JP7039926B2 - Transport equipment, developing equipment, and image forming equipment - Google Patents

Description

The present invention relates to a transport device, a developing device, and an image forming device.

The developing apparatus of Patent Document 1 includes a developing container for accommodating a developing agent composed of a magnetic carrier and toner, and a transport screw for transporting a developing agent rotatably held in the developing container and supplied to a developing roller. There is. This developing device includes a toner concentration detecting means that detects the mixing ratio of the carrier and the toner in the developer conveyed by the rotation of the conveying screw and outputs the toner concentration detecting voltage. Further, the developing apparatus includes a scraping member installed between the outer peripheral portions of the screw blades constituting the transport screw for scraping the developer in the vicinity of the toner concentration detecting means.

Japanese Unexamined Patent Publication No. 2009-115862

An object of the present invention is to improve the concentration detection accuracy as compared with the case where the concentration is detected on the upstream side of the detection unit without giving vibration to the developer.

The invention of the first aspect is in a transport path in which the developer is transported, a transport member in which the spiral blades rotated in the transport path and forming an outer peripheral portion transport the developer, and the transport path. A detection unit that comes into contact with the developer to detect the concentration of the developer and a detection unit provided on the upstream side in the transport direction of the developer from the detection point by the detector, and extend from the inner surface of the transport path to the transport member side. It is a transport device including a vibrating member in which a free end is arranged between the blades and which vibrates with the rotation of the transport member.

The invention of the second aspect is the transport device according to the first aspect , wherein the vibration member extends from the inner surface located above the transport member toward the transport member side in the installed state.

The invention of the third aspect is the transport device according to the second aspect , wherein the vibrating member has an upper end portion fixed above a shaft portion constituting the central portion of the transport member.

In the invention of the fourth aspect , the vibrating member has a plate shape having the transport direction as the thickness direction, and the plate width in the direction intersecting the transport direction is longer than the outer diameter dimension of the shaft portion in the transport member. The transport device according to the third aspect .

In the invention of the fifth aspect , one side edge of the vibrating member is located on one side of the shaft portion of the transport member, and the other side edge of the vibrating member is located on the other side of the shaft portion of the transport member. The transport device according to the fourth aspect , which is located.

The invention of the sixth aspect is the transport device according to the first aspect , wherein the vibration member extends from the inner surface located on the side of the transport member to the transport member side in the installed state.

The invention of the seventh aspect is the sixth aspect in which the detection unit is provided on one side of the transport member as a boundary, and the vibration member is provided on the other side of the transport member as a boundary. The transport device described.

In the invention of the eighth aspect , the vibrating member has a plate shape having the transport direction as the thickness direction, and the plate width in the vertical direction is longer than the outer diameter dimension of the shaft portion constituting the central portion of the transport member . The transport device according to the seventh aspect .

In the invention of the ninth aspect , the upper edge of the vibrating member is located above the shaft portion of the transport member, and the lower edge of the vibrating member is located below the shaft portion of the transport member. The transport device according to the embodiment .

The tenth aspect of the invention is the transfer device according to any one of the third to fifth aspects , the eighth aspect , and the ninth aspect in which the vibration member is in contact with the shaft portion of the transfer member.

In the invention of the eleventh aspect , in the transport member, a stirring unit that stirs the developer with rotation is provided between the blades at a portion corresponding to the detection unit, and the transport member is the same. Any one of the third to fifth aspects , the eighth aspect , and the ninth aspect in which the stirring unit passes the developer on the detection unit side from the shaft portion from above the detection unit toward the detection unit side. It is a transport device according to.

The invention of the twelfth aspect is a developing device including the transport device according to any one of the first to eleventh aspects and a developing roll to which the developer transported by the transport device is transferred. ..

The invention of the thirteenth aspect is an image forming apparatus including a latent image holder and a developing device according to the twelfth aspect for developing a latent image on the latent image holder.

In the first aspect , the concentration detection accuracy can be improved as compared with the case where the concentration is detected on the upstream side of the detection unit without giving vibration to the developer.

In the second aspect , the durability of the vibrating member can be enhanced as compared with the case where the vibrating member extends from the inner surface on the side of the transport path.

In the third aspect , the developer can be vibrated at the center of the transport path.

In the fourth aspect , vibration can be applied in a wide range in the radial direction of the shaft portion as compared with the case where the vibrating member has a plate shape narrower than the outer diameter of the shaft portion of the transport member.

In the fifth aspect , the developer on both sides of the shaft portion can be vibrated as compared with the case where the side edge portion of the vibrating member extends only to one side from the shaft portion of the transport member.

In the sixth aspect , the portion where the vibrating member is located in the developer can be made larger than the case where the vibrating member extends from the inner surface above the transport path.

In the seventh aspect , the concentration detection accuracy can be improved as compared with the case where the vibrating member is provided on the inner surface on the side where the concentration detection unit is provided.

In the eighth aspect , vibration can be applied in a wide range as compared with the case where the vibrating member has a plate shape narrower than the outer diameter of the shaft portion of the transport member.

In the ninth aspect , the developer can be vibrated above and below the shaft portion as compared with the case where one edge portion of the vibrating member does not extend above or below the shaft portion of the transport member.

In the tenth aspect , the cissing noise can be reduced as compared with the case where the vibrating member does not come into contact with the shaft portion of the conveying member.

In the eleventh aspect , in a structure in which the stirring unit scrapes the developer toward the concentration detection unit, the concentration detection accuracy can be improved as compared with the case where the vibrating member is not provided.

In the twelfth aspect , development spots can be suppressed as compared with the case where the concentration is detected without giving vibration to the developer.

In the thirteenth aspect , image spots can be suppressed as compared with the case where the density is detected without giving vibration to the developer.

It is a block diagram which shows the image forming apparatus which concerns on 1st Embodiment. It is sectional drawing which shows the developing apparatus which concerns on 1st Embodiment. It is a perspective view which shows the developing apparatus which concerns on 1st Embodiment. It is a partial breakage figure which shows the main part of the transfer apparatus which concerns on 1st Embodiment. It is sectional drawing which follows the AA line of FIG. It is an enlarged view which shows the relationship between the stirring part and the concentration detection part of the transport member which concerns on 1st Embodiment. It is a figure which shows the toner carrier ratio in the comparative example. It is a figure which shows the toner carrier ratio in 1st Embodiment. It is a partial breakage figure which shows the main part of the transfer apparatus which concerns on 2nd Embodiment. 9 is a cross-sectional view taken along the line BB of FIG.

