-sectional view taken along the line AA in FIG. 6, showing the configuration of the image forming unit according to the first embodiment. FIG. 2 is a perspective view showing the configuration of an image forming main body section according to the first embodiment. FIG. 3 is a perspective view showing the configuration of the image forming main body section with the image forming cover removed. FIG. 2 is a perspective view showing the configuration of an image forming cover according to the first embodiment. It is a perspective view of the front side which shows the structure (1) of a duct part. It is a perspective view of the back side which shows the structure (2) of a duct part. FIG. 14 is a cross-sectional view taken along the line AA in FIG. 13, showing the structure (3) of the duct portion. The configuration of the head fixing unit partition member is shown, with (A) being a perspective view of the back side and (BA) being a perspective view of the front side. FIG. 3 is a perspective view showing the configuration of a head image forming unit partition member. FIG. 3 is a perspective view showing the configuration of a head unit. FIG. 3 is a perspective view showing the configuration of a head holder. FIG. 7 is a cross-sectional view showing a configuration (1) of a duct portion, a head unit, and an image forming unit according to a second embodiment. FIG. 7 is a cross-sectional view showing a configuration (2) of a duct portion, a head unit, and an image forming unit according to a second embodiment. FIG. 7 is a perspective view showing the configuration of an image forming cover according to a second embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, modes for carrying out the invention (hereinafter referred to as embodiments) will be described using the drawings.

[1. First embodiment]
[1-1. External configuration of image forming apparatus]
First, the external configuration of the image forming apparatus 1 will be described. As shown in FIGS. 1, 2, and 3, the image forming apparatus 1 has a substantially rectangular parallelepiped-shaped device housing 2 formed by resin molding as an exterior. Here, the direction from the front side to the rear side of the device case 2 is the rear direction, the direction from the back side to the front side of the device case 2 is the front direction, and the direction from the bottom side to the top side of the device case 2 is the upward direction. , the direction from the top to the bottom of the device case 2 is defined as the downward direction, the direction from the right side to the left side of the device case 2 is defined as the left direction, and the direction from the left side to the right side of the device case 2 is defined as the right direction.

The device case 2 has a device case front part 2f on the front side, a device case top part 2u on the top side, a device case rear part 2b on the rear side, a device case right side part 2r on the right side, and a device case on the left side. A housing left side portion 2l is formed respectively.

The upper surface portion 2u of the apparatus housing is provided with a fixing unit insertion/removal port 6 above a fixing unit 17 (described later). The fixing unit insertion/removal port 6 is a hole elongated in the left-right direction, and communicates between the upper and lower sides of the upper surface portion 2u of the device housing. Further, the device housing 2 is provided with a top cover 3 that can open and close the fixing unit insertion/removal port 6 on the top surface portion 2u of the device housing. The upper surface cover 3 has a shape in which the upper surface closes the fixing unit insertion/removal port 6 and forms the rear part of the paper stacker section 5 as a medium stacker section. As shown in FIGS. 3 and 4, the top cover 3 opens or closes the fixing unit insertion/removal port 6 by rotating about a rotation shaft provided at the rear end and extending in the left-right direction. In the image forming apparatus 1, the fixing unit 17 is removably attached to the main body frame 8 through the fixing unit insertion/ejection opening 6 in an open state (FIG. 4).

The front surface portion 2f of the apparatus housing is provided with an image forming unit insertion/removal port 7 in front of and above the image forming unit 12 (described later). The image forming unit insertion/removal port 7 is a hole portion that is elongated in the left-right direction, and communicates the front and rear portions of the device housing front portion 2f. Further, the apparatus housing 2 is provided with a front cover 4 that can open and close the image forming unit insertion/removal opening 7 on the front side 2f of the apparatus housing. The front cover 4 covers the image forming unit insertion/removal port 7 with its front surface and upper surface. As shown in FIGS. 3 and 4, the front cover 4 opens or closes the image forming unit insertion/removal port 7 by rotating about a rotation shaft provided at the lower end and extending in the left-right direction. In the image forming apparatus 1, the image forming unit 12 is removably attached to the main body frame 8 through the image forming unit insertion/ejection opening 7 in an open state.

In the right side portion 2r of the device case, a device case intake portion 10r is provided on the right side of a duct portion 59 (described later). The device casing intake section 10r includes a plurality of ventilation holes, and communicates the right side and the left side of the device casing right side section 2r. In the left side portion 2l of the device casing, a device casing intake portion 10l is provided on the left side of the duct portion 59. The device casing intake section 10l is composed of a plurality of ventilation holes, and communicates between the left side and the right side of the device casing left surface section 2l. The front cover 4 is provided with a device housing intake section 10f in front of the duct section 59. The device housing intake section 10f is composed of a plurality of ventilation holes, and communicates the front and rear sides of the front cover 4. The image forming apparatus 1 takes air AR from outside the apparatus housing 2 into the interior through the apparatus housing intake sections 10r, 10l, and 10f. Hereinafter, the device casing intake sections 10r, 10l, and 10f will also be collectively referred to as the device casing intake section 10.

Further, in the right side portion 2r of the device casing, a device casing exhaust portion 11 is provided near the upper end near the rear end, that is, on the rear lower side of the paper stacker portion 5. The device casing exhaust section 11 includes a plurality of ventilation holes, and communicates the right side and the left side of the device casing right side section 2r.

[1-2. Internal configuration of image forming apparatus]
Next, the internal configuration of the image forming apparatus 1 will be explained. As shown in FIG. 3, the image forming apparatus 1 is a monochrome electrophotographic printer that performs monochrome printing, and prints a desired monochrome image on paper P having a size such as A3 size or A4 size. . Inside the device housing 2, various parts are arranged along a conveyance path R that conveys the paper P.

As shown in FIGS. 2 and 5, body frames 8r and 8l formed of sheet metal, a head fixing unit partition member 9, and a head image forming unit partition member 23 are provided inside the apparatus housing 2. ing. The main body frame 8r is a plate-like member that extends in the up-down and front-back directions inside the device casing 2, slightly to the left of the right side portion 2r of the device casing. Further, the main body frame 8l is a plate-like member that extends in the up-down and front-back directions inside the device casing 2, slightly to the right of the left side portion 2l of the device casing. Below, the main body frames 8r and 8l are also collectively referred to as the main body frame 8. This body frame 8 supports the device casing 2 by fixing the device casing 2 thereto. An inter-frame gap SPr between the device casing and main body frames is formed between the main body frame 8r and the right side portion 2r of the device casing. Various members are arranged in this gap SPr between the device housing body frames. Furthermore, an inter-frame gap SPl between the device casing and main body frames is formed between the main body frame 8l and the left side portion 2l of the device casing. Various members are arranged in this gap SPl between the device housing body frames. Hereinafter, the device casing body frame gaps SPr and SPl will also be collectively referred to as the device casing body frame gap SP.

An inter-frame shielding portion 58r of the device casing body is provided between the main body frame 8r and the right side portion 2r of the device casing in the left-right direction, and between the fixing unit 17 and the duct portion 59 in the front-rear direction. Further, an inter-frame shielding portion 58l of the device casing is provided between the main body frame 8l and the left side portion 2l of the device casing in the left-right direction, and between the fixing unit 17 and the duct portion 59 in the front-back direction. Hereinafter, the device casing main frame interframe shielding parts 58r and 58l are also collectively referred to as the device casing main body interframe shielding part 58.

The device casing main frame interframe shielding portion 58r is a plate-like member extending in the vertical and horizontal directions, and is fixed to the right side 2r of the device casing, for example, and extends from the top 2u of the device casing to the bottom of the device casing 2 in the vertical direction. It is distributed throughout. For this reason, the device casing body interframe shielding portion 58r divides the device casing body interframe gap SPr into a front space and a rear space, and the device casing body frame interframe shielding portion 58r divides the device casing body interframe gap SPr into a front space and a rear space. This makes it difficult for air to move between spaces.

The device casing main frame interframe shielding portion 58l is a plate-like member extending in the vertical and horizontal directions, and is fixed to the left side 2l of the device casing, for example, from the top surface 2u of the device casing to the bottom surface of the device casing 2 in the vertical direction. It is distributed over the entire section. For this reason, the device casing body interframe shielding portion 58l divides the device casing body interframe gap SPl into a front space and a rear space, and the device casing body frame interframe shielding portion 58l divides the device casing body interframe gap SPl into a front space and a rear space. This makes it difficult for air to move between spaces.

The head fixing unit partition member 9 is made of a highly rigid member such as a sheet metal, and is disposed between the fan 72, the image forming unit 12, and the fixing unit 17 in the front-rear direction, as shown in FIGS. 6 and 8. ing. As shown in FIG. 16, the head fixing unit partition member 9 has a cross section shaped like a capital letter "J" inverted from front to back when viewed from the left side, and the right end portion is shaped like the main body frame 8r (FIG. 5). ), the strength of the main body frame 8 is maintained by having the left end portions connected and fixed to the main body frame 8l (FIG. 5).

