JP2005070181A - Liquid developing device, image forming apparatus, and image forming system - Google Patents

Abstract

A liquid developer is prevented from adhering to a recess of a developer holding roller.
A liquid developing device having a developer holding roller having a recess for holding a liquid developer on a surface thereof, and a supply roller for supplying the liquid developer to the developer holding roller. The upper end of the supply roller is positioned above the lower end of the developer holding roller in the vertical direction, and the supply roller moves the liquid developer from the upper side to the lower side. It is characterized by supplying to.
[Selection] Figure 4

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 liquid developing device described above has a developer holding surface provided with a recess for holding the liquid developer in order to realize the above-described function of developing the latent image formed on the photoreceptor. A roller, and a supply roller for supplying the liquid developer to the developer holding roller.

In such a liquid developing device, the liquid developer supplied to the developer holding roller by the supply roller is held in a recess provided on the surface of the developer holding roller.
JP 2001-282002 A

  By the way, in the above liquid developing device, the liquid developer supplied to the developer holding roller by the supply roller may adhere to the recess of the developer holding roller.

  The present invention has been made in view of such a problem, and an object thereof is to prevent the liquid developer from adhering to the recess of the developer holding roller.

The main aspect of the present invention is a liquid development comprising: a developer holding roller provided with a recess for holding a liquid developer on a surface thereof; and a supply roller for supplying the liquid developer to the developer holding roller. A device,
In the vertical direction, the upper end of the supply roller is located above the lower end of the developer holding roller, and the supply roller supplies the liquid developer from the upper side to the lower side to the developer holding roller. A liquid developing device characterized by the above.

  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, it is possible to suppress the liquid developer from adhering to the recess of the developer holding roller.

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

A liquid developing apparatus comprising: a developer holding roller provided with a recess for holding a liquid developer on a surface; and a supply roller for supplying the liquid developer to the developer holding roller.
In the vertical direction, the upper end of the supply roller is located above the lower end of the developer holding roller, and the supply roller supplies the liquid developer from the upper side to the lower side to the developer holding roller. A liquid developing apparatus characterized by the above.
According to such a liquid developing device, it is possible to suppress the liquid developer from adhering to the depression of the developer holding roller.

  Further, in the liquid developing device, a first coordinate axis that passes vertically through the center of the developer holding roller and a second coordinate axis that passes through the center of the developer holding roller and extends from the left side to the right side of the first coordinate axis; The rotation direction of the developer holding roller is a direction passing through the second quadrant following the third quadrant, and the rotation direction of the supply roller is the rotation of the developer holding roller. The supply roller may be located on the left side of the first coordinate axis.

Further, in such a liquid developing device, the liquid developing device has an amount regulating member that abuts the developer holding roller and regulates the amount of the liquid developer held in the depression, and the supply roller is in the third quadrant, The amount regulating members may be located in the second quadrant.
According to such a liquid developing device, the amount regulating member can regulate the liquid developer held without adhering to the recess to a constant amount.

In the liquid developing device, in the vertical direction, the contact position of the amount regulating member with the developer holding roller is located above the liquid level of the liquid developer. Also good.
According to such a liquid developing device, the amount of the liquid developer held without being fixed to the recess can be more reliably regulated to a constant amount.

In the liquid developing device, the developer holding roller and the supply roller may not be in contact with each other.
When the developer holding roller and the supply roller are in contact with each other, the supply roller can scrape off the liquid developer held in the recess, and the liquid developer may be prevented from sticking to the recess. However, such a possibility is low when the developer holding roller and the supply roller are not in contact with each other. Therefore, when the developer holding roller and the supply roller are not in contact with each other, the above-described effect, that is, the effect that the liquid developer can be prevented from adhering to the depression of the developer holding roller is more effective. Played effectively.

Further, such a liquid developing device may not have a cleaning member for cleaning the liquid developer held in the recess.
When the cleaning member for cleaning the liquid developer held in the depression is not provided, the liquid developer is held in the depression as it is, and the possibility that the liquid developer adheres to the depression becomes higher. Therefore, the above-described effect, that is, the effect that the liquid developer can be prevented from adhering to the depression of the developer holding roller is more effectively achieved.

  In the liquid developing device, the recess may be a spiral groove, and a plurality of the spiral grooves may be provided on the surface of the developer holding roller at a predetermined interval.

