JP5656740B2 - Developer container, image forming unit, and image forming apparatus - Google Patents

Description

  The present invention relates to a developer container, an image forming unit, and an image forming apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus such as a printer, a copier, a facsimile machine, or a multifunction machine, for example, a printer includes an image forming unit, an LED head, a transfer roller, a fixing device, and the like. , An image forming unit main body, and a toner cartridge as a developer container that contains toner as a developer. A photosensitive drum, a charging roller, a developing roller, a toner supply roller, a cleaning member, and the like are disposed in the image forming unit main body.

  In the printer, the surface of the photosensitive drum uniformly charged by the charging roller is exposed by the LED head to form an electrostatic latent image, and the electrostatic latent image is supplied from the toner cartridge to the electrostatic latent image by the developing roller. The toner is adhered to form a toner image as a developer image on the surface of the photosensitive drum. The toner image is transferred onto a sheet as a medium by a transfer roller, and is fixed by a fixing device (see, for example, Patent Document 1).

JP 2004-341122 A

  However, in the conventional printer, the toner is easily clogged in the toner cartridge, and the toner cannot be consumed sufficiently.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a developer container, an image forming unit, and an image forming apparatus capable of solving the problems of the conventional toner and sufficiently consuming the developer in the developer container. To do.

  Therefore, in the developer container of the present invention, the stored developer is dropped by its own weight and supplied to the image forming unit main body.

  A second housing portion having a constricted portion having a wedge shape and a second shape having a circular shape and having a supply port for supplying developer to the image forming unit main body at the lower end. And a receiving portion.

The angle formed by the line connecting the circular center of the second housing part and the inner edge of the supply port is α, and the angle formed by the line connecting the circular center and the inner edge of the lower end of the constricted part is β. The angle α is not less than 35 ° and not more than 45 °, and the angle β is not less than 90 ° and not more than 110 °.
The developer has toner base particles prepared by mixing at least primary particles made of a binder resin and a colorant, and an external additive added to the surface of the toner base particles.
The bulk density of the developer is 0.300 [g / ml] or more and 0.420 [g / ml] or less.
The aggregation degree of the developer is 10% or more and 45% or less.

  According to the present invention, in the developer container, the stored developer is dropped by its own weight and supplied to the image forming unit main body.

  A second housing portion having a constricted portion having a wedge shape and a second shape having a circular shape and having a supply port for supplying developer to the image forming unit main body at the lower end. And a receiving portion.

The angle formed by the line connecting the circular center of the second housing part and the inner edge of the supply port is α, and the angle formed by the line connecting the circular center and the inner edge of the lower end of the constricted part is β. The angle α is not less than 35 ° and not more than 45 °, and the angle β is not less than 90 ° and not more than 110 °.
The developer has toner base particles prepared by mixing at least primary particles made of a binder resin and a colorant, and an external additive added to the surface of the toner base particles.
The bulk density of the developer is 0.300 [g / ml] or more and 0.420 [g / ml] or less.
The aggregation degree of the developer is 10% or more and 45% or less.

In this case, the bulk density of the developer is 0.300 [g / ml] or more and 0.420 [g / ml] or less, the aggregation degree of the developer is 10 [%] or more, and 45 [%] Since it is as follows, the fluidity of the developer can be made appropriate. Therefore, the developer in the developer container can be sufficiently consumed.
In addition, an angle formed by a line connecting the circular center of the second housing portion and the inner edge of the supply port is α, and an angle formed by a line connecting the circular center and the inner edge of the lower end of the constricted portion is β. When the angle α is not less than 35 ° and not more than 45 °, and the angle β is not less than 90 ° and not more than 110 °, the developer in the first storage portion The actual remaining amount of can be reduced. Therefore, it is possible not only to sufficiently consume the developer in the first storage unit, but also to prevent the image from being stained.

FIG. 3 is a cross-sectional view of the toner cartridge in the first embodiment of the present invention. 1 is a schematic diagram of a printer according to a first embodiment of the present invention. 1 is a schematic diagram of an image forming unit according to a first embodiment of the present invention. It is a figure which shows the evaluation result of a toner when the bulk density and aggregation degree in the 1st Embodiment of this invention are changed. FIG. 10 is a diagram illustrating evaluation results of a toner cartridge when angles α and β are changed in the second embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this case, a printer as an image forming apparatus will be described.

  FIG. 2 is a schematic view of the printer according to the first embodiment of the present invention.

  As shown in the figure, the printer 10 includes a main body of the printer 10, that is, an apparatus main body Bd, and an image forming unit 20 that is detachably attached to the apparatus main body Bd. A photosensitive drum 21 as an image carrier is disposed on the surface. In the present embodiment, only one image forming unit 20 for forming a black image is provided. However, in order to form a color image, black, yellow, magenta, and cyan are used. Each image forming unit can be arranged.