The head image forming unit partition member 23 is made of a highly rigid member such as a sheet metal, and as shown in FIGS. placed in between. As shown in FIG. 17, the head image forming unit partition member 23 has a cross section shaped like a capital letter "L" rotated 180 degrees when viewed from the left side, and the right end portion is shaped like the main body frame 8r ( As shown in FIG. 5), the strength of the main body frame 8 is maintained by having the left end portions connected and fixed to the main body frame 8l (FIG. 5). Further, as shown in FIG. 7, the head image forming unit partition member 23 extends from the rear side above the head holder 51 toward the front between the head holder 51 and the developer container 27, and then toward the bottom. It is bent approximately 90 degrees and extends along the vertical direction to a point slightly above the image forming cover intake port 46 of the image forming cover 32 of the image forming unit 12 .

As shown in FIGS. 2 and 3, inside the device housing 2, a developer (for example, black (K) One image forming unit 12 corresponding to the color of the toner is provided. Hereinafter, the left-right direction that is perpendicular to the transport direction of the paper P and the thickness direction perpendicular to the paper surface of the paper P is also referred to as the transport width direction.

The image forming unit 12 forms an electrostatic latent image on the surface of the photoreceptor drum 38 by exposing the surface of the photoreceptor drum 38 to light using an LED head 50 (described later) of the head unit 29 . A developer image is formed on the surface of the photoreceptor drum 38 by making the developer supplied from the developer container 27 adhere to the electrostatic latent image.

Furthermore, a transfer unit 14 is provided below the image forming unit 12 between the main body frame 8r and the main body frame 8l inside the apparatus housing 2. The transfer unit 14 includes an annular conveyance belt (not shown) provided so as to be freely movable in the front-rear direction along the conveyance path R, and a transfer unit disposed opposite to each other below the photoreceptor drum 38 with the conveyance belt in between. It has a roller 15. The transfer roller 15 charges each color of the paper P formed on the photoreceptor drum 38 by charging the paper P to a polarity opposite to that of the developer when the paper P passes between the photoreceptor drum 38 and the conveyor belt. Transfer the developer image to paper P.

Furthermore, a paper tray 16 for storing paper P is provided below the transfer unit 14 (that is, at the bottom of the apparatus case 2) between the main body frame 8r and the main body frame 8l inside the apparatus case 2. Furthermore, a pair of conveyance rollers for conveying the paper P are provided between the main body frame 8r and the main body frame 8l inside the apparatus housing 2 on the conveyance path R between the paper tray 16 and the transfer unit 14. It is being

Furthermore, a fixing unit 17 is provided inside the apparatus housing 2 on the downstream side (that is, at the rear) of the image forming unit 12 in the paper conveyance direction between the main body frame 8r and the main body frame 8l. As shown in FIGS. 6 and 7, the fixing unit 17 has various parts arranged inside a fixing unit housing 17E formed in a substantially box shape. Further, in the fixing unit 17, a grip portion 17G shaped like a capital letter "U" rotated 180 degrees when viewed from the rear is located at the center in the left-right direction on the upper surface of the fixing unit housing 17E. It is provided so as to protrude upward from the top surface of the. This gripping portion 17G is gripped by the user when the fixing unit 17 is attached to and removed from the main body frame 8 (FIG. 2). Further, the fixing unit 17 has a paper intake port, which is an opening that communicates the inside and outside of the fixing unit housing 17E, at a location facing the transport path R, approximately at the vertical center of the front surface of the fixing unit housing 17E. A mouth 17I is formed. The fixing unit 17 takes in the paper P conveyed along the conveyance path R into the interior of the fixing unit housing 17E through the paper inlet 17I serving as a medium inlet.

The fixing unit 17 includes a heating roller 18 above the conveyance path R, and a pressure roller 19 disposed oppositely below the heating roller 18 with the conveyance path R in between. The developer image transferred to the sheet P is heated and pressed by the heating roller 18 and the pressure roller 19 to be fixed on the paper P. Further, between the main body frame 8r and the main body frame 8l inside the device housing 2, there is a paper stacker for accumulating the paper P on the transport path R between the fixing unit 17 and the paper discharge port 20 (FIG. 3). A pair of ejection rollers and the like are provided to eject the paper P to the section 5 from the paper ejection port 20.

Further, between the main body frame 8r and the main body frame 8l inside the apparatus housing 2, as shown in FIG. A duct portion 59 is provided on the upstream side (that is, the front) in the conveyance direction, that is, between the image forming unit 12 and the fixing unit 17 in the conveyance direction (front-back direction).

Furthermore, in the vicinity of the upper end of the main body frame 8r (FIG. 2) near the rear end, the right side and the left side of the main body frame 8r are connected to each other at a location facing the device case exhaust part 11 of the device case 2. An exhaust fan 22 is fixed to the ventilation hole drilled in this manner. The exhaust fan 22 absorbs heat generated and raised by the fixing unit 17, heat raised as the paper P moves from the fixing unit 17 toward the paper discharge port 20, and heat discharged from an exhaust duct exhaust port 68 (described later). The increased heat and the like are exhausted to the outside of the device casing 2 via the device casing exhaust section 11 provided in the device casing 2.

[1-3. Configuration of image forming unit]
Next, the configuration of the image forming unit 12 will be explained. As shown in FIGS. 7, 9, 10, and 11, the image forming unit 12 is broadly divided into an image forming body 26 and a developer container 27. Incidentally, the image forming unit 12 and each component constituting it have a sufficient length in the left-right direction depending on the length of the paper P in the left-right direction. For this reason, many components in the image forming unit 12 are relatively longer in the left-right direction than in the front-rear direction or the up-down direction, and are formed in an elongated shape along the left-right direction.

The developer container 27 stores a developer therein, and is configured to be detachable from the image forming unit 12 . Incidentally, the developer container 27 is sometimes called a toner cartridge. This developer container 27 is attached to the image forming main body section 26 when attached to the image forming unit 12 . A supply hole 30 that communicates the space inside the developer container 27 with the outside space is bored at approximately the center of the bottom of the developer container 27 in the left and right directions, and the supply hole 30 can be opened or closed. A shutter is provided.

The image forming main body section 26 is disposed below the developer container 27, and most of its outer periphery is closed off by the main body section 24, which is composed of an image forming frame 31 and an image forming cover 32, and there is relatively little space inside. It forms a large space. The image forming frame 31 is disposed on the lower side of the main body 24, has a cross section shaped like a capital letter "U", and has a supply roller 35, a developing roller 36, a developing blade holding plate 42, a photosensitive It holds the body drum 38, the charging roller 39, the sub-charging roller 40, and the cleaning blade holding plate 44.

The image forming cover 32 is disposed above the main body 24 and is fixed to the image forming frame 31. The image forming cover 32 is made of resin molded to a certain degree of thickness, is formed from the rear side of the charging roller 39 to the front side of the developer storage space 34, and covers the upper side of the image forming frame 31. There is. The image forming cover 32 bulges upward near the rear end so as to cover the charging roller 39, the sub-charging roller 40, etc. from above, is recessed downward to avoid the head unit 29 in front of it, and further in front of it bulges downward to avoid the head unit 29. , extends upward along the substantially vertical direction to above the developing blade holding plate 42, and further extends to the front side of the front upper end of the developer storage space 34.

Further, the image forming cover 32 is provided with an exposure hole 47, which is a hole elongated in the left-right direction, right below the head unit 29, that is, right above the photoreceptor drum 38. The exposure hole 47 serving as an opening of the image forming unit communicates the upper side and the lower side of the image forming cover 32 (air passage AD1 in the image forming unit (described later)).

Further, the image forming cover 32 has a developing hole portion located directly below the supply hole 30 of the developer container 27 that is elongated in the left-right direction to communicate the internal space of the developer container 27 and the developer storage space 34 . A drug passage port 49 is provided.

Further, the image forming cover 32 is provided with an image forming cover intake port 46 in a portion facing the rear surface of the upper end portion of the developing blade holding plate 42 of the developing blade portion 37 . As shown in FIGS. 10 and 12, the image forming cover intake port 46 as an opening of the image forming unit is an image forming unit in which a substantially square hole is formed extending from the left end to the right end of the image forming cover 32. There are two rows of cover intake ports, one above the other. The image forming cover intake port 46 communicates the rear and front sides of the image forming cover 32 (the air passage AD1 within the image forming unit). Therefore, the image forming cover intake port 46 exposes a portion of the developing blade holding plate 42 in the developing blade section 37 to the outside of the image forming cover 32 . Thereby, the image forming cover intake port 46 makes a part of the developing blade holding plate 42 of the developing blade portion 37 visible from the rear of the image forming cover 32 through the image forming cover intake port 46.

