JP4398421B2 - Development device - Google Patents

Description

  The present invention relates to a developing device, for example, a developing device mounted on a printing device included in a copying machine or a printer.

  A developing device is mounted on a printing apparatus provided in a copying machine, a printer, or the like. The developing device is configured such that the toner storage chamber, the supply roller, and the developing roller are accommodated in one housing. When the toner is consumed, the developing device is discarded and a new developing device is purchased to obtain a printing device. It is attached to. However, due to the recent increase in environmental awareness, there is an increasing need for a long-life developing device capable of additionally replenishing toner, instead of a conventional developing device.

  When additional toner is supplied to the developing device, it is necessary to detect the amount of toner in the developing device. As a detection method, a method using a piezoelectric sensor or an optical sensor or a method using a magnetic permeability sensor is generally used. Among them, the optical sensor is inexpensive and is widely used.

In Japanese Patent Laid-Open No. 11-73004 (Patent Document 1), the amount of transmission that allows light to pass between the light emitting member and the light receiving member on the other end side in the first direction, which is the width direction of the paper of the developing device. A method for detecting whether or not the remaining amount of toner in the toner storage portion has become smaller than a predetermined amount is described.
Japanese Patent Laid-Open No. 11-73004 (paragraph numbers 0196 to 99, FIG. 36)

  The toner storage portion is provided with an agitating member for agitating the toner at a bottom portion when the toner is supplied to the developing device. For this reason, when the optical sensor is provided in the toner storage portion, it is necessary to provide the stirring member so as not to block light from the light emitting member to the light receiving member. In particular, in a small developing device, since the toner storage portion is also downsized, it is difficult to secure a place for installing the optical sensor.

  If the level of toner detected is too low, when additional toner is replenished, the replenished toner will not be agitated and will not be sufficiently charged and will be supplied to the developing part, and will adhere to uncharged parts. There has been a problem that replenishment fog is likely to occur.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a developing device that can secure a detection optical path of an optical sensor even in a small-sized device and can stably obtain an appropriate toner amount detection level.

The present invention is a developing device capable of replenishing toner, and includes a toner storage chamber for storing toner, and is provided in the toner storage chamber so as to extend in a first direction and be rotatable so as to stir the toner. A first advancing unit having an optical axis extending in parallel to the first direction and causing light from the outside to be incident on one end of the agitating member, and light that has traveled straight through the first rectilinear unit. A first reflecting portion that reflects in a direction crossing the first direction, receives the light reflected by the first reflecting portion, and receives the light from the first reflecting portion. A second reflecting portion that reflects in the first direction, and a second reflecting portion that is provided in parallel to the first direction, causes light reflected by the second reflecting portion to travel straight, and is emitted from the other end to the outside of the toner storage chamber. and a second straight portion, and a second optical means provided in the toner accommodating chamber, first and second The optical axis is formed in parallel to the first direction by the optical means is characterized by being arranged so as not to overlap the stirring member.

The present invention is a developing device capable of replenishing toner, and includes a toner storage chamber for storing toner, and is provided in the toner storage chamber so as to extend in a first direction and be rotatable so as to stir the toner. And a third optical means provided in the toner storage chamber, wherein the optical axis extends parallel to the first direction, and light from the outside is incident on one end and radiates straight from the other end. A third reflecting portion that reflects the light emitted from the third optical means in a direction intersecting the first direction, and a first reflecting portion that reflects the light reflected by the third reflecting portion straight from one end to the other end. 3, a fourth reflecting portion that reflects light that has traveled straight to the other end in the first direction so as to face the outside of the toner storage chamber, and a fourth reflecting portion that is longer than the third optical means. And a fourth rectilinear portion that radiates the light reflected from the toner to the outside of the toner storage chamber. And a fourth optical means provided in the pay room, the optical axis is formed in parallel by the third and fourth optical means, characterized in that it is arranged so as not to overlap the stirring member.

  More specifically, the predetermined interval between the first and second optical means is at least 10 mm apart.