  The apparatus main body Bd is provided with a transfer roller 17 as a transfer member in contact with the photosensitive drum 21, and an LED head 23 as an exposure apparatus facing the photosensitive drum 21. Arranged. The image forming unit 20, the transfer roller 17 and the LED head 23 constitute an image forming unit.

  The LED head 23 exposes the surface of the photosensitive drum 21 to form an electrostatic latent image as a latent image.

  Further, the transfer roller 17 is formed of a conductive material, in the present embodiment, rubber or the like, and a paper P using a toner image as a developer image formed on the surface of the photosensitive drum 21 as a medium. Transcript to. For this purpose, a voltage for forming a potential difference between the surface potential of the photosensitive drum 21 and the surface potential of the transfer roller 17 is applied to the transfer roller 17 by a transfer power source (not shown).

  Below the image forming unit 20 in the apparatus main body Bd, a paper cassette 11 as a medium storage unit is disposed, and a plurality of papers P are stored in the paper cassette 11. A hopping roller 12 as a medium supply member and as a feeding member is disposed at the front end of the paper cassette 11, and the paper P is separated one by one by the hopping roller 12 and fed to the transport path Rt. . A first conveying roller pair composed of a pinch roller 13 and a conveying roller 15 is provided downstream of the hopping roller 12 in the conveying direction of the paper P, and a pinch roller 14 and a resist are provided downstream of the first conveying roller pair. A second conveyance roller pair composed of the rollers 16 is disposed. The sheet P is sandwiched between the pinch roller 13 and the transport roller 15 in the first transport roller pair and is sent to the second transport roller pair. In the second transport roller pair, the pinch roller 14 and the registration roller 16 are transported. And the skew is corrected and sent between the photosensitive drum 21 and the transfer roller 17 in the image forming unit. The hopping roller 12, the transport roller 15, and the registration roller 16 are rotated by transmission of rotation from a first drive source (not shown) via a gear or the like.

  A fixing device 31 as a fixing device is disposed downstream of the image forming unit 20 in the transport direction of the paper P. The fixing device 31 is a first rotating body and a heat roller 32 as a heating member, and a second rotating body disposed in pressure contact with the heat roller 32 below the heat roller 32. In addition, a backup roller (pressure roller) 33 as a pressure member is provided, and the toner image on the paper P is fixed by heating and pressing.

  The heat roller 32 is formed of a cylindrical body formed by coating the surface of an aluminum base tube with a fluorine resin such as PFA or PTFE. A halogen lamp 34 as a heat source is disposed inside the heat roller 32. It consists of a cylindrical body formed of an elastic body.

  Further, a first discharge roller pair composed of a pinch roller 35 and a discharge roller 36 is provided downstream of the fixing device 31 in the conveyance direction of the paper P, and a pinch roller 37 is provided downstream of the first discharge roller pair. And the 2nd discharge roller pair which consists of discharge roller 38 is arranged. The paper P is sandwiched between the pinch roller 35 and the discharge roller 36 in the first discharge roller pair, and is sent to the second discharge roller pair. The pinch roller 37 and the discharge roller 38 in the second discharge roller pair. And is discharged to the stacker unit 39. The heat roller 32, the discharge rollers 36, 38, and the like are rotated by transmission of rotation from a second drive source (not shown) via gears.

  Next, the image forming unit 20 will be described.

  FIG. 3 is a schematic view of the image forming unit according to the first embodiment of the present invention.

  As shown in the figure, the image forming unit 20 is a main body of the image forming unit 20, that is, an image forming unit main body 20a and a developer container that is detachably attached to the image forming unit main body 20a. The toner cartridge 26 is provided as a developer cartridge, and a toner storage chamber 52 as a developer storage chamber for storing toner T as a developer is formed in the toner cartridge 26. In the present embodiment, the toner cartridge 26 is detachably disposed with respect to the image forming unit main body 20a. However, the image forming unit main body 20a and the toner cartridge 26 can be integrally formed.

  The toner cartridge 26 is provided with a toner sensor (not shown) as a developer amount detection unit for detecting the remaining amount of toner T in the toner storage chamber 52. The developer amount detection processing means of the control unit (not shown) performs the developer amount detection processing, reads the sensor output of the toner sensor, and when the remaining amount of the toner T in the toner storage chamber 52 falls below the threshold value, The display processing display means performs display processing, and displays a toner low indicating that the remaining amount of toner T has become equal to or less than a threshold value on a display unit (not shown) disposed at a predetermined position of the apparatus main body Bd (FIG. 2). indicate. When the remaining amount of toner T in the toner storage chamber 52 becomes 0, the display processing means displays a toner empty indicating that the remaining amount of toner T has become 0 on the display unit, and the control The stop processing unit of the unit performs stop processing and stops the printer 10.