In the liquid developing apparatus, the liquid developer may be a non-volatile liquid developer that is non-volatile at normal temperature.
The nonvolatile liquid developer is a high-viscosity liquid developer. In the case of a high-viscosity liquid developer, the possibility that the liquid developer adheres to the recess becomes higher. Therefore, the above-described effect, that is, the effect that the liquid developer can be prevented from adhering to the depression of the developer holding roller is more effectively achieved.

Furthermore, the liquid developing device includes a developer holding roller having a recess for holding the liquid developer on a surface thereof, and a supply roller for supplying the liquid developer to the developer holding roller. And
In the vertical direction, the upper end of the supply roller is located above the lower end of the developer holding roller, and the supply roller supplies the liquid developer from above to the developer holding roller,
Of four quadrants divided by a first coordinate axis that passes vertically through the center of the developer holding roller and a second coordinate axis that passes through the center of the developer holding roller and moves from the left side to the right side of the first coordinate axis. The rotation direction of the developer holding roller is a direction passing through the second quadrant following the third quadrant, and the rotation direction of the supply roller is the same direction as the rotation direction of the developer holding roller, The supply roller is located on the left side of the first coordinate axis,
An amount restricting member for restricting an amount of the liquid developer held in contact with the developer holding roller and held in the depression; the supply roller in the third quadrant; and the amount restricting member in the second quadrant Each located in
In the vertical direction, the contact position of the amount regulating member with the developer holding roller is located above the liquid level position of the liquid developer,
The developer holding roller and the supply roller do not abut,
There is no cleaning member for cleaning the liquid developer held in the depression,
The recess is a spiral groove, and a plurality of the spiral grooves are provided on the surface of the developer holding roller at predetermined intervals.
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.

And a liquid developing device having a developer holding roller having a recess for holding the liquid developer on a surface thereof, and a supply roller for supplying the liquid developer to the developer holding roller. An image forming apparatus,
In the vertical direction, the upper end of the supply roller is located above the lower end of the developer holding roller, and the supply roller supplies the liquid developer from the upper side to the lower side to the developer holding roller. An image forming apparatus characterized by the above can also be realized.

Furthermore, a computer and an image forming apparatus connectable to the computer,
An image including a liquid developing device having a developer holding roller provided with a recess for holding the liquid developer on a surface thereof, and a supply roller for supplying the liquid developer to the developer holding roller. In an image forming system having a forming apparatus,
The upper end of the supply roller is positioned above the lower end of the developer holding roller in the vertical direction, and the supply roller supplies the liquid developer from above to the developer holding roller. An image forming system characterized by the above can also be realized.

=== Example of Overall Configuration 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 are arranged in the lower part of the printer 10, and the intermediate transfer member 70 is arranged in the upper part of the printer 10. Is arranged.

  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 a notification unit for the user, and a control unit 100 (see FIG. 2) that controls these units and operates as a printer.

  The developing units 15Y, 15M, 15C, and 15K have a function of developing a latent image with a yellow (Y) developer, a magenta (M) developer, a cyan (C) developer, and a black (K) developer, respectively. ing. 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. 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 rotationally driven in a direction indicated by an arrow in FIG. 1 while being in contact with 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.

  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 are 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 of the apparatus main body (charging units 30Y, 30M, 30C, 30K, exposure units 40Y, 40M, 40C, 40K, developing units 50Y, 50M, 50C, 50K, primary transfer units 60Y, 60M, 60C, 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.

=== Configuration Example of Development Unit ===
Next, a configuration example of the developing unit will be described with reference to the drawings. FIG. 3 is a cross-sectional view showing main components of the developing unit. FIG. 4 is a cross-sectional view showing a quadrant in which main components of the developing unit are arranged. FIG. 5 is a perspective conceptual view showing the surface of the application roller 550. 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. FIG. 7 is a view showing the shape of the developer pumping roller 540.

  3 and 4, as in FIG. 1, the vertical direction is indicated by an arrow. For example, the developing roller 510 is above the developer pumping roller 540. In FIG. 4, the Y axis is an example of a first coordinate axis that passes vertically through the center of the application roller 550 and the X axis passes through the center of the application roller 550 and is a second that extends from the left side to the right side of the Y axis. It is an example of a coordinate axis. In FIG. 4, I, II, III, and IV indicate a first quadrant, a second quadrant, a third quadrant, and a fourth quadrant, respectively.