  In a preferred embodiment, the toner storage chamber has a wall surface extending in a second direction crossing the first direction, and the first optical means is provided at a position for receiving light from the outside, The optical means is provided at a position for emitting light to the outside, and the optical path formed by the first and second optical means has a predetermined angle with the wall surface in the toner storage chamber.

  Preferably, the stirring member includes a shaft member extending in the first direction and a blade member provided on the shaft member so as to extend in the first direction. The blade member is formed of a flexible material, and the blade member is , Including a portion where the trajectory at the time of rotation of the tip parallel to the first direction protrudes from the optical path formed by the first and second optical means.

  In the present invention, since the optical path formed by the first and second optical means is arranged so as not to overlap the stirring member, the detection optical path of the optical sensor can be secured even in a small-sized device, and an appropriate amount of toner can be detected. The level can be obtained stably.

  FIG. 1 is a diagram schematically showing an example of a color image forming apparatus including a developing device according to an embodiment of the present invention. In FIG. 1, the image forming apparatus 10 includes a photosensitive drum 11, a laser scanning unit 12, a charging member 13, and a rotary developing device 14.

  The developing device 14 includes developing units 14a to 14d corresponding to the respective colors. For example, the developing device 14 includes a black (BK) developing unit 14a, a magenta (M) developing unit 14b, a cyan (C) developing unit 14c, and a yellow (Y) developing unit 14d. Each color developing unit 14 a to 14 d includes a developing container 15, a toner supply roller 16, and a developing roller 17.

  The developing device 14 is rotationally driven by a driving force applied from a driving unit (not shown) via a clutch, and sequentially forms toner images on the photosensitive drum 11 by the developing rollers 17 of the developing units 14a to 14d for the respective colors. Around the photosensitive drum 11, a cleaning rubbing member 18 and a cleaning device 19 are disposed. An intermediate transfer belt 20 is disposed in contact with the photosensitive drum 11, and the intermediate transfer belt 20 is interposed therebetween. The photosensitive drum 11 and the primary transfer roller 21 face each other.

  The intermediate transfer belt 20 is stretched between the primary transfer roller 21, the drive roller 22, and the driven roller 23, and the intermediate transfer belt 20 is rotationally driven in the direction of the arrow. Further, a secondary transfer roller 24 is provided to face the driving roller 22 with the intermediate transfer belt 20 interposed therebetween. The toner image on the photosensitive drum 11 is primarily transferred onto the intermediate transfer belt 20 by the primary transfer roller 21. The recording paper is conveyed from the paper feed cassette 25 through the paper feed path 26 to a secondary transfer position that is a nip portion between the drive roller 22 and the secondary transfer roller 24, and is transferred onto the intermediate transfer belt 20 at the secondary transfer position. The toner image is secondarily transferred to the paper. Thereafter, the recording sheet is conveyed to the fixing unit 27 where the toner image on the sheet is fixed, and the sheet is discharged to the discharge tray 29 through the discharge path 28.

  FIG. 2 is a sectional view showing details of the black developing portion 14a shown in FIG. The other developing units 14b to 14d shown in FIG. 1 are configured in the same manner as the black developing unit 14a. In FIG. 2, the developing container 15 is provided with a toner storage chamber 15 a that extends in a first direction that is the width direction of the recording sheet and stores toner (one-component developer), a supply roller 16, and a developing roller 17. The toner storage chamber 15a and the roller storage chamber 15b are partitioned by a boundary wall 15c. First and second openings 15d and 15e are formed in the boundary wall 15c.

  The toner storage chamber 15a includes first and second wall portions 15g and 15h that cross each other and extend in the first direction, and the first and second wall portions 15g and 15h that are not shown in the drawing. First and second end surfaces supported at both ends of the direction. In the vicinity of the intersection of the first and second wall portions 15g and 15h of the toner storage chamber 15a, a stirring member 30 extending in the first direction and stirring the toner is rotatably provided. The toner storage chamber 15a is provided with first and second optical systems 46 and 47 for detecting the remaining amount of toner, and the optical axes of the first and second optical systems 46 and 47 are agitated. It arrange | positions so that it may not overlap with the member 30. FIG. The first and second optical systems 46 and 47 will be described in detail later with reference to FIGS.