  The image forming unit main body 20a is provided with the photosensitive drum 21 and a charging roller 22 as a charging device that is disposed in contact with the photosensitive drum 21 and uniformly charges the surface of the photosensitive drum 21. A developing roller 24 as a developer carrying member that is disposed in contact with the photosensitive drum 21 and forms a toner image (development is performed) by attaching toner T to the surface of the photosensitive drum 21; a sponge; A roller, disposed in contact with the developing roller 24, disposed in contact with the developing roller 24, a toner supply roller 25 as a developer supplying member that supplies toner T to the developing roller 24, A developing blade 27 as a developer regulating member for thinning the toner T on the surface of the developing roller 24 is disposed in contact with the photosensitive drum 21, and a toner image is placed on the photosensitive drum 21. Such as a cleaning roller 28 as a cleaning member is arranged to scrape the toner T remaining on the developing roller 24 after being photographed. A positive or negative voltage is applied to the cleaning roller 28 by a cleaning power source (not shown).

  The charging roller 22 includes a conductive shaft and a conductive elastic layer formed on the shaft, and the conductive elastic layer is made of an ion conductive rubber mainly composed of epichlorohydrin rubber (ECO). Become. In this case, a surface treatment is performed by allowing a surface treatment liquid containing an isocyanate (HDI) component to penetrate into the conductive elastic layer, and the surface is cured. Therefore, since the releasability of the surface of the charging roller 22 can be increased, it is possible to prevent the toner T, the external additive added to the toner T, and the like from adhering to the surface of the charging roller 22, It is possible to prevent the photosensitive drum 21 from being soiled by the toner T, external additives, and the like.

  The hardness of the charging roller 22 is measured by a hardness meter (manufactured by Kobunshi Keiki Co., Ltd.), 73 [°] by Asker C, and 6.3 [log Ω]. In measuring the resistance value of the charging roller 22, a conductive metal drum having the same outer diameter and surface roughness as the photosensitive drum 21 is used, and the temperature is 20 ° C. and the relative humidity is 50%. Under the conditions, the charging roller 22 was pressed against the conductive metal drum with the same pressure as when assembled in the image forming unit 20, and a DC voltage of 500 [V] was applied to the charging roller 22.

  The developing roller 24 includes a conductive shaft, an elastic layer made of semiconductive silicone rubber formed on the shaft and subjected to ultraviolet treatment, and urethane resin on the surface of the elastic layer. A surface coating layer (coat layer) formed by applying and surface-treating with a silane coupling agent is provided.

  The thickness of the surface coating layer is 7 [μm] or more and 13 [μm] or less. Further, silica particles are mixed in the urethane resin, and the surface coating layer has a surface roughness Rz of 3 [μm] or more and 12 [μm] or less (according to JIS B0601-1994). Polished. In order to secure the print density, it is preferable to increase the surface roughness Rz as much as possible.

  The resistance value of the developing roller 24 is set to 100 [MΩ] or more and 5000 [MΩ] or less. In measuring the resistance value of the developing roller 24, a ball bearing made of stainless steel having a width of 2.0 [mm] and a diameter of 6.0 [mm] is pressed against the developing roller 24 with a force of 20 [gf], and the shaft A DC voltage of 100 [V] was applied between the ball bearing and the ball bearing.

  The toner supply roller 25 includes a conductive shaft and an elastic layer formed on the shaft and made of semiconductive foamed silicone rubber. The surface of the elastic layer is formed by the toner supply roller 25. Polishing to have a predetermined outer diameter.

  The silicone rubber compound for forming the semiconductive foamed silicone rubber includes various raw rubbers such as dimethyl silicone raw rubber and methylphenyl silicone raw rubber, a filler made of silica as a reinforcing material, and vulcanization necessary for vulcanization and curing. It is created by adding an agent and a foaming agent. As the foaming agent, an inorganic foaming agent such as sodium bicarbonate or an organic foaming agent such as ADCA is used.

  The hardness of the toner supply roller 25 is 48 ± 5 [°] by Asker F, and the toner supply roller 25 is set to 1.0 [mm] ± 0.15 by the developing roller 24 in the image forming unit main body 20a. The pressing amount is [mm].

  The resistance value of the toner supply roller 25 is set to 1 [MΩ] or more and 100 [MΩ] or less. In measuring the resistance value of the toner supply roller 25, the same ball bearing as that for measuring the resistance value of the developing roller 24 is pressed against the toner supply roller 25 with a force of 20 gf, and the gap between the shaft and the ball bearing is measured. A DC voltage of 300 [V] was applied.

  The cleaning roller 28 is formed by adhering a metal cored bar having a diameter of 6 [mm] and EPDM (ethylene-propylene-diene rubber) as a main material via a primer on the cored bar. A conductive foam layer is provided. The average foam cell diameter of the conductive foam layer measured using a stereomicroscope is 100 [μm] or more and 300 [μm] or less.

