JP4363135B2 - Liquid developing device, image forming apparatus, and image forming system - Google Patents

Description

  The present invention relates to a liquid developing device, an image forming apparatus, and an image forming system.

  As this type of image forming apparatus, for example, a photoconductor as an example of an image carrier for carrying a latent image and a latent image carried on the photoconductor by a liquid developer (hereinafter also simply referred to as a developer). There is known an image forming apparatus having a liquid developing device for developing an image. Such an image forming apparatus forms a latent image on a photoreceptor when an image signal or the like is transmitted from an external device such as a host computer. Then, the latent image formed and carried on the photosensitive member reaches the developing position as the photosensitive member rotates, and is developed by the liquid developing device, so that a developer image is formed on the photosensitive member.

  The above liquid developing device includes a holding roller for holding the liquid developer supplied to the developer carrying member in order to realize the above-described function of developing the latent image formed on the photoreceptor. A conveying roller for conveying the liquid developer to the holding roller, an amount regulating member for regulating the amount of the liquid developer on the holding roller, and an accommodating portion for accommodating the liquid developer, have.

In such a liquid developing device, the amount of the liquid developer that is transported from the container to the holding roller by the transport roller and is held by the holding roller is regulated by the quantity regulating member, and then supplied to the developer carrier. . Then, the liquid developer supplied to the developer carrying member is used for developing the latent image.
JP 2001-282002 A

  By the way, in the above liquid developing device, when the transport roller transports the liquid developer to the holding roller, the liquid developer may get over the amount regulating member.

  For example, when the transport roller is positioned below the amount regulating member, the liquid developer is raised by viscosity when the transport roller transports the liquid developer to the holding roller, and the container is a separate member. From the gap between the charging member and the charging member, the raised liquid developer may get over the amount regulating member. Alternatively, when the transport roller transports the liquid developer, the liquid developer scatters, so that the splattered liquid developer gets over the amount regulating member from the gap between the housing portion and the charging member which is another member. Sometimes. In addition, when the transport amount of the liquid developer by the transport roller is large, the liquid developer can easily get over the amount regulating member.

  The present invention has been made in view of such a problem, and an object of the present invention is to ensure that the liquid developer gets over the amount regulating member when the conveying roller conveys the liquid developer to the holding roller. Is to prevent.

The main present invention comprises a developer carrying member for carrying a liquid developer having an elastic layer,
Pressed against the developer carrying member, a holding roller for holding the liquid developer supplied to the developer carrying member,
A transport roller for transporting the liquid developer to the holding roller;
A regulating blade for regulating the amount of liquid developer on the holding roller by the trail regulation ;
In a liquid developing device having a storage portion for storing a liquid developer,
A center axis of the transport roller is below a rotation center axis of the holding roller, and the developer carrier is provided above the transport roller,
A lower portion of the transport roller is immersed in the liquid developer accommodated in the accommodating portion;
There is a gap between the back surface of the regulating blade and the accommodating portion,
A groove is provided on the surface of the holding roller,
Of the four quadrants divided by a first coordinate axis that passes vertically through the center of the holding roller and a second coordinate axis that passes through the center of the holding roller and extends horizontally from the left side to the right side of the first coordinate axis,
When the transport roller is located in the third quadrant, the regulation blade is located in the first quadrant,
When the transport roller is located in the fourth quadrant, the regulating blade is located in the second quadrant.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  According to the present invention, when the transport roller transports the liquid developer to the holding roller, it is possible to reliably prevent the liquid developer from getting over the amount regulating member.

  At least the following will be made clear by the description of the present specification and the accompanying drawings.

A holding roller for holding the liquid developer supplied to the developer carrier, a conveying roller for conveying the liquid developer to the holding roller, and the amount of the liquid developer on the holding roller are regulated. In a liquid developing device having an amount regulating member for accommodating a housing portion for housing a liquid developer,
Of the four quadrants divided by a first coordinate axis that passes vertically through the center of the holding roller and a second coordinate axis that passes through the center of the holding roller and extends horizontally from the left side to the right side of the first coordinate axis, When the transport roller is located in the third quadrant, the amount restricting member is located in the first quadrant, and when the transport roller is located in the fourth quadrant, the amount restricting member is the second quadrant. A liquid developing device, which is located in a quadrant.

  According to such a liquid developing device, when the transport roller transports the liquid developer to the holding roller, it is possible to reliably prevent the liquid developer from getting over the amount regulating member.

In the liquid developing device, the upper end of the transport roller may be positioned above the lower end of the holding roller in the vertical direction.
When the amount of the liquid developer stored in the storage portion is small, the upper end of the transport roller is higher than the lower end of the holding roller than when the upper end of the transport roller is located below the lower end of the holding roller. The position of the liquid developer is more advantageous in conveying the liquid developer to the holding roller.

In the liquid developing device, the amount regulating member may include a contact portion that contacts the surface of the holding roller and a support portion that supports the contact portion.
Since the amount regulating member abuts the surface of the holding roller and the amount of the liquid developer on the holding roller is regulated, when the liquid developer gets over the amount regulating member and adheres to the amount regulating member, It becomes difficult for the amount regulating member to properly regulate the amount of the liquid developer on the holding roller. Therefore, the effect of the present invention, that is, the effect that the liquid developer can be surely prevented from getting over the amount regulating member when the transport roller transports the liquid developer to the holding roller, is more effectively achieved. Is done.

In the liquid developing device, the abutting portion abuts the surface of the holding roller at one end, and the one end of the abutting portion is positioned above the other end in the vertical direction. It is good to be.
The amount regulating member may perform so-called trail regulation in which one end of the abutting portion that abuts on the surface of the holding roller is positioned above the other end of the abutting portion. However, with this trail restriction, the liquid developer can easily get over the amount restriction member via the other end of the contact portion. Therefore, the effect of the present invention, that is, the effect that the liquid developer can be surely prevented from getting over the amount regulating member when the transport roller transports the liquid developer to the holding roller, is more effectively achieved. Is done.