Further, the image forming unit 12 is located above the upper end of the cleaning blade holding plate 44 of the cleaning section 41 and at the rear of the charging roller 39, and the rear end of the image forming cover 32 and the rear upper end of the image forming frame 31. An image forming cover exhaust port 48, which is a hole elongated in the left and right direction, is formed between the image forming cover and the image forming cover. The image forming cover exhaust port 48 communicates the upper and lower sides of the image forming cover 32 (the air passage AD1 within the image forming unit).

In this way, the image forming unit 12 has the image forming cover intake port 46 near the developing blade 43 that is a heat source, the exposure hole 47 near the LED head 50 that is a heat source, and the cleaning blade 45 that is a heat source. An image forming cover exhaust port 48 is provided nearby. The image forming cover intake port 46, the exposure hole 47, and the image forming cover exhaust port 48 are located on the side where the paper P does not travel between the developing blade holding plate 42 and the cleaning blade holding plate 44, that is, the developing blade portion 37, The developing roller 36, the photosensitive drum 38, the charging roller 39, the sub-charging roller 40, and the cleaning section 41 are provided on the opposite side of the conveyance path R.

The image forming main body section 26 incorporates a developer storage space 34, a supply roller 35, a developing roller 36, a developing blade section 37, a photosensitive drum 38, a charging roller 39, a sub-charging roller 40, and a cleaning section 41. . Among these, the supply roller 35 , the developing roller 36 , the photosensitive drum 38 , the charging roller 39 , and the sub-charging roller 40 are each configured in a cylindrical shape with the center axis aligned in the left-right direction, and are rotated by the image forming frame 31 . Possibly supported.

The developer storage space 34 stores the developer supplied from the developer storage container 27 . The supply roller 35 is arranged in front of the photoreceptor drum 38, and has an elastic layer made of a conductive urethane rubber foam or the like formed on the circumferential side thereof. The developing roller 36 is disposed between the photosensitive drum 38 and the supply roller 35, and has an elastic layer having elasticity, a surface layer having conductivity, etc. formed on the circumferential side thereof. The developing roller 36 has its circumferential surface in contact with the circumferential surface 38S of the photoreceptor drum 38 on the rear side, and has its circumferential surface in contact with the supply roller 35 on its front side.

A developing blade section 37 is provided above the developing roller 36. The developing blade section 37 as a layer regulating member is composed of a developing blade holding plate 42 and a developing blade 43. The developing blade holding plate 42, which serves as a developing blade supporting member, is a metal plate-like member whose cross section is shaped like a capital letter "L", and its upper end is fixed to the image forming frame 31 and extends vertically. The upper end portion extends so as to be slightly inclined rearward, and supports the developing blade 43. The developing blade 43 is made of a metal such as stainless steel or phosphor bronze, or a rubber material such as silicone rubber, and its upper side is fixed to the developing blade holding plate 42 . The developing blade 43 extends so that its upper end is slightly inclined backward with respect to the vertical direction, and its lower end is brought into contact with the circumferential side of the developing roller 36 in a slightly elastically deformed state. The developing blade section 37 transmits heat generated when the lower end of the developing blade 43 comes into contact with the developing roller 36 from the developing blade 43 to a metal developing blade holding plate 42, and radiates the heat from the developing blade holding plate 42. do.

The photoreceptor drum 38 has a thin film-like charge generation layer and a charge transport layer sequentially formed on its circumferential surface, and can be charged. The lower surface of the photoreceptor drum 38 in the image forming frame 31 is open over a relatively wide range. For this reason, when the image forming unit 12 is mounted on the main body frame 8 (FIG. 2), the lower surface of the photoreceptor drum 38 is brought into contact with a transfer belt (not shown) or paper P placed on the transfer belt. .

The charging roller 39 is disposed above and behind the photoreceptor drum 38 , has a circumferential surface covered with a conductive elastic material, and brings the circumferential surface into contact with the circumferential surface of the photoreceptor drum 38 . The sub-charging roller 40 is disposed above the charging roller 39 and has its circumferential side in contact with the circumferential side of the charging roller 39 .

A cleaning section 41 is provided behind the photoreceptor drum 38 . The cleaning section 41 includes a cleaning blade holding plate 44 and a cleaning blade 45. The cleaning blade holding plate 44 is a metal plate-like member whose cross section is shaped like the English capital letter "L", and its upper end is fixed to the image forming frame 31 and its upper end is inclined rearward with respect to the vertical direction. The cleaning blade 45 is extended to support the cleaning blade 45. The cleaning blade 45 is made of, for example, a thin plate of resin, and its upper side is fixed to the cleaning blade holding plate 44 . The cleaning blade 45 extends so that its upper end is inclined rearward with respect to the vertical direction, and its lower end is brought into contact with the circumferential side of the photoreceptor drum 38 in a slightly elastically deformed state. The cleaning section 41 transmits heat generated when the lower end of the cleaning blade 45 comes into contact with the photoreceptor drum 38 from the cleaning blade 45 to a metal cleaning blade holding plate 44, and radiates the heat from the cleaning blade holding plate 44. do.

In this way, the image forming unit 12 extends from the rear side of the developing blade holding plate 42, the rear side of the developing blade 43, and from the contact point of the developing roller 36 with the developing blade 43 to the contact point of the photosensitive drum 38 (that is, the developing roller 36), from the contact point with the developing roller 36 on the photoreceptor drum 38 to the contact point with the charging roller 39 (i.e., the circumferential side surface from the upper front side to the rear upper side of the photoreceptor drum 38), charging Image formation is performed on the circumferential side of the roller 39 other than the contact point with the photosensitive drum 38, the circumferential side of the sub-charging roller 40 other than the contact point with the charging roller 39, the front side of the cleaning blade 45, and the front side of the cleaning blade holding plate 44. It is arranged so as to face the inner wall surface of the cover 32.

Further, in the image forming unit 12, the developing blade holding plate 42 and the image forming frame 31 are brought into contact with each other, the lower end of the developing blade 43 is brought into contact with the developing roller 36, and the developing roller 36 and the photosensitive drum 38 are brought into contact with each other. The photoreceptor drum 38 and the charging roller 39 are brought into contact with each other, the charging roller 39 and the sub-charging roller 40 are brought into contact with each other, the cleaning blade 45 is brought into contact with the photoreceptor drum 38, and the cleaning blade is held. The plate 44 and the image forming frame 31 are brought into contact with each other.

As a result, the image forming unit 12 extends from the rear side of the developing blade holding plate 42, the rear side of the developing blade 43, the circumferential side of the developing roller 36 from the upper side to the rear side, and the upper front side of the photoreceptor drum 38 from the upper rear side. , the peripheral side of the charging roller 39 other than the contact point with the photoreceptor drum 38 , the peripheral side of the sub-charging roller 40 other than the contact point with the charging roller 39 , the front side of the cleaning blade 45 , the front of the cleaning blade holding plate 44 An image forming unit internal air passage AD1, which is a space through which cooling air passes, is formed between the side surface and the image forming cover 32.

The head unit 29 is located above the photosensitive drum 38 in the image forming main body section 26 . The LED head 50 of this head unit 29 has a plurality of light emitting element chips arranged in a straight line along the left and right direction, and each light emitting element is activated in a light emitting pattern based on an image data signal supplied from a control section (not shown). Make it emit light.

The image forming main body section 26 rotates the supply roller 35, the developing roller 36, and the charging roller 39 in the direction of arrow R1 (clockwise in the figure) by being supplied with driving force from a motor (not shown), and rotates the photosensitive drum. 38 in the direction of arrow R2 (counterclockwise in the figure). Further, the image forming main body section 26 charges each of the supply roller 35, the developing roller 36, the developing blade 43, and the charging roller 39 by applying a predetermined bias voltage to each of them.

The supply roller 35 causes the developer in the developer storage space 34 to adhere to the circumferential side by being charged, and causes the developer to adhere to the circumferential side of the developing roller 36 by rotating. The developing roller 36 has excess developer removed from its circumferential side by the developing blade 43, and the circumferential side is brought into contact with the circumferential side of the photoreceptor drum 38 with the developer adhered in a thin film.

On the other hand, the charging roller 39 uniformly charges the circumferential surface of the photoreceptor drum 38 by contacting the photoreceptor drum 38 in a charged state. The LED head 50 sequentially exposes the photoreceptor drum 38 by emitting light at predetermined time intervals in a light emission pattern based on an image data signal supplied from the control section. As a result, electrostatic latent images are sequentially formed on the circumferential side surface of the photoreceptor drum 38 near its upper end. The sub-charging roller 40 removes the developer that has moved from the circumferential side 38S of the photoreceptor drum 38 to the circumferential side of the charging roller 39.