  The hardness of the cleaning roller 28 is set to 35 [°] or more and 45 [°] or less with Asker C in a state where a load of 4.9 [N] is applied.

  Note that springs (not shown) as urging members are disposed at both ends of the cleaning roller 28, and the cleaning roller 28 is pressed against the photosensitive drum 21 by the urging force of each spring.

The resistance value (entire surface resistance) of the cleaning roller 28 is set to 2.0 × 10 ⁶ [Ω] or more and 2.0 × 10 ⁷ [Ω] or less. In measuring the resistance value of the cleaning roller 28, the cleaning roller 28 was rotated by pressing the photosensitive drum 21 having a diameter of 30 [mm] by 0.25 [mm], and a DC voltage of 400 [V] was applied.

  The transfer roller 17, the photosensitive drum 21, the charging roller 22, the developing roller 24, the toner supply roller 25, and the cleaning roller 28 are rotated by a rotation transmitted from a third driving source (not shown). Therefore, a transfer gear (not shown) on the transfer roller 17, a drum gear (not shown) on the photosensitive drum 21, a charge gear (not shown) on the charging roller 22, and a development gear (not shown) on the developing roller 24 are not shown on the toner supply roller 25. A toner supply gear and a cleaning gear (not shown) are fixed to the cleaning roller 28 by press-fitting or other methods. An idle gear (not shown) is disposed between the developing gear and the toner supply gear.

  A predetermined bias voltage is applied to the developing roller 24 and the toner supply roller 25 by a developing power source (not shown).

  Next, the toner cartridge 26 will be described.

  FIG. 1 is a sectional view of a toner cartridge according to the first embodiment of the present invention.

  In the figure, reference numeral 26 denotes a toner cartridge, and 51 denotes a housing. The housing 51 includes a first housing portion 53 in an upper half portion and a second housing portion 54 in a lower half portion. The accommodating portion 53 includes a zenith portion 55 having a substantially rectangular cross section, and a constricted portion 56 formed from the lower end of the zenith portion 55 to the second accommodating portion 54 and having a wedge-shaped cross section.

  A cylindrical shutter 58 having a circular cross section is disposed in the second housing portion 54 so as to be slidable and rotatable with respect to the inner peripheral surface of the second housing portion 54. Established. A supply port 61 is formed in the vicinity of the lower end of the second housing portion 54, and an opening 62 is formed in a predetermined portion of the shutter 58. The operator is illustrated as an operation portion disposed in the toner cartridge 26. When the lever 58 is operated to rotate the shutter 58 so that the supply port 61 and the opening 62 communicate with each other, the toner T in the toner storage chamber 52 passes through the opening 62 and the supply port 61 by its own weight and passes through the image forming unit main body. 20a is supplied.

  By the way, the toner cartridge 26 becomes narrower in the region AR1 of the constricted portion 56 in the toner storage chamber 52 and the region AR2 of the supply port 61 and the opening 62, so that the toner T is clogged in the regions AR1 and AR2. The toner T cannot be consumed sufficiently.

  Therefore, in order to prevent the toner T from being clogged in the areas AR1 and AR2, lines connecting the center Cn of the circle (circular portion) of the second container 54 and the inner edges ε1 and ε2 at the lower end of the supply port 61. The angle α formed by L1 and L2 is 40 °, and the angle β formed by lines L3 and L4 connecting the center Cn and the inner edges ε3 and ε4 at the lower end of the constricted portion 56 is 100 °. A cartridge 26 is formed.

  Next, the operation of the image forming unit 20 having the above configuration will be described.

  First, when a printing instruction is generated in the control unit, the third drive source is driven, rotation is transmitted to the drum gear through several gears (not shown), and the photosensitive drum 21 is moved in the direction of arrow a ( 3). Then, the rotation is transmitted from the drum gear to the developing gear, the developing roller 24 is rotated in the direction of arrow b, the rotation is transmitted from the developing gear to the toner supply gear via the idle gear, and the toner supply roller 25 is moved to the arrow c. Rotated in the direction. Further, rotation is transmitted from the drum gear to the charge gear, the charging roller 22 is rotated in the direction of the arrow d, rotation is transmitted from the drum gear to the cleaning gear, and the cleaning roller 28 is rotated in the direction of the arrow e, and transferred from the drum gear. The rotation is transmitted to the gear, and the transfer roller 17 is rotated in the direction of arrow f.

  By applying a voltage to the charging roller 22, the surface of the photosensitive drum 21 is uniformly charged, and the surface potential is set to 600 [V], for example. Then, when the charged portion of the photosensitive drum 21 reaches the portion facing the LED head 23 with the rotation, the LED head 23 is operated based on the image data sent from the control unit, and the photosensitive member. An electrostatic latent image is formed on the drum 21. At this time, for example, a bias voltage of −300 [V] is applied to the toner supply roller 25, and a bias voltage of −200 [V] is applied to the developing roller 24, for example.