  The stirring member 30 has a rotating shaft 30a attached with a stirring blade 30b formed of, for example, a PET film having a thickness of 40 μm. The toner is supplied to the roller storage chamber 15 b from the second opening 15 e of the boundary wall 15 c while being stirred by the stirring member 30, and is supplied to the developing roller 17 by the supply roller 16.

  The toner layer on the developing roller 17 is, for example, a SUS foil having a thickness of 0.08 mm. The layer thickness is regulated by the layer thickness regulating member 31 set to a regulating pressure = 25 N / m, and is triboelectrically charged. The electrostatic latent image on the photosensitive drum 11 is developed by the roller 17. In addition, between the developing roller 17 and the developing container 15, for example, a conductive high molecular weight PE film is used, and a seal member 32 backed up with a urethane sponge so as to uniformly contact the developing roller 17 is disposed. The seal member 32 prevents toner leakage.

  When replenishing toner to the developing unit 14a, the developing device 14 is rotationally driven so that the developing unit 14a is positioned at a toner replenishing position in the vicinity of the replenishing pipe 33 shown in FIG. Then, the tip of the supply pipe 33 is inserted into the connecting portion 35 shown in FIG. 2 of the developing unit 14a, and the toner is supplied from the toner container 34 to the toner storage chamber 15a.

  The first opening 15d is provided with an overfill prevention valve 15f on the toner storage chamber 15a side. The overfill prevention valve 15f is opened when the toner in the roller storage chamber 15b is overfilled. By discharging the toner from the roller storage chamber 15b to the toner storage chamber 15a, overfilling of the toner in the roller storage chamber 15b is prevented.

  Furthermore, when the supply roller 16 and the developing roller 17 are rotated in the direction of the arrow shown in FIG. 2, the first opening 15d is formed downstream of the second opening 15e in the rotation direction of the supply roller 16, The first opening 15 d is located above the upper end of the supply roller 16. The agitating member 30 agitates and flows the new toner replenished from the replenishing pipe 33 so that the toner in the toner storage chamber 15a becomes horizontal.

  The boundary wall 15c described above is partly formed of, for example, a PET film having a thickness of 100 μm. Specifically, the PET film is disposed along the outer peripheral surface of the supply roller 16, and the PET film is provided with a second film. Two openings 15e are formed. The overfill prevention valve 15f is formed of, for example, a PET film having a thickness of 50 μm, and toner is supplied from the second opening 15e to the roller storage chamber 15b as described above. When the amount of toner in the chamber 15b increases, the overfill prevention valve 15f is pushed open by the toner due to the toner powder pressure, the first opening 15d opens, and excess toner is transferred from the roller storage chamber 15b side to the toner storage chamber 15a. Returned to

  As a result, toner overfilling in the roller storage chamber 15b is prevented, and poor toner circulation due to toner filling is eliminated. That is, the toner does not stay in the roller storage chamber 15b. As a result, the rotation load of the supply roller 16 does not increase, and not only the toner can be stably supplied to the developing roller 17, but also the toner. Charging defects do not occur and image quality defects such as image fogging can be avoided.

  Furthermore, the second opening 15e is formed upstream of the first opening 15d in the rotation direction of the supply roller 16, that is, the second opening 15e is rotated by the supply roller 16. Since the toner is formed downstream of the shaft, the toner supplied to the roller storage chamber 15b through the second opening 15e does not immediately reach the layer thickness regulating member 31. Such as image quality defects do not occur.

  As described above, the PET film constituting the boundary wall 15c is disposed along the outer peripheral surface of the supply roller 16, and passes from the toner storage chamber 15a to the roller storage chamber through the second opening 15e. The toner replenished to 15b is regulated by the opening area of the second opening 15e and the gap between the PET film and the supply roller 16, so that a large amount of toner is replenished to the roller storage chamber 15b at a time. There is nothing.

