JP2013130782A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that can reduce power consumption, and ensures the degree of freedom of layout of the apparatus.SOLUTION: An image forming apparatus comprises: a toner conveying tube 49 for conveying a toner in a toner cartridge 48 to a developing device 23; and an air pump 90 that generates air flow inside the toner conveying tube 49 that flows to the developing device 23 from the toner cartridge 48; and conveys the toner in the toner cartridge 48 to the developing device 23 by the air flow. A toner containing a pressure-phase transition resin is used for the image forming apparatus.

Description

  The present invention relates to an image forming apparatus.

  Conventionally, an image provided with a toner conveying device that conveys toner as a developer in a toner accommodating portion, which is a developer accommodating portion, to a developing device by an air flow generated in a conveying tube using a pump such as an air pump or a screw pump. A forming apparatus is known (for example, Patent Document 1).

  Since the toner is conveyed by the air current, the stress on the toner can be reduced as compared with the case where the toner is mechanically conveyed by a coil screw or the like. Further, since the conveyance tube can be formed of a flexible tube, the degree of freedom of the layout of the entire image forming apparatus is improved as compared with a device in which a coil screw is provided in the conveyance tube and mechanically conveyed.

  As a toner used in an image forming apparatus, a toner using a low melting point toner formed of a resin material having a low glass transition temperature is known. A toner with a low glass transition temperature also exhibits a low melting temperature. Such low melting point properties allow toner to be fixed or fused at low temperatures onto an image receiving substrate such as paper, thereby enabling energy savings and increased device processing speed.

  By the way, in order to save power of the image forming apparatus, when the toner having the low melting point characteristic is used in the image forming apparatus provided with the above-described toner conveying device, the following problems occur. That is, if the conveying tube is moved to a place where the temperature inside the apparatus is high, such as in the vicinity of a heat source such as a fixing device or a motor, the toner moving in the conveying tube is heated and the viscosity increases. As a result, there is a risk of toner clogging in the transport tube. For this reason, it is necessary to avoid the place where the temperature inside the machine is high and rotate the transfer pipe. In addition, the arrangement location of the toner container is limited so that the conveyance tube is not arranged in a place where the temperature inside the apparatus is high. As a result, there is a problem that the degree of freedom of the layout of the apparatus is greatly impaired.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus that can save power and does not impair the degree of freedom of layout of the apparatus.

  In order to achieve the above object, the invention of claim 1 includes a toner image forming means for forming a toner image on a recording medium, a fixing means for fixing the toner image on the recording medium, and a developer having at least toner. The stored developer storage section, a transport pipe for transporting the developer in the developer storage section to the toner image forming means, and an air flow from the developer storage section toward the toner image forming means are generated in the transport pipe And a developer conveying device that conveys the developer in the developer containing portion to the toner image forming means by the air current. A pressure phase change resin is used as the toner. The toner containing the toner is used.

  The pressure phase transition resin refers to a resin that exhibits fluidity due to a phase transition phenomenon accompanying pressure stimulation.

According to the present invention, by using a toner containing a pressure phase change resin, a toner image on a recording medium can be fixed only by pressure, and power can be saved without lowering the melting point of the toner. .
In addition, if a toner containing a pressure phase change resin having a glass transition temperature higher than that of the low-melting-point toner is used, even if the conveying pipe is moved to a place where the temperature is high in the apparatus, Thus, the increase in the viscosity of the toner can be suppressed. As a result, the location of the transport pipe and the location of the developer container are not limited, and the degree of freedom in the layout of the apparatus is not impaired.

1 is a schematic configuration diagram showing a copier according to an embodiment. 1 is a schematic configuration diagram of a fixing device. FIG. 3 is a schematic configuration diagram of a state in which the pressure applied by the pressure roller pair of the fixing device is lowered. FIG. 3 is a block diagram illustrating an example of a control system that controls a pressure generated by a pair of pressure rollers of a fixing device based on image information. The schematic block diagram which shows an image creation part. Sectional drawing which looked at the image development part to the longitudinal direction. 1 is an overall configuration diagram illustrating a toner conveying device. FIG. Configuration diagram showing a toner conveying device of Modification A 10 is a timing chart of toner replenishment in the toner conveyance device of Modification A. FIG. 9 is a configuration diagram illustrating an image forming unit of an image forming apparatus including a toner conveying device according to modification B. FIG. 10 is a configuration diagram illustrating a toner conveyance device and a toner conveyance device according to Modification B. FIG. 9 is a cross-sectional view illustrating a relay portion of a toner conveyance device according to Modification C. FIG. 9 is a cross-sectional view illustrating a relay portion of a toner conveying device according to Modification D. FIG. 10 is a cross-sectional view illustrating a relay portion of a toner conveying device according to Modification E. FIG. 7 is a schematic configuration diagram of an image forming apparatus according to a first modification. FIG. 9 is an explanatory diagram illustrating an example of a main configuration of an image forming apparatus according to a first modification. Explanatory drawing which shows the ON / OFF state of a control pulse. FIG. 4A is an explanatory diagram illustrating an example of a printing surface of a toner control unit viewed from the intermediate transfer belt side. FIG. 4B is an explanatory diagram illustrating an example of a toner supply side surface of the toner control unit viewed from the toner carrier side. FIG. 4 is an explanatory diagram showing electric lines of force passing through a toner passage hole based on a simulation result of a two-dimensional cross-sectional electric field intensity distribution of a toner carrier, toner control means, and an intermediate transfer belt. Overall configuration diagram showing an example of the overall configuration of the image forming apparatus of Modification 2 (A) is a plane explanatory view schematically showing a configuration example of a toner carrier. (B) is a cross-sectional explanatory view of the toner carrier. FIG. 3 is an explanatory diagram illustrating an example of a pulse voltage applied to an electrode of a toner carrier. (A) is a plane explanatory view schematically showing another configuration example of the toner carrier. (B) is a cross-sectional explanatory view of the toner carrier. FIG. 10 is a schematic configuration diagram illustrating another configuration example of a toner image forming unit in the image forming apparatuses according to Modifications 1 and 2; FIG. 4 is a schematic configuration diagram illustrating another configuration example of a toner image forming unit.

Hereinafter, an embodiment in which the present invention is applied to a copying machine as an image forming apparatus will be described.
FIG. 1 is a schematic configuration diagram illustrating a copying machine according to an embodiment.
A color copying machine 1 as an image forming apparatus includes a writing unit 2 that emits laser light based on input image information, and process cartridges 20Y, 20M, 20C, and 20BK corresponding to each color (yellow, magenta, cyan, and black). Yes.
Each of the process cartridges 20Y, 20M, 20C, and 20BK includes a photosensitive drum 21 as a latent image carrier, a charging unit 22 that charges the photosensitive drum 21, and a cleaning unit that collects transfer residual toner on the photosensitive drum 21. 25. Each color process cartridge 20Y, 20M, 20C, 20BK is configured to be detachable from the apparatus main body. Further, developing units 23Y, 23M, 23C, and 23BK for developing the electrostatic latent image formed on the photosensitive drum 21 are provided.

  The toner image formed on the photosensitive drum 21 is primarily transferred to an intermediate transfer belt 27 as an image carrier by a transfer bias roller 24 as a primary transfer unit.

  The color copying machine 1 also includes a second transfer bias roller 28 serving as a transfer unit that transfers the toner image formed on the intermediate transfer belt 27 to the recording medium P, and an intermediate that collects untransferred toner on the intermediate transfer belt 27. A transfer belt cleaning unit 29 is provided. That is, the color copying machine of the present embodiment forms a toner image on the recording medium P by the writing unit 2, the charging unit 22, the developing device 23, the transfer bias roller 24, the intermediate transfer belt 27, and the second transfer bias roller 28. A toner image forming unit is configured. In addition, a paper feeding unit 61 that accommodates a transfer paper P as a recording medium, a conveyance belt 30 that conveys the transfer paper P on which a four-color toner image is transferred, and a fixing that fixes an unfixed image on the transfer paper P. A portion 66 is provided. In addition, carrier replenishing units 32Y, 32M, 32C, and 32BK that replenish carriers to the developing units 23Y, 23M, 23C, and 23BK, and toner replenishing units that replenish each color toner to the developing units 23Y, 23M, 23C, and 23BK, respectively. 47Y, 47M, 47C, 47BK.

  Hereinafter, an operation during normal color image formation in the image forming apparatus will be described. First, the document D is transported from the document table in the direction of the arrow in the drawing by the transport roller of the document transport unit 51 and placed on the contact glass 53 of the document reading unit 55. Then, the document reading unit 55 optically reads the image information of the document D placed on the contact glass 53.

  Specifically, the document reading unit 55 scans the image of the document D on the contact glass 53 while irradiating light emitted from the illumination lamp. Then, the light reflected by the document D is imaged on the color sensor via the mirror group and the lens. The color image information of the document D is read for each RGB (red, green, blue) color separation light by the color sensor, and then converted into an electrical image signal. Further, an image processing unit (not shown) performs color conversion processing, color correction processing, spatial frequency correction processing, and the like on the basis of RGB color separation image signals, so that yellow, magenta, cyan, and black are processed. Get color image information.

  Image information of each color of yellow, magenta, cyan, and black is transmitted to the writing unit 2. Laser light (exposure light) based on the image information of each color is emitted from the writing unit 2 toward the photosensitive drums 21 of the corresponding process cartridges 20Y, 20M, 20C, and 20BK.

  On the other hand, the four photosensitive drums 21 rotate in the clockwise direction in FIG. First, the surface of the photosensitive drum 21 is uniformly charged at a position facing the charging unit 22 (charging process). Thus, a charged potential is formed on the photosensitive drum 21. Next, the charged surface of the photosensitive drum 21 reaches the irradiation position of each laser beam. In the writing unit 2, laser light corresponding to the image signal is emitted from the light source corresponding to each color. The laser light is incident on the polygon mirror 3 and reflected, and then passes through the lenses 4 and 5. The laser light after passing through the lenses 4 and 5 passes through different optical paths for each of the yellow, magenta, cyan, and black color components (this is an exposure process).

  The laser beam corresponding to the yellow component is reflected by the mirrors 6 to 8 and then irradiated onto the surface of the photosensitive drum 21 of the first process cartridge 20Y from the left side of the drawing. At this time, the yellow component laser light is scanned in the rotation axis direction (main scanning direction) of the photosensitive drum 21 by the polygon mirror 3 that rotates at high speed. Thus, an electrostatic latent image corresponding to the yellow component is formed on the photosensitive drum 21 charged by the charging unit 22.

  Similarly, the laser beam corresponding to the magenta component is reflected by the mirrors 9 to 11 and then irradiated to the surface of the photosensitive drum 21 of the second process cartridge 20M from the left side of the paper, thereby causing an electrostatic latent image corresponding to the magenta component. An image is formed. The cyan component laser light is reflected by the mirrors 12 to 14 and then irradiated on the surface of the photosensitive drum 21 of the third process cartridge 20C from the left side of the paper, thereby forming an electrostatic latent image of the cyan component. The black component laser light is reflected by the mirror 15 and then irradiated on the surface of the photosensitive drum 21 of the fourth process cartridge 20BK from the left side of the paper, thereby forming an electrostatic latent image of black component.

  Next, the surface of the photosensitive drum 21 on which the electrostatic latent images of the respective colors are formed reaches positions facing the developing units 23Y, 23M, 23C, and 23BK, respectively. Then, the respective color toners are supplied onto the photosensitive drum 21 from the developing units 23Y, 23M, 23C, and 23BK, and the latent image on the photosensitive drum 21 is developed (development process). The surface of the photosensitive drum 21 after the development process reaches a position facing the intermediate transfer belt 27. Here, the transfer bias roller 24 is installed at each facing position so as to contact the inner peripheral surface of the intermediate transfer belt 27. Then, at the position of the transfer bias roller 24, the images of the respective colors formed on the photosensitive drum 21 are sequentially superimposed and transferred onto the intermediate transfer belt 27 (first transfer step).

  The surface of the photosensitive drum 21 after the first transfer process reaches a position facing the cleaning unit 25. The untransferred toner remaining on the photosensitive drum 21 is collected by the cleaning unit 25 (this is a cleaning process). Thereafter, the surface of the photosensitive drum 21 passes through a static elimination unit (not shown), and a series of image forming processes on the photosensitive drum 21 is completed.

  On the other hand, the surface of the intermediate transfer belt 27 on which the images of the respective colors on the photosensitive drum 21 are transferred in an overlapping manner travels in the direction of the arrow in the drawing and reaches the position of the second transfer bias roller 28. Then, the full-color image on the intermediate transfer belt 27 is secondarily transferred onto the recording medium P at the position of the second transfer bias roller 28 (second transfer step). The surface of the intermediate transfer belt 27 reaches the position of the intermediate transfer belt cleaning unit 29. Then, the untransferred toner on the intermediate transfer belt 27 is collected by the intermediate transfer belt cleaning unit 29, and a series of transfer processes on the intermediate transfer belt 27 is completed.

  The recording medium P at the position of the second transfer bias roller 28 is transported from the paper feeding unit 61 via the transport guide 63, the registration roller 64, and the like. Specifically, the transfer paper P fed by the paper feed roller 62 from the paper feed unit 61 that stores the recording medium P passes through the conveyance guide 63 and is guided to the registration roller 64. The transfer paper P that has reached the registration roller 64 is conveyed toward the position of the second transfer bias roller 28 in synchronization with the toner image on the intermediate transfer belt 27.

  The recording medium P on which the full-color image is transferred is guided to the fixing unit 66 by the conveyance belt 30. In the fixing unit 66, the color image is fixed on the transfer paper P (this is a fixing process). Then, the transfer paper P after the fixing process is discharged as an output image outside the apparatus main body 1 by the paper discharge roller 69, and a series of image forming processes is completed.

  In this embodiment, a toner having a resin that exhibits fluidity due to a phase transition phenomenon accompanying pressure stimulation (hereinafter referred to as “pressure phase transition resin”) is used, and a toner image is transferred by pressure in the fixing device 66. Fix on paper. Accordingly, the toner image can be fixed without being heated when the toner image is fixed on the transfer paper, and the power consumption of the image forming apparatus can be suppressed.