  Subsequently, when the portion where the electrostatic latent image is formed on the photosensitive drum 21 with rotation reaches the position facing the developing roller 24, the potential of the portion where the electrostatic latent image is formed (for example, −20 [V]) and the developing roller 24 cause the toner T on the developing roller 24 thinned by the developing blade 27 to move onto the photosensitive drum 21 to form a toner image.

  When the portion on the photosensitive drum 21 where the toner image is formed reaches the portion facing the transfer roller 17, the toner image is transferred onto the paper P by the transfer roller 17.

  Subsequently, when the paper P is sent to the fixing device 31, the toner image is melted by heat from the heat roller 32 heated by the halogen lamp 34, pressed by the backup roller 33, and fixed on the paper P. . In this way, an image is formed on the paper P.

  On the other hand, after the toner image is transferred to the paper P, the toner T remaining on the surface of the photosensitive drum 21 is scraped off by the cleaning roller 28, and after the printing operation is completed, the toner T is collected according to the sequence set by the control unit. Is done.

  Next, a method for manufacturing toner T made of non-magnetic one-component toner used in the printer 10 in the present embodiment will be described.

  In the production method of the toner T, first, a polymer which is a binder resin of the toner T in a solvent (aqueous solvent) by the emulsion polymerization method, and in this embodiment, primary particles of a styrene acrylic copolymer resin are prepared. did. Subsequently, the primary particles and a colorant emulsified with an emulsifier (surfactant) are mixed in the solvent, and a wax, a charge control agent, and the like are further mixed as necessary. The base toner as toner particles was prepared in a solvent by agglomerating the obtained mixture. Then, the base toner was taken out from the solvent, washed and dried to remove the solvent component and the by-product component, thereby obtaining toner base particles (non-externally added toner) having a volume average particle size of 7.0 [μm].

  Subsequently, an external additive such as silica fine powder, titanium oxide fine powder, and acrylic resin fine particles was added to the surface of the toner base particles and mixed with a mixer to prepare toner T.

  In the present embodiment, the styrene-acrylic copolymer resin is produced from styrene, acrylic acid, methylmethacrylic acid or the like. Further, carbon black is used as the colorant for the black toner T, and stearyl stearate, which is a higher fatty acid ester wax, is used as the wax.

  Next, the volume average particle size of the toner base particles was calculated by measuring 30000 counts using a cell counting analyzer “Coulter Multiplier 3” (manufactured by Beckman Coulter) with an aperture diameter of 100 [μm]. . Further, the circularity ρ of the toner base particles is determined by using a flow type particle image analyzer “FPIA-2100” (manufactured by Sysmex Corporation), and the circumference L1 and particle projection of a circle having the same area as the area of the particle projection image. By calculating the peripheral length L2 of the image, it was calculated based on the following equation (1).

ρ = L1 / L2 (1)
The circularity ρ represents the shape of the particle by a numerical value. When the particle size is 1.00, the particle has a true sphere shape, and the particle shape becomes indefinite as the particle size becomes smaller than 1.00. Become. Subsequently, the average of the circularity ρ of the 10 toner base particles, that is, the average circularity aρ was calculated. In the present embodiment, the average circularity aρ of the toner base particles was 0.97.

  By the way, when the fluidity of the toner T is low, the toner T is easily clogged in the areas AR1 and AR2.

  Therefore, in order to evaluate whether the fluidity of the toner T is high, a toner base particle having an average circularity aρ of 0.97 is set to A, and the toner base particle A includes silica fine powder, titanium oxide fine powder, acrylic Toners A-1 to A-32 were prepared by adding predetermined external additives such as resin fine particles and mixing toner base particles A and external additives for a predetermined external addition time.

  In the present embodiment, “Aerosil RX50” (manufactured by Nippon Aerosil Co., Ltd.) as the silica fine powder, and “TTO-55” (manufactured by Ishihara Sangyo Co., Ltd.) having a particle size of 30 nm as the titanium oxide fine powder. ) Was used as the acrylic resin fine particles, “Polymethylmethacrylate MP-1000” (manufactured by Nippon Kaken)

  First, 0.5 [parts by weight] silica fine powder was added to 100 parts [parts by weight] of toner base particles A and mixed for 15 [minutes] to prepare toner A-1.

  Similarly, silica fine powder 0.5 [parts by weight] is added to toner base particles A100 [parts by weight], mixed for 20 [minutes], and mixed with toner A-2 for 25 [minutes], and toner A- 3 was mixed for 30 minutes to prepare toner A-4.

  Further, 0.7 [parts by weight] of silica fine powder is added to toner base particles A100 [parts by weight], mixed for 15 [minutes], and then mixed with toner A-5 for 20 [minutes], and toner A-6. Was mixed for 25 minutes to prepare toner A-7, and mixed for 30 minutes to prepare toner A-8.