(First Embodiment)
Hereinafter, an example of the image apparatus according to the first embodiment will be described with reference to the drawings.

(overall structure)
As shown in FIG. 1, the image forming apparatus 1 according to the present embodiment is provided with an automatic document conveying device 2 on the upper part of the apparatus main body 1A, in which documents (not shown) are conveyed one by one in a separated state. Further, the image forming apparatus 1 includes an image reading device 3 that reads an image of a document conveyed by an automatic document conveying device 2 or placed on a platen glass (not shown).

The image forming apparatus 1 is an example of a recording medium in which an image forming unit 10 for forming a toner image developed by toner constituting a developer and a toner image formed by the image forming unit 10 are recorded inside the apparatus main body 1A. A transfer device 15 for transferring to the recording paper P is provided. Further, the image forming apparatus 1 receives a paper feeding device 50 that accommodates and conveys the required recording paper P to be supplied to the transfer position of the transfer device 15, and a toner image on the recording paper P transferred by the transfer device 15. It is provided with a fixing device 40 or the like for fixing. The device main body 1A is formed of a support structural member, an exterior cover, and the like.

The image forming unit 10 includes a rotating photoconductor drum 11 as an example of a latent image holder, and around the photoconductor drum 11, each device as an example of the following toner image forming means is provided. It is mainly placed. The main devices are a charging device 12 that charges the peripheral surface (image holding surface) capable of forming an image of the photoconductor drum 11 to a required potential, and image information (image information) on the charged peripheral surface of the photoconductor drum 11. An exposure device 13 as an example of an electrostatic latent image forming means that irradiates light based on a signal) to form an electrostatic latent image having a potential difference, and the electrostatic latent image is developed with toner of a developer to form a toner image. The developing device 14 as an example of the developing means, the transfer device 15 as an example of the transfer means for transferring the toner image to the recording paper P, and the photoconductor drum 11 remaining and adhering to the image holding surface after the transfer. A drum cleaning device 16 or the like that removes and cleans deposits such as toner.

The photoconductor drum 11 is formed with an image holding surface having a photoconducting layer (photosensitive layer) made of a photosensitive material on the peripheral surface of a cylindrical or columnar base material to be grounded. The photoconductor drum 11 is supported so as to be rotated in the direction indicated by the arrow A by transmitting power from a drive device (not shown).

The charging device 12 is composed of a contact-type charging roll arranged in contact with the photoconductor drum 11. A charging voltage is supplied to the charging device 12. As the charging voltage, when the developing device 14 performs reverse development, a voltage or current having the same polarity as the charging polarity of the toner supplied from the developing device 14 is supplied. Further, the charging device 12 is arranged so that the cleaning roll 121 for cleaning the surface of the charging device 12 comes into contact with the charging device 12. As the charging device 12, a non-contact type charging device such as a scorotron arranged on the surface of the photoconductor drum 11 in a non-contact state may be used.

The exposure device 13 is charged with light configured according to the image information of the document read by the image reading device 3 and the image information input from an external personal computer or the like to the image forming device 1. The peripheral surface of the photoconductor drum 11 is irradiated to form an electrostatic latent image. When the latent image is formed, the image information of the original read by the image reading device 3 and the image information (signal) input to the image forming device 1 by any means are transmitted to the exposure device 13.

The exposure device 13 irradiates the photoconductor drum 11 with light according to image information by LEDs (Light Emitting Diodes) as a plurality of light emitting elements arranged along the axial direction of the photoconductor drum 11 to perform an electrostatic latent image. It consists of an LED print head that forms the above. As the exposure apparatus 13, a device that deflects and scans a laser beam configured according to image information along the axial direction of the photoconductor drum 11 may be used.

As shown in FIG. 2, the developing apparatus 14 includes an apparatus housing 140 as an example of a developing container in which an opening and a storage chamber for the developing agent G are formed. The apparatus housing 140 includes a developing roll 141 that holds the developing agent G and conveys it to the developing region facing the photoconductor drum 11, and a feeding and conveying member 142 such as a screw auger that supplies the developing agent G to the developing roll 141 while stirring. And are provided.

The apparatus housing 140 is provided with a stirring and transporting member 143, which is an example of a transporting member such as a screw auger, which transports the developer G to and from the supply and transporting member 142 while stirring. Further, the apparatus housing 140 is provided with a layer thickness regulating member 144 that regulates the amount (layer thickness) of the developing agent G held on the developing roll 141, and the developing agent G includes a non-magnetic toner and a magnetic carrier. A two-component developer containing is used. The developing device 14 will be described in detail later.

As shown in FIG. 1, the transfer device 15 is a contact-type transfer device provided with a transfer roll that contacts and rotates around the photoconductor drum 11 and is supplied with a transfer voltage. As the transfer voltage, a DC voltage showing a polarity opposite to the charging polarity of the toner is supplied from a power supply device (not shown).

As shown in FIGS. 2 and 3, the drum cleaning device 16 comes into contact with the container-shaped main body 160 having a part of the lower end surface opened and the peripheral surface of the photoconductor drum 11 after transfer with a required pressure. A cleaning plate 161 that is arranged to remove residual toner and other deposits for cleaning, and a screw auger that collects the toner and other deposits removed by the cleaning plate 161 and transports them to the developing device 14 and a recovery system (not shown). It is composed of the delivery member 162 and the like. In this embodiment, the deposits such as toner removed by the cleaning plate 161 are collected and sent to the developing device 14 via the reuse device. As the cleaning plate 161, a plate-shaped member (for example, a cleaning blade) made of a material such as rubber is used.