FIG. 2 is a schematic configuration diagram of the fixing device 66.
The fixing device 66 includes a pressure roller pair including an upper roller 67 and a lower roller 68 having a smooth surface, and a pressure adjusting mechanism for adjusting the pressure applied to the pressure roller pair. The upper roller 67 and the lower roller 68 are solid metal rolls obtained by applying hard chrome plating to the surface of the quenched general structural carbon steel (S45C). They are arranged to intersect at an angle of 1.5 degrees. By arranging in this way, a gap is formed between the upper roller 67 and the lower roller 68 at both ends in the axial direction, and the transfer paper can be conveyed at a high-pressure nip portion.

  The pressure adjusting mechanism includes a lever 131 having one end pivotally supported by a fulcrum 140 of the casing 115 of the fixing device 66 and a multi-end side supported by a compression spring 133. A roller 132 that abuts the cam 134 is provided at the end of the lever 131 supported by the compression spring 133, while supporting the bearing 68 a of the lower roller 68 of the pressure roller pair at a substantially central portion of the lever 131. . The lever 131 is configured to swing by rotation of the cam 134 (rotation by a motor or the like (not shown)). Further, on the opposite side across the cam 134, an arm 136 supported by shafts 137 and 138 provided on the casing 115 of the fixing device 66 and a compression spring 139 is provided. A roller 135 provided at the tip of the arm 136 is in contact with the cam 134. With this configuration, the pressure generated by the upper roller 67 and the lower roller 68 can be changed according to the rotation of the cam 134.

FIG. 3 is a diagram showing a state in which the pressure applied by the pressure roller pair is lowered.
As shown in FIG. 3, when the pressure applied by the pressure roller pair is lowered, the cam 134 is rotated to contact the roller 132, and the lever 131 is pushed downward by the cam 134. As a result, the lever 131 swings counterclockwise in the figure around the fulcrum 140, and the pressure generated by the upper roller 67 and the lower roller 68 can be reduced.

  The pressure Pb of the pressure nip formed by the pressure roller pair for fixing the toner image on the transfer paper is set to 0.5 MPa to 10 MPa, preferably 1 MPa to 5 MPa. When the pressure is 0.5 MPa or less, fixing failure occurs and toner peeling occurs. If it is greater than 10 MPa, it is difficult to transport the transfer paper P.

Further, the pressure Pb of the pressure nip may be adjusted by a pressure adjustment mechanism based on the image information.
FIG. 4 is a block diagram illustrating an example of a control system that controls the pressure generated by the pressure roller pair of the fixing device 66 in the pressure adjustment mechanism based on the image information. The control device 900 includes, for example, a CPU 901, a RAM 902, a ROM 903, an I / O interface 904, and the like, and is connected to the fixing device 66. The control device 900 can control the applied pressure in the fixing device 66 based on the image information by executing a predetermined control program incorporated in advance.

  For example, the control device 900 determines whether the image formed on the transfer paper P is an image formed with a single color or an image formed with a plurality of colors based on the image information. Based on the determination result, the control device 900 changes the set value of the pressurizing force generated by the pressure roller pair 67 and 68 of the fixing device 66 to a value suitable for each image, and uses the changed set value. Based on this, a control signal is sent to the fixing device 66. The fixing device 66 changes the pressure generated by the pressure roller pair 67 and 68 based on a control signal from the control device 900.

  Here, since a plurality of color images generally have a large amount of toner adhesion and a thick toner layer compared to a single color image, for example, in the case of a monochrome (single color) image, the pressure generated by the pressure roller pairs 67 and 68 is applied. When the image is a small color (a plurality of colors), the pressure generated by the pressure roller pairs 67 and 68 is set large, and the pressure is changed to a value suitable for each image pattern. In this way, it is determined whether or not the image formed on the transfer paper P is a single color, and the pressure generated on the pressure roller pair of the fixing device 66 is automatically changed to the optimum value depending on the difference in the image on the transfer paper P. As a result, it is possible to prevent problems such as fixing failure due to insufficient pressurization and wrinkles caused by excessive pressurization.

  Further, the image area ratio of the image formed on the transfer paper P is determined based on the image information. Based on the determination result, the control device 900 changes the set value of the pressurizing force generated by the pressure roller pair 67 and 68 of the fixing device 66 to a value suitable for each image, and uses the changed set value. Based on this, a control signal is sent to the fixing device 66. The fixing device 66 changes the pressure generated by the pressure roller pair 67 and 68 based on a control signal from the control device 900.

  Here, the toner adhesion amount on the transfer paper P increases in proportion to the image area ratio, and the toner layer also becomes thicker. Therefore, for example, when the image area ratio of each color is an image that is equal to or less than a preset threshold value (for example, 50%), the pressure generated by the pressure roller pair 67 and 68 is set small, and the image area ratio is set to the threshold value ( For example, if the pressure is greater than 50%, the pressure generated by the pressure roller pair 67 and 68 is set to a large value, and the pressure is changed to a value suitable for each image area ratio. In this way, the image area ratio of the image formed on the transfer paper is judged, and the pressure generated in the pressure roller pair 67, 68 of the fixing device 66 is automatically changed to the optimum value depending on the difference in the image area ratio. Accordingly, it is possible to prevent problems such as fixing failure due to insufficient pressurization and wrinkles generated by excessive pressurization.

  Further, for example, a heat source such as a halogen heater as a heat source may be provided so as to oppose the upper roller 67, and the upper roller 67 may be heated so that heat is supplementarily applied.

Next, the image forming unit of the image forming apparatus will be described in detail.
FIG. 5 is a schematic cross-sectional view showing the image forming portion, and FIG. 6 is a cross-sectional view in the longitudinal direction (the direction perpendicular to the paper surface of FIG. 5) showing the developing portion. Since the four image forming units installed in the apparatus main body 1 have substantially the same structure except that the color of the toner T used in the image forming process is different, the process cartridge, the developing unit, the toner supply unit, and the carrier supply unit In the drawing, alphabets (Y, M, C, BK) of symbols are omitted. In FIG. 5, the toner replenishing unit 47 and the carrier replenishing unit 32 are shown in a simplified manner.

  As shown in FIG. 5, the process cartridge 20 mainly contains a photosensitive drum 21 as a latent image carrier, a charging unit 22, and a cleaning unit 25 integrally in a case 26. The cleaning unit 25 is provided with a cleaning blade 25 a and a cleaning roller 25 b that are in contact with the photosensitive drum 21.

  The developing unit 23 mainly includes a developing roller 23a facing the photosensitive drum 21, a first conveying screw 23b facing the developing roller 23a, and a second conveying screw facing the first conveying screw 23b via a partition member 23e. 23c and a doctor blade 23d facing the developing roller 23a.

  Further, the developing unit 23 is provided with a first developer containing portion 23g and a second developer containing portion 23h separated by a partition member 23e. As shown in FIG. 6, the first developer accommodating portion 23g and the second developer accommodating portion 23h are communicated with each other at both longitudinal end portions (the range in which the partition member 23e is not interposed), and the developer circulation path. Is forming. A developing roller 23a, a first conveying screw 23b, and a doctor blade 23d are disposed in the first developer accommodating portion 23g. A second transport screw 23c and a magnetic sensor 40 are disposed in the second developer accommodating portion 23h.

  The developing roller 23a includes a magnet 23a1 fixed inside and forming a magnetic pole on the circumferential surface of the roller, and a sleeve 23a2 made of a nonmagnetic material and rotating around the magnet 23a1. A plurality of magnetic poles (main pole, transport pole, pumping pole, agent cutting pole, etc.) are formed on the developing roller 23a (sleeve 23a2) by the magnet 23a1.

  The developing roller 23a (sleeve 23a2) is connected to a drive motor (not shown) installed in the apparatus main body 1 and is rotationally driven by the drive motor. Although not shown, the developing roller 23a, the first transport screw 23b, and the second transport screw 23c are drivingly connected by a gear train. Thereby, as the developing roller 23a is rotationally driven by the drive motor, the first transport screw 23b and the second transport screw 23c are also rotationally driven following the development roller 23a.

  A two-component developer G composed of toner T and carrier C is accommodated in the developing unit 23.

  The above-described image forming process will be described in more detail with a focus on the developing process. The developing roller 23a rotates in the direction of the arrow in FIG. As shown in FIG. 6, the developer G in the developing unit 23 is generated by the rotation of the first conveying screw 23 b and the second conveying screw 23 c arranged so as to interpose the partition member 23 e therebetween in the arrow direction. The toner T (new toner) replenished from the replenishing section 47 through the toner conveying tube 49 is circulated in the longitudinal direction while being agitated and mixed (circulation in the direction of the broken arrow in FIG. 6). The first transport screw 23b transports the developer G to the left side in FIG. 6, and the second transport screw 23c transports the developer G to the right side in FIG. 6 (in a direction opposite to the transport direction of the first transport screw 23b). Is transported to.

  The toner T that is frictionally charged and adsorbed on the carrier C is carried on the developing roller 23 a together with the carrier C. The developer G carried on the developing roller 23a then reaches the position of the doctor blade 23d. The developer G on the developing roller 23a is adjusted to an appropriate amount at the position of the doctor blade 23d, and then reaches a position facing the photosensitive drum 21 (developing area).

  In the development area, the toner T in the developer G adheres to the electrostatic latent image formed on the surface of the photosensitive drum 21. Specifically, the toner T is latently exposed by the electric field formed by the potential difference (development potential) between the latent image potential (exposure potential) of the image area irradiated with the laser light L and the development bias applied to the development roller 23a. Adhere to the image.

  Most of the toner T adhering to the photosensitive drum 21 in the developing process is transferred onto the intermediate transfer belt 27. The untransferred toner T remaining on the photosensitive drum 21 is collected in the cleaning unit 25 by the cleaning blade 25a and the cleaning roller 25b.

  Here, the toner replenishing unit 47 provided in the apparatus main body 1 includes a toner cartridge 48 configured to be replaceable, and a toner as a developer conveying device that guides the new toner T discharged from the toner cartridge 48 to the developing unit 23. Consists of a transport device. The toner conveying device includes a toner conveying tube 49 as a conveying tube, an air pump that sends air from the toner conveying tube 49 and conveys the toner together with air. The toner cartridge 48 contains new toner T (any of yellow, magenta, cyan, and black).

  The toner T in the toner cartridge 48 is appropriately supplied into the developing unit 23 from the toner supply port 23m as the toner T in the developing unit 23 is consumed. The toner T in the developing unit 23 is consumed by a magnetic sensor 40 (toner density detecting means) installed below the second conveying screw 23c of the developing unit 23 or a photo sensor (not shown) facing the photosensitive drum 21. Is detected). The toner replenishing port 47m is moved from the toner replenishing port 23m so that the detection result of the magnetic sensor 40 or the photo sensor becomes an output value corresponding to the target toner density (the ratio of the toner T in the developer G). Thus, the toner is supplied to the developing unit 23. Adjustment of the amount of toner replenished to the developing unit 23 is performed by controlling the drive time of the screw pump. The configuration and operation of the toner conveyance device will be described in detail later.

  Further, the developing unit 23 in the present embodiment uses a trickle developing system. As shown in FIG. 5, discharging means 23k for discharging a part of the developer G accommodated in the developing unit 23 to the outside of the developing unit 23, and a carrier supplying unit 32 for newly supplying the carrier C into the developing unit 23. And are provided.

  Specifically, a carrier replenishing unit 32 is connected to the second developer accommodating unit 23 h separately from the toner replenishing unit 47. The carrier supply unit 32 includes a carrier cartridge 33 configured to be replaceable, and a carrier transfer device as a developer transfer device that guides the new carrier C discharged from the carrier cartridge 33 to the developing unit 23 through the carrier supply port 23f. It consists of The carrier transport device includes a carrier transport pipe 34, an air pump that feeds air into the carrier transport pipe 34, and transports toner together with air. A new carrier C is accommodated in the carrier cartridge 33.

  On the other hand, a developer discharge portion 23k as discharge means is provided above the wall surface of the second developer storage portion 23h. When the new carrier C is supplied from the carrier supply unit 32 into the developing unit 23 and the amount of developer in the developing unit 23 exceeds a predetermined amount, the excess developer G is transferred from the developer discharging unit 23k to the developing unit. 23 is discharged outside. The developer G discharged from the developer discharge portion 23k is conveyed to the developer recovery portion 23k2 via the developer recovery path 23k1. In this way, as the new carrier C is replenished, the developer surface rises and the developer G exceeding the height of the developer discharge portion 23k is discharged out of the development portion 23, so the agent in the development portion 23 The surface (developer amount) is always kept constant. In this embodiment, the overflow method is used as the discharging unit for discharging the developer from the developing unit 23. However, the developer discharging unit 23k is provided with an openable / closable shutter, and the developer is discharged by opening and closing the shutter. You can also.

Hereinafter, the configuration and operation of the toner conveying device as the developer conveying device will be described in detail.
FIG. 7 is a schematic configuration diagram of the toner conveying device.
As shown in FIG. 7, the toner conveying device includes a toner conveying tube 49, an air pump 90 (pump), a nozzle 75, a toner feeder 70, a merging unit 78, and the like.

  The toner conveying tube 49 is a tube made of a material excellent in flexibility and toner resistance, and has an inner diameter of 2 to 8 mm. As a material for the toner conveying tube 49, a rubber material such as polyurethane, nitrile, EPDM, or silicon, or an elastomer resin can be used. By using such a flexible toner conveyance tube 49 and air conveyance of toner, the degree of freedom of the layout of the toner conveyance path is increased, and the image forming apparatus can be downsized. The toner conveying device in the present embodiment is configured to transfer toner by generating pressure in the toner conveying tube 49 by an air pump. Therefore, the toner cartridge 48 can be disposed at a position lower than the developing unit 23.