  Then, silica fine powder 0.9 [parts by weight] is added to toner base particles A100 [parts by weight], mixed for 15 [minutes], and mixed with toner A-9 for 20 [minutes], and toner A-10. Was mixed for 25 minutes to prepare toner A-11, and mixed for 30 minutes to prepare toner A-12.

  Further, 1.1 [parts by weight] of silica fine powder is added to toner base particles A100 [parts by weight], mixed for 15 [minutes], and then mixed with toner A-13 for 20 [minutes], and toner A-14. Was mixed for 25 minutes to prepare toner A-15, and mixed for 30 minutes to prepare toner A-16.

  Further, 1.3 [parts by weight] of silica fine powder is added to toner base particle A100 [parts by weight], mixed for 15 [minutes], and mixed with toner A-17 for 20 [minutes], and toner A-18. Was mixed for 25 minutes to prepare toner A-19, and mixed for 30 minutes to prepare toner A-20.

  Then, silica fine powder 1.5 [parts by weight] is added to toner base particles A100 [parts by weight], mixed for 15 [minutes], and mixed with toner A-21 for 20 [minutes], and toner A-22. Was mixed for 25 minutes to prepare toner A-23, and mixed for 30 minutes to prepare toner A-24.

  Further, 0.7 [parts by weight] silica fine powder and 0.4 [parts by weight] titanium oxide fine powder are added to toner base particle A100 [parts by weight] and mixed for 15 [minutes] to obtain toner A-25. Toner A-26 was prepared by mixing for 20 minutes, toner A-27 was mixed for 25 minutes, and toner A-28 was prepared by mixing for 30 minutes.

  In addition, silica fine powder 1.3 [parts by weight] and acrylic resin fine particles 0.6 [parts by weight] are added to toner base particles A100 [parts by weight] and mixed for 15 [minutes] to add toner A-29 to 20 parts by weight. The toner A-30 was mixed for [minutes], the toner A-31 was mixed for 25 minutes, and the toner A-32 was mixed for 30 minutes.

  Subsequently, the bulk density δ was calculated for each of the toners A-1 to A-32. For this purpose, a multi-tester (manufactured by Seishin Enterprise) is used, and when the toners A-1 to A-32 are placed on a 250 [μm] sieve and the sieve is vibrated with an amplitude of 1 [mm], it falls from the sieve. The toners A-1 to A-32 are received by a measuring cylinder having a volume of 100 [ml], and the weight of the measuring cylinder itself is subtracted from the weight when the measuring cylinder is filled with the toners A-1 to A-32. The weights of toners A-1 to A-32 were calculated. The bulk density δ was calculated by dividing the weight of the toners A-1 to A-32 by the toner volume.

Next, using a powder tester (manufactured by Hosokawa Micron Corporation), the degree of aggregation η was measured as a parameter representing the fluidity of the toners A-1 to A-32. In the powder tester, each sieve having openings of 150 [μm], 75 [μm] and 45 [μm] is stacked in three stages from the top, and the toner is placed on the top sieve by 2 [g]. Each sieve was vibrated with an amplitude of 0.8 ± 0.05 [mm] for a predetermined time, for example, 95 [seconds]. The weight of the toner remaining on the sieve having a mesh opening of 150 [μm] after vibration is M1 [g], and the weight of the toner remaining on the sieve having a mesh opening of 75 [μm] is M2 [g]. And the weight of the toner remaining on the sieve having an opening of 45 [μm] is M3 [g], and the weight of the toner first placed on the top sieve is Mt [g], The aggregation degree η of the toner is
η = (5 × M1 + 3 × M2 + M3) × 20 ÷ Mt
It is represented by The lower the aggregation degree η (the smaller the value), the higher the fluidity of the toner.

  Subsequently, 150 [g] of toner was stored in the toner cartridge 26, the toner cartridge 26 was attached to the image forming unit main body 20a, and printing was performed.

In this case, A4 standard paper (for example, Xerox-P paper, whiteness 82 [%], basis weight 64 [g / m < ² >]) is used as the paper P, and the vertical direction (2 of the four sides is short). The image is conveyed on the standard paper (in the form of an ISO pattern (ISO IEC 19752, 4.2 [% duty]) in this embodiment). In this case, printing was repeated until a toner empty was displayed on the display section and the printing operation of the printer 10 was stopped. Note that an image having a black portion of 100% is defined as an image having 100% duty.

  In the present embodiment, when the toner empty is displayed on the display unit and the printing operation of the printer 10 is stopped, the weight of the toner cartridge 26 is measured, so that the actual remaining amount of toner T, that is, The actual remaining amount was examined.

  Table 1 shows the bulk density δ and the aggregation degree η of each of the toners A-1 to A-32 and the actual remaining amount and evaluation of each of the toners A-1 to A-32 in the toner storage chamber 52. In Table 1, RX50 is silica fine powder, Ti02 is titanium oxide fine powder, and PMMA is acrylic resin fine particles.