Subsequently, the photosensitive drum 38 rotates in the direction of arrow R2, thereby bringing the portion where the electrostatic latent image is formed into contact with the developing roller 36. As a result, developer adheres to the circumferential side of the photoreceptor drum 38 based on the electrostatic latent image, and a developer image based on the image data is developed. The photoreceptor drum 38 further rotates in the direction of arrow R2, thereby causing the developer image to reach the vicinity of the lower end of the photoreceptor drum 38.

At this time, the image forming apparatus 1 causes the paper P to reach the lower side of the image forming unit 12 by the transfer unit 14 (FIG. 1), and charges the transfer roller 15 to have a property opposite to that of the developer. Therefore, the image forming unit 12 sandwiches the paper P between the portion of the photoreceptor drum 38 on which the developer image is formed and the charged transfer roller 15, and transfers the developer image to the paper P. Transcribe. If developer remains on the circumferential side surface 38S of the photosensitive drum 38 after the developer image is transferred to the paper P, this developer is removed by the cleaning blade 45.

Here, the range from the contact point with the developing roller 36 to the contact point with the transfer belt (not shown) or the paper P placed on the transfer belt in the direction of arrow R2 on the circumferential side surface 38S of the photosensitive drum 38 is , an image forming area AIF (FIG. 9) in which developer is formed as an image on the circumferential side surface 38S.

[1-4. Configuration of duct part]
As shown in FIGS. 13, 14, and 15, the duct section 59 mainly includes an intake duct section 60 on the front side, an exhaust duct section 66 on the rear side, a duct partition wall 60b, and a fan 72. ing.

The intake duct section 60 is formed on the front side of the exhaust duct section 66, that is, on the upstream side in the conveyance direction of the paper P. The intake duct section 60 includes an intake duct front plate 60f on the front side, an intake duct upper plate 60u on the upper side, an intake duct lower plate 60d on the lower side, and a duct partition wall 60b on the rear side. The space surrounded by the front side plate 60f, the intake duct upper side plate 60u, the intake duct lower side plate 60d, and the duct partition wall 60b is an intake duct internal space 63.

The intake duct front plate 60f is formed with an intake duct front plate vertical portion 60f1 and an intake duct front plate recessed portion 60f2. The intake duct front plate vertical portion 60f1 is a plate-like member that extends in the vertical and horizontal directions.

An intake duct intake port 62 is provided between the upper end of the intake duct front plate 60f and the upper end of the duct partition wall 60b. Further, air intake duct intake ports 62 are also provided between both left and right ends of the front side plate 60f of the air intake duct and both left and right ends of the duct partition wall 60b. The intake duct intake port 62 is a ventilation hole, and exposes a portion of the intake duct internal space 63 to the outside.

The intake duct front plate concave portion 60f2 is recessed toward the rear of the intake duct front plate vertical portion 60f1 on the lower side and inside in the left-right direction of the intake duct front plate vertical portion 60f1. Three fan fixing parts 61 are formed in the intake duct front plate recess 60f2 along the left-right direction. The fan fixing portion 61 is formed with a hole that communicates the front side of the intake duct front plate recess 60f2 with the lower end of the intake duct internal space 63. A fan 72 is fixed to each fan fixing part 61. The fan 72 is arranged to face the rear surface of the head holder 51, and its air blowing direction faces diagonally downward and forward so as to face the image forming cover intake port 46 (FIG. 7) of the image forming unit 12. The intake duct upper plate 60u is a plate-like member that extends in the front, rear, left and right directions. The intake duct lower plate 60d is a part of the head fixing unit partition member 9, and is a plate-like member extending in the horizontal direction. (Fig. 7). Further, an extension line along the upper surface of the lower intake duct plate 60d enters the image forming cover intake port 46 (FIG. 7) of the image forming unit 12.

The duct partition wall 60b is a plate-like member that extends in the vertical and horizontal directions, and is disposed along the vertical direction between the intake duct front side plate 60f and the exhaust duct rear side plate 66b. The duct internal space 69 is divided into two spaces.

The exhaust duct section 66 is partially constituted by the head fixing unit partition member 9, and is formed on the rear side of the air intake duct section 60, that is, on the downstream side in the conveyance direction of the paper P. The exhaust duct section 66 has an exhaust duct front plate 66f below the intake duct lower plate 60d of the intake duct section 60 on the lower side of the front side, an exhaust duct lower side plate 66d on the lower side, and an exhaust duct rear side plate on the rear side. 66b are respectively formed, and the space surrounded by the exhaust duct front plate 66f, the exhaust duct lower plate 66d, the exhaust duct rear plate 66b, and the duct partition wall 60b is the exhaust duct internal space 69.

The exhaust duct front plate 66f is a plate-like member extending in the vertical and horizontal directions. This exhaust duct front plate 66f is provided with an exhaust duct intake port 67. The exhaust duct intake port 67 is composed of a plurality of ventilation holes arranged in the left-right direction, and communicates the front side of the exhaust duct front plate 66f with the exhaust duct internal space 69. The exhaust duct lower plate 66d is a plate-like member extending in the front, rear, left and right directions.

The exhaust duct rear side plate 66b is a plate-like member that extends so that its upper end is inclined forward in the vertical and horizontal directions. This exhaust duct rear side plate 66b is provided with an exhaust duct exhaust port 68 at its upper end. The exhaust duct exhaust port 68 is composed of a plurality of ventilation holes arranged in the left-right direction, and communicates the rear of the exhaust duct rear side plate 66b with the upper end of the exhaust duct internal space 69. This exhaust duct exhaust port 68 is arranged at a position sufficiently above and away from the upper end of the grip portion 17G in the fixing unit 17 (FIG. 7). Therefore, the exhaust duct exhaust port 68 is arranged with the fixing unit housing 17E sandwiched between the exhaust duct exhaust port 68 and the paper intake port 17I of the fixing unit 17.

[1-5. Head unit configuration]
As shown in FIGS. 9, 18, and 19, the head unit 29 includes an LED head 50 and a head holder 51 that holds the LED head 50. 9).

The head holder 51 is formed by resin molding, and has a rectangular parallelepiped shape that is thin in the front-rear direction, long in the up-down direction, and elongated in the left-right direction. This head holder 51 has a holder body part 51m at both left and right ends, and a guide part 51g in a range that occupies about half the length of the head holder 51 in the left-right direction between the left and right holder body parts 51m. It is formed.

The holder main body 51m of the head holder 51 is supported at both ends by main body frames 8l and 8r (FIG. 5), and is supported by a spring 57 provided between the holder main body 51m and the vicinity of both left and right ends of the LED head 50. is biased downward toward the photoreceptor drum 38. The head unit 29 transmits heat generated by the LED head 50 emitting light to the head holder 51, and radiates the heat from the head holder 51.

The guide portion 51g of the head holder 51 includes a shielding plate 52, a holder opening 53, and a partition plate 54. The shielding plate 52 constitutes the upper end of the head holder 51, is formed above the holder opening 53, and has a flat plate shape whose front side is inclined downward with respect to the horizontal direction. The partition plate 54 as a guide member is formed below the holder opening 53 and has a flat plate shape extending in the horizontal direction.

The holder opening 53 is a space surrounded by the shielding plate 52 on the upper side, the partition plate 54 on the lower side, and the holder main body part 51m on both left and right sides, and allows the front and rear of the head holder 51 to communicate with each other. The holder opening 53 has a plurality of holder openings 53a arranged in a row at substantially constant intervals in the left-right direction.

The holder opening 53 is disposed at a position facing the fan 72 (FIG. 7) of the duct portion 59 disposed at the rear of the head holder 51, that is, at the front lower side of the fan 72 facing downward. Cooling air sent from 72 toward the lower front side is passed forward through the head holder 51 toward the image forming cover intake port 46 of the image forming unit 12 disposed in front of the head holder 51. Further, the holder opening 53 directs the cooling air sent from the fan 72 toward the lower front side toward the exposure hole 47 of the image forming unit 12 disposed below the head holder 51 so that the inside of the head holder 51 is directed downward. pass to.

The holder opening 53a is a square column-shaped space surrounded by the shielding plate 52 on the upper side, the partition plate 54 on the lower side, and the holder opening support part 55 on both left and right sides, and communicates the front and rear of the head holder 51. I'm letting you do it. A holder opening support portion 55 is provided between adjacent holder openings 53a. The holder opening support part 55 is a plate-like member that is thin in the left-right direction and long in the vertical direction, and its upper end is connected to the shielding plate 52 and its lower end is connected to the partition plate 54, thereby maintaining the strength of the head holder 51. There is.