As shown in FIG. 1, the fixing device 40 includes a belt-shaped or roll-shaped heating rotating body 41 that is heated by a heating means so that the surface temperature is maintained at a required temperature, and the heating rotating body 41. It is configured by arranging a rotating body 42 for pressurization in the form of a roll or a belt, which rotates in contact with a predetermined pressure in a state substantially along the axial direction. In the fixing device 40, the contact portion where the rotating body 41 for heating and the rotating body 42 for pressurization come into contact is a fixing process section for performing the required fixing process (heating and pressurization).

The paper feeding device 50 is arranged so as to exist at a position on the lower side of the image forming unit 10. The paper feeding device 50 is a single (or a plurality) paper accommodating body 51 that accommodates recording paper P of a desired size, type, etc. in a loaded state, and a sending device that sends out recording paper P one by one from the paper accommodating body 51. It is mainly composed of 52 and 53. The paper container 51 is attached so that it can be pulled out to the front side (side surface facing the user during operation) of the device main body 1A, for example.

Examples of the recording paper P include plain paper and OHP sheets used in electrophotographic copying machines, printers, and thin paper such as tracing paper. In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the recording paper P is as smooth as possible, for example, coated paper in which the surface of plain paper is coated with resin or the like, art paper for printing, or the like. So-called thick paper with a relatively large basis weight can also be used.

Between the paper feed device 50 and the transfer device 15, a single (or multiple) paper transfer roll pairs 54, 55 for transporting the recording paper P sent out from the paper feed device 50 to the transfer position, a transfer guide (not shown), or the like is used. A configured paper feed transfer path 56 is provided. The paper transport roll pair 55 is configured as, for example, a roll (resist roll) for adjusting the transport timing of the recording paper P.

Further, a paper transport path 57 for transporting the recording paper P after transfer, which is sent out from the transfer device 15, to the fixing device 40 is provided between the transfer device 15 and the fixing device 40. Further, in a portion close to the discharge port of the recording paper P formed in the apparatus main body 1A, the fixed recording paper P sent out from the outlet roll 43 of the fixing device 40 is provided in the paper ejection section on the upper part of the apparatus main body 1A. A paper ejection roll pair 59 for ejecting to 58 is arranged.

A switching gate (not shown) for switching the paper transport path is provided between the fixing device 40 and the paper ejection roll pair 59. The paper ejection roll pair 59 is configured so that the rotation direction thereof can be switched between the normal rotation direction (ejection direction) and the reverse rotation direction. When an image is formed on both sides of the recording paper P, after the rear end of the recording paper P on which the image is formed on one side passes through a switching gate (not shown), the rotation direction of the paper ejection roll pair 59 is the normal rotation direction ( Switch from the discharge direction) to the reverse direction.

The recording paper P, which is conveyed in the reverse direction by the paper ejection roll pair 59, has its transfer path switched by a switching gate (not shown), and is formed along the side surface of the apparatus main body 1A so as to be substantially vertical. Transported to 60. The double-sided transport path 60 includes a plurality of paper transport roll pairs 61 for transporting the recording paper P to the paper transport roll pair 55 with the front and back reversed, and a transport guide (not shown).

The fixing device 40 ejects the fixed recording paper P sent out from the outlet roll 43 of the fixing device 40 to the second paper for face-down ejection provided on the upper part of the apparatus main body 1A via the paper transport roll pair 62. A paper ejection roll pair 64 for ejecting to the unit 63 is provided at the upper part. Further, the fixing device 40 switches the transport direction by the switching gate 65 and discharges the fixed recording paper P to a third paper ejection unit 66 for face-up ejection provided on the upper side surface of the apparatus main body 1A. It has a paper ejection roll pair 67.

In FIG. 1, reference numeral 70 indicates a manual feed tray provided on the left side surface of the apparatus main body 1A of the image forming apparatus 1 so as to be openable and closable. Between the manual feed tray 70 and the paper transport roll pair 54, the transmission device 71 that feeds out the recording paper P contained in the manual feed tray 70 one by one and the recording paper P that is sent out by the delivery device 71 are separated one by one. Separation rolls 72 and the like are arranged.

Further, reference numeral 100 in FIG. 1 indicates a control device that comprehensively controls the operation of the image forming apparatus 1. The control device 100 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory) (not shown), a bus for connecting the CPU, the ROM, and the like, a communication interface, and the like.

<Operation of image forming device>
Hereinafter, the basic image forming operation by the image forming apparatus 1 will be described.

When the image forming apparatus 1 receives the command information of the request for the image forming operation (printing), the image forming unit 10, the transfer apparatus 15, the fixing apparatus 40, and the like are started. In addition, the image reading device 3 reads an image of a document (not shown) transported by the automatic document transporting device 2 or an image of a document (not shown) placed on the platen glass as needed along with the image forming operation.

Then, in the image forming unit 10, the photoconductor drum 11 first rotates in the direction indicated by the arrow A, and the charging device 12 charges the surface of the photoconductor drum 11 to a required polarity (negative polarity in the embodiment) and potential. Subsequently, the exposure device 13 converts the image information of the original read by the image reading device 3 and the image information input to the image forming device 1 into black and white components on the surface of the photoconductor drum 11 after charging. The light emitted based on the signal of the image obtained is irradiated, and an electrostatic latent image composed of a required potential difference is formed on the surface thereof.

Subsequently, the developing apparatus 14 supplies toner charged with a required polarity (minus polarity) from the developing roll 141 to the electrostatic latent image formed on the photoconductor drum 11 and electrostatically adheres the toner. Perform development. By this development, the electrostatic latent image formed on the photoconductor drum 11 is visualized as a monochrome toner image developed with black toner.

Subsequently, when the toner image formed on the photoconductor drum 11 of the image forming unit 10 is conveyed to the transfer position, the transfer device 15 transfers the toner image to the recording paper P.

Further, in the image forming unit 10 in which the transfer is completed, the drum cleaning device 16 cleans the surface of the photoconductor drum 11 by scraping off the deposits such as toner. As a result, the image forming unit 10 is in a state where the next image forming operation can be performed. The toner or the like scraped off by the drum cleaning device 16 is conveyed to the developing device 14 by the reusing device and used again for development.