  In Table 1, when the actual remaining amount of toner T in the toner storage chamber 52 is 10 [g] or less, the toner T is discharged even if the toner cartridge 26 is removed from the image forming unit main body 20a and the toner cartridge 26 is tapped. Therefore, the toner T in the toner storage chamber 52 is sufficiently consumed, and the evaluation is “good”. The toners A-21 to A-24 and A-28 have an excessively low aggregation degree η and an excessively high fluidity, and the image forming unit main body 20a is between the toner cartridge 26 and the image forming unit main body 20a. Since the toner T leaked from between the case and the photosensitive drum 21, the evaluation was x.

  FIG. 4 is a diagram showing the evaluation results of the toner when the bulk density and the degree of aggregation are changed in the first embodiment of the present invention. In the figure, the horizontal axis represents the bulk density δ, and the vertical axis represents the degree of aggregation η.

  In the figure, when the aggregation degree η is lower than 10 [%], the toner T leaks. Therefore, the evaluation is x. When the aggregation degree η is higher than 45 [%], the actual residual toner T in the toner storage chamber 52 is evaluated. Since the amount increased, the evaluation was x. When the bulk density δ is lower than 0.300 [g / ml] or higher than 0.420 [g / ml], the toner T leaks or the actual remaining amount in the toner storage chamber 52 increases. Evaluation was made into x.

  The bulk density δ is 0.300 [g / ml] or more and 0.420 [g / ml] or less, and the aggregation degree η is 10 [%] or more and 45 [%] or less. Since the toner T does not leak or the actual remaining amount of the toner T in the toner storage chamber 52 does not increase, the evaluation is “good”.

  Thus, in the present embodiment, the bulk density δ is 0.300 [g / ml] or more and 0.420 [g / ml] or less, the aggregation degree η is 10 [%] or more, and , 45% or less, the fluidity of the toner T can be made appropriate, so that the actual remaining amount of the toner T in the toner storage chamber 52 can be reduced and the toner storage chamber 52 The toner T can be sufficiently consumed.

  By the way, in this embodiment, in order to prevent the toner T from being clogged in the areas AR1 and AR2 (FIG. 1) in the toner storage chamber 52, the angle α is 40 ° and the angle β is 100 °. ] Is set.

  However, depending on the shape of the casing 51 of the toner cartridge 26, that is, when the angle α deviates from an appropriate range including 40 °, or the angle β deviates from an appropriate range including 100 °, the area AR1. The toner T cannot be prevented from being clogged in AR2, and the actual remaining amount of the toner T in the toner storage chamber 52 cannot be reduced. As a result, the toner T in the toner storage chamber 52 cannot be consumed sufficiently.

  Therefore, the second embodiment of the present invention is configured such that the actual remaining amount of the toner T in the toner storage chamber 52 can be surely reduced, and the toner T in the toner storage chamber 52 can be sufficiently consumed. A form is demonstrated. In addition, about the thing which has the same structure as 1st Embodiment, the same code | symbol is provided and the effect of the same embodiment is used about the effect of the invention by having the same structure.

  In this case, the angle α and the angle β of the toner cartridge 26 as the developer container and as the developer cartridge are changed, and the toner T as the developer in the toner storage chamber 52 as the developer storage chamber is changed. The actual remaining amount was examined. The angle α was changed in units of 5 ° in the range of 30 to 50 °, and the angle β was changed in units of 10 ° in the range of 80 to 120 °. As the toner T, toners A-6, A-20, A-27, and A-30, which were evaluated as “good” in the first embodiment, were used.

  For each of the toners A-6, A-20, A-27, and A-30, as in the first embodiment, an ISO pattern image is printed and arranged at a predetermined location on the apparatus main body Bd. A toner empty indicating that the remaining amount of toner T has become 0 is displayed on a display unit (not shown), and printing is continued until the printer 10 as the image forming apparatus is stopped, and the printer 10 is stopped. The actual remaining amount of toner T in the toner storage chamber 52 was examined.

  Table 2 shows the actual remaining amount and evaluation of the toners A-6, A-20, A-27, and A-30 in the toner storage chamber 52 when the angles α and β are changed.

  In Table 2, when the actual remaining amount of the toner T in the toner storage chamber 52 is 10 [g] or less, the evaluation is “good”, and when it is more than 10 [g], the evaluation is “poor”.

  FIG. 5 is a diagram showing the evaluation results of the toner cartridge when the angles α and β are changed in the second embodiment of the present invention. In the figure, the horizontal axis represents the angle α and the vertical axis represents the angle β.