In the liquid developing device, the developer carrying member is provided in the liquid developing device, the developer carrying member is a developing roller, and the rotation direction of the developing roller is the rotation of the holding roller. The conveyance roller may be positioned in the fourth quadrant, and the amount regulating member may be positioned in the second quadrant.
When the liquid developing device is configured as described above, it is possible to reliably prevent the liquid developer from getting over the amount regulating member when the conveying roller conveys the liquid developer to the holding roller.

In the liquid developing device, the rotation direction of the transport roller may be the same direction as the rotation direction of the holding roller.
According to such a liquid developing device, when the conveying roller conveys the liquid developer to the holding roller, the conveying roller and the holding roller rub against each other, so that the liquid developer conveyed by the conveying roller adheres to the holding roller. It becomes easy.

In the liquid developing apparatus, the liquid developer may be a non-volatile liquid developer that is non-volatile at normal temperature.
When the liquid developer is a non-volatile liquid developer, the high-viscosity liquid developer clings to the conveyance roller, so that the conveyance roller may convey a large amount of the liquid developer. When the transport roller transports a large amount of liquid developer to the holding roller, the possibility that the liquid developer gets over the amount regulating member is further increased. Therefore, the effect of the present invention, that is, the effect that the liquid developer can be surely prevented from getting over the amount regulating member when the transport roller transports the liquid developer to the holding roller, is more effectively achieved. Is done.

Further, a holding roller for holding the liquid developer supplied to the developer carrier, a conveying roller for conveying the liquid developer to the holding roller, and an amount of the liquid developer on the holding roller In a liquid developing device having an amount regulating member for regulating, and an accommodating portion for accommodating a liquid developer,
Of the four quadrants divided by a first coordinate axis that passes vertically through the center of the holding roller and a second coordinate axis that passes through the center of the holding roller and extends horizontally from the left side to the right side of the first coordinate axis, When the transport roller is located in the third quadrant, the amount restricting member is located in the first quadrant, and when the transport roller is located in the fourth quadrant, the amount restricting member is the second quadrant. Located in the quadrant,
The upper end of the conveying roller is positioned above the lower end of the holding roller in the vertical direction,
The amount regulating member includes a contact portion that contacts the surface of the holding roller, and a support portion that supports the contact portion.
The abutting portion abuts the surface of the holding roller at one end thereof, and the one end of the abutting portion is positioned above the other end in the vertical direction,
The developer carrying member is provided in the liquid developing device, the developer carrying member is a developing roller, and the rotation direction of the developing roller is opposite to the rotation direction of the holding roller, The transport roller is located in the fourth quadrant, the amount regulating member is located in the second quadrant,
The rotation direction of the transport roller is the same as the rotation direction of the holding roller,
It is also possible to realize a liquid developing device in which the liquid developer is a non-volatile liquid developer that is non-volatile at normal temperature.

An image carrier for carrying the latent image; a holding roller for holding the liquid developer supplied to the developer carrier; and a conveying roller for conveying the liquid developer to the holding roller; And an amount regulating member for regulating the amount of the liquid developer on the holding roller, and an accommodating portion for accommodating the liquid developer, and the liquid developer carried on the developer carrier An image forming apparatus comprising: a liquid developing device that develops a latent image carried on the image carrier.
Of the four quadrants divided by a first coordinate axis that passes vertically through the center of the holding roller and a second coordinate axis that passes through the center of the holding roller and extends horizontally from the left side to the right side of the first coordinate axis, When the transport roller is located in the third quadrant, the amount restricting member is located in the first quadrant, and when the transport roller is located in the fourth quadrant, the amount restricting member is the second quadrant. An image forming apparatus characterized by being located in a quadrant can also be realized.

Furthermore, a computer and an image forming apparatus connectable to the computer, an image carrier for carrying a latent image, and a holding roller for holding a liquid developer supplied to the developer carrier A conveying roller for conveying the liquid developer to the holding roller, an amount regulating member for regulating the amount of the liquid developer on the holding roller, and an accommodating portion for accommodating the liquid developer, An image forming apparatus comprising: a liquid developing device that develops a latent image carried on the image carrier by a liquid developer carried on the developer carrier. ,
Of the four quadrants divided by a first coordinate axis that passes vertically through the center of the holding roller and a second coordinate axis that passes through the center of the holding roller and extends horizontally from the left side to the right side of the first coordinate axis, When the transport roller is located in the third quadrant, the amount restricting member is located in the first quadrant, and when the transport roller is located in the fourth quadrant, the amount restricting member is the second quadrant. An image forming system characterized by being located in the quadrant can also be realized.

=== Overview of Image Forming Apparatus ===
Next, an outline of a laser beam printer (hereinafter also referred to as a printer) 10 as an example of the image forming apparatus will be described with reference to FIG. FIG. 1 is a diagram illustrating main components constituting the printer 10. In FIG. 1, the vertical direction is indicated by arrows. For example, the developing units 50Y, 50M, 50C, and 50K, which are examples of the liquid developing device, are disposed at the lower part of the printer 10 and are intermediate transfer members. Reference numeral 70 denotes an upper part of the printer 10.

<<< Overall Configuration of Image Forming Apparatus >>>
As shown in FIG. 1, the printer 10 according to the present embodiment includes four developing units 15Y, 15M, 15C, and 15K, an intermediate transfer member 70, a secondary transfer unit 80, and a fixing unit (not shown). The display unit includes a liquid crystal panel that serves as an informing means for the user, and a control unit 100 (FIG. 2) that controls these units and operates as a printer.

  The developing units 15Y, 15M, 15C, and 15K are latent in yellow (Y) developer, magenta (M) developer, cyan (C) developer, and black (K) developer, respectively, as an example of a liquid developer. It has a function of developing an image. Since the developing units 15Y, 15M, 15C, and 15K have the same configuration, the developing unit 15Y will be described below.

  As shown in FIG. 1, the developing unit 15Y includes a charging unit 30Y, an exposure unit 40Y, a developing unit 50Y, a primary transfer unit 60Y, a charge eliminating unit 73Y, and a photoreceptor cleaning unit 75Y along the rotation direction of the photoreceptor 20Y. is doing.