On the other hand, in the paper feed device 50, the required recording paper P is sent out to the paper feed transfer path 56 in accordance with the developing operation. In the paper feed transport path 56, the paper transport roll pair 55 as a resist roll feeds and supplies the recording paper P to the transfer position in accordance with the transfer timing.

Subsequently, the recording paper P on which the toner image is transferred from the photoconductor drum 11 is conveyed to the fixing device 40 via a transfer guide (not shown). In the fixing device 40, necessary fixing treatment (heating and pressurization) is performed by introducing and passing the recording paper P after transfer into the contact portion between the rotating rotating body 41 for heating and the rotating body 42 for pressurization. To fix the unfixed toner image on the recording paper P. Finally, the recording paper P after the fixing is completed is the paper installed on the upper part of the apparatus main body 1A by the paper ejection roll pair 59 or the like when the image forming operation is only to form an image on one side of the recording paper P. It is discharged to the discharge unit 58 or the like.

When an image is formed on both sides of the recording paper P, the recording paper P having an image formed on one side is not ejected to the paper ejection unit 58 by the paper ejection roll pair 59, and the paper ejection roll pair 59 is the rear end of the recording paper P. The rotation direction of the paper ejection roll pair 59 is switched to the reverse direction while holding.

The recording paper P, which is conveyed in the reverse direction by the paper ejection roll pair 59, passes through a switching gate (not shown), and then has front and back sides via a double-sided transport path 60 provided with a paper transport roll pair 61, a transport guide (not shown), and the like. In the inverted state, the paper is conveyed again to the paper conveying roll pair 55. The paper transport roll pair 55 sends out the recording paper P to the transfer position at the transfer time and supplies it, forms an image on the back surface of the recording paper P, and installs it on the upper part of the apparatus main body 1A by the paper ejection roll pair 59 or the like. It is discharged to the paper ejection unit 58 or the like.

By the above operation, the recording paper P on which the monochrome image is formed is output.

<Structure of developing device>
FIG. 4 is an enlarged view showing a main part of the image forming unit 10 according to the present embodiment, and FIG. 5 is a cross-sectional view taken along the line AA of FIG.

The developing device 14 of the image forming unit 10 includes a device housing 140 as an example of a developing container. The device housing 140 is roughly classified into a lower housing 140A arranged at the lower part of the developing device 14 and an upper housing 140B arranged at the upper part of the developing device 14.

As shown in FIG. 5, a developer accommodating chamber 151 for accommodating a two-component developer G composed of a non-magnetic toner and a magnetic carrier is formed inside the apparatus housing 140. An opening 152 is provided in a region of the apparatus housing 140 facing the photoconductor drum 11. Inside the apparatus housing 140, a developing roll 141 as an example of a developer holder is rotatably arranged along the arrow B direction so that a part of the developing roll 141 is exposed to the opening 152.

The developing roll 141 is fixedly arranged inside, and includes a magnet roll 141A in which a plurality of magnetic poles having a required polarity are arranged at a required position along the circumferential direction. Further, the developing roll 141 has a developing sleeve 141B rotatably arranged on the outer periphery of the magnet roll 141A along the arrow B direction at a required rotational speed. The developing sleeve 141B is formed in a cylindrical shape by a non-magnetic material made of aluminum, non-magnetic stainless steel, or the like.

In the present embodiment, the rotation direction of the developing sleeve 141B is set to be opposite to the rotation direction of the photoconductor drum 11. That is, the rotation direction A of the photoconductor drum 11 is set in the clockwise direction, while the rotation direction B of the developing sleeve 141B is set in the counterclockwise direction. As a result, the outer peripheral surface of the developing sleeve 141B moves in the same direction as the moving direction of the surface of the photoconductor drum 11 in the developing region facing the photoconductor drum 11. The rotation direction of the developing sleeve 141B may be set in the same direction as the rotation direction of the photoconductor drum 11. In this case, the outer peripheral surface of the developing sleeve 141B moves in the direction opposite to the moving direction of the surface of the photoconductor drum 11 in the developing region facing the photoconductor drum 11.

Inside the apparatus housing 140, a supply transport member 142 made of a screw auger (supply auger) or the like that pumps up the developer G stored in the developer storage chamber 151 and supplies it to the developing roll 141 is diagonally below the developing roll 141. Is located in. The supply / transport member 142 is rotationally driven in the counterclockwise direction by a drive device (not shown). On the side surface of the developing roll 141, a cylindrical layer thickness regulating member 144 that regulates the amount (layer thickness) of the developing agent held on the developing roll 141 is arranged.

Inside the device housing 140, a stirring and transporting member 143 made of a screw auger (admix auger) or the like that transports the developer G supplied to the inside of the device housing 140 while stirring is located on the back surface side of the supply and transporting member 142. Have been placed. The stirring and transporting member 143 is also rotationally driven in the clockwise direction by a driving device (not shown).

As a result, the image forming unit 10 is formed with a conveying device 300 for conveying the developer G.

The supply transport member 142 and the agitation transport member 143 have the same basic structure. Here, the configuration of the stirring and transporting member 143 will be described as a representative.

As shown in FIGS. 4 and 5, the stirring and transporting member 143 is an example of a blade that is integrally provided spirally on the outer periphery of the shaft portion 143A formed in a cylindrical shape and the shaft portion 143A. It is equipped with 143B.

As shown in FIG. 6, in the supply transport member 142 and the stirring transport member 143, the pitch L of the transport blades 143B is set to be equal to or smaller than the diameter d of the density detection unit 172 of the toner concentration sensor 170 described later, and in the present embodiment, The pitch L is smaller than the diameter d.

As shown in FIG. 5, the lower housing 140A has a substantially semi-cylindrical cross section at the bottom for accommodating the supply transport member 142 and the stirring transport member 143 for transporting the developer G, and has a first transport path 302 and a first transport path. (2) The transport path 304 is formed. The first transport path 302 and the second transport path 304 are partitioned by a partition wall 155 provided in the lower housing 140A.

The length of the supply transfer member 142 and the stirring transfer member 143 along the axial direction is set to be longer than that of the developing roll 141. Both ends of the supply transport member 142 and the agitation transport member 143 are rotatably supported by the lower housing 140A. As shown in FIG. 3, a supply portion 158 formed in a square cylinder shape is provided on the device housing 140 so as to project from one end of the stirring and transporting member 143 in the axial direction. A supply port 158A for dropping the developer G supplied from the toner cartridge into the inside of the apparatus housing 140 and supplying the developer G is opened in the supply unit 158.