Further, an inter-holder head space 56 is formed between the partition plate 54 and the LED head 50. This holder-head space 56 communicates the front and rear sides of the head holder 51.

The guide portion 51g forms two different flow paths (air blow paths) that guide the air coming out of the fan 72 in a direction toward the developing blade 43 in the image forming unit 12. The first flow path is a space sandwiched between the shielding plate 52 and the partition plate 54, that is, the holder opening 53a, and is a space between the shielding plate 52 and the partition plate 54, which is the holder opening 53a. This is a flow path that pushes and bends the image forming unit 12 downward. The second flow path is a space between the partition plate 54 and the LED head 50, that is, the inter-holder head space 56, and is a flow path that directs the cooling air coming out of the fan 72 toward the developing blade 43 in front. It is. These two flow paths merge behind the image forming cover intake port 46 in the image forming cover 32 of the image forming unit 12 and enter the inside of the image forming unit 12 via the image forming cover intake port 46 and the exposure hole 47. connected (described later).

[1-6. About the ventilation duct]
In this configuration, the image forming apparatus 1 rotates the fan 72 to suck in outside air, which is air outside the apparatus case 2, through the apparatus case intake part 10 (FIG. 2) and into the apparatus case 2. The air is taken in and collected behind the fan 72 in the interior space 63 of the intake duct via the intake duct intake port 62 (FIGS. 14 and 15). The outside air collected in the intake duct internal space 63 is discharged forward, ie, toward the image forming unit 12, by the fan 72.

As shown in FIGS. 7 and 9, the cooling air Ca, which is the air emitted from the fan 72, is divided into two channels, a lower flow path f1 and an upper flow path f2, by a partition plate 54 in the head holder 51. Branches into a flow path.

Further, the lower portion of the cooling air Ca discharged from the fan 72 toward the lower front side collides with the upper surface of the lower side plate 60d of the intake duct, is guided forward to the lower side of the partition plate 54, and is guided to the lower side of the partition plate 54 in the flow path f1. along. The cooling air Ca along the flow path f<b>1 advances forward toward the developing blade holding plate 42 in the image forming unit 12 , that is, toward the image forming cover intake port 46 of the image forming cover 32 .

On the other hand, the upper part of the cooling air Ca discharged from the fan 72 toward the lower front side collides with the lower surface of the shielding plate 52, is guided toward the lower front side, and flows along the flow path f2 to the head image forming unit partition. It collides with the member 23 and is guided downward. The cooling air Ca along the flow path f<b>2 advances forward toward the photosensitive drum 38 in the image forming unit 12 , that is, toward the exposure hole 47 of the image forming cover 32 .

The cooling air Ca along the flow path f1 and the cooling air Ca along the flow path f2 merge behind the image forming cover intake port 46. Thereafter, the cooling air Ca along the flow path f1 passes through the image forming cover intake port 46 and flows into the inside of the image forming cover 32. On the other hand, the cooling air Ca along the flow path f2 passes in front of the LED head 50 and cools the LED head 50, while passing through the exposure hole 47 and flowing into the inside of the image forming cover 32.

The cooling air Ca flowing into the image forming cover 32 from the image forming cover intake port 46 first hits the developing blade holding plate 42 and the developing blade 43, thereby cooling the developing blade 43. Next, this cooling air Ca flows into the image forming unit internal air passage AD1, that is, the upper and rear sides of the developing roller 36 and the upper side of the photoreceptor drum 38, thereby flowing into the inside of the image forming cover 32 from the exposure hole 47. It merges with the cooling air Ca. Subsequently, the combined cooling air Ca flows through the air passage AD1 in the image forming unit, that is, the front upper side of the charging roller 39, the upper side of the sub-charging roller 40, the rear upper side of the charging roller 39, the upper front side of the cleaning blade 45, and the cleaning blade holder. It sequentially flows into the upper front side of the plate 44, passes through the image forming cover exhaust port 48, and exits to the outside of the image forming cover 32. At this time, the cooling air Ca hits the cleaning blade holding plate 44 and the cleaning blade 45, thereby cooling the cleaning blade 45. Incidentally, the cooling air Ca also cools the contact points between the developing roller 36 and the photoreceptor drum 38, the contact points between the photoreceptor drum 38 and the charging roller 39, and the contact points between the charging roller 39 and the sub-charging roller 40.

The cooling air Ca that has passed through the image forming cover exhaust port 48 and is discharged to the outside of the image forming cover 32 enters the exhaust duct internal space 69 inside the exhaust duct portion 66 through the exhaust duct intake port 67 of the exhaust duct portion 66. Flow into. Subsequently, this cooling air Ca passes through an exhaust duct exhaust port 68 provided above the fixing unit 17 and exits to the outside of the exhaust duct section 66 . The cooling air Ca that has gone out of the exhaust duct section 66 is discharged to the outside of the device casing 2 via the device casing exhaust section 11 provided in the device casing 2 by the exhaust fan 22 (FIG. 2). As a result, the air is exhausted from the image forming apparatus 1.

[1-7. Effects, etc.]
In the above configuration, the image forming apparatus 1 supplies the cooling air Ca sent from the fan 72 to the head holder 51 of the head unit 29 provided between the image forming unit 12 and the fan 72 in the conveying direction. A holder opening 53 is provided on the 12 side for passage. Further, the image forming apparatus 1 is configured to provide an inter-holder head space 56 between the head holder 51 and the LED head 50 through which the cooling air Ca sent from the fan 72 passes toward the image forming unit 12 side. Therefore, the image forming apparatus 1 can prevent the wind from the fan 72 from being blocked by the head unit 29 located between the fan 72 and the image forming unit 12, and improve the cooling efficiency of the image forming unit 12 by the fan 72. I can do that.

Furthermore, conventionally, in the image forming apparatus 1, the fixing unit 17 is disposed apart from the image forming unit 12 to prevent the developer inside the image forming unit 12 from melting due to the heat generated by the fixing unit 17. There is a certain amount of space between the unit 17 and the image forming unit 12. Furthermore, since the developer container 27 is arranged above the image forming main body 26, it is practical to arrange a fan above the image forming main body 26 to send cooling air into the inside of the image forming main body 26. Not the point.

In contrast, in the image forming apparatus 1, the fan 72 is disposed in the space that originally existed between the fixing unit 17 and the image forming unit 12. Therefore, in the image forming apparatus 1, there is no need to provide a separate space for arranging the fan 72, and the originally vacant space can be effectively utilized, and the fan 72 can be arranged while preventing the apparatus from becoming larger.

Further, in the image forming apparatus 1, the fan 72 is disposed inside the apparatus housing 2 at a central portion separated from the apparatus housing intake section 10l and the apparatus housing intake section 10r in the left-right direction. For this reason, in the image forming apparatus 1, a fan is disposed inside the apparatus housing 2, for example, near the apparatus housing intake part 10l and the apparatus housing intake part 10r, and the cooling air is sent inward in the left-right direction. In comparison, the sound generated when the fan moves is less likely to leak outside the device housing 2, and the device as a whole can be made quieter.

Further, the image forming apparatus 1 forms an image forming cover intake port 46 near the developing blade 43 and an image forming cover exhaust port 48 near the cleaning blade 45 in the image forming cover 32 in the image forming unit 12. I did it like that. For this reason, the image forming apparatus 1 transfers the cooling air Ca taken into the image forming cover 32 from the image forming cover intake port 46 to the developing blade holding plate 42, the developing blade 43, the developing roller 36, the photoreceptor drum 38, and the charging roller. 39, the sub charging roller 40, the cleaning blade 45, and the cleaning blade holding plate 44, and then can be discharged to the outside of the image forming cover 32 from the image forming cover exhaust port 48. Thereby, the image forming apparatus 1 can effectively cool the developing blade 43 and the cleaning blade 45, which are heat sources in the image forming unit 12.

Here, in the image forming unit 12, the influence of frictional heat generation of the developing blade 43 due to the contact of the developing blade 43 with the developer on the circumferential side of the developing roller 36 is large. In contrast, in the image forming apparatus 1, the two flow paths f1 and f2 of the cooling air Ca are merged on the outside of the image forming cover 32 in the vicinity of the developing blade 43. Therefore, in the image forming apparatus 1, the air can be disturbed around the developing blade 43, and the heat exchange efficiency of the developing blade 43 can be improved.

Further, in the image forming apparatus 1, the cooling air Ca emitted from the fan 72 is first applied to the developing blade portion 37 within the image forming unit 12. Therefore, the image forming apparatus 1 can apply the cooling air Ca that has not yet cooled other heat sources to the developing blade section 37, which is the most heat source in the image forming unit 12, and efficiently 37 can be cooled. In addition, the image forming apparatus 1 allows the cooling air Ca, which is warmer than when it is emitted from the fan 72, to pass through the image forming unit air passage AD1 by cooling the developing blade section 37. Therefore, the image forming apparatus 1 can cool each member in the image forming unit 12 by diverting the cooling air Ca heated by cooling the developing blade section 37.