  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 includes a developing roller 510, a developer container 530, a developer scooping roller 540 as an example of a supply roller, a coating roller 550 as an example of a developer holding roller, and an example of a quantity regulating member. The regulating blade 560 and the developing roller cleaning unit 570 are provided. As shown in FIG. 4, the developer scooping roller 540 and the amount regulating blade 560 are located on the left side of the Y axis. More precisely, the developer scooping roller 540 is located in the third quadrant, and the regulating blade 560 is located in the second quadrant. On the other hand, the developing roller 510 is located above the X axis.

  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 has a low concentration (about 1 to 2 wt%) and a low viscosity with Isopar (trademark: exon) as a carrier, which is generally used conventionally. It is not a volatile liquid developer having volatility, but a non-volatile liquid developer D having a high concentration and high viscosity and having non-volatility at room temperature. 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 supplies the developer D to the application 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 spaced apart from the application roller 550 with a width of about 1 mm. That is, the developer drawing-up roller 540 supplies the developer D to the application roller 550 without contacting the application roller 550.

  Further, the developer scooping roller 540 can rotate around its central axis, and the central axis is below the rotational central axis of the application roller 550. Further, the developer scooping roller 540 is rotated in the same direction (clockwise in FIG. 4) as the rotation direction of the application roller 550 (in FIG. 4, the direction passing through the second quadrant II following the third quadrant III, ie, clockwise). ). The developer pump-up roller 540 has a function of pumping up the developer D stored in the developer storage unit 530 and supplying the developer D to the application roller 550, and also maintains the developer D in an appropriate state. It also has a function of stirring.

  Further, as shown in FIG. 7, 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.

  Furthermore, as shown in FIG. 4, the upper end 540T of the developer pumping roller is located above the lower end 550U of the application roller in the vertical direction. In such an arrangement, the developer scooping roller 540 supplies the developer D to the application roller 550 from the top to the bottom as indicated by the arrow in FIG. Thus, when the developer pumping roller 540 supplies the developer D to the application roller 550, the developer D held in the groove 550a can be replaced.

  The application roller 550 applies the developer D supplied from the developer container 530 by the developer pumping roller 540 to the developing roller 510. The application roller 550 is formed by spirally forming a groove 550a as shown in FIG. 5 on the surface of a metallic roller such as iron and nickel-plating, and has a diameter of about 25 mm. A plurality of the spiral grooves 550a are provided on the surface of the application roller 550 at a predetermined interval. The application roller 550 in the present embodiment includes a groove 550a having a trapezoidal cross section as shown in FIG. 6A as the groove, but includes, for example, a groove having an inverted triangular cross section as shown in FIG. 6B. Alternatively, a groove having a semicircular cross section as shown in FIG. 6C may be provided. As shown in FIG. 6A, the groove dimensions of the application 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 application roller 550 is in pressure contact with the developing roller 510 in order to appropriately apply the developer D on the application roller 550 to the developing roller 510. Further, the application 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 rotation direction of the application roller 550 (clockwise in FIG. 4) is opposite to the rotation direction of the developing roller 510 (counterclockwise in FIG. 4).

  The regulating blade 560 abuts on the surface of the application roller 550 and regulates the amount of developer D held in the groove 550a. That is, the regulating blade 560 plays a role of scraping off the excess developer D on the groove 550 a and measuring the developer D on the groove 550 a applied to the developing roller 510. The regulating blade 560 also regulates the developer D attached to the surface on the application roller 550 other than the groove 550a. The regulating blade 560 includes a rubber part 560a that contacts the application roller 550, and a rubber support part 560b that supports the rubber part 560a. The rubber part 560a is made of urethane rubber, and its rubber hardness is about 62 degrees according to JIS-A. The rubber support portion 560b is a metal plate such as iron.

  Further, the regulation blade 560 performs so-called edge regulation because the edge of the rubber portion 560a is in contact with the application roller 550. Further, as shown in FIG. 3, the regulating blade 560 is arranged so that the tip thereof faces the downstream side in the rotation direction of the application roller 550, and performs so-called trail regulation. As shown in FIG. 3, in the present embodiment, the trail angle is about 10 degrees. Further, the contact position where the regulating blade 560 contacts the surface of the application roller 550 is located above the liquid level position of the developer D as shown in FIG.

  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 ° A is provided. The developing roller 510 is in elastic contact with the application 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.