The partition wall 155 of the apparatus housing 140 (see FIG. 5) is provided with openings at both ends in the longitudinal direction thereof, and the first transport path 302 and the second transport path 304 partitioned by the partition wall 155 are provided. It is possible to transfer the developer G between them. As a result, at one end of the apparatus housing 140, a first passage portion 156 for transferring the developing agent G from the first transport path 302 to the second transport path 304 is provided. Further, at the other end of the apparatus housing 140, a second passage portion 157 for transferring the developing agent G from the second transport path 304 to the first transport path 302 is provided (the position is shown in FIG. 3). ).

As shown in FIG. 3, the developer G conveyed while being stirred from the right side to the left side in FIG. 3 by the stirring transfer member 143 and conveyed to the axial end portion is passed through the first passage portion 156. It is transported to the supply transport member 142 side. The developer G is supplied to the developing roll 141 while being transported from the left to the right in FIG. 3 by the supply and transport member 142.

The developer G transported to the end along the axial direction by the supply transport member 142 is transported to the stirring transport member 143 side via the second passage portion 157 and circulates and moves. Further, the toner supplied from the supply port 158A to the inside of the apparatus housing 140 is stirred with the developer G contained in the apparatus housing 140 while being conveyed by the stirring and conveying member 143.

As shown in FIG. 5, a toner concentration sensor 170 is provided inside the device housing 140 as an example of a concentration detection unit that detects the toner concentration of the developer G contained in the device housing 140. There is.

The toner concentration sensor 170 has a sensor body 171 formed in a substantially elongated flat rectangular parallelepiped shape, and a density detection unit 172 formed so as to project from one side surface of the sensor body 171 into a cylindrical shape.

As shown in FIG. 3, the toner concentration sensor 170 is located inside the second transport path 304 near the end of the downstream side KR along the transport direction S of the developer G of the stirring transport member 143. It is arranged on the upstream side JR of the first passage portion 156.

The toner concentration sensor 170 detects the magnetic permeability of the developer G composed of the non-magnetic toner and the magnetic carrier, measures the amount of the magnetic carriers, and detects the toner concentration of the developer G from the ratio occupied by the magnetic carriers.

Further, as shown in FIG. 5, the toner concentration sensor 170 has a connection portion between the side surface 154B of the lower housing 140A forming the second transport path 304 and the bottom surface 154C formed in an arcuate cross section, in FIG. It is arranged within the range from the 3 o'clock position to the 6 o'clock position.

More specifically, an opening 154A is provided at a connecting portion between the side surface 154B of the lower housing 140A forming the second transport path 304 and the bottom surface 154C formed in an arcuate cross section. A cylinder portion 154D extends outward from the opening edge portion of the opening portion 154A, and the density detection portion 172 of the toner concentration sensor 170 is inserted and fixed in the cylinder portion 154D.

The concentration detection unit 172 is configured so that the end surface 172A is exposed on the inner surface of the second transport path 304, and the end surface 172A of the concentration detection unit 172 comes into contact with the developer G in the second transfer path 304 to bring the developer. The concentration of G can be detected.

Further, the stirring and transporting member 143 is integrally provided with a plate-shaped stirring member 173 that stirs the developer G as the stirring and transporting member 143 rotates at a position corresponding to the concentration detection unit 172 of the toner concentration sensor 170. Has been done.

As shown in FIG. 6, the stirring member 173 is integrally provided in parallel along the axial direction of the stirring and transporting member 143 between adjacent transporting blades 143B along the axial direction of the stirring and transporting member 143. It is composed of a flat plate.

The drive gear of the supply transfer member 142 and the drive gear of the agitation transfer member 143 are configured to mesh with each other without interposing an idle gear in order to reduce the size, and the rotation direction of the agitation transfer member 143 is determined. Therefore, as shown in FIG. 5, in the stirring and transporting member 143, the developer G on the concentration detection unit 172 side from the shaft portion 143A is directed by the stirring member 173 from the UP above the concentration detection unit 172 to the concentration detection unit 172 side. And the developer G is scraped down to the concentration detection unit 172 side and stirred.
As a result, the developer G located in front of the density detection unit 172 of the toner concentration sensor 170 is agitated, and the developer G is suppressed from adhering (fixing) to the density detection unit 172 of the toner concentration sensor 170.

As shown in FIG. 4, an upper vibration member 310 is provided on the upstream side JR in the transport direction S of the developer G from the detection location by the density detection unit 172 of the toner density sensor 170. As shown in FIG. 5, the upper vibration member 310 extends from the top surface 140B1 which is an example of the inner surface of the upper housing 140B constituting the inner surface of the second transfer path 304 toward the stirring transfer member 143 side. The upper vibrating member 310 is arranged between the transport blades 143B of the stirring and transporting member 143, and constitutes a vibrating member that vibrates with the rotation of the stirring and transporting member 143.

The upper vibrating member 310 is arranged on the upstream side from the toner concentration sensor 170 so that the region where the tip of the free end of the vibrating member vibrates due to the spiral blades of the transport member does not cover the toner concentration sensor position. Specifically, it is provided on the upstream side by 10 mm with reference to the central portion of the density detection unit 172 of the toner concentration sensor 170.

The upper vibrating member 310 may have a rod shape as long as it vibrates with the rotation of the stirring and transporting member 143, but in the present embodiment, a plate-shaped member can be mentioned as an intermediate concept thereof. And, as the subordinate concept, a flat plate and a film can be mentioned.

Further, when the upper vibrating member 310 is captured from multiple surfaces, a cantilever member having one end fixed and a leaf spring having one end fixed and a free end swingable can be mentioned.

Examples of the material of this plate-shaped member include PET (polyethylene-terephthalate), and one example thereof is Mylar of DuPont. The plate thickness of the upper vibrating member 310 is preferably 0.1 mm to 1 mm, and is 1 mm as an example.