  In addition, there are heat sources such as a motor in the apparatus, and there are places in the machine where the temperature is high, and there are places where the temperature is 45 ° C. or higher at the maximum. As a toner for reducing the fixing temperature of the fixing device and saving the energy of the device, the glass transition temperature is, for example, about 45 to 85 ° C., for example, about 50 to 65 ° C. or about 50 to 60 ° C. Melting point toners are known. Such low melting point toners also exhibit a low fixing or fusing temperature. For example, the minimum fusing temperature is about 75 to about 150 ° C, for example about 80 to 150 ° C, or about 90 to 130 ° C. Such low melting point properties are desirable in that they enable toner to be fixed or fused at low temperatures onto an image receiving substrate such as paper, thereby enabling energy savings and increased device processing speeds to be achieved.

  The toner, which is a polymer, becomes a rubbery region from the glass transition temperature or higher, and the viscosity increases. As a result of the increase in viscosity, the fluidity decreases and aggregation starts. When the low melting point toner is used, the low melting point toner aggregates at 45 ° C. or higher. Therefore, when the toner transport tube 49 is arranged at a place where the temperature in the apparatus is high, the toner aggregates in the transport tube and the toner is transported in the transport tube 49. There is a risk of clogging. However, the toner including the pressure phase change resin as in this embodiment can reduce the fixing temperature of the fixing device and save energy of the device even if the glass transition temperature is high. As the toner containing the phase change resin, for example, a toner containing a phase change resin having a glass transition point of 50 ° C. or higher is used. It does not agglomerate in the conveying tube 49 and clog in the toner conveying tube. As a result, the inside of the apparatus can be crushed without being restricted by the toner transport tube, so that the degree of freedom in the layout of the apparatus is not impaired.

  The toner transport tube 49 has a discharge port 49b connected to the toner replenishing port 23m of the developing unit 23 serving as a transport destination, and a toner cartridge (developer container) whose transport port 49a serves as a transport source via the merging unit 78 and the nozzle 75. 48. Further, the inlet 49 a of the transport pipe 49 is connected to the air pump 90 via the junction portion 78 and the tube 97. An opening 76 is provided at the tip of the nozzle 75, and the toner T in the toner cartridge 48 falls by its own weight into the nozzle 75 through the opening 76. The toner dropped into the nozzle 75 is held in a hole 71 provided in the rotating part 72 of the toner feeder 70. The rotating unit 72 is rotationally driven in the direction of the arrow by a motor (not shown).

  As a result, the toner held in the hole 71 falls by its own weight into the merging portion 78. In this way, a constant amount of toner is fed by the toner feeder 70 to the vicinity of the feeding port 49a (merging portion 78) of the toner transport tube 49. The toner is transported in the transport pipe 49 together with the air fed by the air pump 90 connected to the junction portion 78. Here, the toner feeder 70 also functions to prevent air sent from the air pump 90 connected to the merging portion 78 from flowing into the toner cartridge 48.

  The toner cartridge 48 is a bottle-shaped (or bag-shaped) container made of a resin material. A base member 48b to which the nozzle 75 is removably attached is welded (or bonded) to the tip of the toner cartridge 48. Further, the base member 48b is provided with a seal member 48a made of foamed polyurethane, rubber or the like. The nozzle 75 is inserted and removed while being in close contact with the seal member 48a, so that the leakage of the toner T from the toner cartridge 48 is suppressed.

  The toner replenishing section 47 (toner conveying device and toner cartridge 48) configured as described above operates as follows. First, the rotating unit 72 of the toner feeder 70 rotates in the direction of the arrow by an electric signal from the control unit. Next, when the hole 71 of the rotating part 72 reaches the lower side, the toner held in the hole 71 falls into the merge part 78. Next, the toner that has fallen into the merging portion 78 passes through the transport pipe 49 together with the air supplied by the air pump 90, and is replenished into the developing portion 23 from the toner replenishing port 23m (discharge port 49b).

  In the present embodiment, as characteristic control, at least when the toner T is sent from the conveyance source (toner cartridge 48, toner feeder 70) to the toner conveyance tube 49 (merging portion 78), the toner conveyance tube by the pump 90 is used. The gas is sent to 49. More specifically, before the toner is dropped from the toner feeder 70 to the merging portion 78, control is performed so that air is fed into the toner transport pipe 49 in advance by the air pump 90. As a result, the toner can be easily dispersed in the toner conveying tube 49, and the toner can be conveyed with less energy (air velocity). As a result, the amount of air transferred to the toner conveying tube 49 by the air pump 90 is also reduced, and an increase in internal pressure in the developing unit 23 can be reduced.

This will be described in detail below.
When the toner is fed from the toner feeder 70 to the junction 78 and then controlled so that air is fed into the toner transport pipe 49 by the air pump 90, the dropped toner becomes a mass and becomes a solid in the toner transport pipe 49. Deposits on the bottom (bottom). When the toner accumulated in this way is accelerated and conveyed while floating with air, a large frictional force is generated between the toner and the lower surface of the conveying tube, and a certain mixing ratio (the weight ratio of air and toner). )) Must be maintained, a large energy (air velocity) is required.

  Further, since the frictional force between the toner and the transport pipe is reduced, the toner containing the pressure phase change resin is softened by the frictional force with the transport pipe in the transport pipe and is prevented from being fixed in the transport pipe. Can do. As a result, toner clogging in the transport tube can be suppressed.

  In this embodiment, before the toner T is sent from the toner feeder 70 to the toner transport pipe 49, the gas is fed into the toner transport pipe 49 by the pump 90, so that the toner does not accumulate on the lower surface. It is conveyed while being mixed with air sequentially. Therefore, the toner is transported with less energy without causing friction between the toner and the toner transport tube 49. Further, since the conveyance is started before the toner is deposited, the dispersibility can be enhanced by maintaining a constant mixing ratio with a small amount of air. In this embodiment, the air flow rate by the air pump 90 is set to 0.5 to 5 m / second, and the air supply time is set to 0.5 to 5 seconds.

  Further, in the present embodiment, control is performed so that the gas is fed into the toner transport pipe 49 by the pump 90 before the toner T is fed into the toner transport pipe 49 from the toner feeder 70. In contrast, the toner is fed into the toner transport pipe 49 from the toner cartridge 48 and the toner feeder 70 as the transport source, and at the same time, the gas is fed into the toner transport pipe 49 by the pump 90. It can also be controlled. Specifically, the timing at which the toner T is fed from the toner feeder 70 to the toner conveyance tube 49 and the timing at which the pump 90 supplies gas to the toner conveyance tube 49 can be made simultaneously. In this case, the toner can be transported with the minimum necessary air transfer amount.

  As described above, according to the present embodiment, when the toner T is sent from the toner cartridge 48 to the transport pipe 49, at least the gas is fed into the transport pipe by the pump 90. Because of the control, the frictional force between the toner T and the transport pipe is reduced, and the toner T can be transported efficiently and reliably without applying stress to the toner T. As a result, it is possible to suppress the toner containing the pressure phase change resin from being softened in the conveyance tube due to stress during conveyance and adhering to the conveyance tube to cause toner clogging. Moreover, since the air transfer amount can be suppressed, an increase in the internal pressure of the developing unit 23 can be suppressed.

  In this embodiment, the air pump 90 that feeds air into the toner transport pipe 49 is used as a pump. However, a pump that sends air from the toner transport pipe 49 (for example, a screw pump) may be used as the pump. . Also in this case, when the toner T is sent from the toner cartridge 48 to the toner conveyance tube 49, the toner is controlled with at least energy that is sent out (sucked) from the conveyance tube by the pump. Can be transported.

  In the present embodiment, the process cartridges 20Y, 20M, 20C, and 20BK are configured by integrating the photosensitive drum 21, the charging unit 22, and the cleaning unit 25, respectively. Further, each developing unit 23Y, 23M, 23C, 23BK is configured as a single unit. On the other hand, the developing units 23Y, 23M, 23C, and 23BK can be integrated with the process cartridges 20Y, 20M, 20C, and 20BK. That is, the process cartridge 20 can also be configured by the photosensitive drum 21, the charging unit 22, the developing unit 23, and the cleaning unit 25. Furthermore, the maintainability of the image forming unit is improved.

  Next, a modified example of the toner conveying device will be described.

[Modification A]
FIG. 8 is a configuration diagram illustrating a toner conveyance device of Modification A. The toner conveying device of Modification A is configured such that a valve 91 is installed between the toner conveying tube 49 and the pump 90, and the gas feeding into the toner conveying tube 49 is controlled by opening and closing the valve 91. Is.

FIG. 9 is a timing chart of toner replenishment in the toner conveyance device of Modification A.
As shown in FIG. 9, when the air feeding into the toner conveying tube 49 is started, the valve 91 is opened after a predetermined time has elapsed since the driving of the air pump 90 was started by receiving the air pump signal. As shown in FIG. 9, the air amount (air flow rate) becomes unstable for a while after the driving of the air pump 90 is started by the reception of the air pump signal, but the driving of the air pump 90 is started and predetermined. By opening the valve 91 after the amount of air (air flow rate) has stabilized after a lapse of time, toner transportability is improved.
Further, when the air feeding into the toner conveying tube 49 is finished, the valve 91 is closed while the air pump 90 is driven.

  The configuration using the valve 91 as in Modification A is particularly useful when the distance between the air pump 90 and the toner transport tube 49 is long. That is, when the distance between the air pump 90 and the toner transport tube 49 is long, the time until the air amount is stabilized varies depending on the state of air flowing through the tube 91 (temperature, humidity). In this modification, since the air supply amount is controlled by opening and closing the valve 91, air can be fed into the toner conveying tube 49 with accurate timing and the minimum necessary air amount.

  Also in the toner conveying device of the modified example A, when the toner T is fed from the toner cartridge 48 to the toner conveying tube 49, control is performed so that at least gas is fed into the conveying tube by the pump 90. To do. Thereby, the toner T can be efficiently and reliably conveyed without damaging the toner T and without increasing the internal pressure of the developing unit 23.

[Modification B]
FIG. 10 is a configuration diagram illustrating an image forming unit of an image forming apparatus including the toner conveyance device according to Modification B, and FIG. 11 is a configuration diagram illustrating the toner conveyance device and the toner conveyance device according to Modification B.
In the toner conveying device (developer conveying device) of Modification B, a relay unit 95 is provided between the discharge port 49b of the toner conveying tube 49 and the replenishing port (toner replenishing port) 23m of the developing unit 23. .

  As shown in FIGS. 10 and 11, in the toner conveyance device of Modification B, a relay unit 95 is installed between the discharge port 49 b of the toner conveyance tube 49 and the toner supply port 23 m of the developing unit 23. The relay unit 95 is connected to the discharge port 49b above the toner supply port 23m, and the toner T discharged from the discharge port 49b falls by its own weight and is guided to the toner supply port 23m. Further, the relay portion 95 has a sufficiently large space (a space having a cross-sectional area wider than at least the discharge port 49b) in the interior thereof, and the air discharged from the discharge port 49b is the developing unit. The internal pressure of the developing unit 23 is prevented from rising directly into the image forming unit 23.

  Further, an exhaust port 95 a (opening) is provided on the upper surface of the relay unit 95. Thereby, since the air discharged from the discharge port 49b is exhausted from the exhaust port 95a, an increase in the internal pressure of the developing unit 23 can be reliably prevented. In order to suppress a problem that the exhaust port 95a is buried by the toner T discharged from the discharge port 49b, the exhaust port 95a is preferably disposed above the discharge port 49b.

  Further, in the modified example B, as shown in FIG. 11, a filter 96 is provided so as to cover the exhaust port 95a. The filter 96 has a mesh set in accordance with the particle size of the toner, and prevents the toner from leaking out of the relay unit 95.

  According to the modified example B, the relay unit 95 that promotes decompression is installed between the discharge port 49b of the toner conveyance tube 49 through which the toner is discharged together with air and the toner supply port 23m of the developing unit 23. The toner T can be efficiently and reliably conveyed without increasing the internal pressure of the portion 23.

[Modification C]
FIG. 12 is a cross-sectional view illustrating the relay portion of the toner conveyance device according to Modification C.
The toner conveying device (developer conveying device) of Modification C is provided with a shutter 100 as an opening / closing means for opening and closing a replenishing port (toner replenishing port) 23m of the developing unit 23.

  As shown in FIG. 12, also in the toner conveyance device in Modification C, a relay unit 95 is installed between the discharge port 49 b of the toner conveyance tube 49 and the toner supply port 23 m of the development unit 23. Further, an exhaust port 95 a covered with a filter 96 is provided on the upper surface of the relay unit 95 (above the discharge port 49 b and the supply port 23 m).

  Further, in Modification C, a shutter 100 is provided as an opening / closing means for opening and closing the toner supply port 23m of the developing unit 23. The shutter 100 is configured to be movable in a double arrow direction by a driving unit (not shown). The shutter 100 normally closes the toner supply port 23m, and opens the toner supply port 23m only for a short time immediately after the toner T and air are discharged from the discharge port 49b to the relay unit 95. Thus, the air discharged to the relay unit 95 is reliably exhausted to the outside through the exhaust port 95a, and the inflow of air into the developing unit 23 is reliably suppressed.

  In addition, by opening and closing the shutter 100 as described above, a problem that the toner floating in the developing unit 23 scatters to the relay unit 95 is also suppressed. The toner floating in the developing unit 23 is likely to occur due to a decrease in the binding force of the carrier with respect to the toner when the charging performance of the carrier accommodated in the developing unit 23 deteriorates.

[Modification D]
FIG. 13 is a cross-sectional view illustrating the relay portion of the toner conveyance device according to Modification D. In the toner transport device in Modification D, the exhaust port 95 a of the relay unit 95 is disposed at a position facing the discharge port 49 b of the transport pipe 49.

  As shown in FIG. 13, in the toner conveyance device in Modification D, the discharge port 49 b of the toner conveyance tube 49 is disposed at a position toward the exhaust port 95 a covered with the filter 96. As a result, the air discharged from the discharge port 49b is efficiently discharged to the outside from the exhaust port 95a along a substantially linear flow path. Even if the toner T discharged from the discharge port 49b reaches the exhaust port 95a along a substantially linear flow path, the toner T falls into its own weight after colliding with the filter 96 and is guided to the toner supply port 23m. Will be.

