Patent Grant
8112027
Disclosed in embodiments herein are apparatuses for cleaning and/or applying release agent to an image forming machine moving surface, such as a photoreceptor, transfer surface, etc., and more specifically a blade engagement apparatus having a blade cassette holding a plurality of blades for individual withdrawal and placement into a working position in engagement with the moving surface for cleaning and/or metering.
In electrophotographic applications such as xerography, a charge retentive moving photoreceptor belt, plate, or drum is electrostatically charged according to the image to be produced. In a digital printer, an input device such as a raster output scanner controlled by an electronic subsystem can be adapted to receive signals from a computer and to transpose these signals into suitable signals so as to record an electrostatic latent image corresponding to the document to be reproduced on the photoreceptor. In a digital copier, an input device such as a raster input scanner controlled by an electronic subsystem can be adapted to provide an electrostatic latent image to the photoreceptor. In a light lens copier, the photoreceptor may be exposed to a pattern of light or obtained from the original image to be reproduced. In each case, the resulting pattern of charged and discharged areas on the moving photoreceptor surface form an electrostatic charge pattern (an electrostatic latent image) conforming to the original image.
The electrostatic image on the moving photoreceptor may be developed by contacting it with a finely divided electrostatically attractable toner. The toner is held in position on the photoreceptor image areas by the electrostatic charge on the surface. Thus, a toner image is produced in conformity with a light image of the original. Once each toner image is transferred to a substrate, the image is affixed thereto forming a permanent record of the image to be reproduced. In the case of multicolor copiers and printers, the complexity of the image transfer process is compounded, as four or more colors of toner may be transferred to each substrate sheet. Once the single or multicolored toner is applied to the substrate, it is permanently affixed to the substrate sheet by fusing, so as to create the single or multicolor copy or print.
Following the photoreceptor to substrate toner transfer process, it is necessary to at least periodically clean the charge retentive surface of the moving photoreceptor surface. In order to obtain the highest quality copy or print image, it is generally desirable to clean the photoreceptor each time toner is transferred to the substrate. In addition to removing excess or residual toner, other particles such as paper fibers, toner additives and other impurities (hereinafter collectively referred to as “residue”) that may remain on the charged moving surface of the photoreceptor must be removed.
Solid ink jet image forming machines generally use an electronic form of an image to distribute ink melted from a solid ink stick or pellet in a manner that reproduces the electronic image. In some solid ink jet imaging systems, the electronic image may be used to control the ejection of ink directly onto a media sheet. In other solid ink jet imaging systems, the electronic image is used to eject ink onto an intermediate imaging member. A media sheet is then brought into contact with the intermediate imaging member in a nip formed between the intermediate member and a transfer roller. The heat and pressure in the nip helps transfer the ink image from the intermediate imaging member to the media sheet.
One issue arising from the transfer of an ink image from an intermediate imaging member to a media sheet is the transfer of some ink to other machine components. For example, ink may be transferred from the intermediate imaging member to a transfer roller when a media sheet is not correctly registered with the image being transferred to the media sheet. The pressure and heat in the nip may cause a portion of the ink to adhere to the transfer roller, at least temporarily. The ink on the transfer roller may eventually adhere to the back side of a subsequent media sheet. If duplex printing operations are being performed, the quality of the image on the back side is degraded by the ink that is an artifact from a previous processed image.
To address these problems, various release agent applicators have been designed, often as part of an image drum maintenance system. These release agent applicators provide a coating of a release agent, such as silicone oil, onto the intermediate imaging member moving surface to reduce the undesired build-up of ink. It is desired to control the amount of release agent applied, since using of too much release agent causes undesirable streaks, also known as oil streaks, on the output prints.
The present application provides a new and improved apparatus for cleaning and/or metering a release agent onto an image forming device moving surface which overcomes these above-described problems.
A blade engagement system for cleaning and/or metering a release agent onto an image forming machine moving surface is provided.
In one exemplary embodiment, the blade engagement system includes a blade cassette including a plurality of blades, and a blade engagement apparatus having a cassette chamber adapted for removably receiving the blade cassette and a blade positioning mechanism moving the blades, one at a time, from the blade cassette to a working position in engagement with the image forming machine moving surface.
Referring now to
The image forming machine 10 includes a blade engagement system 102 including blade engagement apparatus 100 adapted to receive a removable blade cassette 150 containing a plurality of blades 1521-152n used for cleaning and/or applying a release agent to the image forming machine moving surface 12.