  The photoreceptor 20Y has a cylindrical base material and a photosensitive layer formed on the outer peripheral surface thereof, and is rotatable about a central axis. In the present embodiment, as shown by an arrow in FIG. Rotate clockwise.

  The charging unit 30Y is a device for charging the photoconductor 20Y, and the exposure unit 40Y is a device for forming a latent image on the photoconductor 20Y charged by irradiating a laser. The exposure unit 40Y has a semiconductor laser, a polygon mirror, an F-θ lens, and the like, and charges the modulated laser based on an image signal input from a host computer (not shown) such as a personal computer or a word processor. Irradiation is performed on the photoconductor 20Y.

  The developing unit 50Y is a device for developing the latent image formed on the photoreceptor 20Y using a yellow (Y) developer. Details of the developing unit 50Y will be described later.

  The primary transfer unit 60Y is a device for transferring the yellow developer image formed on the photoreceptor 20Y to the intermediate transfer body 70. When the four color developers are sequentially transferred by the primary transfer units 60Y, 60M, 60C, and 60K, a full color developer image is formed on the intermediate transfer member 70.

The intermediate transfer member 70 is an endless belt stretched around a plurality of support rollers, and is driven to rotate while contacting the photoreceptors 20Y, 20M, 20C, and 20K.
The secondary transfer unit 80 is a device for transferring a single color developer image or a full color developer image formed on the intermediate transfer body 70 to a medium such as paper, film, or cloth.

A fixing unit (not shown) is a device for fusing a single color developer image or a full color developer image transferred onto a medium onto a medium such as paper to form a permanent image.
The neutralization unit 73Y is a device that removes residual charges on the photoreceptor 20Y after the developer image is transferred onto the intermediate transfer body 70 by the primary transfer unit 60Y.

  The photosensitive member cleaning unit 75Y has a rubber photosensitive member cleaning blade 76Y that is in contact with the surface of the photosensitive member 20Y. After the developer image is transferred onto the intermediate transfer member 70 by the primary transfer unit 60Y, the photosensitive member cleaning unit 75Y is photosensitive. This is a device for scraping and removing the developer remaining on the body 20Y by the photoreceptor cleaning blade 76Y.

  As shown in FIG. 2, the control unit 100 includes a main controller 101 and a unit controller 102. An image signal and a control signal are input to the main controller 101, and in response to a command based on the image signal and the control signal. A unit controller 102 controls each of the units and forms an image.

<<< Operation of Image Forming Apparatus >>>
Next, the operation of the printer 10 configured as described above will be described with reference to other components.

  First, when an image signal and a control signal from a host computer (not shown) are input to the main controller 101 of the printer 10 via the interface (I / F) 112, the unit controller 102 based on a command from the main controller 101. Under the control, the photoconductors 20Y, 20M, 20C, and 20K, the developing rollers (described later) provided in the developing units 50Y, 50M, 50C, and 50K, the intermediate transfer body 70, and the like rotate. The photoconductors 20Y, 20M, 20C, and 20K are sequentially charged by the charging units 30Y, 30M, 30C, and 30K at the charging positions while rotating.

  The charged regions of the photoconductors 20Y, 20M, 20C, and 20K reach the exposure position as the photoconductors 20Y, 20M, 20C, and 20K rotate, and are exposed to yellow Y and magenta by the exposure units 40Y, 40M, 40C, and 40K. A latent image corresponding to the image information of M, cyan C, and black K is formed in the area.

  The latent images formed on the photoreceptors 20Y, 20M, 20C, and 20K reach the development position as the photoreceptors 20Y, 20M, 20C, and 20K rotate, and are developed by the development units 50Y, 50M, 50C, and 50K. . As a result, developer images are formed on the photoreceptors 20Y, 20M, 20C, and 20K.

  The developer images formed on the photoconductors 20Y, 20M, 20C, and 20K reach the primary transfer position as the photoconductors 20Y, 20M, 20C, and 20K rotate, and are transferred by the primary transfer units 60Y, 60M, 60C, and 60K. Then, it is transferred to the intermediate transfer body 70. At this time, a primary transfer voltage having a polarity opposite to the charging polarity of the developer is applied to the primary transfer units 60Y, 60M, 60C, and 60K. As a result, the four color developer images formed on the respective photoconductors 20Y, 20M, 20C, and 20K are transferred to overlap with the intermediate transfer member 70, and a full color developer image is formed on the intermediate transfer member 70. Is done.

  The full color developer image formed on the intermediate transfer member 70 reaches the secondary transfer position as the intermediate transfer member 70 rotates, and is transferred to the medium by the secondary transfer unit 80. The medium is transported from a paper feed tray (not shown) to the secondary transfer unit 80 via various rollers (the arrows in FIG. 1 indicate the transport direction of the medium). When performing the transfer operation, the secondary transfer unit 80 is pressed against the intermediate transfer body 70 and a secondary transfer voltage is applied.

The full color developer image transferred to the medium is heated and pressed by the fixing unit and fused to the medium.
On the other hand, the photoreceptors 20Y, 20M, 20C, and 20K are neutralized by the neutralization units 73Y, 73M, 73C, and 73K after passing the primary transfer position, and further supported by the photoreceptor cleaning units 75Y, 75M, 75C, and 75K. The developer adhering to the surface is scraped off by the photoconductor cleaning blades 76Y, 76M, 76C, and 76K to prepare for charging to form the next latent image. The developer that has been scraped off is collected in a remaining developer collecting section provided in the photoreceptor cleaning units 75Y, 75M, 75C, and 75K.

=== Overview of Control Unit ===
Next, the configuration of the control unit 100 will be described with reference to FIG. The main controller 101 of the control unit 100 is connected to a host computer via an interface 112 and includes an image memory 113 for storing image signals input from the host computer.