[Modification E]
FIG. 14 is a cross-sectional view illustrating the relay portion of the toner conveying device according to Modification E.
In the toner conveying apparatus according to the modified example E, a second conveying pipe 99 that connects the relay unit 95 and the replenishing port (toner replenishing port) 23m of the developing unit 23 is installed.

  As shown in FIG. 14, in the toner conveyance device of Modification E, the relay unit 95 is connected to the toner supply port 23 m via a flexible second conveyance tube 99 (tube). The inclination angle α of the second conveyance tube 99 is set to be equal to or greater than the repose angle with respect to the toner T so that the toner is reliably conveyed toward the developing unit 23 without stagnation in the second conveyance tube 99. Yes. As a result, the relay unit 95 and the developing unit 23 can be arranged apart from each other, and the degree of freedom of layout in the image forming apparatus is improved.

  In each of the above-described modifications, new toner T is supplied from the toner supply unit 47. However, a new two-component developer G may be supplied from the supply unit 47. In this case, the developer transport device transports the two-component developer G.

  In the above description, the present invention is applied to the toner transport device as the developer transport device. However, the present invention can also be applied to the carrier transport device as the developer transport device in the carrier replenishment unit 32. .

  Next, a modified example of the image forming apparatus will be described.

[Modification 1]
FIG. 15 is a schematic configuration diagram of an image forming apparatus according to the first modification.
The image forming unit that forms a toner image on the intermediate transfer belt 27 that is the image carrier of the above embodiment forms a latent image on the photosensitive member as a latent image carrier, and then attaches toner to the latent image to form a toner image. Then, the toner image is transferred to the intermediate transfer belt 27 to form a toner image on the intermediate transfer belt 27, so that a toner image is formed on the intermediate transfer belt 27 indirectly. In the first modification, the image forming unit forms toner images directly on the intermediate transfer belt by selectively attaching toner to the dot formation region of the intermediate transfer belt 27 where a latent image is not formed. It is composed.

  FIG. 16 is an explanatory diagram illustrating an example of a main configuration of the image forming apparatus according to the first modification. The image forming apparatus according to the first modification includes a roller-shaped toner carrier 101 that carries the toner T including the pressure phase change resin in a clouded state, and a toner control unit 104. The toner control unit 104 is disposed between the toner carrier 101 and the intermediate transfer belt 27 to which the toner T is attached.

  The toner carrier 101 is formed on the surface side along the direction (axial direction in this example) orthogonal to the direction in which the toner T is conveyed at a predetermined interval in the direction (circumferential direction in this example) in which the toner T is conveyed. It has a plurality of control electrodes 111 provided at a predetermined pitch. A pulse voltage (cloud pulse) Vs whose potential changes with time is applied to each control electrode 111 of the toner carrier 101 from a bias voltage applying means (power source) 106. For example, a pulse voltage Vs having a frequency of 0.5 kHz to 7 kHz is applied. Since the distance between the electrodes 111 and 110 is set at a fine pitch, a strong electric field is formed between the electrodes 111 and 110. Therefore, the toner T flies vigorously from the surface of the electrode 111 at a potential repelling the charged polarity of the toner T, and the flying toner T is attracted to the electrode 111 to which the potential of the attracting polarity is applied. By switching the pulse voltage Vs, the vertical flight according to the pulse frequency is repeated, and the toner T is in a cloud state.

  The toner control means 104 is provided such that a plurality of toner passage holes (openings) 41 through which the toner T can pass (only one is shown in FIG. 16) are arranged in a plurality of rows. A control electrode 42 is provided in a ring shape around the toner passage hole 41 on the toner supply side surface (surface on the toner carrier) of the toner control unit 104. Further, a common electrode 43 is provided on the surface on the printing side (surface on the recording medium side) that is slightly away from the toner passage hole 41 of the toner control unit 104.

  For example, a control pulse Vc as shown in FIG. 17 is applied to the control electrode 42 of the toner control unit 104 from a drive circuit 107 constituting a control voltage application unit (control pulse application unit) P. In this case, the voltage Vc-on is applied to the control electrode 42 when the toner passage hole 41 is in a state where the toner T can pass (ON state). On the other hand, when the toner T cannot pass (OFF state), the voltage Vc-off is applied to the control electrode 42. Further, a voltage Vrg is always applied to the common electrode 43 on the surface on the printing side from a power source 108 as a voltage applying unit, so that mutual interference of electric fields in the region on the printing side of the toner control unit 104 is prevented. Yes.

  The control electrode 42 of the toner control means 104 can operate only by being provided around the toner passage hole 41, but may be provided on the inner wall surface of the toner passage hole 41, or the toner It may be provided on both the inner wall surface of the passage hole 41 and the periphery of the toner passage hole 41 on the toner carrier side.

  On the back surface of the intermediate transfer belt 27 opposite to the toner adhesion surface, a back electrode 105 as a counter electrode means is disposed so as to contact and face. A bias voltage Vp for causing the toner T that has passed through the toner control means 104 to adhere to the intermediate transfer belt 27 is applied to the back electrode 105 from a bias power supply 109 as a bias voltage application means.

  Further, a configuration in which an electrode is embedded in the intermediate transfer belt 27 (a configuration in which the counter electrode means on the recording medium side is an internal electrode) may be employed. In this case, the bias voltage Vp is applied to the electrode inside the intermediate transfer belt 27.

  Here, as a means for clouding the toner carried on the surface of the toner carrier 101, a plurality of electrodes 111 provided on the surface of the toner carrier 101 are provided, and a voltage Vs is applied to each electrode 111. At this time, two or more electrodes 111 adjacent to each other apply a voltage p having a relationship of alternately repeating a direction of attracting toner T and a direction of repelling between the electrodes, or a pitch p between two electrodes or every two electrodes. Each electrode 111 is arranged at a pitch between two electrodes for applying a two-phase voltage to each electrode 111.

  18A is an explanatory view showing an example of a printing surface of the toner control unit 104 viewed from the intermediate transfer belt side, and FIG. 18B is a toner supply side surface of the toner control unit 104 viewed from the toner carrier side. It is explanatory drawing which shows an example. In the example of FIG. 18, a ring-like shape having a predetermined width (for example, 10 to 100 μm width) surrounding the toner passage hole 41 on the toner supply side (toner carrier 101 side) surface of the insulating substrate (base material) 45. A control electrode 42 is provided. The toner passage hole 41 is determined by the size of the dot diameter of the image to be formed, and has a diameter of, for example, φ50 μm to φ200 μm.

  The control electrode 42 of the toner control means 104 is connected to a lead pattern 42a for connecting to a driver circuit (drive circuit) for controlling ON / OFF of the passage of the toner T individually. In addition, a common electrode 43 is provided in a region excluding the peripheral portion of the toner passage hole 41 on the printing surface side of the toner control unit 104. A DC potential is applied to the common electrode 43 so that it is not affected by the electric field between adjacent ones regardless of the voltage application of Vc-on and Vc-off to the control electrode 42. In other words, since the electric force formed between the bias potential on the transfer paper side and the toner supply side can be formed as an independent line of electric force for each toner passage hole, multi-drive (drive that causes toner to fly from a plurality of nozzle toner passage holes) ) At the time of (), (to receive the state of other toner passage holes).

  The toner control means 104 having the above configuration can be manufactured as follows, for example. First, a resin film (for example, polyimide, PET, PEN, PES, etc.) is used as the insulating member that is the base material 45 from the viewpoint of cost and manufacturing process. The thickness of the resin film is preferably 30 μm to 100 μm. An Al vapor deposition film of 0.2 μm to 1 μm is formed on the front and back surfaces of this resin film. Next, as a photolithographic process on the surface (front surface) of the resin film on which the Al vapor deposition film is formed, after applying a photoresist with a spinner, performing pre-baking and mask exposure, developing, and then heating and curing the photoresist To do. Similarly, a pattern on the printing surface side is formed on the back surface of the resin film on which the Al vapor deposition film is formed by the same photolithography process as described above. Thereafter, Al patterning with an Al etching solution is performed. The formation of the through hole serving as the toner passage hole 41 is performed after the Al pattern is formed. As a process for forming the through hole, a dry etching process such as a mechanical process using a press, an excimer laser process for the formed pattern, or a sputter etching process using a metal mask can be used. By adopting these processes, it is possible to process a through hole with high accuracy without positional deviation.

  In the image forming apparatus according to the first modification including the image forming unit configured by the toner carrier 101 and the toner control unit 104 having the above-described configuration, the two-phase pulse having a phase difference of 180 degrees with respect to the electrode 111 of the toner carrier 101. By applying a voltage, the toner T flies on the toner carrier 101 and is clouded. Further, the toner T is transported by transporting the toner carrier 101 by rotation. On the other hand, the printing bias voltage Vp is applied to the back electrode 105 on the intermediate transfer belt 27 side. In this state, the voltage Vrg is applied to the common electrode 43 of the toner control unit 104. When the toner T is allowed to pass through the toner passage hole 41 (ON state) with respect to the control electrode 42, the ON voltage Vc-on shown in FIG. Is set to a state where it cannot pass through (OFF state), an OFF-time voltage Vc-off shown in FIG. 17 is applied. In this case, the voltage applied to each of these electrodes 111, 105, 42, 43 is set as will be described later, so that the toner T of the toner carrier 101 can pass toward the intermediate transfer belt 27 through the toner control means 104. At the time of applying the Vc-on in the state, electric lines of force 110 are formed from the intermediate transfer belt 27 side to the toner supply side (see FIG. 19). As a result, the toner clouded on the toner carrier 101 rides on the electric field generated by the electric force lines 110, passes through the toner passage hole 41 of the toner control unit 104, and lands on the intermediate transfer belt 27. Therefore, the toner image can be directly formed on the intermediate transfer belt 27 by ON / OFF control (open / close control) of each toner passage hole 41 of the toner control unit 104 according to the image to be formed.

FIG. 19 shows a state in which a pulse voltage Vs to the electrode 111 of the toner carrier 101, a bias voltage Vp to the back electrode 105 on the intermediate transfer belt 27 side, and a control pulse voltage Vc to the control electrode 42 of the toner control unit 104 are applied. 4 is an explanatory diagram showing electric lines of force passing through a toner passage hole based on a simulation result of electric field strength distribution in a two-dimensional cross section of the toner carrier 101, the toner control unit 104, and the intermediate transfer belt 27. FIG.
A pulse voltage (a potential at which the potential varies with time) Vs is applied to the electrode 111 of the toner carrier 101. In this case, the peak value of the bias voltage Vp is set according to the electrode pitch, the toner used, and the like. According to a normal experimental result, the toner can fly by setting the peak value of the bias voltage Vp within a range of ± 60 to ± 300 Vpp (pp is peak-peak).

  In the simulation example of FIG. 19, a voltage of ± 200 Vpp and a DC voltage component of 0 V is applied. The distance d between the toner carrier 101 and the toner control means 104 is 0.2 mm. In this example, the diameter of the toner passage hole 41 of the toner control means 104 is 120 μm, the width of the ring-shaped control electrode 42 in the center direction of the hole is 50 μm, and the distance between the common electrode 43 and the hole is 50 μm. The voltage applied to the common electrode 43 of the toner control means 104 is 0V. The control electrode 42 of the toner control unit 104 has a control pulse voltage Vc-on of +250 V when the toner T is allowed to pass through the toner passage hole 41 (ON state), except when the toner T is allowed to pass. The voltage Vc-off in the blocking state (to make it impossible to pass) is set to 0V.

  The bias voltage Vp to the back electrode 105 of the intermediate transfer belt 27 depends on the interval between the toner control unit 104 and the intermediate transfer belt 27, but a DC voltage of +200 to +1500 V, for example, may be applied. In the example of FIG. 19, the distance between the toner control unit 104 and the intermediate transfer belt 27 is 0.3 mm, a DC voltage of +800 V is applied to the back electrode 105, and a potential that draws negatively charged toner to the surface of the intermediate transfer belt 27. Forming a gradient.

  By setting the relationship between the potentials applied to the electrodes 111, 42, 43, and 105 as described above, for example, when a negatively charged toner is allowed to pass through the toner passage hole 41 (ON state) ( In FIG. 19A, electric lines of force are formed as follows. That is, most of the electric force lines that pass through the toner passage hole 41 of the toner control unit 104 out of the electric force lines that emerge from the electrode 105 on the intermediate transfer belt side that has the highest potential on the positive side pass through the toner passage hole 41. The electrode having the lowest potential, that is, the electrode to which −200 V of the toner carrier electrode 111 is applied is entered.

  As shown in FIG. 19A, when the toner T is allowed to pass through the toner passage hole 41 (ON state), the electric force line 110 passing through the toner passage hole 41 from the electrode 105 on the intermediate transfer belt side. Is the result of entering the two electrodes 43 at the lowest potential of -200V. Therefore, the negatively charged toner that is in the cloud state on the toner carrier 101 or the toner near the carrier electrode to which −200 V is applied passes through the toner passage hole 41 along the electric force line 110 and passes through the intermediate transfer belt 27. The toner T can fly on the surface.

  On the other hand, when the toner T is in a blocking state (OFF state) in which the toner T cannot pass through the toner passage hole 41 (FIG. 19B), −200 V is applied to the control electrode 42. Further, although the low potential side of the electrode 111 of the toner carrier 101 is also −200 V, all the electric lines of force enter the control electrode 42 at a position close to the electric lines of force from the electrode 105 on the intermediate transfer belt side. Become. Therefore, the toner on the surface of the toner carrier 101 and the supply region above the toner carrier 101 does not fly toward the electrode 105 on the intermediate transfer belt side. The voltage applied to the control electrode 42 in the blocking state (OFF state) does not have to be the same potential as the low potential side of the electrode 111 of the toner carrier 101, and the electric lines of force that have passed through the toner passage hole 41 do not carry the toner. If the condition does not reach the surface of the body 101, the passage of the toner T can be blocked (turned off).