Furthermore, the developer formed as an image on the photoreceptor drum 38 in the image forming unit 12 may fly and scatter when exposed to strong wind, potentially staining the inside of the image forming apparatus 1 and the paper P. There is. In contrast, the image forming apparatus 1 is designed to cool the outside of the image forming area AIF of the photoreceptor drum 38 within the image forming unit 12. Therefore, the image forming apparatus 1 can prevent the developer from scattering even if strong wind is applied to the photoreceptor drum 38. Thereby, the image forming apparatus 1 can actively cool the image forming unit 12 while preventing the inside of the image forming apparatus 1 and the paper P from becoming dirty.

Further, when the exhaust heat from the fixing unit 17 enters the gap SP between the device casing 2 and the main body frame 8, the outside air taken in from the device casing intake sections 10r and 10l. temperature rises inside the gap SP between the device housing body frames, which may reduce cooling efficiency. In contrast, the image forming apparatus 1 is provided with an inter-frame shielding section 58 between the apparatus casing main body frames and between the apparatus casing suction parts 10r and 10l and the fixing unit 17 in the apparatus casing main body frame gap SP. . For this reason, in the image forming apparatus 1, the exhaust heat from the fixing unit 17 is directed forward toward the apparatus case intake sections 10r and 10l in the apparatus case main body frame gap SP by the apparatus case main frame interframe shielding part 58. Waste heat can be blocked to prevent As a result, the image forming apparatus 1 prevents the temperature of the outside air taken in from the apparatus casing intake parts 10r and 10l from rising inside the apparatus casing main body frame gap SP, and allows the image forming apparatus 1 to operate a fan from the apparatus casing main body frame gap SP. 72, the cooling efficiency can be improved.

Furthermore, if the fan 72 is provided between the fixing unit 17 and the image forming unit 12, the fan 72 may suck in air warmed by the exhaust heat from the fixing unit 17, reducing the cooling efficiency. There is. In contrast, in the image forming apparatus 1, an exhaust duct rear side plate 66b of the duct portion 59 is provided between the fan 72 and the fixing unit 17, and an exhaust duct internal space 69 is formed. Therefore, in the image forming apparatus 1, the exhaust duct rear side plate 66b blocks the exhaust heat from the fixing unit 17 so that it does not go to the fan 72, and the fixing unit It is possible to insulate the fan 72 so that exhaust heat from the fan 17 is not transmitted to the fan 72. Thereby, the image forming apparatus 1 can prevent the fan 72 from sucking in air warmed by the fixing unit 17, and can improve cooling efficiency.

Furthermore, if the image forming unit 12 is cooled and the air discharged from the image forming unit 12 hits the fixing unit 17, the temperature of the fixing unit 17 will drop and the developer on the paper P will not be properly heated. There is a possibility that you will not be able to do it. In contrast, in the image forming apparatus 1, an exhaust duct rear side plate 66b is provided between the image forming unit 12 and the fixing unit 17, and an exhaust duct internal space 69 is formed. Therefore, the image forming apparatus 1 can prevent the cooling air Ca from the image forming unit 12 from flowing toward the fixing unit 17 by the exhaust duct rear side plate 66b. Thereby, the image forming apparatus 1 can prevent the cooling air Ca discharged from the image forming unit 12 from directly hitting the fixing unit 17, and can improve printing quality.

Furthermore, the image forming apparatus 1 provides the exhaust duct exhaust port 68 of the duct portion 59 above the fixing unit 17, that is, with the fixing unit housing 17E sandwiched between it and the paper intake port 17I of the fixing unit 17. I did it like that. Therefore, the image forming apparatus 1 can exhaust the cooling air Ca discharged from the exhaust duct exhaust port 68 above the fixing unit 17, and can be blocked by the fixing unit housing 17E so that it does not flow toward the paper intake port 17I. As a result, in the image forming apparatus 1, the cooling air Ca that has passed through the image forming unit 12 enters the inside of the fixing unit housing 17E from the paper intake port 17I of the fixing unit 17, thereby cooling the fixing unit 17. can be prevented.

According to the above configuration, the image forming apparatus 1 includes the apparatus housing 2, the image forming unit 12 having the photoreceptor drum 38 that forms an electrostatic latent image, and the LED head as a head member that exposes the photoreceptor drum 38. 50 and a head holder 51 that holds the LED head 50, and a fan 72 that is provided inside the device housing 2 and cools the image forming unit 12. A holder opening 53a is provided as an opening for allowing the cooling air Ca to pass through to the image forming unit 12 side.

As a result, the image forming apparatus 1 can allow the cooling air Ca sent from the fan 72 to pass through the holder opening 53a of the head holder 51 and hit the image forming unit 12 without being blocked by the head holder 51. The forming unit 12 can be efficiently cooled.

The image forming unit 12 also includes a main body 24 , a photosensitive drum 38 , at least a portion of which is provided inside the main body 24 and carries an electrostatic latent image; A supply roller 35 that supplies developer to the main body drum 38 and a developing blade section 37 that is provided at least partially inside the main body 24 and regulates the developer layer adhering to the supply roller 35 are provided. The image forming cover 32 has an image forming cover intake port 46 provided near the developing blade 43 and an image forming cover exhaust port 48 provided at a position different from the image forming cover intake port 46. The intake port 46 and the image forming cover exhaust port 48 are arranged to communicate with each other.

As a result, the image forming unit 12 allows the cooling air Ca taken into the image forming cover 32 from the image forming cover intake port 46 to pass through the vicinity of various members inside the image forming cover 32, and then to the image forming cover exhaust port 48. The air can be discharged from the image forming cover 32 to the outside of the image forming cover 32, and the cooling efficiency of the image forming unit 12 by the fan 72 can be improved.

Furthermore, the image forming apparatus 1 includes the above-described image forming unit 12, a fixing unit 17 that fixes the image formed by the image forming unit 12 onto paper P as a medium, and a fixing unit 17 and an image forming unit in the paper conveyance direction. A fan 72 is provided between the image forming unit 12 and the fixing unit 17 to cool the image forming unit 12, and a duct part 59 is provided between the image forming unit 12 and the fixing unit 17 in the transport direction. a duct partition wall 60b as a first partition wall provided on the 72 side, and an exhaust duct rear side plate 66b as a second partition wall facing the duct partition wall 60b and provided on the fixing unit 17 side; The duct partition wall 60b and the exhaust duct rear side plate 66b form a flow path through which the air that cools the image forming unit 12 by the fan 72 flows between the fixing unit 17 and the fan 72.

As a result, the image forming apparatus 1 can prevent the cooling air Ca discharged from the image forming unit 12 from leaking to the fixing unit 17 and cool the fixing unit 17 by the exhaust duct rear side plate 66b, and the exhaust duct rear side plate 66b and The duct partition wall 60b can prevent heat from the fixing unit 17 from being transmitted to the image forming unit 12 and heating the image forming unit 12, thereby improving printing quality.

[2. Second embodiment]
[2-1. Configuration of image forming apparatus]
An image forming apparatus 101 according to the second embodiment (FIGS. 1 to 4) is different from the image forming apparatus 1 according to the first embodiment in that it includes an image forming unit 112 in place of the image forming unit 12. Although they are different, they are configured similarly in other respects.

[2-2. Configuration of image forming unit]
As shown in FIG. 20 and FIG. 21, in which members corresponding to those in FIG. ), it is different in that it has an image forming cover 132 of the main body part 124 in place of the image forming cover 32 of the main body part 24, and a developing blade part 137 in place of the developing blade part 37, but other points are the same. are configured similarly.

As shown in FIG. 22, in which members corresponding to those in FIG. ) is different in that it has an image forming cover inlet 146 instead of the image forming cover inlet 46, but has the same structure in other respects.

The image forming cover intake port 146 is formed to be wider in the vertical direction than the hole in the image forming cover intake port 46 (FIG. 12), and is elongated in the left and right direction. This image forming cover intake port 146 faces the rear surface of the developing blade holding plate 42 of the developing blade section 137 (FIGS. 20 and 21), and extends in the vertical direction from the upper end to the lower end of the developing blade holding plate 42. It is drilled over a wide range.

Further, behind the image forming cover intake port 146 of the image forming cover 132 (FIG. 22), a plate-like member that is thin in the left-right direction and long in the vertical direction is arranged so as to be arranged at approximately constant intervals in the left-right direction. A mouth support portion 73 is provided. The inlet support part 73 is integrally formed with the image forming cover 132 from above the image forming cover inlet 146 to below the image forming cover inlet 146 in the image forming cover 132, so that the image forming The strength of the cover 132 is maintained.