  The unit controller 102 includes units (charging units 30Y, 30M, 30C, and 30K, exposure units 40Y, 40M, 40C, and 40K, developing units 50Y, 50M, 50C, and 50K, primary transfer units 60Y, 60M, and 60C, and the like. 60K, static elimination units 73Y, 73M, 73C, 73K, photoconductor cleaning units 75Y, 75M, 75C, 75K, secondary transfer unit 80, fixing unit, display unit), and signals from sensors included in these , Each unit is controlled based on a signal input from the main controller 101 while detecting the state of each unit.

=== Overview of Development Unit ===
Next, the outline of the developing unit will be described with reference to FIG. FIG. 3 is a cross-sectional view showing main components of the developing unit. FIG. 4 is a view showing an example of the shape of the developer scooping roller 540. FIG. 5 is a perspective conceptual view showing the surface of the developer supply roller 550. FIG. 6A is a cross-sectional view showing that the groove 550a provided on the surface of the developer supply roller 550 has a trapezoidal cross section. FIG. 6B is a cross-sectional view showing that the groove 550a provided on the surface of the developer supply roller 550 has an inverted triangular cross section. FIG. 6C is a cross-sectional view showing that the groove 550a provided on the surface of the developer supply roller 550 has a semicircular cross section.
In FIG. 3, the vertical direction is indicated by arrows as in FIG. 1. For example, the developing roller 510 is above the developer pumping roller 540. In FIG. 3, the Y axis is an example of a first coordinate axis that passes vertically through the center 550 </ b> C of the developer supply roller 550, and the X axis passes through the center 550 </ b> C of the developer supply roller 550. It is an example of the 2nd coordinate axis which goes to the right side from. In FIG. 3, I, II, III, and IV indicate the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant (the same applies to FIGS. 9 to 11).

<<< Development Unit Configuration >>>
The printer 10 includes, as developing units, a black developing unit 50K containing black (K) developer, a magenta developing unit 50M containing magenta (M) developer, and a cyan developing unit 50C containing cyan (C) developer. , And a yellow developing unit 50Y containing a yellow (Y) developer is provided. Since each developing unit has the same configuration, the yellow developing unit 50Y will be described below.

  The yellow developing unit 50Y is an example of a developing roller 510 that is an example of a developer carrying member, a developer containing unit 530 that is an example of a containing unit, a developer pumping roller 540 that is an example of a conveying roller, and an example of a holding roller. A developer supply roller 550, a regulation blade 560 which is an example of an amount regulation member, and a development roller cleaning unit 570 are provided.

  The developer storage unit 530 stores a developer D for developing the latent image formed on the photoconductor 20Y. The developer D accommodated in the developer accommodating portion 530 is a low-concentration (about 1 to 2 wt%) and low-viscosity volatile material using Isopar (trademark: exon) as a carrier, which is generally used conventionally. It is not a liquid developer but a non-volatile liquid developer D having a high concentration and high viscosity. That is, the liquid developer D according to the present embodiment has a high concentration of toner particles made of resin, pigment, and the like having an average particle diameter of about 0.1 to 5 μm in a non-volatile and insulating carrier liquid such as silicone oil ( Developer D having a high viscosity (about 100 to 10,000 mPa · s) dispersed in about 5 to 40 wt%.

  The developer pump-up roller 540 pumps up the developer D stored in the developer storage unit 530 and conveys it to the developer supply roller 550. The lower part of the developer pumping roller 540 is immersed in the developer D accommodated in the developer accommodating portion 530, and is separated from the developer supply roller 550 with a width of about 1 mm.

  Further, the developer scooping roller 540 can rotate around its central axis, and the central axis is below the rotational central axis of the developer supply roller 550. Further, the developer scooping roller 540 is rotated in the same direction (clockwise in FIG. 3) as the rotation direction of the developer supply roller 550 (in FIG. 3, the direction passing through the second quadrant following the third quadrant, ie, the clockwise direction). ). The developer pump-up roller 540 has a function of pumping up the developer D stored in the developer storage section 530 and transporting it to the developer supply roller 550, and developing the developer D in an appropriate state. It also has a function of stirring the agent D.

  Further, as shown in FIG. 4, the developer pumping roller 540 is provided with two screws 542 a and 542 b having different winding directions on the roller shaft 541. The two functions of the developer pumping roller 540 are more effectively exhibited by the screws 542a and 542b.

  Further, as shown in FIG. 3, the developer pumping roller 540 is located in the fourth quadrant IV, and the upper end 540T of the developer pumping roller is positioned above the lower end 550U of the developer supply roller in the vertical direction. Yes.

  The developer supply roller 550 supplies the developer D conveyed from the developer container 530 by the developer pumping roller 540 to the developing roller 510. The developer supply roller 550 is obtained by uniformly and spirally forming grooves 550a as shown in FIG. 5 on the surface of a metallic roller such as iron and nickel plating, and the diameter thereof is about 25 mm. A plurality of the spiral grooves 550a are provided on the surface of the developer supply roller 550 at a predetermined interval. The developer supply roller 550 in the present embodiment includes a groove 550a having a trapezoidal cross section as shown in FIG. 6A as the groove, for example, a groove having an inverted triangular cross section as shown in FIG. 6B. Or a groove having a semicircular cross section as shown in FIG. 6C. As shown in FIG. 6A, the groove dimensions of the developer supply roller 550 in the present embodiment are a groove pitch of about 170 μm, a peak width of about 45 μm, a valley width of about 30 μm, and a groove depth of about 50 μm.

  Further, the developer supply roller 550 is in pressure contact with the developing roller 510 in order to appropriately transfer the developer D on the developer supplying roller 550 to the developing roller 510. Further, the developer supply roller 550 can rotate around its central axis, and the central axis is below the rotation central axis of the developing roller 510. Further, the developer supply roller 550 rotates in a direction (clockwise in FIG. 3) opposite to the rotation direction of the developing roller 510 (counterclockwise in FIG. 3).

  The regulating blade 560 is in contact with the surface of the developer supply roller 550 and regulates the amount of the developer D on the developer supply roller 550. That is, the regulation blade 560 plays a role of scraping off the excess developer D on the developer supply roller 550 and measuring the developer D on the developer supply roller 550 supplied to the development roller 510.