  In addition, a cleaning member for cleaning the developer D held in the groove 550a may be provided. However, in this embodiment, when the developer scooping roller 540 supplies the developer D to the application roller 550. Since the developer D held in the groove 550a can be replaced, no cleaning member is provided.

  In the yellow developing unit 50 </ b> Y configured as described above, the developer scooping roller 540 rotates around its central axis, so that the developer D stored in the developer storing unit 530 is pumped and supplied to the coating roller 550. To do.

  The developer D supplied to the application roller 550 reaches the contact position of the regulating blade 560 by the rotation of the application roller 550. Then, when passing through the contact position, the excess amount of developer D is scraped off by the regulating blade 560, and the amount of developer D applied to the developing roller 510 is measured. That is, since the groove 550a is provided in the application roller 550 as described above, the regulating blade 560 that contacts the application roller 550 leaves the developer D on the application roller 550 leaving the developer D in the groove 550a. Will be scraped off. In addition, since the dimension of the groove 550a is determined so that the developer D applied to the developing roller 510 becomes an appropriate amount, when the regulating blade 560 scrapes off the developer D on the applying roller 550, The developer D measured to an appropriate amount by the groove 550a remains in the groove 550a.

  The developer D remaining in the groove 550a of the application roller 550 reaches a pressure contact position with the development roller 510 by further rotation of the application roller 550, and is applied from the application roller 550 to the development roller 510 at the pressure contact position. Then, the developer D in the groove 550a is stretched by the action of pressure generated when the application roller 550 and the development roller 510 come into pressure contact during the application, and the uniform developer D is formed on the development roller 510. The thin film is formed.

  The developer D thin film formed on the developing roller 510 in this manner 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.

=== Cause of Fixing of Developer D in Groove 550a ===
Incidentally, as described in the section of the problem to be solved by the invention, the developer D supplied to the application roller 550 by the developer pumping roller 540 may be fixed to the groove 550a of the application roller 550. Hereinafter, an example of the cause of the fixing of the developer D in the groove 550a will be described. FIG. 8A is a conceptual diagram showing a state before the developer D held in the groove 550 a is applied to the developing roller 510. FIG. 8B is a conceptual diagram showing a state in which the developer D held in the groove 550 a is applied to the developing roller 510. FIG. 8C is a conceptual diagram showing a state in which the aggregate T of toner particles is fixed to the groove 550a.

  As described above, the developer D on the application roller 550 that has reached the contact position of the regulating blade 560 is scraped off leaving the developer D held in the groove 550a at the contact position, and is held in the groove 550a. The remaining developer D is conveyed to a pressure contact position with the developing roller 510 and applied to the developing roller 510.

  FIG. 8A shows the state of the developer D that is regulated by the regulating blade 560 and held in the groove 550 a before being applied to the developing roller 510. Here, the amount of developer D held in the groove 550a before being applied to the developing roller 510 is smaller than the volume of the groove 550a holding the developer D.

  The developer D held in the groove 550a as described above is applied to the developing roller 510 as shown in FIG. 8B. The developer D applied to the developing roller 510 is the developer D in the upper part of the groove 550a out of the developer D held in the groove 550a. On the other hand, the developer D at the bottom of the groove 550a is not applied to the developing roller 510 and remains held in the groove 550a.

  Then, the developer D that is not applied to the developing roller 510 and is held in the groove 550a may be fixed to the groove 550a. More specifically, the aggregate T of powdery toner particles dispersed in the developer D may be fixed to the bottom portion of the groove 550a as shown in FIG. 8C.

=== Effect of Preventing Fixing of Developer in Groove 550a According to Embodiment of the Present Invention ===
Therefore, like the printer 10 according to the present embodiment, the upper end 540T of the developer pumping roller is positioned above the lower end 550U of the application roller (see FIG. 4), and the developer pumping roller 540 is the developer pump. Suppose that D is supplied to the coating roller 550 from the top to the bottom. In this way, it is possible to prevent the developer D from adhering to the groove 550a of the application roller 550. Below, it demonstrates in detail using figures.