  As shown in FIG. 15, in the image forming apparatus according to the first modification, the intermediate transfer belt 27 is wound around the two rollers 132 and 133 and moves in the direction indicated by the arrow. A back electrode 105 is disposed on the back surface (inside) of the intermediate transfer belt 27 corresponding to each image forming unit. Further, a cleaning unit 25 is provided for removing residual toner on the intermediate transfer belt 27 after the toner image is transferred onto the transfer paper.

In addition to the toner carrier 101 and the control unit 104, the image forming unit 100 includes a rotating toner supply roller 113 that supplies toner to the toner carrier 101, and a blade 114 that regulates the amount of toner on the toner carrier 101. It has.
Here, toner is replenished from the toner replenishing roller 113 to the toner carrier 101 and frictional charging of the toner is performed by friction between the toner on the toner replenishing roller 113 and the toner carrier 101.
The blade 114 on the downstream side of the toner replenishing roller 113 keeps the toner amount on the surface of the toner carrying member 101 constant by a thin layer and stabilizes the toner charge amount.
Then, the toner transported by the toner carrier 101 is ON / OFF controlled according to the image by the toner control unit 104, so that it flies onto the intermediate transfer belt 27, and a color toner image is formed on the intermediate transfer belt 27. Is done.

  Below the image forming unit 100, a paper feed unit 61 that accommodates the transfer paper P is disposed, and the transfer paper P is fed from the paper feed unit 61 by a pickup roller (paper feed roller) 62. The toner image on the intermediate transfer belt 27 is transferred to the transfer paper P fed from the paper supply unit 61 by the transfer roller 28 arranged to face the roller 132 around the intermediate transfer belt 27.

  The transfer paper P onto which the toner image has been transferred is conveyed to a fixing device 66, where the toner is pressure-fixed on the transfer paper P by the fixing device 66, and then discharged.

  Further, as described above, the intermediate transfer belt 27 is cleaned of residual toner by the cleaning unit 135 as an intermediate transfer member cleaning unit, and the next image formation is performed.

As described above, the image forming apparatus according to the first modification forms a four-color toner image on the intermediate transfer belt 27 and then transfers the four-color toner image on the intermediate transfer belt 27 from the paper feeding unit 61. This is an intermediate transfer recording method for transferring to P.
In the case of this intermediate transfer recording method, it is easy to ensure the accuracy of maintaining a constant distance between the printing surface (also referred to as “the surface on which the toner lands” or “image forming surface”) and the toner control means 104. High image quality can be achieved under conditions of low flight speed.
In the case of the intermediate transfer recording method, a printing surface that is smooth and does not accumulate charges by adjusting the volume resistivity and has no potential fluctuation can be obtained. An image forming apparatus that directly prints on transfer paper by turning on / off the passing of toner in the cloud form has high sensitivity to potential, and image quality fluctuations easily occur due to fluctuations in the printing surface bias potential. With this configuration, it is possible to obtain a reliable and high-quality color image.

[Modification 2]
FIG. 20 is an overall configuration diagram illustrating an example of the overall configuration of the image forming apparatus according to the second modification. In FIG. 6, the same components as those in FIG.
The image forming apparatus in FIG. 20 is an example in which the toner that has passed through the toner control unit is directly landed on a transfer sheet as a recording medium to form a toner image. In other words, in the image forming apparatus according to the first modification, the transfer paper P supplied from the paper supply unit 61 is electrostatically attracted to the paper transport belt 161 and passed through a region facing the toner supply unit 100 to thereby control the toner. A color image is directly formed on the transfer paper by ON / OFF control corresponding to the image 104.

  In FIG. 20, a paper transport belt 161 is formed of polyimide or the like, for example, and is driven around two rollers 162 and 163 so as to move around in the direction of the arrow. The paper transport belt 161 is charged by a charging means such as a charging roller (not shown), and transports the transfer paper P while electrostatically holding it. Further, a guide 164 and a registration roller 165 for guiding the transfer paper P from the paper supply unit 61 to the paper transport belt 161 are also arranged.

  In the image forming apparatus having the configuration shown in FIG. 20, a sheet of paper such as polyimide is conveyed between the toner control unit 104 that controls the passage of toner and the back electrode 105 that applies a bias for guiding the toner after the passage to the transfer sheet P. There are a belt 161 and a transfer paper P. For this reason, it is difficult to set the distance between the toner control means 104 and the back electrode 105 very narrow, but on the other hand, since a color image is formed directly on the transfer paper P and there is no transfer process, the image quality is reduced by toner scattering due to transfer. It will not drop. Further, the image forming apparatus of FIG. 20 does not require a belt cleaning mechanism as in the configuration described with reference to FIG. 15, and is advantageous for realizing a small and low-cost image forming apparatus.

  In the image forming apparatus configured to fly the toner as shown in FIGS. 15 and 20, it is possible to guide the toner with a low bias on the printing surface. The landing speed can be set low, and a high-quality image forming apparatus in which toner scattering does not occur can be obtained.

Next, a configuration example of the toner carrier 101 that can be used in the image forming apparatuses according to the first and second modifications will be described.
FIG. 21A is an explanatory plan view schematically showing a configuration example of the toner carrier 101, and FIG. 21B is a sectional explanatory view of the toner carrier. The example shown in the figure is an example in which a plurality of electrodes are provided on the surface of the toner carrier 101 and two sets of these electrodes are used in common to form a two-phase electrode. Two sets of two-phase electrodes are each applied with a two-phase pulse having a phase difference of 180 ° (see, for example, the A-phase pulse and the B-phase pulse in FIG. 22), and suction and repulsion occur between adjacent electrodes. A repeating two-phase electric field is formed.

  In FIG. 21, a toner carrier 101 includes an A electrode (first electrode) 111A and a B phase electrode (second electrode) 111B as a plurality of electrodes 111 on the surface of an insulating substrate 101A. A surface protective layer 101B is provided thereon. The electrodes 111A and 111B are each formed in a comb-like shape, arranged in a fine pitch in the toner transport direction, and provided in parallel to the direction orthogonal to the toner transport direction. Common bus lines 111Aa and 111Ba are provided on both sides in the direction orthogonal to the toner conveyance direction, and each bus line 111Aa and 111Ba is connected to an external two-phase pulse generation circuit (not shown).

  The pulse voltage applied to the electrodes 111A and 111B is, for example, a pulse voltage having a frequency of 0.5 kHz to 7 kHz and including a DC voltage as a bias. The peak value of the pulse voltage is set in the range of ± 60 to ± 300 V, for example, and is set according to the electrode width, the electrode interval, the type of toner used, and the like. By applying this pulse voltage, a two-phase electric field is formed between the electrode 111A and the electrode 111B that repeats the repulsion flight and suction flight of the toner in accordance with the switching of the electric field direction between adjacent electrodes. By repeating this toner repulsion flight and suction flight, the toner reciprocates between the electrodes 111A and 111B. The entire toner carrier 101 rotates so that the surface moves in the direction in which the toner is conveyed.

  The toner carrier 101 in FIG. 21 has a plurality of electrodes 111A and 111B that extend in the direction perpendicular to the toner conveyance direction and are arranged at predetermined intervals on the surface thereof, and are adjacent to the electrodes 111A and 111B. A pulse voltage having a relationship that alternately repeats the direction of attracting and repelling toner between the electrodes is applied, and the toner carrier 101 is rotationally driven in a predetermined direction. By configuring the toner carrier 101 so as to perform toner conveyance and clouding as described above, it is possible to stably convey the toner regardless of the charge quality of the toner with respect to the toner conveyance on the surface of the toner carrier 101. A highly reliable image forming apparatus can be realized as the entire apparatus.

  FIG. 23A is an explanatory plan view schematically showing another configuration example of the toner carrier 101, and FIG. 23B is a cross-sectional explanatory view of the toner carrier 101. The example of FIG. 23 is an example in which a plurality of electrodes are provided on the surface of the toner carrier, and all the electrodes on the surface layer side are common. A two-phase pulse (see FIG. 22) having a phase difference of 180 ° is applied between each electrode on the surface layer side and a conductor base electrode provided on the lower layer via an insulating layer, and the surface layer side electrode and the lower layer conductor are applied. This is an example of a toner carrier that repeats suction and repulsion by a mutual electric field formed between the substrate electrode. In FIG. 23, components similar to those in FIG.

  In FIG. 23, a toner carrier 101 is provided with an A-phase electrode 111A as a plurality of electrodes on the surface of an insulating substrate 101A disposed therein, and a solid conductor base material (B-phase) on the lower surface of the insulating substrate 101A. Electrode) 111B. Protective layers 101B and 101B are provided on the surfaces of these electrodes 111A and 111B. The front-side electrodes 111A are arranged at a fine pitch in the toner transport direction and are parallel to each other in a direction perpendicular to the toner transport direction. A common bus line 111Aa is provided on both sides in the direction orthogonal to the toner conveyance direction. The bus line 111Aa of the electrode 111A and the electrode 111B on the lower surface of the insulating substrate 101A are connected to an external two-phase pulse generation circuit (not shown).

  The two-phase pulse voltage applied to the electrodes 111A and 111B is also a pulse voltage having a frequency of 0.5 KHz to 7 KHz and including a DC voltage as a bias, for example. The peak value of the pulse voltage is set in the range of ± 60 to ± 300 V, for example, and is set according to the electrode width, the electrode interval, the type of toner used, and the like. The configuration for applying the pulse voltage is the same as in FIG. By applying this pulse voltage, the toner repeatedly flies between the electrodes 111A and 111A on the surface layer side (between spaces) in accordance with the switching of the two-phase pulse. The entire toner carrier 101 rotates so that the surface moves in the direction in which the toner is conveyed.

In the specific configuration of the toner carrier 101 in FIG. 23, an insulating substrate 101A as a base substrate is, for example, a substrate made of an insulating material such as resin or ceramics, or a base material made of a conductive material such as aluminum. A film formed of an insulating film such as SiO ₂ or a film made of a flexible and deformable material such as a polyimide film can be used.

  In addition, the electrode 111 is formed by forming a conductive material such as Al or Ni—Cr with a thickness of 0.1 to 1 μm on the base substrate and patterning it into a required electrode shape using a photolithography technique or the like. A copper foil may be formed by lamination, plating or the like and then patterned by photolithography. The lower conductor base electrode 111B may be a conductive material such as Al, Ni—Cr, for example.

As the surface protective layer 101B, for example, SiO ₂ , TiO ₂ , TiN, Ta ₂ O ₅ or the like is formed by vapor deposition with a thickness of 0.5 to ₂ μm, or an organic material such as polycarbonate, polyimide, or methyl methacrylate. May be applied by thin film printing to a thickness of 2 to 10 μm and heat-cured.

  In the toner carrier 101 configured as described above, a flying pulse is applied from the driving circuit 107 to form a flying electric field, whereby the charged toner on the toner carrier 101 has a repulsive force and an attractive force. Upon receipt, it is transported in the traveling wave direction while flying up and down.

  FIG. 24 is a schematic configuration diagram illustrating another configuration example of the image forming unit 100 in the image forming apparatuses according to the first and second modifications. In this configuration example, a two-component developer including a magnetic carrier and a nonmagnetic toner is used as a recording agent. The recording agent storage unit 201 is divided into two chambers 201 </ b> A and 201 </ b> B and is connected by recording agent passages (not shown) at both ends in the image forming unit 100. The recording agent storage unit 201 stores a two-component recording agent and is transported through the recording agent storage unit 201 while being stirred by the stirring transport screws 202A and 202B in the chambers 201A and 201B. A toner replenishing port 203 is disposed in the chamber 201A of the recording agent accommodating unit 201, and the recording agent accommodating unit passes through the toner replenishing port 203 from the toner accommodating unit (not shown) by the toner conveying device shown in FIGS. 201 is replenished.

  A toner concentration sensor (not shown) that detects the magnetic permeability of the developer is installed in the recording agent storage unit 201 to detect the concentration of the developer. When the toner concentration in the recording agent storage unit 201 decreases, toner is supplied into the recording agent storage unit 201 from the toner supply port 203. A magnet brush 204 as a toner replenishing roller is disposed at a position facing the agitating and conveying screw 202B. A fixed magnet is disposed inside the mag brush roller 204, and the two-component developer in the recording material container 201 is pumped up to the surface of the mag brush roller 204 by the rotation and magnetic force of the mag brush roller 204. A developer layer regulating member 205 is provided at a position facing the mag brush roller 204 upstream of the developer pumping position in the rotational direction of the mag brush roller 204. The developer pumped up at the pumping position is regulated to a certain amount of developer layer thickness by the recording material layer regulating member 205.

The developer that has passed through the developer layer regulating member 205 is conveyed to a position facing the toner carrier 101 as the mag brush roller 204 rotates. A supply bias is applied to the magnet brush roller 204 by the first voltage applying means 211.
The toner carrier 101 is applied with the voltage shown in FIG. 12 to the electrode 111 by the second voltage applying means 212.

  At a position facing the mag brush roller 204, an electric field is generated between the toner carrier 101 and the mag brush roller 204 by the first and second voltage applying means 211 and 212. Under the electrostatic force from the electric field, the toner is separated from the carrier and moves to the surface of the toner carrier 101.

  The toner that has reached the surface of the toner carrier 101 is clouded by the electric field formed by the voltage applied to the electrode 111 from the second voltage application unit 212, and is generated by the rotation of the toner carrier 101 or the traveling wave electric field of the toner carrier 101. Be transported. Then, the toner conveyed to a position facing the toner control means 104 is selectively jumped to the recording medium side by the control electric field of toner control ON / OFF of the control electrode 42, and the dot printing of the toner is controlled. .