  As described above, by suppressing the toner circulation between the toner storage chamber 15a and the roller storage chamber 15b, it is possible to suppress the toner selection that the toner having a small particle size is consumed first, thereby preventing the image defect. . Since the overfilling prevention valve 15f is arranged on the toner storage chamber 15a side, it is not necessary to provide a gap between the supply roller 16 and the overfilling prevention valve 15f, and the toner passes through the second opening 15e. Since the roller storage chamber 15b is replenished, it is possible to reduce the size of the developing device and prevent image defects from occurring over a long period of time.

  FIG. 3 is an external perspective view of the developing unit shown in FIG. 2, and FIG. 4 shows an internal optical system, a reflecting mirror, and a stirring member by opening the upper part of the toner storage chamber of the developing unit shown in FIG. FIG. 5 is a diagram showing a configuration of a toner remaining amount detection sensor, an optical system, and a reflecting mirror.

The developing device 14a is provided with a side wall 14f that is an end surface for supporting the first and second wall portions 15g and 15h of the toner storage chamber 15a shown in FIG. 2 at both ends in the first direction. As shown in FIG. 3, the toner remaining amount detecting sensor 43 is fixedly provided at a predetermined position with a certain interval facing the side wall 14f. As shown in FIG. 5, the remaining toner detection sensor 43 includes a light emitting diode 44 and a phototransistor 45. The developing device 14a includes a first straight part (hereinafter referred to as “ first optical system ” 46) , a first reflecting mirror 48, and a second straight part (hereinafter referred to as “ second optical system ” 47). And a second reflecting mirror 49 is provided in the vicinity of the side wall 14f.

  The first optical system 46 is provided so that one end is exposed from the side wall 14f and faces the light emitting diode 44 and extends in the first direction in the toner storage chamber 15a. The second optical system 47 is provided in the toner storage chamber 15a so that one end is exposed from the side wall 14f, faces the phototransistor 45, and extends in parallel with the first optical system 46. . First and second reflecting mirrors 48 and 49 are provided at the other ends of the first and second optical systems 46 and 47, respectively, and an optical axis formed by each of them intersects the first direction of the toner storage chamber 15a. It is provided so as to face each other. As shown in FIG. 2, the optical axes of the first and second optical systems 46 and 47 are arranged so as to be substantially parallel to the first wall portion 15g of the toner storage chamber 15a. Further, instead of the reflecting mirrors 48 and 49, prisms or other reflecting means may be used.

  The light emitted from the light emitting diode 44 is incident from the end surface of the first optical system 46, is emitted from the first reflecting mirror 48, passes through the toner in the toner storage chamber 15 a, and is transmitted from the second reflecting mirror 49. The light enters the phototransistor 45 through the second optical system 47. When the remaining amount of toner is large, the amount of light incident on the second reflecting mirror 49 from the first reflecting mirror 48 is reduced. When the remaining amount of toner is decreased, the first reflecting mirror 48 to the second reflecting mirror 49 are reduced. Since the amount of light incident on the toner increases, the remaining amount of toner can be detected by the light reception output of the phototransistor 45.

  The optical path formed by the first and second optical systems 46 and 47 and the first and second reflecting mirrors 48 and 49 is not blocked by the stirring member shaft 30a of the stirring member 30. It is provided on the opening side of the shaft 30a. The stirring member 30 will be described in detail with reference to FIG. 9 described later. As shown in FIG. 4, an opening blade 30b having an opening 30c is attached to the stirring member shaft 30a.

  Further, in order to remove the toner adhering to the exit surface of the first reflecting mirror 48 and the entrance surface of the second reflecting mirror 49, as shown in FIG. 4, removal blades 41, which remove the toner by rotating, 42 is provided on the rotary rotor 40. The rotary rotor 40 is disposed so as to be located on the opening side of the stirring member shaft 30a. When detecting the remaining amount of toner, it is necessary that the removal blades 41 and 42 do not block the optical path formed by the reflecting mirrors 48 and 49. Therefore, the rotation of the rotary rotor 40 is controlled so as to stop at a position rotated 90 degrees from the position shown in FIG.