  FIG. 9 is an enlarged conceptual view of a portion P where the developer scooping roller 540 supplies the developer D to the application roller 550 in FIG. Here, the plurality of grooves 550a provided on the surface of the application roller 550 are expressed as, for example, a groove 550a1, a groove 550a2, and a groove 550a3. In FIG. 9, grooves 550a1 to 550a3 indicate grooves before the developer D supplied by the developer scooping roller 540 is held. On the other hand, grooves 550a4 to 550a8 indicate grooves in which the developer D supplied by the developer scooping roller 540 is held.

  As described above, the developer scooping roller 540 supplies the developer D to the application roller 550 (more specifically, the groove 550a) from the top to the bottom as shown in FIG. Gravity acts on the developer D supplied by the developer scooping roller 540. When the developer D subjected to the gravity is supplied to the groove 550a by the developer pumping roller 540, the developer D held in the groove 550a, for example, the grooves 550a1 to 550a3, is replaced. Then, the replaced developer D is held in the groove 550a, for example, the grooves 550a4 to 550a8. Therefore, the toner particle aggregate T as described above is not fixed to the bottom portion of the groove 550a, and the replaced developer D is held in the groove 550a.

  In the above, the description has been given focusing on the grooves 550a1 to 550a8 among the plurality of grooves 550a provided on the surface of the application roller 550, but the same thing as described above also occurs for the other grooves 550a.

  Accordingly, the upper end 540T of the developer pumping roller is positioned above the lower end 550U of the application roller (see FIG. 4), and the developer pumping roller 540 is directed to the application roller 550 with the developer D directed downward from above. In the case of supplying the developer D, the developer D held in the groove 550a is replaced when the developer D is supplied to the groove P by the developer pumping roller 540. The problem that the developer D is fixed to the groove 550a can be suppressed.

=== 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 relates to a developer holding roller (for example, an application roller 550) provided with a recess (for example, a groove 550a) for holding a liquid developer (for example, developer D), and the developer holding. The present invention relates to a liquid developing device (for example, developing units 50Y, 50M, 50C, and 50K) having a supply roller (for example, a developer pumping roller 540) for supplying the liquid developer to the roller.

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-described embodiment, the regulation blade 560 is arranged so that the tip thereof faces the downstream side in the rotation direction of the application roller 550 and performs so-called trail regulation. However, the present invention is not limited to this. It is not a thing.
For example, as shown in FIG. 10, the restriction blade 560 is disposed so that the front end thereof faces the upstream side in the rotation direction of the application roller 550, and so-called counter restriction may be performed.

In the above embodiment, it has been described that 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 this.
For example, the roller shaft 541 may be provided with one screw.

In the above-described embodiment, the application roller 550 has been described as the direction (clockwise in FIG. 3) opposite to the rotation direction of the developing roller 510 (counterclockwise in FIG. 3), but is not limited thereto. is not.
For example, as shown in FIG. 11, the application roller 550 may be in the same direction (counterclockwise in FIG. 11) as the rotation direction of the developing roller 510 (counterclockwise in FIGS. 3 and 11). In this case, the arrangement of the developer pumping roller 540 and the regulating blade 560 shown in FIG. 11 is different from the arrangement of the developer pumping roller 540 and the regulating blade 560 shown in FIG. FIG. 11 is a cross-sectional view showing an example of main components of the developing unit.

Further, in the above-described embodiment, a first coordinate axis (for example, Y axis) that passes vertically through the center of the application roller 550 and a second coordinate axis (for example, that extends from the left side to the right side of the Y axis through the center of the application roller 550). , X axis), and the rotation direction of the coating roller 550 is a direction passing through the second quadrant following the third quadrant (that is, clockwise in FIG. 4), and the developer. The rotation direction of the scooping roller 540 is the same as the rotation direction of the application roller 550 (clockwise in FIG. 4), and the developer scooping roller 540 is positioned on the left side of the Y axis. It is not limited.
For example, as shown in FIG. 12, the rotation direction of the developer pumping roller 540 is the reverse direction (counterclockwise in FIG. 4) to the rotation direction of the application roller 550 (clockwise in FIG. 4). 540 may be located on the right side of the Y-axis. FIG. 12 is a cross-sectional view showing an example of main components of the developing unit.

Further, in the above-described embodiment, it has a regulation blade 560 that abuts the application roller 550 and regulates the amount of the developer D held in the groove 550a, and the developer pumping roller 540 is in the third quadrant. Although the regulating blade 560 is located in the second quadrant, it is not limited to this.
For example, the regulation blade 560 that abuts the application roller 550 and regulates the amount of the developer D held in the groove 550a may not be provided.
However, in the case of having a regulating blade 560 that abuts the application roller 550 and regulates the amount of the developer D held in the groove 550a, the developer D held without adhering to the groove 550a is removed. The regulating blade 560 can regulate to a certain amount.
Therefore, the above embodiment is more desirable.