  FIG. 25 is a schematic configuration diagram illustrating another configuration example of the image forming unit. The image forming unit shown in FIG. 25 is an example using a one-component developer made of nonmagnetic toner. The toner is stored in the recording material storage unit 201. The toner is frictionally charged with the toner supply roller 113 by the charging roller 220, and is pumped up onto the toner supply roller 113 by electrostatic force. The toner on the toner supply roller 113 is made into a thin layer by the developer layer regulating member 114 and is conveyed to a position facing the toner carrier 101 as the toner supply roller 113 rotates. At this time, a supply bias is applied to the toner supply roller 113 by the first voltage applying unit 221. In addition, a voltage is applied to the electrode 111 by the second voltage applying unit 222 in the toner carrier 101. Accordingly, at the position facing the toner carrier 101, an electric field is generated between the toner carrier 101 and the toner supply roller 113 by the first and second voltage applying means 221 and 222, and the electrostatic force from the electric field is received. The toner is separated from the toner supply roller 113 and moves to the surface of the toner carrier 101.

  Similarly to the configuration example of FIG. 24 described above, the toner that has reached the surface of the toner carrier 101 is clouded by the electric field formed by the voltage applied to the electrode 111 from the second voltage application unit 222, and the toner carrier 101 It is conveyed by a rotating or traveling wave electric field of the toner carrier 101.

  Then, the toner conveyed to a position facing the toner control means 104 is selectively jumped to the recording medium side by the control electric field of toner control ON / OFF of the control electrode 42, and the dot printing of the toner is controlled. .

  In each of the image forming units 100, the toner that has not contributed to the printing is further conveyed by the toner carrier 101 and is collected from the surface of the toner carrier 101 by a collecting unit (not shown). The collected toner is returned again to the recording material container 201 and circulates in the image forming unit 100.

Next, toner used in the image forming apparatus according to the embodiment will be described.
The toner according to the exemplary embodiment is obtained by adding an additive to toner base particles including a pressure phase change resin and a colorant.
As the pressure phase change resin constituting the toner in the exemplary embodiment, those having a microphase separation structure are preferable, and a resin having a block copolymer or a core-shell structure is more preferable. The block copolymer is more preferably composed of a hard segment polymer having a high glass transition temperature Tg and a soft segment polymer having a low glass transition temperature Tg or a low melting point. In the case of the resin having the core-shell structure, either the core or the shell is made of a hard segment polymer having a high glass transition temperature Tg (hereinafter referred to as “hard segment component phase” as necessary), and the other is made. More preferably, the polymer is composed of a soft segment polymer having a low glass transition temperature Tg or melting point (hereinafter referred to as “soft segment component phase” if necessary).

  When the pressure phase change resin is used as an image forming toner, the fluidity of the resin is expressed by pressure stimulation, and a desired resin fluidity necessary for the fixing step is obtained in an image forming process having a predetermined fixing step. be able to.

As the pressure phase transition resin having the above structure, for example, a resin polymerized by a polycondensation mechanism or a resin obtained by polymerizing an ethylenically unsaturated monomer by a radical polymerization mechanism can be used.
The resin polymerized by the above polycondensation mechanism is obtained by using a conventionally known method described in, for example, “Polycondensation” (Chemical Doujin, 1971), “Polyester Resin Handbook” (edited by Nikkan Kogyo Shimbun, 1988) and the like. Can be synthesized. The resin polymerized by the polycondensation mechanism can also be synthesized by using a transesterification method, a direct polycondensation method, or the like alone or in combination of these methods. A preferred example of the resin polymerized by the polycondensation mechanism is a polyester resin.
As the resin obtained by polymerizing the ethylenically unsaturated monomer, for example, a block copolymer can be obtained by a living anionic polymerization method. In the case of core-shell particles, a nano-size with a different glass transition temperature consisting of a core component polymer and a shell component polymer is obtained by a method called a two-stage feed method in which a monomer is supplied stepwise to a polymerization system. The core-shell resin particles can be synthesized, which is preferable.

  The glass transition temperature Tg of the hard segment component phase is preferably 45 to 120 ° C, more preferably 50 to 110 ° C. The glass transition temperature Tg of the soft segment component phase is preferably 20 ° C. or more lower than the glass transition temperature Tg of the hard segment component phase, and in order to make the fluidity of the resin due to pressure stimulation appear efficiently, it is 30 ° C. or more. More preferably, it is low. Here, the value of the glass transition temperature Tg is stipulated in ASTM D3418-82 when measured with a differential scanning calorimeter (DSC) from −80 to 140 ° C. at a heating rate of 10 ° C. per minute. Means the value measured by the specified method.

  For the above block copolymer and polycondensation polyester resin, various mechanical high shearing forces such as rotary shearing homogenizer, ball mill with media, sand mill, dyno mill, pressure discharge type disperser (Gorin homogenizer, manufactured by Gorin) A shear emulsification method in which the resin is dissolved in an organic solvent, a phase inversion emulsification method in which the aqueous medium is added and phase-inverted, a block copolymer or a precursor thereof (living terminal low molecular weight or block) Using existing dispersion methods such as mixing with a small amount of ethylenically unsaturated compound, shear emulsion emulsification or phase inversion emulsification, mini emulsion polymerization, suspension polymerization to prepare block copolymer resin particle dispersion. As in the case of nano-sized core-shell particles, a resin particle dispersion can be obtained. For example, using the obtained resin dispersion, a colorant-containing dispersion and, if necessary, a release agent-containing dispersion can be blended in appropriate amounts, and a toner for image formation can be produced by an emulsion aggregation method.

  In the manufacturing method of the toner for image formation, the resin particles, the release agent particles and other added particles in the dispersion are aggregated (aggregated) using a known aggregation method. It is possible to adjust the toner particle size and particle size distribution.

  Specifically, the resin particle dispersion and the release agent particle dispersion are mixed with the colorant particle dispersion and the like, and further, an aggregating agent is added to form heteroaggregation to form aggregated particles having a toner diameter. Thereafter, the blended dispersion system is heated to a temperature not lower than the glass transition temperature of the resin particles or higher than the melting point so as to fuse and coalesce the aggregated particles, and is washed and dried to obtain a toner. At this time, the toner shape can be controlled from an indeterminate shape to a spherical shape by selecting the heating temperature condition.

The polycondensation resin is preferably an amorphous polyester resin or a crystalline polyester resin. The polyester resin is a direct ester using a polycondensation monomer such as a polycarboxylic acid, a polyhydric alcohol, or a hydroxycarboxylic acid. It can be prepared by performing polycondensation by a conversion reaction, a transesterification reaction or the like. In the case of polycondensation, it is preferable to use a polycondensation catalyst in combination in order to promote polycondensation.
Polyvalent carboxylic acids include aliphatic, alicyclic and aromatic polycarboxylic acids, their alkyl esters, acid anhydrides and acid halides.
The polyhydric alcohol includes polyhydric alcohols and ester compounds thereof.

  The alkyl ester of polyvalent carboxylic acid is preferably a lower alkyl ester. Here, the “lower alkyl ester” represents an alkyl ester having 1 to 8 carbon atoms in the alkoxy moiety of the ester. Specific examples include methyl ester, ethyl ester, n-propyl ester, isopropyl ester, n-butyl ester, and isobutyl ester.

Further, the polyvalent carboxylic acid is a compound containing two or more carboxy groups in one molecule. Among these, dicarboxylic acid is a compound containing two carboxy groups in one molecule. For example, oxalic acid, succinic acid, maleic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid , Decanedicarboxylic acid, undecanedicarboxylic acid, dodecenyl succinic acid, dodecanedicarboxylic acid, fumaric acid, citraconic acid, diglycolic acid, cyclohexanedicarboxylic acid, cyclohexane-3,5-diene-1,2-dicarboxylic acid, 2,2-di Methylol butanoic acid, malic acid, citric acid, hexahydroterephthalic acid, malonic acid, pimelic acid, tartaric acid, mucoic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenyl Acetic acid, p-phenylenediacetic acid, m-phenol Range glycolic acid, p-phenylene diglycolic acid, o-phenylene diglycolic acid, diphenylacetic acid, diphenyl-p, p'-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene Examples include -2,6-dicarboxylic acid, anthracene dicarboxylic acid, dodecenyl succinic acid and the like.
Examples of the polyvalent carboxylic acid other than dicarboxylic acid include trimellitic acid, pyromellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, and pyrenetetracarboxylic acid.
These polyvalent carboxylic acids can be used alone or in combination of two or more.

  A polyhydric alcohol (polyol) is a compound containing two or more hydroxyl groups in one molecule. Among these, the diol is a compound containing two hydroxyl groups in one molecule. For example, ethylene glycol, propylene glycol, butanediol, diethylene glycol, triethylene glycol, hexanediol, cyclohexanediol, octanediol, decanediol, dodecanediol. Bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, bisphenoxy alcohol fluorene (bisphenoxyethanol fluorene), and the like.

  Examples of polyols other than diols include glycerin, pentaerythritol, hexamethylol melamine, hexaethylol melamine, tetramethylol benzoguanamine, and tetraethylol benzoguanamine. These polyhydric alcohols (polyols) can be used alone or in combination of two or more.

  The ethylenically unsaturated compound is a compound having at least one ethylenically unsaturated bond, and may be a monomer having a hydrophilic group and an ethylenically unsaturated bond. Examples of the ethylenically unsaturated compound include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, lauryl acrylate, and 2-ethylhexyl acrylate. , (Meth) acrylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; ethylenic polymers such as acrylonitrile and methacrylonitrile Saturated nitriles; ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl methyl ketone, vinyl ethyl ketone and vinyl Vinyl ketones such as isopropenyl ketone; isoprene, butene, and the like olefins such as butadiene, beta-carboxyethyl acrylate can be preferably exemplified. A homopolymer composed of these monomers, a copolymer obtained by copolymerizing two or more of these, and a mixture thereof can be used.

  Examples of the hydrophilic group include polar groups, such as acidic polar groups such as carboxy group, sulfo group, and phosphonyl group: basic polar groups such as amino group, amide group, hydroxy group, cyano group, and formyl group. Neutral polar groups and the like can be mentioned, but are not limited thereto. Of these, acidic polar groups are particularly preferably used in the toner of the exemplary embodiment. The presence of the monomer having an acidic polar group and an ethylenically unsaturated bond in a specific range on the surface of the resin particles gives the resin particles cohesion, and the resin particles can be made into a toner. Sufficient chargeability can be imparted to the toner. Examples of the acidic polar group preferably used include a carboxy group and a sulfo group. Examples of the monomer having an acidic polar group include an α, β-ethylenically unsaturated compound having a carboxy group and an α, β-ethylenically unsaturated compound having a sulfo group. Examples of the α, β-ethylenically unsaturated compound having a carboxy group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, monomethyl maleate, monobutyl maleate, and maleic acid. Mention may be made of monooctyl esters. These monomers may be used individually by 1 type, and may use 2 or more types together.

  When the resin having a glass transition temperature Tg of 40 ° C. or higher is a polymer of an ethylenically unsaturated compound, it is preferably a random copolymer. Moreover, the resin which contains the ethylenically unsaturated compound which has a hydrophilic group as a monomer unit is preferable, and it is preferable to contain 0.1-10 mol% of ethylenically unsaturated compounds which have a hydrophilic group by copolymerization ratio. A copolymerization ratio within this range is preferable since a resin having a Tg of 40 ° C. or more easily forms a toner shell layer in the production process of the toner in an aqueous medium. The polycondensation resin such as a polymer of an ethylenically unsaturated compound having a Tg of 40 ° C. or higher and a polyester resin is preferably 50% by weight or less, more preferably 5 to 20% by weight, based on the total binder resin contained in the toner. When the copolymerization ratio is within the above range, toner durability is improved and stable image quality characteristics can be obtained.

Examples of the colorant that can be used in the toner of the exemplary embodiment include the following.
For example, examples of the black pigment include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, and magnetite.
Examples of yellow pigments include yellow lead, zinc yellow, yellow iron oxide, cadmium yellow, chrome yellow, hansa yellow, hansa yellow 10G, benzidine yellow G, benzidine yellow GR, selenium yellow, quinoline yellow, and permanent yellow NCG. It is done. Examples of the orange pigment include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, benzidine orange G, indanthrene brilliant orange RK, indanthrene brilliant orange GK and the like.
Also, red pigments include Bengala, Cadmium Red, Lead Red, Mercury Sulfide, Watch Young Red, Permanent Red 4R, Risor Red, Brilliantamine 3B, Brilliantamine 6B, Daypon Oil Red, Pyrazolone Red, Rhodamine B Lake, Lake Examples include Red C, Rose Bengal, Eoxin Red, Alizarin Lake and the like.
Blue pigments include bitumen, cobalt blue, alkali blue rake, Victoria blue rake, fast sky blue, indanthrene blue BC, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite. Green ox sale rate. Examples of purple pigments include manganese purple, fast violet B, and methyl violet lake. Examples of the green pigment include chromium oxide, chromium green, pigment green, malachite green lake, final yellow green G, and the like.
Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide.
These colorants are used alone or in combination.

  These colorants can be used in any desired manner, for example, a ball shearing machine having a rotating shear type homogenizer, a media mill such as a sand mill or an attritor, a high-pressure counter-collision dispersing machine, or a general dispersion such as a dyno mill. By using the method, a dispersion of colorant particles is prepared. These colorants are dispersed in an aqueous system by a homogenizer using a polar surfactant, and may be added together with other particle components in a mixed solvent at once, or divided into multiple stages. It may be added.

  The colorant is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, and dispersibility in the toner. The colorant is added in the range of 4 to 15% by weight with respect to the total weight of the toner constituting solids. When a magnetic material is used as the black colorant, 12 to 240% by weight is added unlike other colorants. The blending amount of the colorant is a preferable amount in order to ensure the color developability at the time of fixing. Moreover, OHP transparency and color developability are ensured by setting the central diameter (median diameter) of the colorant particles in the toner to 100 to 330 nm. The center diameter of the colorant particles is measured with, for example, a laser diffraction particle size distribution measuring device (LA-920, manufactured by Horiba, Ltd.).