  Similarly, first and second optical systems 46 and 47 and first and second reflecting mirrors 48 and 49 are provided in the other developing units 14b to 4d. The toner remaining amount detection sensor 43 has a light emitting diode 44 and a phototransistor 45, which are opposed to the side walls of the developing units 14a to 14d as the developing device 14 rotates, and first and second optical systems 46 and 47, respectively. When it is opposed to, the remaining amount of toner in the corresponding developing unit is detected. Thus, each of the developing units 14a to 14d is rotated by each of the developing units 14a to 14d without the toner remaining amount detecting sensor 43 being provided. The remaining amount of toner 14d can be sequentially detected.

  However, it is assumed that the toner remaining amount detection sensor 43 can detect the toner remaining amount of each color in common. However, the toners of the respective colors have different light transmission amounts. In particular, the light transmission amount is greatly different between the yellow toner and the black toner. Therefore, in the embodiment of the present invention, the arrangement of the first and second optical systems 46 and 47 and the first and second reflecting mirrors 48 and 49 is considered. This will be described in detail.

  FIG. 6 is a characteristic diagram showing the relationship between the distance between the light emitting side and the light receiving side of the toner remaining amount detecting sensor shown in FIG. 5 and the signal output of the phototransistor. In FIG. 6, the horizontal axis indicates the distance between the light emitting side and the light receiving side, that is, the distance between the exit surface of the first reflecting mirror 48 and the incident surface of the second reflecting mirror 49 shown in FIG. Indicates the signal output of the phototransistor 45.

  Graph a shows the signal output level of the phototransistor 45 when black toner is present between the exit surface of the first reflecting mirror 48 and the entrance surface of the second reflecting mirror 49. Graph b Indicates the signal output level of the phototransistor 45 when yellow toner is present.

  When the interval between the light emitting side and the light receiving side is set to 0, that is, when the emission surface of the first reflecting mirror 48 and the incident surface of the second reflecting mirror 49 are brought into contact with each other, the signal output level of the phototransistor 45 is The signal output level of the phototransistor 45 decreases as the distance between the two increases and the distance between the two increases.

  Even if the distance between the exit surface of the first reflecting mirror 48 and the entrance surface of the second reflecting mirror 49 is about 2 mm, for example, if black toner exists between them, the signal output of the phototransistor 45 is output. Is significantly reduced. This is because black toner is difficult to transmit light. On the other hand, since the yellow toner easily transmits light, the output signal of the phototransistor 45 is output while the distance between the exit surface of the first reflecting mirror 48 and the entrance surface of the second reflecting mirror 49 is narrow. The level of is not greatly reduced.

  In order for the output signal level of the phototransistor 45 due to the presence of the yellow toner shown in the graph b to be equal to the output signal level of the phototransistor 45 due to the presence of the black toner shown in the graph a, the first reflecting mirror The distance between the 48 exit surfaces and the entrance surface of the second reflecting mirror 49 may be 10 mm or more. As a result, it is possible to detect the remaining amounts of the four different color toners with the single toner remaining amount detecting sensor 43.

FIG. 7 is a diagram showing another example of an optical system and a reflecting mirror provided in the toner storage chamber. In the example shown in FIG. 5, the first and second reflecting mirrors 48 and 49 are opposed to each other in order to provide an optical path so as to intersect the first direction in the toner storage chamber 15a. In the example shown in FIG. 7 , an optical path is provided in parallel with the first direction of the toner storage chamber 15a.

That is, a third optical means (hereinafter referred to as “ third optical system ”) 50 having a short length is arranged so as to extend in the first direction of the toner storage chamber 15a so as to face the light emitting diode 44. Then, a fourth rectilinear portion (hereinafter referred to as “ fourth optical system ”) 54, which is formed longer than the third optical system 50, is opposed to the phototransistor 45 with respect to the third optical system 50. Are arranged in parallel with each other, and a fourth reflecting portion (hereinafter referred to as a “ third reflecting mirror ”) 53 is opposed to an end portion in the first direction of the fourth optical system 54 and intersects the first direction. Thus, the third rectilinear part (hereinafter referred to as “ fifth optical system ”) 52 is made to face the third reflecting mirror 53, and the third reflecting part (hereinafter referred to as “ fifth optical system ”) is opposed to the fifth optical system 52 . referred to as "fourth reflecting mirror") 51 is provided, that is opposed to the fourth reflecting mirror 51 to the first end face of the third optical system 50 of A. The distance between the first direction end face of the third optical system 50 and the fourth reflecting mirror 51 is set to a predetermined distance of 10 mm or more. Even if the optical systems 50, 52, 54 and the reflecting mirrors 51, 53 are configured in this way, the remaining amount of toner in the toner storage chamber 15 a can be detected by the remaining toner detection sensor 43.