For the purposes of example, the blade cassette 150 is shown to contain four blades 1521-1524, however it should be appreciated that the cassette can house more than four blades. The blade engagement apparatus 100 includes a blade positioning mechanism 110 for moving one of the blades 1521-1524 from the cassette into a working position, also referred to as an operational position, in controlled engagement with surface 12, as shown in
The blade engagement apparatus 100 (and system 102) can be a release agent application apparatus (and system) for applying a controlled amount (i.e. thickness) of release agent 11 onto the surface 12, in a process referred to herein as metering. During metering, the release agent 11 is initially applied to the surface 12 using a roller 14, or in other known manners, and then metered to a desired thickness by a blade disposed in a working position. The blade engagement apparatus 100 (and system 102) can be a cleaning apparatus (and system) for cleaning debris from the moving surface 12 with the blade disposed in the working position. The blade engagement apparatus 100 (and system 102) can be configured for cleaning, or metering, or both simultaneously.
After a blade has reached the end of its operational life, the blade positioning mechanism 110 moves the used blade from the working position into the blade cassette 150 for storage and moves another, unused blade into the working position in a manner described below. This process can be repeated until all the blades have been used, at which time the blade cassette 150 can be removed from the blade engagement mechanism 100 and a new one inserted in its place.
Referring now to
The blade engagement apparatus 100 also includes a pair of spaced apart walls 118a & 118b forming a chute 120 communicating with the chamber 114 and extending downwards therefrom. The chute 120 includes an opening forming a blade window 122 disposed adjacent to the surface 12. The blade window 122 extends laterally across the width of the surface 12 to be engaged by the blade while in the operational position as described in further detail below.
A blade cassette 150 having a plurality of blades 1521-152n is slid through the blade receptacle 116 and into the cassette chamber 114. The cassette 150 has a cassette housing 160 having a top 161, a bottom 162 sides 163, a first end 164, and a second end 16 disposed opposite the first end. The cassette includes a first internal portion 166, referred to as the unused blade storage section of the cassette, for storing unused blades, as shown in
The cassette 150 includes a first pair of protrusions, each extending from the interior of the side walls 163 forming a pair of first rails 168 extending along the side walls for the length of the unused blade storage section 166 from the second end 165 to a mid portion of the cassette. The first rails 168 include flat upper surfaces 168a which are laterally aligned forming surfaces for supporting unused blades stored in the unused blade section of the cassette as described below.
The cassette 150 also includes a second pair of protrusions, each extending from the interior of the side walls 163 forming a pair of second rails 169 extending along the side walls for the length of the used blade storage section 167 from the first end 164 to a mid portion of the cassette. The second rails 169 include flat upper surfaces 169a which are laterally aligned forming surfaces for supporting used blades stored in the used blade section of the cassette as described below.
The cassette 150 also includes a laterally extending aperture 170 disposed in a mid portion of the cassette bottom 162 between the new blade storage section 166 and the used blade storage section 167, referred to as the loading/unloading aperture. The blades 152 are ejected from the cassette 150 through the loading/unloading aperture 170 and moved into the working position for use. One blade can occupy the working position at a time. At the end of a blade's operational life, it is placed back into the cassette through the loading/unloading aperture 170 and stored in the used blade section 167 while the next blade is moved from the cassette and placed into operation in the working position.
It should be appreciated that the blades 1521-152n are similar and shall be referred to generally as blade 152. As shown in
The rigid blade holder 202 is connected to, or integrated with, a compliant blade member 210 to evenly distribute the application forces applied to the blade 152 by the blade positioning mechanism 110. The blade member 210 extends from the bottom 208 of the blade holder 202 and includes a blade tip or edge 211 extending along most of the length of the holder. The blade member 210 is formed of a compliant material, such as polyurethane, which bends, or deflects, as the blade 152 is moved into the working position in which the blade tip 211 is pressed against, or towards, surface 12 generating a blade load at the tip against the surface, or material on the surface such as a release agent being metered. The tip 211 can be coated with PMMA, SureLube, toner or other initial blade lubricant to prevent blade flip as the blade 152 is moved into the working position, if so desired.
The blade holder body 203 also includes oppositely disposed lateral ends 212. A recess 214 is formed in the body 203 at each end 212 beneath the flange 206 defining a tang 215 extending from each end of the body below the recess. The blade member 210 extends along the blade holder bottom between the tangs 215. The ends of the flange 206 extending laterally outwards over the recess 214 form laterally extending tabs 216. In the unused blade storage section 166 of the cassette 150, the rails 168 extend into the recesses 214 supporting unused blades 152 in a sequential line of individual/unattached blades, each blade oriented in a similar manner with its tabs supported on the upper rail surfaces 168a. In the used blade storage section 167, rails 169 extend into the recesses 214 of the used blades 152 supporting the used blades for sliding movement as blades are moved back into the cassette through the loading/unloading aperture 170 for storage.
The cassette 150 includes a blade conveyor assembly 190, shown in
The blade conveyor assembly 190 includes a plurality of laterally extending conveyer bars 192 having ends 193 supported on the rails 168, 169. The blade conveyor assembly 190 also includes a pair of spaced apart link members 194 extending at right angles to the bars 192 connecting the bars together in a spaced apart manner such that one bar is disposed between each blade 152. A different bar 192 abuts the blade holder flange 206 behind each blade 1521-152n for moving that blade in a direction towards the loading/unloading aperture 170.