  Specific examples of the release agent that can be used in the toner of the exemplary embodiment include, for example, various ester waxes, low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene, silicones that exhibit a softening point by heating, oleic amides, Fatty acid amides such as erucic acid amide, ricinoleic acid amide, stearic acid amide, etc., plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil, etc., animal systems such as beeswax Mineral / petroleum waxes such as wax, montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, and modified products thereof. These waxes are hardly dissolved in a solvent such as toluene at room temperature or very little even if dissolved. These waxes are dispersed in water together with ionic surfactants, polymer electrolytes such as polymer acids and polymer bases, heated to the melting point or higher, and homogenizers and pressure discharge type dispersers with strong shearing ability. (Gorin homogenizer, manufactured by Gorin Co., Ltd.) is used to disperse the particles in the form of particles to produce a submicron or smaller particle dispersion. The particle size of the obtained release agent particle dispersion can be measured, for example, with a laser diffraction particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.).

  The release agent mentioned in the above specific example is preferably added in the range of 5 to 25% by weight with respect to the total weight of the toner constituting solids, in order to ensure the releasability of the fixed image in the oilless fixing system.

  In addition, when using the above release agent, after the resin particles, the colorant particles and the release agent particles are aggregated, it is possible to add a resin particle dispersion to adhere the resin particles to the surface of the aggregated particles. From the viewpoint of ensuring durability.

  Further, a magnetic material may be added to make the toner magnetic. Specifically, a substance that is magnetized in a magnetic field is used as the magnetic material, but a ferromagnetic powder such as iron, cobalt, or nickel, or a compound such as ferrite or magnetite is used. In the present embodiment, when toner is obtained in an aqueous medium, it is necessary to pay attention to the water phase transferability of the magnetic material. Preferably, the surface of the magnetic material is modified in advance and subjected to, for example, a hydrophobic treatment. Is preferred.

  The toner may contain a small amount of a charge control agent in order to efficiently apply the charge. As the charge control agent, various commonly used charge control agents such as quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments can be used. A material that is difficult to dissolve in water is preferable from the viewpoint of controlling the ionic strength that affects the stability of coagulation and temporary suspension and reducing wastewater contamination.

  Further, the toner may contain a polarity control agent for setting the charging polarity to a predetermined polarity. As the polarity control agent, metal complex salts of monoazo dyes, nitrohumic acid and salts thereof, salicylic acid, naphthoic acid, metal complexes of dicarboxylic acid such as Co, Cr or Fe, organic dyes, quaternary ammonium salts and the like can be used. .

  In addition, inorganic fine particles may be added to the toner as an additive. As inorganic fine particles, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, copper oxide, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite Diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, parium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, and the like can be used. Among these, when two types of silica and titanium oxide are used, the effect of suppressing the burying of the additive in the toner and the effect of stabilizing the charging of the toner are particularly exhibited.

  Examples of surfactants used for polymerization, pigment dispersion, resin particle production and dispersion, release agent dispersion, aggregation, or stabilization thereof include sulfate ester, sulfonate, and phosphate ester types. , Soap type anionic surfactants, amine salt type, quaternary ammonium salt type cationic surfactants, polyethylene glycol type, alkylphenol ethylene oxide adduct type, polyhydric alcohol type nonionic surface active It is also effective to use an agent in combination, and general means such as a rotary shear homogenizer, a ball mill having a media, a sand mill, and a dyno mill are used for dispersion.

Next, the carrier used in this embodiment will be described.
The carrier is obtained by forming a coating layer on magnetic core particles. As the carrier core particles, ferromagnetic metals such as iron, cobalt, nickel, alloys such as magnetite, hematite, ferrite, or compounds thereof are used.

  Examples of the resin for forming the coating layer of the carrier include polyolefin resins such as polyethylene, polypropylene, chlorinated polyethylene, and chlorosulfonated polyethylene; polyvinyl and polyvinylidene resins such as polystyrene, acrylic resin (for example, polymethyl methacrylate), poly Acrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether and polyvinyl ketone; vinyl chloride / vinyl acetate copolymer; styrene / acrylic acid copolymer; straight silicone resin composed of organosiloxane bond Such silicone resins or modified products thereof (for example, modified products by alkyd resin, polyester, epoxy resin, polyurethane, etc.); fluorine resins, eg Polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene; polyamides; polyesters such as polyethylene terephthalate; polyurethanes; polycarbonates; amino resins such as urea / formaldehyde resins; it can. Among these resins, acrylic resin, silicone resin or a modified product thereof, and fluorine resin are preferable from the viewpoint of preventing toner spent (particularly silicone resin or modified product thereof is preferable). As a method for forming the coating layer, a method in which a resin is applied to the surface of the carrier core particles by a spraying method, a dipping method or the like is used.

  Further, a fine powder can be added to the coating layer in order to adjust carrier resistance and the like. The fine powder dispersed in the coating layer preferably has a particle size of about 0.01 to 5.0 μm. Moreover, it is preferable that 2-30 weight part (especially 5-20 weight part) is added with respect to 100 weight part of coating resin. As the fine powder, metal oxides such as silica, alumina and titania, and pigments such as carbon black can be used.

Next, a method for producing a toner containing the pressure phase change resin of the present embodiment and a method for producing a developer comprising a toner containing the pressure phase change resin and a carrier will be described.
[Measurement of molecular weight of resin particles]
The weight average molecular weight Mw and the number average molecular weight Mn were measured by gel permeation chromatography (GPC) under the conditions described below. At a temperature of 40 ° C., a solvent (tetrahydrofuran) is allowed to flow at a flow rate of 1.2 ml / min, and 3 mg of a tetrahydrofuran sample solution having a concentration of 0.2 g / 20 ml is injected as a sample weight for measurement. When measuring the molecular weight of a sample, select the measurement conditions that fall within the range in which the logarithm of the molecular weight of the prepared calibration curve and the count number are linear, using several monodisperse polystyrene standard samples. . Here, the reliability of the measurement results is that the NBS706 polystyrene standard sample obtained under the above measurement conditions has a weight average molecular weight Mw = 28.8 × 10 ⁴ and a number average molecular weight Mn = 13.7 × 10 ⁴ , Can be confirmed. As the GPC column, TSK-GEL, GMH (manufactured by Tosoh Corporation), etc. satisfying the above conditions were used.

[Measurement of Glass Transition Temperature Tg of Resin]
A differential scanning calorimeter DSC / RDC220 (manufactured by Seiko Instruments Inc.) was used for measuring the glass transition temperature Tg of the resin. The particle diameter of the resin particles in the resin particle dispersion was measured using a laser diffraction particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.). The particle diameters of the toner particles, carrier particles, and recording agent were measured using a Coulter Multisizer II type (manufactured by Beckman Coulter).

[Preparation of resin particle dispersion (1)]
A resin dispersion (1) comprising an ethylenically unsaturated compound polymer was prepared as follows. First, in a separable flask, 300 parts by weight of ion-exchanged water and 1.5 parts by weight of TTAB (tetradecyltrimethylammonium bromide, manufactured by Sigma) were charged, purged with nitrogen for 20 minutes, and then stirred at 65 ° C. The temperature was raised to. Thereafter, 40 parts by weight of n-butyl acrylate monomer was added and further stirred for 20 minutes. Then, 0.5 part by weight of the polymerization initiator V-50 (2,2′-azobis (2-methylpropionamidine) dihydrochloride, manufactured by Wako Pure Chemical Industries, Ltd.) was previously added to 10 parts by weight of ion-exchanged water. After dissolution, it was put into a flask. The mixture was held at 65 ° C. for 3 hours, and 61 parts by weight of styrene monomer, 9 parts by weight of n-butyl acrylate monomer, 2 parts by weight of acrylic acid and 0.8 part by weight of dodecanethiol were dissolved in 0.5 part by weight of TTAB. The emulsified liquid emulsified in 100 parts by weight of ion-exchanged water was continuously charged into the flask using a metering pump over 2 hours. Thereafter, the temperature was raised to 70 ° C. and held for another 2 hours to complete the polymerization. By this polymerization, a core-shell type resin particle dispersion (1) having a weight average molecular weight Mw of 25,000, an average particle diameter of 150 nm, and a solid content of 25% by weight was obtained. The resin particles were air-dried at 40 ° C. and then subjected to DSC analysis in the temperature range of −80 ° C. to 140 ° C. As a result, glass transition due to polybutyl acrylate was observed around −50 ° C. Moreover, the glass transition of the resin by the copolymer considered to consist of a styrene-butyl acrylate-acrylic acid copolymer was observed at around 60 ° C.

[Preparation of Colorant Particle Dispersion (C1)]
The colorant particle dispersion (C1) was prepared as follows. Here, an example of the preparation of the colorant particle dispersion (C1) corresponding to cyan will be described. Cyan pigment 100 parts by weight (Daiichi Seika Kogyo Co., Ltd., copper phthalocyanine CI Pigment Blue 15: 3) Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) 10 parts by weight ion-exchanged water 400 parts by weight The above components are mixed and dissolved, dispersed for 15 minutes with a homogenizer (IKA, Ultra Tarrax), then dispersed for 10 minutes with an ultrasonic bath, and a cyan colorant having a center diameter of 210 nm and a solid content of 21.5% A particle dispersion was obtained.

[Preparation of release agent particle dispersion (R1)]
The release agent particle dispersion (R1) was prepared as follows. 2 parts by weight of an anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) and 215 parts by weight of carnauba wax were mixed with 800 parts by weight of ion-exchanged water and heated to 100 ° C. to melt. Thereafter, the mixture was emulsified with a homogenizer (manufactured by IKA, Ultra Tarrax) for 15 minutes, and further emulsified at 100 ° C. using a gorin homogenizer. As a result, a release agent particle dispersion having a particle central diameter of 230 nm, a melting point of 83 ° C., and a solid content of 21.5% was obtained.

[Formulation and creation of toner (1)]
Toner (1) was prepared as follows using the various dispersions prepared above. Resin particle dispersion (1) 168 parts (resin 42 parts) Colorant particle dispersion (C1) 40 parts (pigment 8.6 parts) Release agent particle dispersion (R1) 80 parts (release agent 17.2 parts) ) 0.15 parts of polyaluminum chloride 300 parts by weight of ion-exchanged water were sufficiently mixed and dispersed in a round stainless steel flask using a homogenizer (manufactured by IKA, Ultra Turrax T50). Thereafter, the flask was heated to 42 ° C. while stirring the flask in an oil bath for heating, and maintained at 42 ° C. for 60 minutes, and then 84 parts by weight (21 parts by weight) of the resin particle dispersion (1) was added and gently stirred. did. Thereafter, the pH in the system was adjusted to 6.0 with a 0.5 mol / liter aqueous sodium hydroxide solution, and then heated to 95 ° C. while stirring was continued. Here, an aqueous sodium hydroxide solution was added dropwise, and the mixture was held at 95 ° C. for 3 hours so that the pH did not become 5.5 or less. After completion of the reaction, the mixture was cooled, filtered, sufficiently washed with ion exchange water, and then solid-liquid separated by Nutsche suction filtration. And it re-dispersed in 40 degreeC ion-exchange water, and it stirred and wash | cleaned at 300 rpm for 15 minutes. This washing operation was repeated 5 times, followed by solid-liquid separation by Nutsche suction filtration, and then vacuum drying for 12 hours to obtain cyan toner particles (1). When the particle size of the toner particles was measured with a Coulter counter, the volume average particle size was 5.8 μm.
1.5 parts by weight of hydrophobic silica (manufactured by Cabot, TS720) was added to 50 parts by weight of the toner, and mixed by a sample mill to obtain a cyan toner (1).

[Formulation of developer (1)]
100 parts by weight of a silicone resin solution (KR50, manufactured by Shin-Etsu Chemical Co., Ltd.), 3 parts by weight of carbon black (BP2000, manufactured by Cabot Corporation) and 100 parts by weight of toluene were dispersed with a homomixer for 30 minutes to prepare a coating layer forming solution. Using this coating layer forming solution and 1000 parts by weight of spherical ferrite carrier having an average particle diameter of 50 μm, a carrier having a coating layer formed on the surface of the spherical ferrite carrier was produced by a fluidized bed type coating apparatus. Next, 90 parts by weight of the toner and 910 parts by weight of the carrier were placed in a ball mill and stirred for 30 minutes to prepare a developer (1). A cyan recording agent (CI pigment yellow 57: 2), a yellow pigment (CI pigment yellow 97), and a black pigment (carbon black R330) were used in place of the cyan pigment. In the same manner as 1), other three-color developers (1) of yellow, magenta, and black were prepared.

[Preparation of resin particle dispersion (2)]
Preparation of a dispersion (2) of resin particles made of polyester resin was performed as follows. 175 parts by weight of 1,4-cyclohexanedicarboxylic acid, 320 parts by weight of bisphenol A 2 mol ethylene oxide adduct, and 0.5 parts by weight of dodecylbenzenesulfonic acid were mixed. Then, the mixed material was put into a reactor equipped with a stirrer and subjected to polycondensation at 120 ° C. for 12 hours under a nitrogen atmosphere. As a result, a uniform transparent polyester resin (1) was obtained. The weight average molecular weight by GPC was 14,000, and the Tg by DSC was 54 ° C.
In addition, 0.36 parts by weight of dodecylbenzenesulfonic acid, 80 parts by weight of 1,6-hexanediol and 115 parts by weight of sebacic acid were mixed with the above materials, and charged into a reactor equipped with a stirrer. When polycondensation was carried out for 5 hours, a uniform white polyester resin (2) was obtained. The weight average molecular weight by GPC was 8,000, and Tg by DSC was -52 ° C.

  100 parts by weight of the polyester resin (1) obtained by the above polycondensation and 100 parts by weight of the polyester resin (2) were put into a reactor equipped with a stirrer and dissolved and mixed at 120 ° C. for 30 minutes. Thereafter, an aqueous solution for neutralization prepared by dissolving 1.0 part by weight of sodium dodecylbenzenesulfonate in 1.0 part by weight of ion-exchanged water heated to 95 ° C. and 1.0 part by weight of 1N NaOH aqueous solution was put into the flask. Manufactured by Ultra Turrax) and shaken for 10 minutes in an ultrasonic bath, and then the flask was cooled with room temperature water. Thus, the center diameter of the resin particles obtained from the resin particle dispersion (2) having a solid content of 20% by weight was 250 nm.