  The regulation blade 560 includes a rubber portion 561 that is an example of a contact portion that contacts the surface of the developer supply roller 550, and a rubber support portion 562 that is an example of a support portion that supports the rubber portion 561. ing. The rubber part 561 is made of urethane rubber, and the rubber hardness is approximately 62 degrees according to JIS-A. The rubber support portion 562 is a metal plate such as iron.

  The rubber part 561 is in contact with the surface of the developer supply roller 550 at one end 561a of the rubber part. The regulating blade 560 performs so-called edge regulation because the edge of the rubber portion 561 is in contact with the developer supply roller 550.

  Furthermore, the regulation blade 560 is located in the second quadrant II as shown in FIG. The regulating blade 560 performs so-called trail regulation because one end 561a of the rubber portion is positioned above the other end 561b of the rubber portion in the vertical direction. In the present embodiment, the trail angle is about 10 degrees.

  Further, there is a gap (A in FIG. 3) between the back surface of the regulating blade 560 and the developer accommodating portion 530. As described above, since the developer scooping roller 540 is located in the fourth quadrant IV and the regulating blade 560 is located in the second quadrant II, when the developer scooping roller 540 conveys the developer D, the gap (A in FIG. 3), it is possible to reliably prevent the developer D from getting over the regulating blade 560.

  The developing roller 510 carries the developer D and conveys it to the developing position facing the photoconductor 20Y in order to develop the latent image carried on the photoconductor 20Y with the developer D. The developing roller 510 includes a conductive elastic layer on the outer peripheral portion of an inner core made of metal such as iron, and has a diameter of about 20 mm. The elastic body layer has a two-layer structure. As the inner layer, urethane rubber having a rubber hardness of about 30 degrees JIS-A and a thickness of about 5 mm is used, and as the surface layer (outer layer), the rubber hardness is JIS. -A urethane rubber having a thickness of about 30 μm at about 85 degrees A is provided. The developing roller 510 is in elastic deformation and is in pressure contact with the developer supply roller 550 and the photoreceptor 20Y.

  Further, the developing roller 510 can rotate around its central axis, and the central axis is below the rotational central axis of the photoconductor 20Y. Further, the developing roller 510 rotates in a direction (counterclockwise in FIG. 3) opposite to the rotation direction of the photoreceptor 20Y (clockwise in FIG. 3). When developing the latent image formed on the photoconductor 20Y, an electric field is formed between the developing roller 510 and the photoconductor 20Y.

  The developing roller cleaning unit 570 has a rubber developing roller cleaning blade 571 in contact with the surface of the developing roller 510, and the developer D remaining on the developing roller 510 after development is performed at the developing position. Is scraped off by the developing roller cleaning blade 571 and removed.

<<< Development Unit Operation >>>
In the yellow developing unit 50Y configured as described above, the developer scooping roller 540 rotates around its central axis, thereby scooping up the developer D accommodated in the developer accommodating portion 530 and developing developer supply roller 550. Transport to.

  The developer D conveyed to the developer supply roller 550 reaches the contact position of the regulating blade 560 by the rotation of the developer supply roller 550. Then, when passing through the contact position, the excess amount of the developer D is scraped off by the regulating blade 560, and the amount of developer D supplied to the developing roller 510 is measured. In other words, since the developer supply roller 550 is provided with the groove 550a as described above, the regulating blade 560 that contacts the developer supply roller 550 causes the developer D on the developer supply roller 550 to pass through the groove 550a. The remaining developer D is scraped off. Further, since the dimension of the groove 550a is determined so that the developer D supplied to the developing roller 510 becomes an appropriate amount, when the regulating blade 560 scrapes off the developer D on the developer supplying roller 550. In this case, the developer D measured in an appropriate amount by the groove 550a remains in the groove 550a.

  The developer D remaining in the groove 550a of the developer supply roller 550 reaches a pressure contact position with the development roller 510 by further rotation of the developer supply roller 550, and from the developer supply roller 550 to the development roller at the pressure contact position. Transferred to 510. The developer D in the groove 550a is stretched by the action of pressure generated by the developer supply roller 550 and the developing roller 510 being brought into pressure contact during the transfer, so that the uniform development is performed on the developing roller 510. A thin film of agent D will be formed.

  The thin film of developer D formed on the developing roller 510 in this way reaches the developing position (that is, the pressure contact position with the photoconductor 20Y) facing the photoconductor 20Y by the rotation of the developing roller 510, and the development The latent image formed on the photoconductor 20Y is subjected to development at a position under an electric field of a predetermined magnitude.

  The developer D on the developing roller 510 that has passed the developing position reaches the contact position of the developing roller cleaning blade 571 as the developing roller 510 further rotates. When passing through the contact position, the developer D attached to the surface of the developing roller 510 is scraped off by the developing roller cleaning blade 571, and the developer D thus scraped off is removed from the developing roller cleaning unit. It is collected in a residual developer collecting unit provided in 570.

=== Effect of Overriding Effect of Liquid Developer Amount Control Member ===
As described above, in the printer 10 according to the present embodiment, the developer scooping roller 540 is located in the fourth quadrant (IV in FIG. 3), and the regulating blade 560 is located in the second quadrant (II in FIG. 3). ing. Thereby, when the developer pumping roller 540 conveys the developer D to the developer supply roller 550, it is possible to reliably prevent the developer D from getting over the regulating blade 560.

  That is, as described in the section of the problem to be solved by the invention, when the developer scooping roller 540 transports the developer D to the developer supply roller 550, the developer D may get over the regulation blade 560. .

  For example, when the developer pumping roller 540 is positioned below the regulating blade 560, the developer pumping roller 540 develops the developer D as shown in FIG. When transported to the developer supply roller 550, the developer D is raised due to the viscosity, and the developer D that has risen from the gap between the developer container 530 and the restriction blade 560, which is a separate member, causes the restriction blade 560 to rise. I sometimes get over it. Alternatively, when the developer pump-up roller 540 transports the developer D, the developer D scatters, so that the developer scatters from the gap between the developer container 530 and the regulating blade 560 which is a separate member. D may get over the regulating blade 560. In addition, when the amount of developer D transported by the developer scooping roller 540 is large, the developer D can more easily get over the regulation blade 560. FIG. 7 is a diagram for explaining a comparative example.