As shown in FIG. 4, the upper vibrating member 310 is formed in an L shape, and a fixed piece 312 to be fixed on the top surface 140B1 and a hanging piece 314 hanging from the fixed piece 312 are formed. ing. As a result, in the installed state in which the image forming unit 10 is installed in the image forming apparatus 1, the hanging piece 314 of the upper vibrating member 310 faces from the top surface 140B1 of the upper housing 140B toward the stirring and conveying member 143 side. It extends and is inserted into the developer G.

As shown in FIG. 5, the hanging piece 314 of the upper vibrating member 310 is provided above the shaft portion 143A constituting the central portion of the stirring and transporting member 143. Further, in the hanging piece 314 of the upper vibrating member 310, the transport direction S is the plate thickness direction, and the plate width W in the direction intersecting the transport direction S is longer than the outer diameter dimension D of the shaft portion 143A in the stirring transport member 143. It has a width dimension.

The one side edge 314A of the hanging piece 314 of the upper vibrating member 310 is located on the supply transport member 142 side, which is one side of the shaft portion 143A of the stirring transport member 143. Further, the other side edge 314B of the hanging piece 314 is located on the opposite side of the supply transport member 142, which is the other side of the shaft portion 143A of the stirring transport member 143. Further, the hanging piece 314 of the upper vibrating member 310 has a length in which the lower edge 314C is in contact with the shaft portion 143A of the stirring and transporting member 143 in a state of being arranged between the transporting blades 143B of the stirring and transporting member 143.

<Operation of developing device>
As shown in FIG. 2, the developing apparatus 14 according to the present embodiment has the developing agent G charged with a required polarity (minus polarity) with respect to the electrostatic latent image formed on the peripheral surface of the photoconductor drum 11. Toner, which is an example, is supplied from the developing roll 141 and electrostatically adhered to perform development. By this development, the electrostatic latent image formed on the photoconductor drum 11 is visualized as a monochrome toner image developed with the black developer G.

At that time, the developer G housed in the apparatus housing 140 of the developing device 14 supplies the developing agent G from the developing roll 141 to the electrostatic latent image formed on the peripheral surface of the photoconductor drum 11 and is static. The developer G is consumed with the developing process of electrically adhering. The toner concentration of the developer G housed in the apparatus housing 140 is detected by the toner concentration sensor 170 arranged on the downstream side KR of the developer G in the stirring transfer member 143 in the transfer direction S.

When the control device 100 determines that the toner concentration of the developer G in the device housing 140 detected by the toner concentration sensor 170 is less than the required threshold value, the control device 100 supplies toner from the toner cartridge to the inside of the device housing 140. The toner supplied to the inside of the apparatus housing 140 is conveyed to the downstream side KR by the conveying blade 143B of the stirring and conveying member 143, and is housed inside the apparatus housing 140 by the stirring member 173 provided in the conveying blade 143B. Stir with developer G.

(Action / effect)
Next, the operation of this embodiment will be described.

An upper vibrating member 310 is provided on the upstream side JR in the transport direction S of the developer G from the detection location by the concentration detecting unit 172 of the toner concentration sensor 170, and the lower end portion of the hanging piece 314 of the upper vibrating member 310 stirs. It is arranged between the transport blades 143B of the transport member 143. Therefore, when the stirring and transporting member 143 rotates, the hanging piece 314 of the upper vibrating member 310 hits the transporting blade 143B of the stirring and transporting member 143 and gets over the transporting blade 143B.

Then, the hanging piece 314 of the upper vibrating member 310 vibrates in the length direction of the stirring and transporting member 143 each time it gets over the transporting blade 143B. As a result, the drooping piece 314 can give vibration (roughness amplitude) to the developer G and stabilize the fluidity of the developer G in front of the toner concentration sensor 170. At this time, the hanging piece 314 can stir the developer G, and in the case of the developer G that is about to become a lump, the lump can be broken.

Therefore, it is possible to improve the concentration detection accuracy as compared with the case where the concentration detection accuracy is structurally low because the concentration is detected without giving vibration to the developer G.

Here, in the present embodiment, the following factors can be mentioned as factors that reduce the density detection accuracy of the toner density sensor 170.

First, due to the structure in which the developer G in front of the concentration detection unit 172 is stirred by the stirring member 173 of the stirring and transporting member 143, the fluidity (transportability) of the developing agent G is lowered in the upstream JR of the concentration detecting unit 172. , A difference in the concentration of the developer G is generated with the stirring member 173 as a boundary.

Secondly, since the stirring and transporting member 143 scrapes the developer G from above the concentration detecting unit 172 toward the concentration detecting unit 172 by the stirring member 173, the concentration of the developing agent G increases in front of the concentration detecting unit 172. It will increase.

On the other hand, as a known structure, the following can be mentioned as factors that reduce the density detection accuracy of the toner density sensor 170.

In a known structure that widens the space between the stirring member 173 and the concentration detecting unit 172 in order to suppress the interference between the stirring member 173 and the concentration detecting unit 172, the fluidity of the developer G in the space is reduced and erroneous detection tends to occur. Will be. In order to solve this problem, a configuration has been devised in which the stirring member 173 is made of an elastic body and is brought into contact with the concentration detection unit 172. Is likely to occur, and maintainability becomes an issue.

Therefore, in the present embodiment, the density of the developer G can be made uniform by giving the developer G a coarse-dense amplitude with the upper vibrating member 310. Thereby, even if it has the above-mentioned configuration, the density detection accuracy by the toner density sensor 170 can be improved.

Then, the development spots can be suppressed as compared with the case where the density is detected without giving vibration to the developer G of the developing apparatus 14. Further, in the image forming apparatus 1, image spots can be suppressed as compared with the case where the density is detected without giving vibration to the developer G.

The present embodiment has a reuse device (reclaim mechanism) (not shown) that returns the toner recovered from the photoconductor drum 11 to the image forming unit 10, and the deposits on the photoconductor drum 11 are added to the developer G as contaminants. Can be mixed. Even when the bulk density of the developer G increases due to an external contaminant or the like, the state of the developer G in the concentration detection unit 172 of the toner concentration sensor 170 can be stably controlled, and the detection accuracy becomes high. Is improved.