The developing blade section 137 (FIGS. 20 and 21) according to the second embodiment has an additional film 74 compared to the developing blade section 37 (FIGS. 8 and 9) according to the first embodiment. Although they differ in some respects, they have the same structure in other respects. The film 74 serving as a shielding portion is a thin plate-like member that is fixed to the lower surface of the developing blade holding plate 42, extends from the developing blade holding plate 42 to the image forming cover 132, and has its tip abutted against the image forming cover 132. ing. For this reason, the image forming apparatus 101 blocks the flow path of the cooling air Ca that has entered the inside of the image forming cover 132 from the image forming cover intake port 146 toward the lower side than the developing blade holding plate 42 .

Therefore, the cooling air Ca that has entered the inside of the image forming cover 132 from the image forming cover intake port 146 hits the developing blade holding plate 42 and then is prevented from going downward by the film 74, forming an image. The air flows toward the outside of the image forming cover 132 from the cover intake port 146, passes through the exposure hole 47, and flows into the inside of the image forming cover 32, and is also discharged from the left and right side surfaces of the image forming unit 112.

Here, as shown in FIG. 9, from the contact point between the developing roller 36 and the developing blade 43 on the circumferential side of the developing roller 36, the developing roller 36 and the photoreceptor drum move along the rotation of the developing roller 36 in the direction of arrow R1. In the exposed developer adhesion area AED, which is the range up to the contact point with 38, the area to which the developer has adhered is exposed to the air passage AD1 within the image forming unit. Therefore, if a strong wind hits such an exposed area of the AED where the developer is adhered, the developer may fly and scatter, potentially staining the inside of the image forming apparatus 1 and the paper P.

In contrast, the image forming apparatus 101 blocks the flow of the cooling air Ca between the developing blade holding plate 42 and the image forming cover 132 in the image forming unit 112, thereby preventing the developer from adhering to the exposed area AED on the developing roller 36. The cooling air Ca was prevented from hitting directly. Therefore, the image forming apparatus 101 can prevent the developer from scattering from the developing roller 36. Thereby, the image forming apparatus 101 can actively cool the image forming unit 112 while preventing the inside of the image forming apparatus 101 and the paper P from becoming dirty.

Further, when a strong wind hits the developing blade 43, the lower end of the developing blade 43 moves, and the developing blade 43 no longer contacts the developing roller 36 with a constant force, causing the developer on the peripheral side of the developing roller 36 to move. The thickness of the print may not be constant, and the print quality may deteriorate.

In contrast, the image forming apparatus 101 prevents the cooling air Ca from directly hitting the developing blade 43 in the image forming unit 112. Therefore, the image forming apparatus 101 can prevent the lower end of the developing blade 43 from moving. As a result, the image forming apparatus 101 can always bring the developing blade 43 into contact with the developing roller 36 with a constant force, keep the thickness of the developer on the peripheral side of the developing roller 36 constant, and maintain printing quality. .

Here, the developing blade section 137 transmits heat generated when the lower end of the developing blade 43 comes into contact with the developing roller 36 from the developing blade 43 to the metal developing blade holding plate 42. Heat is radiated from 42. Therefore, the image forming apparatus 101 can sufficiently cool the developing blade 43 indirectly by applying the cooling air Ca to the developing blade holding plate 42 without directly applying the cooling air Ca to the developing blade 43.

In this way, the image forming unit 112 includes the main body 124 , the photoreceptor drum 38 that is at least partially provided inside the main body 124 and carries an electrostatic latent image, and the photosensitive drum 38 that is at least partially provided inside the main body 124 . , a supply roller 35 that supplies developer to the photoreceptor drum 38, and a developing blade section 137 that is provided at least partially inside the main body section 124 and regulates the developer layer adhering to the supply roller 35. The image forming cover 132 of No. 124 has an image forming cover intake port 146 that exposes the developing blade section 137 to the outside of the main body section 124.

This allows the image forming unit 112 to apply the cooling air Ca taken into the image forming cover 132 from the image forming cover intake port 146 to the developing blade section 137, thereby improving the cooling efficiency of the image forming unit 112 by the fan 72. I can do it.

In other respects as well, the image forming apparatus 101 according to the second embodiment can achieve substantially the same effects as the image forming apparatus 1 according to the first embodiment.

[3. Other embodiments]
In the first embodiment described above, a case has been described in which the partition plate 54 in the head holder 51 is shaped like a flat plate along the horizontal direction. The present invention is not limited to this, and the partition plate 54 may be formed into various shapes, such as tilted forward or curved, in correspondence with the image forming cover intake ports 46 formed at various positions on the image forming cover 32. In this way, the cooling air Ca may be guided toward the image forming cover intake port 46. The same applies to the second embodiment.

Furthermore, in the above-described embodiment, a case has been described in which the holder opening 53a is a quadrangular prism-shaped space. The present invention is not limited to this, and by forming the shielding plate 52, the partition plate 54, and the holder opening support portion 55 into various shapes, the holder opening 53a may be formed into a space with various shapes.

Furthermore, in the above-described first embodiment, a case has been described in which the shielding plate 52 in the head holder 51 is formed into a flat plate whose front side is inclined downward with respect to the horizontal direction. The present invention is not limited to this, and in short, the end of the shielding plate 52 on the fan 72 side (rear side) so that the cooling air Ca along the flow path f2 is directed toward the LED head 50 located below the fan 72. The end portion on the image forming unit 12 side (front side) may be positioned lower than the image forming unit 12 side (front side). Alternatively, if the cooling air Ca along the flow path f2 is directed toward the LED head 50, the shielding plate 52 may be arranged, for example, along the horizontal direction instead of downwardly forward. The same applies to the second embodiment.

Furthermore, in the embodiment described above, the holder opening support portion 55 may be omitted as long as the strength of the head holder 51 can be ensured.

Further, in the embodiment described above, a case has been described in which the exhaust duct exhaust port 68 is arranged at a position sufficiently above and away from the upper end of the grip portion 17G of the fixing unit 17. The present invention is not limited to this, and the exhaust duct exhaust port 68 is arranged so that the cooling air Ca discharged from the exhaust duct exhaust port 68 hits the grip portion 17G of the fixing unit 17. The gripping portion 17G may be cooled by applying cooling air to the gripping portion 17G.

Furthermore, in the embodiment described above, a case has been described in which the fan 72 is arranged to face the rear side of the head holder 51. The present invention is not limited to this, and the fan 72 may be arranged to face at least either the right side or the left side of the head holder 51, for example.

Furthermore, in the second embodiment described above, by providing the film 74 on the lower surface of the developing blade holding plate 42, the developing blade is The case where the flow path toward the lower side of the developing blade holding plate 42 of the portion 137 is blocked has been described. The present invention is not limited to this, and the developing blade portion 137 is replaced with the developing blade portion 37 (FIG. 9), and the cooling air Ca entering the inside of the image forming cover 132 from the image forming cover intake port 146 is removed from the developing blade holding plate 42. There is no need to block the flow path toward the lower side.

Furthermore, in the second embodiment described above, the case where the film 74 is provided on the developing blade holding plate 42 has been described. The invention is not limited to this, and the film 74 may be provided on the main body portion 124.

Furthermore, in the second embodiment described above, the intake port support portion 73 may be omitted as long as the strength of the image forming cover 132 can be ensured.

Further, the image forming cover intake port 46 of the image forming cover 32 in the first embodiment described above may be replaced with the image forming cover intake port 146 of the image forming cover 132 in the second embodiment.

Furthermore, in the embodiment described above, the case where the device casing intake portion 10 is provided on the device casing right side portion 2r, the device casing left side portion 2l, and the front cover 4 has been described. The present invention is not limited to this, and the device housing intake section 10 may be provided at various other locations.

Furthermore, in the first embodiment described above, a case was described in which the present invention is applied to the image forming apparatus 1 which is a monochrome printer that has one image forming unit 12 corresponding to the color black and performs monochrome printing. . The present invention is not limited to this, and includes, for example, an image forming apparatus that is a color printer that has four image forming units corresponding to each color of yellow, magenta, cyan, and black and performs color printing, or an image forming apparatus that has four image forming units corresponding to each color of yellow, magenta, cyan, and black, The present invention may be applied to various image forming apparatuses, such as an image forming apparatus having the above-described image forming unit. In that case, one duct section 59 may be provided for each image forming unit, or only one duct section 59 may be provided within the image forming apparatus so that the cooling air Ca can be directed toward the plurality of image forming units. may be formed.