  FIG. 8 is a cross-sectional view showing another example of the developing unit shown in FIG. In the example shown in FIG. 2, the optical axes connecting the optical systems 46 and 47 are arranged so as to be substantially parallel to the first wall portion 15g. However, as shown in FIG. 1, the developing unit 14 a is inclined by a predetermined angle with respect to the bottom surface of the image forming apparatus 10 when facing the photosensitive drum 11. For this reason, in the example shown in FIG. 2, the optical systems 46 and 47 are connected even though the surface of the toner is substantially horizontal when the developing unit 14 a faces the photosensitive drum 11. The remaining amount of toner is detected with the optical axis tilted.

  Therefore, in the example shown in FIG. 8, when the developing unit 14a faces the photosensitive drum 11, the optical axis connecting the optical systems 46 and 47 is parallel to the toner surface. It is arranged so that the remaining amount of toner can be detected. As described above, the optical axis connecting the optical systems 46 and 47 with respect to the toner surface is predetermined with respect to the first wall 15g in a state where the toner surface is substantially horizontal in the toner storage chamber 15a. By disposing the optical systems 46 and 47 so as to have the angles, and detecting the remaining amount of toner, the remaining amount of toner can be detected more accurately.

  9 and 10 are diagrams illustrating examples of the stirring member. The agitating member 30 is obtained by providing, for example, a cylindrical agitating member shaft 30a having a diameter of 5 mm and an agitating blade 30b made of a PET film having a thickness of 100 μm, for example. The stirring blade 30b is formed to have a height of, for example, 15 mm and a width of 180 mm so as to extend along the axial direction of the stirring member shaft 30a, and a plurality of openings 30c and ribs 30d are alternately formed. Yes.

  The opening 30c is formed in, for example, a square shape having a length of 10 mm on one side, and the width dimension of the rib 30d is formed in, for example, 4 to 5 mm. The shape of the opening 30c is not limited to a quadrangle, and may be a rectangle, a trapezoid, or a triangle, or a trapezoid or a triangle that is alternately inverted upside down.

  As shown in FIG. 10, the length of the stirring blade 30b is shortened so that the stirring blade 30b does not cross the optical path between the first and second reflecting mirrors 48 and 49 shown in FIG. However, as shown in FIG. 9, a notch 30e is formed at one end of the stirring blade 30b so that the stirring blade 30b does not cross the optical path formed by the first and second reflecting mirrors 48 and 49. You may keep it. However, the locus at the time of rotation of the tip parallel to the axial direction of the stirring blade 30b protrudes above the optical path between the light-emitting diode 44 and the first optical system 46, thereby further increasing the toner surface on the detection surface. Can be parallel.

  When the pulverized toner, the amount of the external additive is small, or when operating in a high-temperature and high-humidity environment, it is preferable that the stirring force is large. Therefore, as shown in FIG. Even if the notch 30e is formed as shown in FIG. 9, it is preferable to leave a part of the stirring blade below the notch 30e.

  Here, as shown in FIG. 2, when the line connecting the optical axes formed by the first and second optical systems 46 and 47 is arranged so as to be parallel to the bottom surface of the developing container 15, as shown in FIG. As described above, the difference in the toner remaining amount detection level when the line connecting the optical axes formed by the first and second optical systems 46 and 47 is arranged in parallel to the bottom surface of the image forming apparatus 10 will be described.