The upper vibrating member 310 extends downward from the upper UP of the second transport path 304 toward the stirring transport member 143 side in the installed state.

Therefore, the distance from the fixed end to the free end of the hanging piece 132B can be increased and the durability can be improved as compared with the case where the vibrating member extends from the side surface 154B side of the second transport path 304.

The upper vibrating member 310 is provided above the shaft portion 143A constituting the central portion of the stirring and transporting member 143.

Therefore, the developer G can be vibrated at the center of the second transport path 304 as compared with the case where the upper vibration member 310 is provided at a position deviated from the shaft portion 143A of the stirring and transport member 143. ..

Further, the upper vibrating member 310 has a plate shape in which the plate width W in the direction intersecting the transport direction S has a width dimension longer than the outer diameter dimension D of the shaft portion 143A in the stirring transport member 143.

Therefore, vibration can be applied in a wide range as compared with the case where the upper vibrating member 310 has a plate shape narrower than the outer diameter dimension D of the shaft portion 143A of the stirring and transporting member 143.

The one side edge 314A of the upper vibrating member 310 is located on one side of the shaft portion 143A of the stirring and transporting member 143, and the other side edge 314B of the upper vibrating member 310 is on the other side of the shaft portion 143A of the stirring and transporting member 143. Located in.

Therefore, the developer G on both sides of the shaft portion 143A can be vibrated as compared with the case where the side edge portion of the upper vibrating member 310 extends only to one side from the shaft portion 143A of the stirring and transporting member 143. ..

Further, the hanging piece 314 of the upper vibrating member 310 is in contact with the shaft portion 143A of the stirring and transporting member 143 in a state where the lower edge 314C is arranged between the transporting blades 143B of the stirring and transporting member 143.

Therefore, the repetitive vibration of the upper vibrating member 310 can be suppressed and the cissing noise can be reduced as compared with the case where the upper vibrating member 310 does not come into contact with the shaft portion 143A of the stirring and transporting member 143.

The stirring and transporting member 143 is a transporting blade 143B in which the stirring member 173, which is an example of the stirring unit that stirs the developer G with rotation, is a portion corresponding to the toner concentration sensor 170 concentration detection unit 172 and is formed in a spiral shape. It is provided between. Further, in the stirring and transporting member 143, the developing agent G on the concentration detecting section 172 side from the shaft portion 143A is moved from above the concentration detecting section 172 to the concentration detecting section 172 side by the stirring member 173 provided between the transporting blades 143B. Squeeze it toward and stir.

In such a structure, as described above, the stirring member 173 of the stirring and transporting member 143 scrapes the developer G toward the concentration detection unit 172, so that the concentration of the developer G increases in front of the concentration detection unit 172. , Concentration detection accuracy tends to decrease.

As described above, in the structure in which the stirring member 173 scrapes the developer G toward the concentration detection unit 172, the concentration detection accuracy can be improved as compared with the case where the upper vibration member 310 is not provided.

At this time, in order to improve the detection accuracy by the toner concentration sensor 170, an idle gear is added to reverse the stirring and transporting member 143, and the developer G is reduced in size and cost as compared with the case where the developer G is rotated in the scraping direction. Can be planned.

(Detection result in comparative example)
FIG. 7 is a diagram showing the detection result by the toner concentration sensor 170 in the transport device not provided with the upper vibrating member, and shows the ratio of the toner and the carrier of the actual developer G (actual TC) and the toner concentration sensor 170. The ratio of the detected toner to the carrier (detection TC) is shown.

TC down indicates the change when the toner ratio is decreased, and TC up indicates the change when the toner ratio is increased. Further, the TC return indicates a change when the toner ratio is decreased and then increased and then returned.

In this comparative example, when the ratio of the actual toner to the carrier (actual TC) is 10% or more, the toner and the carrier detected by the toner concentration sensor 170 from the ratio of the actual toner to the carrier (actual TC). It can be seen that the ratio with (detection TC) appears low.

(Detection result in the embodiment)
On the other hand, FIG. 8 is a diagram showing the detection result by the toner concentration sensor 170 in the transport device 300 of the present embodiment provided with the upper vibrating member 310, and shows the ratio of the actual toner to the carrier (actual TC) and the toner. The ratio of the toner and the carrier detected by the density sensor 170 (detection TC) is shown.

Similar to the above, TC down indicates the change when the toner ratio is decreased, and TC up indicates the change when the toner ratio is increased. Further, the TC return indicates a change when the toner ratio is decreased and then increased and then returned.

In the present embodiment, the ratio of the actual toner to the carrier (actual TC) and the ratio of the toner to the carrier detected by the toner concentration sensor 170 (detection TC) are TC down, TC up, and TC return. In all cases, the error is smaller than that of the comparative example.

(Second embodiment)
9 and 10 are diagrams showing the second embodiment, and the same or equivalent parts as those in the first embodiment are designated by the same reference numerals, the description thereof will be omitted, and different parts will be described.

In the transfer device 300 according to the image forming unit 10 of the image forming apparatus 1 according to the present embodiment, as compared with the first embodiment, the vibration member that imparts vibration to the developer G with the rotation of the stirring transfer member 143 is provided. The fixed position is different.

That is, the transfer device 300 includes a side vibration member 320 that applies vibration to the developer G in the second transfer path 304.

The side vibrating member 320 has a plate shape, and the material thereof is PET (polyethylene-terephthalate), and an example thereof is Mylar of DuPont. The plate thickness of the side vibrating member 320 is preferably 0.1 mm to 1 mm, and is 0.1 mm as an example.

As shown in FIG. 9, the side vibrating member 320 is formed in an L shape by the fixed piece 322 and the extending piece 324 extending from the edge of the fixed piece 322. As shown in FIGS. 9 and 10, the fixed piece 322 of the side vibrating member 320 is fixed to the inner surface 155A of the partition wall 155 located on the opposite side of the concentration detection unit 172 of the toner concentration sensor 170. The extension piece 324 of the side vibration member 320 extends from the inner surface 155A of the partition wall 155 toward the stirring and transporting member 143 in the installed state in which the image forming unit 10 is installed in the image forming apparatus 1.