Furthermore, in the embodiments described above, the case where the present invention is applied to a printer has been described. The present invention is not limited to this, and the present invention may be applied to various devices that perform various processes related to images, such as a facsimile, an MFP (MultiFunction Printer), and a copying machine.

Furthermore, the present invention is not limited to the above-described embodiments and other embodiments. In other words, the scope of application of the present invention extends to embodiments in which each of the above-mentioned embodiments and a part or all of the other embodiments described above are arbitrarily combined, and embodiments in which a part is extracted. It is.

Furthermore, in the embodiment described above, the device casing 2 as the device casing, the image forming unit 12 or 112 as the image forming unit, the head unit 29 as the head unit, and the fan 72 as the cooling member are used. , the case of configuring the image forming apparatus 1 or 101 as an image forming apparatus has been described. However, the present invention is not limited to this, and an image forming apparatus may be configured by an apparatus housing having various other configurations, an image forming unit, a head unit, and a cooling member.

Furthermore, in the first embodiment described above, the main body section 24 as a main body section, the photosensitive drum 38 as an image carrier, the supply roller 35 as a supply roller, and the developing blade section 37 as a layer regulating section. The image forming unit 12 is configured as an image forming unit, and the main body has an image forming cover intake port 46 or an exposure hole 47 as a first opening, and an image forming cover exhaust port 48 as a second opening. We have described the case where the However, the present invention is not limited to this, and an image forming unit is configured by a main body having various other structures, an image carrier, a supply roller, and a layer regulating section, and the main body may have various other structures. It is also possible to have a first opening and a second opening.

Furthermore, in the second embodiment described above, the main body section 124 as a main body section, the photosensitive drum 38 as an image carrier, the supply roller 35 as a supply roller, and the developing blade section 37 as a layer regulating section. A case has been described in which the image forming unit 112 is configured as an image forming unit, and the main body portion has the image forming cover intake port 146 as an opening. However, the present invention is not limited to this, and an image forming unit is configured by a main body having various other structures, an image carrier, a supply roller, and a layer regulating section, and the main body may have various other structures. It may have an opening.

Further, in the embodiment described above, the image forming apparatus is configured by the image forming unit 12 or 112, the fixing unit 17 as the fixing unit, the fan 72 as the cooling member, and the duct part 59 as the duct part. The case has been described in which the duct part has the duct partition wall 60b as the first partition wall and the exhaust duct rear side plate 66b as the second partition wall. However, the present invention is not limited to this, and an image forming apparatus may be configured by an image forming unit having various other configurations, a fixing unit, a cooling unit, and a duct unit, and the duct unit may have various other configurations. It may have a first partition wall and a second partition wall.

The present invention can be used not only in computers that cause printers to print images, but also in various electronic devices that perform various processes related to images, such as image scanners, facsimile machines, and copying machines.

1, 101...Image forming apparatus, 2...Device housing, 2f...Device casing front part, 2u...Device casing top part, 2b...Device casing rear part, 2r...Device casing right side Surface portion, 2l... Left side of device housing, 3... Top cover, 4... Front cover, 5... Paper stacker section, 6... Fixing unit insertion/removal port, 7... Image forming unit insertion/removal port, 8... Main body frame, SP...Device casing gap between main body frames, 9...Head fixing unit partition member, 10r, 10l, 10f...Device casing intake section, 11...Device casing exhaust section, 12, 112... Image forming unit, 14... Transfer unit, 15... Transfer roller, 16... Paper tray, 17... Fixing unit, 17E... Fixing unit housing, 17I... Paper intake port, 17G... Gripping section, 18... Heating roller, 19... Pressure roller, 20... Paper discharge port, 22... Exhaust fan, 23... Head image forming unit partition member, 24, 124... Main body, 26... Image forming main body Part, 27... Developer container, 29... Head unit, 30... Supply hole, 31... Image forming frame, 32, 132... Image forming cover, AD1... Image forming unit internal air passage, 34... ...Developer storage space, 35... Supply roller, 36... Developing roller, 37, 137... Developing blade section, 38... Photosensitive drum, 38S... Circumferential side, 39... Charging roller, 40... Sub Charging roller, 41...Cleaning section, 42...Developing blade holding plate, 43...Developing blade, 44...Cleaning blade holding plate, 45...Cleaning blade, P...Paper, R...Transport path, 46, 146...Image forming cover intake port, 47...Exposure hole, 48...Image forming cover exhaust port, 49...Developer passage port, 50...LED head, 51...Head holder, 51m...Holder main body , 51g... Guide part, 52... Shielding plate, 53... Holder opening, 53a... Holder opening, 54... Partition plate, 55... Holder opening support part, 56... Space between holder heads, 57... ...Spring, 58...Device housing body frame interframe shielding part, 59...Duct part, 60...Intake duct part, 60f...Intake duct front side plate, 60f1...Intake duct front side plate vertical part, 60f2...Intake Duct front plate recess, 61...Fan fixing part, 60u...Intake duct upper plate, 60b...Duct partition wall, 60d...Intake duct lower plate, 62...Intake duct intake port, 63...Intake duct internal space , 66...Exhaust duct part, 66f...Exhaust duct front side plate, 66d...Exhaust duct lower side plate, 66b...Exhaust duct rear side plate, 67...Exhaust duct intake port, 68...Exhaust duct outlet, 69... ...Exhaust duct internal space, 72...Fan, 73...Inlet support section, 74...Film, AIF...Image forming area, AED...Exposed area where developer is attached, Ca...Cooling air.

Claims (14)

The main body and
an image carrier, at least a portion of which is provided inside the main body and carries an electrostatic latent image;
a supply roller, at least a portion of which is provided inside the main body, and which supplies developer to the image carrier;
a layer regulating member, at least a portion of which is provided inside the main body, and which regulates a developer layer adhering to the supply roller ;
a cleaning section, at least a portion of which is provided inside the main body section, and which removes the developer attached to the image carrier;
The main body has:
a first opening provided near the layer regulating member;
a second opening provided near the cleaning section ;
An image forming unit, wherein the first opening and the second opening communicate with each other. The first opening is
The image forming unit according to claim 1, characterized in that the opening is disposed closer to the layer regulating member than at least the supply roller and is penetrated toward the layer regulating member. The image forming unit according to claim 2, wherein the first opening is arranged to face the layer regulating member. The image forming unit according to claim 2 or 3, wherein an air passage through which the air passes is formed from the first opening to the second opening. further comprising a cleaning section, at least a portion of which is provided inside the main body, and which removes the developer attached to the image carrier;
The image forming unit according to any one of claims 1 to 4, wherein the second opening is provided near the cleaning section. The first opening is
exposing the layer regulating member to the outside of the main body portion;
The image forming unit according to any one of claims 1 to 5, characterized in that: The layer regulating member includes a developing blade that comes into contact with the supply roller, and a developing blade support member that has one end fixed to the main body and the other end that supports the developing blade,
The image forming unit according to claim 6, wherein the first opening exposes the developing blade support member to the outside of the main body. The image forming unit according to claim 7, further comprising a shielding portion provided between the main body portion and the developing blade support member to cover a gap between the main body portion and the developing blade support member. . The image forming unit according to any one of claims 1 to 8,
a fixing unit that fixes the image formed by the image forming unit onto a medium;
a cooling member that is provided between the fixing unit and the image forming unit in the conveyance direction of the medium and cools the image forming unit;
a duct section provided between the image forming unit and the fixing unit in the transport direction;
The duct portion includes a first partition wall provided on the cooling member side, and a second partition wall opposite to the first partition wall and provided on the fixing unit side with respect to the first partition wall. ,
The first partition wall and the second partition wall form a flow path through which air that has cooled the image forming unit by the cooling member flows between the fixing unit and the cooling member. Forming device. The duct portion has an intake port that takes in the wind sent from the image forming unit, and an exhaust port that exhausts the wind that flows between the first partition wall and the second partition wall,
The image forming apparatus according to claim 9, wherein the exhaust port is provided at a position away from the fixing unit. The fixing unit is formed with a medium intake port that takes in the medium on which the image is to be fixed from the outside,
The image forming apparatus according to claim 10, wherein the exhaust port is provided at a position where the air sent from the image forming unit does not enter the medium intake port. The fixing unit has a fixing unit housing surrounding the fixing unit,
The image forming apparatus according to claim 11, wherein the exhaust port is provided above an upper surface of the fixing unit housing. The fixing unit further includes a grip provided on the upper side of the fixing unit housing,
The image forming apparatus according to claim 12, wherein the exhaust port is provided at a position that directs the air sent from the image forming unit toward the gripping section. The image forming apparatus further includes a medium stacker section for accumulating the medium on which the image has been fixed by the fixing unit and discharged to the outside of the image forming apparatus. The image forming apparatus according to claim 12, wherein the image forming apparatus is provided at a position facing the stacker section.

Images