Furthermore, in the above embodiment, the contact position of the regulating blade 560 with the application roller 550 is positioned above the liquid level position of the developer D in the vertical direction. It is not limited.
For example, the contact position of the regulating blade 560 with the application roller 550 may be positioned below the liquid level position of the developer D in the vertical direction.
However, when the contact position of the regulating blade 560 with the application roller 550 is positioned higher than the liquid level position of the developer D in the vertical direction, the regulating blade 560 is held without being fixed to the groove 550a. The regulating blade 560 can more reliably regulate the developer D being in a certain amount. Therefore, the above embodiment is more desirable.

Further, in the above embodiment, the application roller 550 and the developer pumping roller 540 are not in contact with each other, but the present invention is not limited to this.
For example, the application roller 550 and the developer pumping roller 540 may be in contact with each other.
When the application roller 550 and the developer pumping roller 540 are in contact with each other, the developer pumping roller 540 can scrape off the developer D in the groove 550a and suppress the developer D from adhering to the groove 550a. Although the possibility increases, such a possibility is low when the application roller 550 and the developer scooping roller 540 are not in contact with each other. Therefore, when the application roller 550 and the developer pumping roller 540 are not in contact with each other, the above-described effect, that is, the effect that the developer D can be prevented from adhering to the groove 550a of the application roller 550, Is played more effectively.
Therefore, the above embodiment is more desirable.

Furthermore, in the above embodiment, the cleaning member for cleaning the developer D held in the groove 550a is not provided, but the present invention is not limited to this.
For example, a cleaning member for cleaning the developer D held in the groove 550a may be provided.
However, if there is no cleaning member for cleaning the developer D held in the groove 550a, the developer D may be held in the groove 550a as it is, and the developer D may adhere to the groove 550a. Becomes higher. Therefore, the above-described effect, that is, the effect that the developer D can be prevented from adhering to the groove 550a of the application roller 550 is more effectively exhibited.
Therefore, the above embodiment is more desirable.

Further, in the above-described embodiment, the recess is the spiral groove 550a, and a plurality of the spiral grooves 550a are provided on the surface of the application roller 550 at a predetermined interval. However, the present invention is not limited thereto. It is not something.
For example, a large number of depressions having a shape as shown in FIGS. 13A and 13B may be provided on the surface of the application roller 550. FIG. 13A is a diagram illustrating an example of a depression provided on the surface of the application roller 550. FIG. 13B is a diagram illustrating an example of a depression provided on the surface of the application roller 550.

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.
However, when the developer D is a non-volatile liquid developer, since the developer D is a high-viscosity developer, the possibility that the developer D adheres to the groove 550a becomes higher. Therefore, the above-described effect, that is, the effect that the developer D can be prevented from adhering to the groove 550a of the application roller 550 is more effectively exhibited.
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. 14 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. However, the reading device 710 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. 15 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. It is sectional drawing which showed the quadrant by which the main component of a developing unit is arrange | positioned. 5 is a perspective view showing a surface of a coating 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. FIG. 6 is a diagram showing the shape of a developer pump roller 540. FIG. 8A is a conceptual diagram showing a state before the developer D held in the groove 550 a is applied to the developing roller 510. FIG. 8B is a conceptual diagram showing a state in which the developer D held in the groove 550 a is applied to the developing roller 510. FIG. 8C is a conceptual diagram showing a state in which the aggregate T of toner particles is fixed to the groove 550a. FIG. 9A is a conceptual diagram illustrating a state in which the developer is supplied to the application roller 550 by the developer scooping roller 540. FIG. 9B is a conceptual diagram illustrating a state in which the developer is supplied to the application roller 550 by the developer scooping roller 540. It is sectional drawing which showed an example of the main components of a developing unit. It is sectional drawing which showed an example of the main components of a developing unit. It is sectional drawing which showed an example of the main components of a developing unit. FIG. 13A is a diagram illustrating an example of a depression provided on the surface of the application roller 550. FIG. 13B is a diagram illustrating an example of a depression provided on the surface of the application roller 550. 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 Upper end of developer pumping roller 541 Roller shaft 542a Screw 542b Screw 550 Application roller 550U Lower end of application roller 550a Groove 560 Restriction blade 560a Rubber portion 560b Rubber support portion 570 Development roller cleaning unit 571 Development 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 T Collective of toner particles