  Further, the developer D that has passed over the regulating blade 560 may adhere to the developer supply roller 550. In this case, even if the amount is regulated to an appropriate amount by the regulation blade 560, the developer D adheres onto the developer supply roller 550, so that the developer D held on the developer supply roller 550 The amount will change.

  Therefore, when the developer scooping roller 540 is located in the fourth quadrant (IV in FIG. 3), it is assumed that the regulating blade 560 is located in the second quadrant (II in FIG. 3). As a result, the developer pumping roller 540 and the regulating blade 560 are positioned in quadrants that are in the most distant positional relationship. Therefore, when the developer pumping roller 540 transports the developer D to the developer supply roller 550. Further, it is possible to reliably prevent the developer D from getting over the regulating blade 560.

  In the above-described series of descriptions, the case where the developer scooping roller 540 is located in the fourth quadrant (IV in FIG. 3) and the regulation blade 560 is located in the second quadrant (II in FIG. 3) has been described. However, the above-described effect is also achieved when the developer pumping roller 540 is located in the third quadrant (III in FIG. 3) and the regulating blade 560 is located in the first quadrant (I in FIG. 3). .

  From the above, the above-described problem, that is, the problem that the developer D may get over the regulating blade 560 when the developer pumping roller 540 transports the developer D to the developer supply roller 550 can be solved. It becomes possible.

=== Other Embodiments ===
The image forming apparatus and the like according to the present invention have been described above based on the above embodiment. However, the above embodiment of the present invention is for facilitating understanding of the present invention and limits the present invention. is not. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.

  The present invention provides a holding roller (for example, developer supply roller 550) for holding a liquid developer (for example, developer D) supplied to a developer carrier (for example, developing roller 510), and the holding roller. A transport roller (for example, a developer scooping roller 540) for transporting the liquid developer, and an amount regulating member (for example, a regulating blade 560) for regulating the amount of the liquid developer on the holding roller; The present invention relates to a liquid developing device (for example, development units 50Y, 50M, 50C, and 50K) having a storage section (for example, a developer storage section 530) for storing a liquid developer.

In the above embodiment, the intermediate transfer type full-color laser beam printer has been described as an example of the image forming apparatus. However, the present invention is not limited to this.
For example, the present invention can be applied to a full color laser beam printer other than the intermediate transfer type. Further, it is applicable not only to a full color laser printer but also to a monochrome laser beam printer. Further, it is applicable not only to a printer but also to various image forming apparatuses such as a copying machine and a facsimile.

In the above-described embodiment, the photoconductor has been described as a configuration in which a photosensitive layer is provided on the outer peripheral surface of a cylindrical conductive base material. However, the present invention is not limited to this.
For example, a so-called photosensitive belt configured by providing a photosensitive layer on the surface of a belt-like conductive substrate may be used.

In the above embodiment, the developer pumping roller 540 is provided with two screws 542a and 542b having different winding directions on the roller shaft 541 as shown in FIG. It is not limited to.
For example, the developer pump-up roller 540 may be provided with a blade portion 543 on the roller shaft 541 as shown in FIGS. 8A and 8B. 8A is a front view showing an example of the shape of the developer scooping roller 540. FIG. FIG. 8B is a top view showing the developer scooping roller 540 shown in FIG. 8A.

Further, in the above-described embodiment, as shown in FIG. 3, the upper end 540T of the developer pumping roller is positioned above the lower end 550U of the developer supply roller in the vertical direction. It is not limited.
For example, the upper end 540T of the developer pumping roller may be positioned below the lower end 550U of the developer supply roller in the vertical direction.
When the amount of the developer D accommodated in the developer accommodating portion 530 is small, the developer scooping roller is higher than when the upper end 540T of the developer scooping roller is located below the lower end 550U of the developer supply roller. In the case where the upper end 540T of the toner is positioned above the lower end 550U of the developer supply roller, it is advantageous in terms of conveying the developer D to the developer supply roller 550.
Therefore, the above embodiment is more desirable.

Further, in the above embodiment, the regulation blade 560 includes the rubber part 561 that contacts the surface of the developer supply roller 550 and the rubber support part 562 that supports the rubber part 561. However, the present invention is not limited thereto. Is not to be done.
For example, the regulating blade 560 may not contact the surface of the developer supply roller 550.
However, when the rubber part 561 comes into contact with the surface of the developer supply roller 550, the regulating blade 560 comes into contact with the surface of the developer supply roller 550 so that the developer on the developer supply roller 550 is in contact with the rubber part 561. Since the amount of D is regulated, if the developer D gets over the regulation blade 560 and adheres to the regulation blade 560, it is difficult for the regulation blade 560 to properly regulate the amount of the developer D on the developer supply roller 550. It becomes. Therefore, the effect of the present invention, that is, the effect that the developer D can be surely prevented from getting over the regulating blade 560 when the developer pumping roller 540 transports the developer D to the developer supply roller 550. , Is played more effectively.
Therefore, the above embodiment is more desirable.

Further, in the above embodiment, as shown in FIG. 3, the rubber part 561 abuts the surface of the developer supply roller 550 at one end 561a of the rubber part, and in the vertical direction, one end 561a of the rubber part is Although it has been located above the other end 561b of the rubber part, it is not limited to this.
For example, as shown in FIG. 9, one end 561a of the rubber part may be positioned below the other end 561b of the rubber part. FIG. 9 is a cross-sectional view showing main components of a developing unit according to another embodiment.
The regulation blade 560 may perform so-called trail regulation in which one end 561a of the rubber portion that contacts the surface of the developer supply roller 550 is positioned above the other end 561b of the rubber portion. However, with this trail restriction, the developer D easily gets over the restriction blade 560 via the other end 561b of the rubber part. Therefore, the effect of the present invention, that is, the effect that the developer D can be surely prevented from getting over the regulating blade 560 when the developer pumping roller 540 transports the developer D to the developer supply roller 550. , Is played more effectively.
Therefore, the above embodiment is more desirable.