[Preparation and creation of toner (2)]
Toner (2) was prepared as follows using the various dispersions prepared above. Resin particle dispersion (2) 210 parts by weight (resin 42 parts by weight), Colorant particle dispersion (C1) 40 parts by weight (colorant 8.6 parts by weight), Release agent particle dispersion (R1) 40 parts by weight (8.6 part by weight of release agent), 0.15 part by weight of polyaluminum chloride and 300 parts by weight of ion-exchanged water were mixed according to the above composition, and the components were homogenized in a round stainless steel flask (manufactured by IKA, Ultra Turrax). Thoroughly mixed and dispersed at T50). Thereafter, the flask was heated to 42 ° C. while stirring the flask in a heating oil bath, and held at 42 ° C. for 60 minutes, and then 105 parts by weight (21 parts by weight of the resin particle dispersion (2)) was added and gently stirred. did. Thereafter, the pH in the system was adjusted to 6.0 with a 0.5 mol / liter aqueous sodium hydroxide solution, and then heated to 95 ° C. while stirring was continued. During the period up to 95 ° C., an aqueous sodium hydroxide solution was added dropwise so that the pH did not become 5.0 or less. Hold at 95 ° C. for 3 hours. After completion of the reaction, the mixture was cooled, filtered, sufficiently washed with ion exchange water, and then solid-liquid separated by Nutsche suction filtration. Then, it was redispersed in 3 liters of ion exchange water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes. This washing operation was repeated 5 times, followed by solid-liquid separation by Nutsche suction filtration, and then vacuum drying for 12 hours to obtain toner particles. When the particle size of the toner particles was measured with a Coulter counter, the volume average particle size was 4.9 μm.
To 50 parts by weight of the toner, 1.5 parts by weight of hydrophobic silica (manufactured by Cabot, TS720) was added and mixed by a sample mill to obtain a cyan toner (2).

[Formulation of developer (2)]
100 parts by weight of a silicon resin solution (KR50, manufactured by Shin-Etsu Chemical Co., Ltd.), 3 parts by weight of carbon black (BP2000, manufactured by Cabot) and 100 parts by weight of toluene were dispersed with a homomixer for 30 minutes to prepare a coating layer forming solution. Using this coating layer forming solution and 1000 parts by weight of spherical ferrite carrier having an average particle diameter of 50 μm, a carrier having a coating layer formed on the surface of the spherical ferrite carrier was produced by a fluidized bed type coating apparatus. Next, 90 parts by weight of the toner and 910 parts by weight of the carrier were placed in a ball mill and stirred for 30 minutes to prepare an electrostatic image developing (2). A cyan toner (2) except that a magenta magenta pigment (CI Pigment Red 57: 2), a yellow pigment (CI Pigment Yellow 97), and a black pigment (carbon black R330) are used instead of the cyan pigment. In the same manner as above, a recording agent (2) of other three colors yellow, magenta and black was prepared.

  It should be noted that the present invention is not limited to the above description, and it is obvious that modifications other than those suggested above may be made as appropriate within the scope of the technical idea of the present invention. Further, the number, position, shape and the like of the constituent members are not particularly limited, and the number, position, shape and the like suitable for carrying out the present invention can be obtained.

What has been described above is merely an example, and the present invention has a specific effect for each of the following aspects (1) to (13).
(1)
Toner image forming means for forming a toner image on a recording medium such as transfer paper P, fixing means such as a fixing device 66 for fixing the toner image on the recording medium, and a toner cartridge 48 containing a developer having at least toner. A developer accommodating portion such as a toner conveying tube 49 for conveying the developer in the developer accommodating portion to the toner image forming unit, and the toner image from the developer accommodating portion to the conveying tube. An air flow generating means such as an air pump 90 that generates an air flow toward the forming means, and a developer conveying device such as a toner conveying device that conveys the developer in the developer containing portion to the toner image forming means by the air flow; In the image forming apparatus provided with the toner, a toner containing a pressure phase change resin is used as the toner.
With such a configuration, as described in the embodiment, the toner can be fixed to the recording medium by pressure, and the power consumption of the apparatus can be reduced. Further, even if the transport pipe is moved to a place where the temperature in the apparatus is high, the toner is not softened by heat in the transport pipe and fixed to the transport pipe. As a result, the transport pipe can be arranged in the machine without any restrictions, and the degree of freedom in the layout of the apparatus is not impaired. In addition, the transport pipe can be moved in the space in which the apparatus is vacant, and the apparatus can be reduced in size.
The use of a toner containing a pressure phase change resin in an image forming apparatus is described in Patent Documents 2 to 5, but is applied to an image forming apparatus provided with a developer conveying apparatus that conveys a developer by an air flow. By doing so, the transport pipe can be arranged in the machine without being restricted, and an effect that the degree of freedom of the layout of the apparatus is not impaired can be newly obtained.

(2)
Further, in the image forming apparatus according to the aspect described in (1), the developer conveying device includes the air flow between the developer discharge port 49b of the conveying tube and the developer supply port 23m of the toner image forming unit. Is provided with a relay portion 95 for suppressing the toner from flowing into the toner image forming means.
With this configuration, it is possible to suppress an increase in the pressure of the toner image forming unit (the developing unit 23 of the toner image forming unit in the embodiment, the toner image forming unit 100 in the first modification), and the toner scattering can be prevented. Can be suppressed.

(3)
In the image forming apparatus according to the aspect described in (2) above, the relay unit 95 is provided with an exhaust port 95a for exhausting the airflow of the transport pipe.
With such a configuration, it is possible to suppress the airflow of the conveying tube from flowing into the toner image forming unit (the developing unit 23 of the toner image forming unit in the embodiment, the toner image forming unit 100 in the first modification), and the toner An increase in the pressure of the image forming unit can be suppressed.

(4)
In the image forming apparatus according to the aspect described in (3), the exhaust port 95a is disposed above the developer discharge port 49b.
By adopting such a configuration, it is possible to suppress a problem that the exhaust port 95a is buried by the toner T discharged from the discharge port 49b.

(5)
In the image forming apparatus according to the aspect described in (3), the exhaust port 95a is provided at a position facing the developer discharge port 49b.
With this configuration, the air discharged from the discharge port 49b is discharged to the outside from the exhaust port 95a along a substantially linear flow path. Thereby, the air exhausted from the exhaust port 49b can be efficiently exhausted from the exhaust port 95a.

(6)
In the image forming apparatus according to any one of (3) to (5), a filter 96 for preventing leakage of developer from the exhaust port 95a is provided at the exhaust port 95a.
With such a configuration, it is possible to prevent the developer from leaking from the exhaust port 95a.

(7)
In the image forming apparatus according to any one of (2) to (6), an opening / closing means such as a shutter 100 for opening / closing the developer supply port 23m is provided.
With such a configuration, the problem that the toner floating in the developing unit 23 is scattered to the relay unit 95 is also suppressed.

(8)
In the image forming apparatus according to the aspect described in (7), the opening / closing means opens the developer supply port after the developer and gas are discharged from the developer discharge port 49b.
With this configuration, it is possible to reliably prevent the air discharged to the toner image forming unit from flowing in.

(9)
In the image forming apparatus according to any one of (2) to (8), the relay unit 95 is disposed above the developer supply port 23m, and the relay unit 95 and the developing unit are arranged. A second conveyance pipe 99 connecting the agent supply port 23m is provided, and an angle formed between the horizontal plane and the second conveyance pipe 99 is equal to or greater than an angle of repose with respect to the developer.
With this configuration, the developer can be transported to the developer supply port 23m by its own weight. The relay unit 95 and the developer supply port 23m can be arranged apart from each other, and the degree of freedom of layout in the image forming apparatus is improved.

(10)
In the image forming apparatus according to any one of the above (1) to (9), the developer is composed of only toner or toner and carrier.

(11)
In the image forming apparatus according to any one of (1) to (10), the toner image forming unit includes a latent image carrier such as the photosensitive member 21 that carries a latent image, and a latent image carrier. A developing unit such as a developing unit 23 that forms a toner image by attaching toner to the image; and a transfer unit that transfers the toner image formed on the latent image carrier to the image carrier or the recording medium. The developer transport device transports the developer in the developer container to the developing unit of the toner image forming unit.
With such a configuration, the developer can be supplied to the developing device.

(12)
In the image forming apparatus according to the aspect described in (11), the developing device includes a discharge unit that discharges the developer.
With such a configuration, it is possible to suppress the deteriorated old developer from staying in the developing device, and it is possible to maintain a high-quality image.

(13)
In the image forming apparatus according to any of the above aspects (1) to (12), the fixing unit is a pressure fixing unit that fixes the toner image transferred to the recording medium to the recording medium by pressure.
With this configuration, the power consumption of the image forming apparatus can be suppressed.

(14)
In the image forming apparatus according to the aspect described in (13), the pressure fixing unit applies a pressure of 0.5 MPa to 10 MPa to the toner image.
With such a configuration, it is possible to fix the toner image on the recording medium satisfactorily and to transport the recording medium satisfactorily.

1: Color copier 2: Writing unit 20: Process cartridge 21: Photoconductor drum 22: Charging unit 23: Developing unit 23f: Carrier supply port 23m: Toner supply port 23k: Developer discharge unit 27: Intermediate transfer belt 28: Transfer Roller 32: Carrier replenishment section 33: Carrier cartridge 34: Carrier transport pipe 41: Toner passage hole 42: Control electrode 43: Common electrode 47: Toner replenishment section 48: Toner cartridge 49: Toner transport pipe 49a: Inlet 49b: Developer Discharge port 66: Fixing device 67: Upper roller 68: Lower roller 90: Air pump 95: Relay unit 95a: Exhaust port 96: Filter 99: Second transport pipe 100: Toner image forming means 101: Toner carrier 104: Toner control Means 105: Back electrode 107: Drive circuit 108: Power source 109: Bias power source 110: Line of electric force 1 1: toner carrier electrode 113 toner supply roller 114 blade 114 developer layer regulating member 115 sebacic acid 115 case 120 under nitrogen atmosphere 131 lever 132 roller 132 roller 133 compression spring 134 cam 135 cleaning unit 135 roller 136 arm 137 shaft 139 compression Spring 140 Support point 161 Paper conveying belt 162 Roller 164 Guide 165 Registration roller 175 Cyclohexanedicarboxylic acid 201A Each chamber 201A Chamber 201 Recording agent storage unit 202A Agitating and conveying screw 202B Agitating and conveying screw 203 Toner supply port 204 Magbrush roller 205 Developer layer regulating member 205 Recording material layer regulating member 210 nm Center diameter 211 First voltage applying means 211 Second voltage applying means 212 Second voltage applying means 215 Carnauba 220 Charging roller 221 First voltage application means 221 Second voltage application means 222 Second voltage application means 300 Ion exchange water 300 parts Ion exchange water 320 Mole ethylene oxide adduct 400 parts by weight Ion exchange water 800 Ion exchange water 900 Controller 904 Interface 910 Carrier

JP 2011-43861 A Japanese Patent No. 458227 Japanese Patent No. 4525828 JP 2009-300848 A JP 2011-28055 A

Claims (14)

Toner image forming means for forming a toner image on a recording medium;
Fixing means for fixing a toner image on a recording medium;
A developer containing portion containing at least a developer containing toner;
A transport pipe for transporting the developer in the developer containing portion to the toner image forming means, and an air flow generating means for generating an air flow from the developer containing portion toward the toner image forming means in the transport pipe; An image forming apparatus comprising: a developer conveying device that conveys the developer in the developer accommodating portion to the toner image forming means by the airflow;
An image forming apparatus using a toner containing a pressure phase change resin as the toner. The image forming apparatus according to claim 1.
The developer conveying device includes a relay portion for suppressing the airflow from flowing into the toner image forming unit between the developer discharge port of the conveying tube and the developer supply port of the toner image forming unit. An image forming apparatus comprising the image forming apparatus. The image forming apparatus according to claim 2.
An image forming apparatus characterized in that an exhaust port for exhausting the airflow of the transfer pipe is provided in the relay section. The image forming apparatus according to claim 3.
An image forming apparatus, wherein the exhaust port is disposed above the developer discharge port. The image forming apparatus according to claim 3.
An image forming apparatus, wherein the exhaust port is provided at a position facing the developer discharge port. The image forming apparatus according to any one of claims 3 to 5,
An image forming apparatus, wherein a filter for preventing leakage of developer from the exhaust port is provided at the exhaust port. The image forming apparatus according to any one of claims 2 to 6,
An image forming apparatus comprising an opening / closing means for opening / closing the developer supply port. The image forming apparatus according to claim 7.
The image forming apparatus, wherein the opening / closing means opens the developer supply port after the developer and gas are discharged from the developer discharge port. The image forming apparatus according to any one of claims 2 to 8,
The relay portion is disposed above the developer supply port,
A second transport pipe connecting the relay unit and the developer supply port;
An image forming apparatus, wherein an angle formed by a horizontal plane and the second transport pipe is set to be an angle of repose with respect to the developer. The image forming apparatus according to claim 1,
The image forming apparatus, wherein the developer is composed of only toner or toner and carrier. The image forming apparatus according to claim 1,
The toner image forming unit includes a latent image carrier that carries a latent image, and a developing unit that forms a toner image by attaching toner to the latent image of the latent image carrier.
The developer conveying apparatus conveys the developer in the developer accommodating portion to the developing means of the toner image forming means. The image forming apparatus according to claim 11.
The image forming apparatus, wherein the developing device includes a discharging unit that discharges the developer. The image forming apparatus according to claim 1.
The image forming apparatus according to claim 1, wherein the fixing unit is a pressure fixing unit that fixes the toner image transferred to the recording medium to the recording medium by pressure. The image forming apparatus according to claim 13.
The image forming apparatus, wherein the pressure fixing unit applies a pressure of 0.5 MPa to 10 MPa to the toner image.

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