  In the figure, when the angle α is smaller than 35 °, the toner T is likely to be clogged in the area AR2, and when the angle β is larger than 110 °, the toner T is likely to be clogged in the area AR1. Further, in any case where the angle α is larger than 45 °, or the angle β is smaller than 90 °, the image on the paper P as a medium is soiled. This is because a large amount of toner T is supplied from the toner storage chamber 52 into the image forming unit main body 20a, the thickness of the toner image on the developing roller 24 as a developer carrier increases, and the toner T serves as an image carrier. This is because it adheres to the photosensitive drum 21.

  Even when a toner other than the toners A-6, A-20, A-27, and A-30 is used, the angle α is not less than 35 ° and not more than 45 °, and the angle β is When the angle is 90 [°] or more and 110 [°] or less, the actual remaining amount of toner T is 10 [g] or less, and the actual remaining amount of toner T in the toner storage chamber 52 can be reduced. It was. Therefore, the toner T in the toner storage chamber 52 can be sufficiently consumed. In addition, it is possible to prevent the image from being stained.

  In each of the above embodiments, the toner T made of non-magnetic one-component toner is used, but toner made of two-component toner can be used.

  In each of the above embodiments, the printer 10 has been described. However, the present invention can be applied to a copying machine, a facsimile machine, a multifunction machine, and the like.

  The present invention is not limited to the above embodiments, and various modifications can be made based on the gist of the present invention, and they are not excluded from the scope of the present invention.

T Toner δ Bulk density η Aggregation degree

Claims (6)

In the developer container to be supplied to the yield capacity has been developer dropped by its own weight the image forming unit main body,
(A) a first accommodating portion having a constricted portion having a wedge shape;
(B) a second container having a circular shape and having a supply port for supplying the developer to the image forming unit main body at the lower end;
(C) The angle formed by the line connecting the circular center of the second housing portion and the inner edge of the supply port is α, and the angle formed by the line connecting the circular center and the inner edge of the lower end of the constricted portion is β When the angle α is 35 [°] or more and 45 [°] or less, the angle β is 90 [°] or more and 110 [°] or less,
(D) The developer has toner base particles prepared by mixing at least primary particles made of a binder resin and a colorant, and an external additive added to the surface of the toner base particles.
(E) The bulk density of the developer is 0.300 [g / ml] or more and 0.420 [g / ml] or less,
(F) A developer container having a cohesion degree of the developer of 10% or more and 45% or less. (A) the toner base particles are made of a styrene acrylic copolymer resin;
(B) The developer container according to claim 1, wherein the external additive is a predetermined external additive among silica fine powder, titanium oxide fine powder, and acrylic resin fine particles. In the image forming unit including a developer container for supplying is dropped by its own weight to yield capacity has been developed into the image forming unit main body,
(A) The developer accommodating body has a first accommodating portion having a constricted portion having a wedge shape, and a supply for supplying developer to the image forming unit main body at the lower end. A second housing part having a mouth formed;
(B) The angle formed by the line connecting the circular center of the second container and the inner edge of the supply port in the developer container is α, and the circular center and the inner edge of the lower end of the constricted part are connected. When the angle formed by the line is β, the angle α is 35 ° or more and 45 ° or less, the angle β is 90 ° or more and 110 ° or less,
(C) The developer has toner base particles prepared by mixing at least primary particles composed of a binder resin and a colorant, and an external additive added to the surface of the toner base particles.
(D) The developer has a bulk density of 0.300 [g / ml] or more and 0.420 [g / ml] or less,
(E) An image forming unit, wherein the developer has an aggregation degree of 10% or more and 45% or less. (A) the toner base particles are made of a styrene acrylic copolymer resin;
(B) The image forming unit according to claim 3, wherein the external additive is a predetermined external additive among silica fine powder, titanium oxide fine powder, and acrylic resin fine particles. An image forming apparatus comprising a developer container supplies is dropped by its own weight to yield capacity has been developed into the image forming unit main body,
(A) The developer accommodating body has a first accommodating portion having a constricted portion having a wedge shape, and a supply for supplying developer to the image forming unit main body at the lower end. A second housing part having a mouth formed;
(B) The angle formed by the line connecting the circular center of the second container and the inner edge of the supply port in the developer container is α, and the circular center and the inner edge of the lower end of the constricted part are connected. When the angle formed by the line is β, the angle α is 35 ° or more and 45 ° or less, the angle β is 90 ° or more and 110 ° or less,
(C) The developer has toner base particles prepared by mixing at least primary particles composed of a binder resin and a colorant, and an external additive added to the surface of the toner base particles.
(D) The developer has a bulk density of 0.300 [g / ml] or more and 0.420 [g / ml] or less,
(E) The image forming apparatus, wherein the developer has an aggregation degree of 10% or more and 45% or less. (A) the toner base particles are made of a styrene acrylic copolymer resin;
(B) The image forming apparatus according to claim 5, wherein the external additive is a predetermined external additive among silica fine powder, titanium oxide fine powder, and acrylic resin fine particles.

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