The side vibrating member 320 has a plate-like shape in which the plate width W in the vertical direction intersecting the transport direction S has a width dimension longer than the outer diameter dimension D of the shaft portion 143A constituting the central portion of the stirring transport member 143. be. In the side vibration member 320, the lower edge portion is inserted into the developer G, and the lower edge 324A of the extension piece 324 is located below the shaft portion 143A of the stirring and transporting member 143.

The upper edge 324B of the extension piece 324 of the side vibrating member 320 is located above the shaft portion 143A of the stirring and transporting member 143, and the upper edge portion of the extension piece 324 extends above the developer G. Further, the side vibrating member 320 has a length in which the tip edge 324C of the extension piece 324 is in contact with the shaft portion 143A of the stirring and transporting member 143.

Even in the present embodiment, the same operation and effect as in the first embodiment can be obtained except for the effect when the vibrating member is in the upper UP.

Further, the side vibration member 320 extends from the inner surface 155A of the partition wall 155 to the stirring and transporting member 143 side in the installed state.

Therefore, the portion located in the developer G can be made larger than the case where the vibrating member extends from above the inner surface of the second transport path 304.

Further, the side vibration member 320 is provided on the inner surface 155A of the partition wall 155 located on the opposite side of the inner surface portion where the density detection unit 172 of the toner concentration sensor 170 is provided.

Therefore, as compared with the case where the side vibration member 320 is provided on the side surface 154B where the concentration detection unit 172 is provided, the influence on the detection by the toner concentration sensor 170 can be suppressed and the concentration detection accuracy can be improved. can.

Further, the side vibrating member 320 has a plate width W in the vertical direction in the direction intersecting the transport direction S, which is longer than the outer diameter dimension D of the shaft portion 143A constituting the central portion of the stirring transport member 143. It is a shape.

Therefore, the side vibration member 320 can vibrate in a wide range as compared with the case where the side vibration member 320 has a plate shape narrower than the outer diameter of the shaft portion 143A of the stirring and transporting member 143.

The upper edge 324B of the extension piece 324 of the side vibration member 320 is located above the shaft portion 143A of the stirring transfer member 143, and the lower edge 324A of the extension piece 324 of the side vibration member 320 is the stirring transfer member 143. It is located below the shaft portion 143A of.

Therefore, the developer G vibrates above and below the shaft portion 143A as compared with the case where one edge of the side vibration member 320 does not extend above or below the shaft portion 143A of the stirring and transporting member 143. Can be given.

In each embodiment, the fixed pieces 312 and 322 of the L-shaped vibrating members 310 and 320 were fixed to the wall surface, and the hanging piece 314 and the extension piece 324 were extended toward the stirring and transporting member 143. However, it is not limited to this. For example, the hanging piece 314 or the extending piece 324 may be extended directly from the wall surface toward the stirring and transporting member 143.

1 Image forming device 11 Photoconductor drum 14 Developing device 100 Control device 140 Device housing 140A Lower housing 140B Upper housing 140B1 Top surface 141 Development roll 143 Stirring transport member 143A Shaft 143B Transport blade 154B Side 154C Bottom 154D Cylinder 155 Partition wall 170 Toner concentration sensor 172 Concentration detector 173 Stirring member 300 Conveying device 304 Second transport path 310 Upper vibrating member 312 Fixed piece 314 Hanging piece 314A One side edge 314B Other side edge 314C Lower edge 320 Side vibrating member 322 Fixed piece 324 Extension Piece 324A Lower edge 324B Upper edge 324C Tip edge G Developer JR Upstream side KR Downstream side W Plate width

Claims (13)

The transport path where the developer is transported and
A transport member whose spiral blades, which are rotated in the transport path and form the outer peripheral portion, transport the developer,
A detector that detects the concentration of the developer in contact with the developer in the transport path within the transport range of the transport member .
It is provided in the transport range on the upstream side in the transport direction of the developer from the detection point by the detection unit, extends from the inner surface of the transport path to the transport member side, and a free end is arranged between the blades. A vibrating member that vibrates with the rotation of the transport member, and
A transport device equipped with. The transport device according to claim 1, wherein the vibrating member extends from the inner surface located above the transport member toward the transport member side in the installed state. The transport device according to claim 2, wherein the vibrating member has an upper end portion fixed above a shaft portion constituting the central portion of the transport member. The transport according to claim 3, wherein the vibrating member has a plate shape having the transport direction as a thickness direction, and the plate width in a direction intersecting the transport direction is longer than the outer diameter dimension of the shaft portion in the transport member. Device. The fourth aspect of claim 4, wherein one side edge of the vibrating member is located on one side of the shaft portion of the transport member, and the other side edge of the vibrating member is located on the other side of the shaft portion of the transport member. Conveyor device. The transport device according to claim 1, wherein the vibrating member extends from the inner surface located on the side of the transport member to the transport member side in the installed state. The transport device according to claim 6, wherein the detection unit is provided on one side of the transport member as a boundary, and the vibration member is provided on the other side of the transport member as a boundary. The transport device according to claim 7, wherein the vibrating member has a plate shape having the transport direction as the thickness direction, and the plate width in the vertical direction is longer than the outer diameter of the shaft portion constituting the central portion of the transport member. .. The transport device according to claim 8, wherein the upper edge of the vibrating member is located above the shaft portion of the transport member, and the lower edge of the vibrating member is located below the shaft portion of the transport member. The transport device according to any one of claims 3, 5, 8, and 9, wherein the vibrating member is in contact with the shaft portion of the transport member. In the transport member, a stirring unit that stirs the developer as it rotates is provided at a portion corresponding to the detection unit and is provided between the blades.
The transport member has claims 3 to 5, 8 and 8 in which the stirring unit passes the developer on the detection unit side from the shaft unit from above the detection unit toward the detection unit. The transport device according to any one of claims 9. The transport device according to any one of claims 1 to 11.
A developing roll to which the developer transported by the transport device is transferred, and
A developing device equipped with. Latent image holder and
The developing apparatus according to claim 12, which develops a latent image on the latent image holder.
An image forming apparatus equipped with.

Images