Furthermore, in the above embodiment, the developer carrier is provided in the development units 50Y, 50M, 50C, and 50K, and the developer carrier is the development roller 510, and the rotation direction of the development roller 510 is The developer supply roller 550 is opposite to the rotation direction, the developer pumping roller 540 is located in the fourth quadrant (IV in FIG. 3), and the regulating blade 560 is located in the second quadrant (II in FIG. 3). However, the present invention is not limited to this.
For example, as shown in FIG. 10, the rotation direction of the developing roller 510 is the same as the rotation direction of the developer supply roller 550, and the developer pumping roller 540 is located in the third quadrant (III in FIG. 3). The regulating blade 560 may be located in the first quadrant (I in FIG. 3). FIG. 10 is a cross-sectional view showing main components of a developing unit according to another embodiment.

Furthermore, in the above embodiment, the rotation direction of the developer scooping roller 540 is the same as the rotation direction of the developer supply roller 550, but the present invention is not limited to this.
For example, as shown in FIG. 11, the rotation direction of the developer pumping roller 540 may be opposite to the rotation direction of the developer supply roller 550. FIG. 11 is a cross-sectional view showing main components of a developing unit according to another embodiment.
However, if the rotation direction of the developer pumping roller 540 is the same as the rotation direction of the developer supply roller 550, when the developer pumping roller 540 transports the developer D to the developer supply roller 550, Since the developer pumping roller 540 and the developer supply roller 550 rub against each other, the developer D conveyed by the developer pumping roller 540 is likely to adhere to the developer supply roller 550.
Therefore, the above embodiment is more desirable.

Furthermore, in the above-described embodiment, the developer D is a non-volatile liquid developer that is non-volatile at normal temperature, but is not limited thereto.
For example, the developer D may be a low-concentration (about 1 to 2 wt%) and low-viscosity volatile liquid developer using Isopar (trademark: exon) as a carrier at room temperature.
When the developer D is a non-volatile liquid developer, the developer D having a high viscosity clings to the developer pumping roller 540, so that the developer pumping roller 540 may transport the developer D in a large amount. . When the developer scooping roller 540 transports a large amount of the developer D to the developer supply roller 550, the possibility that the developer D gets over the regulating blade 560 is further increased. Therefore, the effect of the present invention, that is, the effect that the developer D can be surely prevented from getting over the regulating blade 560 when the developer pumping roller 540 transports the developer D to the developer supply roller 550. , Is played more effectively.
Therefore, the above embodiment is more desirable.

=== Configuration of Image Forming System etc. ===
Next, an image forming system according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 12 is an explanatory diagram showing an external configuration of the image forming system. The image forming system 700 includes a computer 702, a display device 704, a printer 706, an input device 708, and a reading device 710.

  In this embodiment, the computer 702 is housed in a mini-tower type housing, but is not limited thereto. The display device 704 is generally a CRT (Cathode Ray Tube), a plasma display, a liquid crystal display device, or the like, but is not limited thereto. As the printer 706, the printer described above is used. In this embodiment, the input device 708 uses a keyboard 708A and a mouse 708B, but is not limited thereto. In this embodiment, the reading device 710 uses a flexible disk drive device 710A and a CD-ROM drive device 710B, but is not limited to this. For example, an MO (Magneto Optical) disk drive device or a DVD (Digital Versatile) is used. Disk) etc. may be used.

  FIG. 13 is a block diagram showing a configuration of the image forming system shown in FIG. An internal memory 802 such as a RAM and an external memory such as a hard disk drive unit 804 are further provided in a housing in which the computer 702 is housed.

  In the above description, the example in which the printer 706 is connected to the computer 702, the display device 704, the input device 708, and the reading device 710 to configure the image forming system has been described. However, the present invention is not limited to this. Absent. For example, the image forming system may include a computer 702 and a printer 706, and the image forming system may not include any of the display device 704, the input device 708, and the reading device 710.

  For example, the printer 706 may have a part of the functions or mechanisms of the computer 702, the display device 704, the input device 708, and the reading device 710. As an example, the printer 706 includes an image processing unit that performs image processing, a display unit that performs various displays, a recording medium attachment / detachment unit for attaching / detaching a recording medium that records image data captured by a digital camera or the like. It is good also as a structure to have.

  The image forming system realized in this way is a system superior to the conventional system as a whole system.

1 is a diagram illustrating main components constituting an image forming apparatus according to an exemplary embodiment. FIG. 2 is a block diagram illustrating a control unit of the image forming apparatus in FIG. 1. It is sectional drawing which showed the main components of the developing unit which concerns on this Embodiment. 6 is a diagram illustrating an example of a shape of a developer pump roller 540. FIG. 5 is a perspective view illustrating a surface of a developer supply roller 550. FIG. FIG. 6A is a cross-sectional view showing that the groove 550a has a trapezoidal cross section. FIG. 6B is a cross-sectional view showing that the groove 550a has an inverted triangular cross section. FIG. 6C is a cross-sectional view showing that the groove 550a has a semicircular cross section. It is a figure for demonstrating a comparative example. FIG. 8A is a front view showing an example of the shape of the developer scooping roller 540. FIG. 8B is a top view showing the developer scooping roller 540 shown in FIG. 8A. It is sectional drawing which showed the main components of the developing unit which concerns on other embodiment. It is sectional drawing which showed the main components of the developing unit which concerns on other embodiment. It is sectional drawing which showed the main components of the developing unit which concerns on other embodiment. 1 is an explanatory diagram showing an external configuration of an image forming system. It is a block diagram which shows the structure of the image forming system shown in FIG.