  In the example shown in FIG. 2, when one side of the opening 30c of the stirring blade 30b is formed with a length of 12 mm, the average toner amount level indicating the amount of toner replenished in the toner storage chamber 15a is 40.5 g. As a result, the variation in the remaining toner detection level indicating that the remaining amount of toner has decreased is ± 3.4 g, and the variation in the remaining toner detection level between the colors is 5.3 g. When one side of the opening 30c of the stirring blade 30b is formed to have a length of 10 mm, assuming that the average toner amount level is 41.0 g, the variation in the remaining toner detection level is ± 5.2 g, The variation was too large to be detected. When one side of the opening 30c of the stirring blade 30b is formed with a length of 8 mm, assuming that the average toner amount level is 40.1 g, the variation in the remaining toner amount detection level is ± 9.6 g. The variation was too large to be detected.

  On the other hand, in the example shown in FIG. 8, when one side of the opening 30c of the stirring blade 30b is formed with a length of 12 mm, the average toner amount level is 42.7 g, and the remaining toner level detection level varies. Was ± 2.8 g, and the variation between colors was 3.0 g, and good results were obtained. That is, in the example shown in FIG. 2, the line connecting the optical axes of the first and second optical systems 46 and 47 is detected in a state inclined with respect to the surface of the toner, whereas FIG. In this example, since the line connecting the optical axes of the first and second optical systems 46 and 47 is detected in a state parallel to the surface of the toner, the variation in the remaining toner level can be reduced.

  In the example shown in FIG. 4, the removal blades 41 and 42 are rotated by the rotary rotor 40, but the removal blades 41 and 42 are attached to the stirring member shaft 30 a without the rotation rotor 40 and stirred. You may make it rotate with the blade | wing 30b.

  Further, as the toner used in the embodiment of the present invention, the circularity such as a polymerized toner having a high degree of circularity (fluorescence polarization immunoassay method: by FPIA) that is easy to obtain fluidity when stirred by the stirring blade 30b. Is preferably 0.930 to 0.995. Further, as the surface treatment for attaching the charging agent to the surface of the toner, it is preferable to add a large amount of external additive (silica) having a small change in fluidity due to durability.

  Further, in order to make the surface of the toner on the detection surface more parallel, a configuration in which a tip portion parallel to the axial direction of the stirring blade 30b protrudes from the detection surface is used, so that the wall surface in the developing device 14a and the stirring blade 30b are used. Since the stress caused by the toner increases, the stress applied to the toner also increases, and the factors that cause the external additive to be buried in the surface of the toner and the toner aggregation increase, but can be suppressed by using the above-mentioned toner.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

1 is a diagram schematically illustrating an example of a color image forming apparatus including a developing device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating details of a black developing unit illustrated in FIG. 1. FIG. 3 is an external perspective view of a developing unit illustrated in FIG. 2. FIG. 3 is a perspective view illustrating an internal optical system, a reflecting mirror, and a stirring member by opening an upper portion of a toner storage chamber of a developing unit illustrated in FIG. 2. It is a figure which shows the structure of a toner remaining amount detection sensor, an optical system, and a reflective mirror. FIG. 6 is a characteristic diagram showing the relationship between the distance between the light emitting side and the light receiving side of the toner remaining amount detection sensor shown in FIG. 5 and the signal output of the phototransistor. FIG. 6 is a diagram illustrating another example of an optical system and a reflecting mirror provided in a toner storage chamber. FIG. 10 is a cross-sectional view illustrating another example of the developing unit illustrated in FIG. 2. It is a figure which shows an example of a stirring member. It is a figure which shows the other example of a stirring member.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Image forming apparatus, 11 Photosensitive drum, 12 Laser scanning unit, 13 Charging member, 14 Rotary developing device, 14a Black (BK) developing part, 14b Magenta (M) developing part, 14c Cyan (C) developing part, 14d Yellow (Y) development section, 14f side wall, 15 developer container, 15a toner storage chamber, 15b roller storage chamber, 15d first opening, 15e second opening, 15f overfill prevention valve, 15g first wall 15h Second wall portion, 16 supply roller, 17 supply roller, 18 cleaning rubbing member, 19 cleaning device, 20 intermediate transfer belt, 21 primary transfer roller, 22 driving roller, 23 driven roller, 24 secondary transfer Roller, 25 paper feed cassette, 26 paper feed path, 27 fixing unit, 28 paper discharge path, 29 paper discharge tray , 30 Stirring member, 30a Stirring member shaft, 30b Stirring blade, 30c Opening, 30d Rib, 30e Notch, 33 Supply pipe, 34 Toner container, 35 Connecting portion, 40 Rotating roller, 41, 42 Removal blade, 43 Toner remaining Quantity detection sensor, 44 Light emitting diode, 45 Phototransistor, 46, 47, 50, 52, 54 Optical system, 48, 49, 51, 53 Reflector.