Claims (11)

A liquid developing apparatus comprising: a developer holding roller provided with a recess for holding a liquid developer on a surface; and a supply roller for supplying the liquid developer to the developer holding roller.
In the vertical direction, the upper end of the supply roller is located above the lower end of the developer holding roller,
The liquid developing device according to claim 1, wherein the supply roller supplies the liquid developer from above to the developer holding roller. The liquid developing apparatus according to claim 1,
Among four quadrants divided by a first coordinate axis that passes vertically through the center of the developer holding roller and a second coordinate axis that passes through the center of the developer holding roller and moves from the left side to the right side of the first coordinate axis. The rotation direction of the developer holding roller is a direction passing through the second quadrant following the third quadrant,
The rotation direction of the supply roller is the same direction as the rotation direction of the developer holding roller,
The liquid developing device according to claim 1, wherein the supply roller is located on the left side of the first coordinate axis. The liquid developing device according to claim 2,
An amount regulating member that abuts the developer holding roller and regulates the amount of liquid developer held in the depression;
The liquid developing apparatus, wherein the supply roller is located in a third quadrant, and the amount regulating member is located in a second quadrant. The liquid developing device according to claim 3,
The liquid developing device according to claim 1, wherein a contact position of the amount regulating member with the developer holding roller is located above a liquid level position of the liquid developer in the vertical direction. In the liquid developing device according to any one of claims 1 to 4,
The liquid developing device, wherein the developer holding roller and the supply roller are not in contact with each other. In the liquid developing device according to any one of claims 1 to 5,
A liquid developing apparatus having no cleaning member for cleaning the liquid developer held in the recess. In the liquid developing device according to any one of claims 1 to 6,
The recess is a spiral groove,
2. A liquid developing device according to claim 1, wherein a plurality of the spiral grooves are provided at predetermined intervals on the surface of the developer holding roller. In the liquid developing device according to any one of claims 1 to 7,
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. A liquid developing apparatus comprising: a developer holding roller provided with a recess for holding a liquid developer on a surface; and a supply roller for supplying the liquid developer to the developer holding roller.
In the vertical direction, the upper end of the supply roller is located above the lower end of the developer holding roller, and the supply roller supplies the liquid developer from the upper side to the lower side to the developer holding roller,
Among four quadrants divided by a first coordinate axis that passes vertically through the center of the developer holding roller and a second coordinate axis that passes through the center of the developer holding roller and moves from the left side to the right side of the first coordinate axis. The rotation direction of the developer holding roller is a direction passing through the second quadrant following the third quadrant, and the rotation direction of the supply roller is the same direction as the rotation direction of the developer holding roller, The supply roller is located on the left side of the first coordinate axis,
An amount restricting member for restricting the amount of the liquid developer held in contact with the developer holding roller and held in the depression is provided, wherein the supply roller is in the third quadrant and the amount restricting member is in the second quadrant. Each located in
In the vertical direction, the contact position of the amount regulating member with the developer holding roller is located above the liquid level position of the liquid developer,
The developer holding roller and the supply roller do not abut,
There is no cleaning member for cleaning the liquid developer held in the depression,
The recess is a spiral groove, and a plurality of the spiral grooves are provided on the surface of the developer holding roller at predetermined intervals.
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 including a liquid developing device having a developer holding roller provided with a recess for holding the liquid developer on a surface thereof, and a supply roller for supplying the liquid developer to the developer holding roller. A forming device,
In the vertical direction, the upper end of the supply roller is located above the lower end of the developer holding roller,
The image forming apparatus according to claim 1, wherein the supply roller supplies the liquid developer from above to the developer holding roller. Computer and
An image forming apparatus connectable to the computer,
An image including a liquid developing device having a developer holding roller provided with a recess for holding the liquid developer on a surface thereof, and a supply roller for supplying the liquid developer to the developer holding roller. Forming equipment,
In an image forming system having
The upper end of the supply roller is positioned above the lower end of the developer holding roller in the vertical direction,
The image forming system, wherein the supply roller supplies the liquid developer from above to the developer holding roller.

Images