Explanation of symbols

10 Laser beam printer 15Y, 15M, 15C, 15K Developing unit 20Y, 20M, 20C, 20K Photoconductor 30Y, 30M, 30C, 30K Charging unit 40Y, 40M, 40C, 40K Exposure unit 50Y, 50M, 50C, 50K Developing unit 60Y , 60M, 60C, 60K Primary transfer unit 70 Intermediate transfer member 73Y, 73M, 73C, 73K Static elimination unit 75Y, 75M, 75C, 75K Photoconductor cleaning unit 76Y, 76M, 76C, 76K Photoconductor cleaning blade 80 Secondary transfer unit 100 Control unit 101 Main controller 102 Unit controller 112 Interface 113 Image memory 120 CPU 510 Developing roller 530 Developer container 540 Developer pumping roller 54 T developer pumping upper 541 roller shaft 542a screw 542b screw 550 developer supplying roller 550H abutting position 550C developer bottom 550a groove 560 regulating blade 561 rubber of central 550U developer supply roller of the supply roller of the roller
561a One end of rubber part 561b The other end of rubber part 562 Rubber support part 570 Developing roller cleaning unit 571 Developing roller cleaning blade 700 Image forming system 702 Computer 704 Display device 706 Printer 708 Input device 708A Keyboard 708B Mouse 710 Reading device 710A Flexible disk drive Device 710B CD-ROM drive device 802 Internal memory 804 Hard disk drive unit D Developer

Claims (9)

A developer carrying member having an elastic layer and carrying a liquid developer;
Pressed against the developer carrying member, a holding roller for holding the liquid developer supplied to the developer carrying member,
A transport roller for transporting the liquid developer to the holding roller;
A regulating blade for regulating the amount of liquid developer on the holding roller by the trail regulation ;
In a liquid developing device having a storage portion for storing a liquid developer,
A central axis of the transport roller is below a rotation central axis of the holding roller, and the developer carrier is provided above the transport roller,
A lower portion of the transport roller is immersed in the liquid developer accommodated in the accommodating portion;
There is a gap between the back surface of the regulating blade and the accommodating portion,
A groove is provided on the surface of the holding roller,
Of the four quadrants divided by a first coordinate axis that passes vertically through the center of the holding roller and a second coordinate axis that passes through the center of the holding roller and extends horizontally from the left side to the right side of the first coordinate axis,
When the transport roller is located in the third quadrant, the regulation blade is located in the first quadrant,
The liquid developing device according to claim 1, wherein when the conveying roller is located in the fourth quadrant, the regulating blade is located in the second quadrant. The liquid developing apparatus according to claim 1,
The liquid developing device according to claim 1, wherein an upper end of the conveying roller is positioned above a lower end of the holding roller in a vertical direction. The liquid developing device according to claim 1 or 2,
The liquid developing device according to claim 1, wherein the regulating blade includes a contact portion that contacts the surface of the holding roller, and a support portion that supports the contact portion. The liquid developing device according to claim 3.
The abutting portion abuts the surface of the holding roller at one end thereof,
The liquid developing device according to claim 1, wherein the one end of the contact portion is positioned above the other end in the vertical direction. In the liquid developing device according to any one of claims 1 to 4,
The developer carrier is a developing roller;
The rotation direction of the developing roller is a direction opposite to the rotation direction of the holding roller,
The liquid developing device, wherein the transport roller is located in a fourth quadrant, and the regulating blade is located in a second quadrant. The liquid developing device according to claim 5,
The liquid developing device according to claim 1, wherein a rotation direction of the transport roller is the same as a rotation direction of the holding roller. In the liquid developing device according to any one of claims 1 to 6,
The liquid developing device according to claim 1, wherein the liquid developer is a non-volatile liquid developer that is non-volatile at normal temperature. An image carrier for carrying a latent image;
An elastic layer, a holding roller for a developer bearing member for bearing the liquid developer in pressure-contact with the developer carrying member, holds the liquid developer supplied to the developer carrying member, A conveying roller for conveying the liquid developer to the holding roller, a regulating blade for regulating the amount of the liquid developer on the holding roller by a trail regulation, and an accommodating portion for accommodating the liquid developer A liquid developing device that develops a latent image carried on the image carrier with a liquid developer carried on the developer carrier;
In an image forming apparatus comprising:
A central axis of the transport roller is below a rotation central axis of the holding roller, and the developer carrier is provided above the transport roller,
A lower portion of the transport roller is immersed in the liquid developer accommodated in the accommodating portion;
There is a gap between the back surface of the regulating blade and the accommodating portion,
A groove is provided on the surface of the holding roller,
Of the four quadrants divided by a first coordinate axis that passes vertically through the center of the holding roller and a second coordinate axis that passes through the center of the holding roller and extends horizontally from the left side to the right side of the first coordinate axis,
When the transport roller is located in the third quadrant, the regulation blade is located in the first quadrant,
2. An image forming apparatus according to claim 1, wherein when the conveying roller is located in the fourth quadrant, the regulating blade is located in the second quadrant. Computer and
An image forming apparatus connectable to the computer,
An image carrier for carrying a latent image;
An elastic layer, a holding roller for a developer bearing member for bearing the liquid developer in pressure-contact with the developer carrying member, holds the liquid developer supplied to the developer carrying member, A conveying roller for conveying the liquid developer to the holding roller, a regulating blade for regulating the amount of the liquid developer on the holding roller by a trail regulation, and an accommodating portion for accommodating the liquid developer A liquid developing device that develops a latent image carried on the image carrier with a liquid developer carried on the developer carrier;
In an image forming system having an image forming apparatus comprising:
A central axis of the transport roller is below a rotation central axis of the holding roller, and the developer carrier is provided above the transport roller,
A lower portion of the transport roller is immersed in the liquid developer accommodated in the accommodating portion;
There is a gap between the back surface of the regulating blade and the accommodating portion,
A groove is provided on the surface of the holding roller,
Of the four quadrants divided by a first coordinate axis that passes vertically through the center of the holding roller and a second coordinate axis that passes through the center of the holding roller and extends horizontally from the left side to the right side of the first coordinate axis,
When the transport roller is located in the third quadrant, the regulation blade is located in the first quadrant,
The image forming system according to claim 1, wherein when the conveying roller is located in a fourth quadrant, the regulating blade is located in a second quadrant.

Images