Claims (10)

A developing device capable of replenishing toner,
A toner storage chamber for storing the toner;
A stirring member that extends in the first direction in the toner storage chamber and is rotatably provided; and for stirring the toner;
An optical axis extends in parallel with the first direction, and a first rectilinear portion in which light from the outside is incident on one end and travels straight, and light that travels straight in the first rectilinear portion is in the first direction. A first reflecting portion that reflects in a direction crossing the first optical means, and is provided in the toner storage chamber;
A second reflecting portion that receives the light reflected by the first reflecting portion and reflects the light in the first direction; and the second reflecting portion that is provided in parallel to the first direction. A second rectilinear portion that linearly reflects the light reflected by the reflecting portion and emits the light from the other end to the outside of the toner storage chamber, and has a predetermined interval with respect to the first optical means in the toner storage chamber. Second optical means provided opposite to each other, and
The developing device, wherein an optical axis formed in parallel with the first direction by the first and second optical means is arranged so as not to overlap the stirring member. A developing device capable of replenishing toner,
A toner storage chamber for storing the toner;
A stirring member that extends in the first direction in the toner storage chamber and is rotatably provided; and for stirring the toner;
Third optical means having an optical axis extending parallel to the first direction, light from the outside is incident on one end, travels straight and is radiated from the other end, and is provided in the toner storage chamber;
A third reflecting portion for reflecting the light emitted from the third optical means in a direction intersecting the first direction, and the light reflected by the third reflecting portion goes straight from one end to the other end; A third rectilinear section, a fourth reflecting section for reflecting light that has traveled straight to the other end in the first direction so as to face the outside of the toner storage chamber, and a length longer than that of the third optical means. A fourth rectilinear portion that causes the light reflected by the fourth reflecting portion to travel straight and radiate out of the toner storage chamber, and has a predetermined interval with respect to the third optical means in the toner storage chamber. And a fourth optical means provided facing and spaced apart ,
The developing device, wherein the optical axes formed in parallel by the third and fourth optical means are arranged so as not to overlap the stirring member. The developing device according to claim 1 , wherein the predetermined distance between the first and second optical means is at least 10 mm or more. The developing device according to claim 2, wherein the predetermined distance between the third and fourth optical means is at least 10 mm or more. The toner storage chamber has a wall surface that is inclined at a predetermined angle with respect to the bottom surface of the apparatus when the remaining amount of toner is detected,
It said first and second optical hand surface thus formed on the stage has the predetermined angle with respect to the wall surface at the time of the toner remaining detecting developing device according to claim 1 or 3. The toner storage chamber has a wall surface that is inclined at a predetermined angle with respect to the bottom surface of the apparatus when the remaining amount of toner is detected,
5. The developing device according to claim 2, wherein a surface formed by the third and fourth optical units has the predetermined angle with respect to the wall surface when the toner remaining is detected. The stirring member, the shaft member extending in a first direction, and a blade member provided so as to extend in the first direction to the shaft member, a developing device according to any one of claims 1 to 6 . The developing device according to claim 7 , wherein the blade member is formed of a flexible material. The blade member has a trajectory at the time of rotation of the tip parallel to the first direction that intersects the first direction and the first direction with respect to the optical axes of the first and second optical means. The developing device according to claim 7, comprising a portion protruding in a third direction intersecting with the second direction. The blade member has a trajectory at the time of rotation of the tip parallel to the first direction in the first direction relative to the optical axis of the third optical means and the fourth rectilinear part of the fourth optical means. The developing device according to claim 7, further comprising a portion protruding in a third direction intersecting with the second direction intersecting with the first direction.

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