The connector members 194 can extend into parallel recessed channels 195 formed in the interior of the top 161 of the cassette housing 160 which enable the blade conveyor assembly 190 to track straight and stay square as it moves the blades towards the loading/unloading aperture for use. The connector members 194 can also extend down, between each blade 152, so that each rests against an inner side of the rails 168 enabling the blade conveyor assembly to track straight and stay square, keeping the blades parallel, and preventing them from skewing and binding as they slide along the rails 168.
The blade conveyor assembly 190 also includes an end plug 180 extending behind the sequentially last blade 152n which is spring biased towards the loading/unloading aperture 170 by a compression spring 182. The spring biased blade conveyor assembly 190 urges the blades 152 towards the loading/unloading aperture 170 as their tabs slide over the rail upper surfaces 168a. A pin 184 extending through each cassette side wall 163 is used to prevent the unused blades from reaching the aperture 170 while the cassette is not in place in the cassette chamber 114.
Referring now to
The arm assemblies 300 are similar and therefore, one shall be described in detail. The arm assembly 300 includes an arm 302 having a rack 303 disposed on a first side for cooperating with a sprocket 362 turned by a powered actuator, such as motor 360 shown in
The first arm 302 includes an upper clamp jaw 306 having an upper surface 307a and a lower surface 307b. The upper clamp jaw 306 can also include downwards facing recess 308 in the lower surface 307b. The second arm 304 includes a lower clamp jaw 310 which can include an upwards facing recess 312 aligned with recess 308. The upper and lower clamp jaws 306 and 310 are arranged in a facing relationship with each other. The second arm 304 is spring biased upwards with respect to the first arm 302 by spring 318 to bias the lower clamp jaw 310 in a direction towards the upper clamp jaw 306 to clamp the blade end 212 between the jaws. The clamp jaws 306, 310 of one arm assembly 300 are arranged in a facing relationship with the jaws the other arm assembly for gripping both ends 212 of the blade holder. In one exemplary embodiment, the jaws 306, 310 can clamp the blade tangs 215 in recesses 308 and 312, as shown in
The second arm 304 includes a projection 314 extending from a side of the arm assembly 300 opposite jaw 310. A stop 330 disposed in the blade engagement apparatus 100 is used to abut the projection 314 preventing movement of the second arm 304, and its lower jaw 310, while the first arm 302 is moved by motor 360 to move the upper jaw relative to the lower jaw for clamping and unclamping the blades 152, as described in further detail below. The stop 330 can be moved away from the projection 314, along a pivot axis 332 or by translating it laterally, such as by using a solenoid 334 connected to the stop. Moving the stop 330 away from projection 314 a sufficient distance to avoid this abutment enables the jaws 306 and 310 to be moved together such as when the arms are withdrawn into the arm housings 124. Alternatively, the first arm can include a projection 320 extending from a side opposite the upper jaw 306 having an upper beveled edge 322 and a lower beveled edge 324 which moves the stop away from the second arm projection 314 on its pivot axis 322 as the first arm is moved.
Referring now to
After the cassette 150 is in place in the chamber 114, the arm assemblies 300 are lowered with motor 360 moving each of the first and second arms 302 and 304 downwards together. The stop 330 is moved away from the second arm projection 314 using solenoid 334, or it is pushed away by projection 320 on the first arm as it passes by, allowing the second arm projection to reach a position below and adjacent the stop 330 as shown in
The motor 360 is then reversed, raising first arms 302 relative to second arms 304, which are prevented from being raised by stop 330, thereby opening the jaws 306 and 310 to accept the first blade 1521, as shown in
The motor 360 is reversed again lowering the first arms 302 while the second arms 304 remain stationary due to the spring bias provided by springs 318. Lowering the first arms 302 moves the upper clamp jaws 306 downwards clamping the tangs 215 in the facing recesses 308 and 312 of the respective jaws 306 and 310, as shown by the stars in
As shown in
The blade engagement apparatus 100 can include blade guides for locating a blade 152 with respect to surface 12 when placing the blade into the working position. In some exemplary embodiments, the blade guides can include one or more surfaces cooperating with the arms as they move a blade into the working position. Referring to
The surfaces 602 and 604 are oriented with respect to moving surface 12 to set and maintain a consistent, predetermined blade angle for each blade 152 as it is placed into the working position. Controlling the positioning of the arms 302 and 304 controls the positioning of the jaws 306 and 308 clamping the blade holders 202 which controls the position of the blade member with respect to the surface 12.
The guide 600 can include an end surface 608 providing a stop for the arm assemblies 300 moving towards the surface 12. Moving the arm assemblies 300 against the stop produces a predetermined blade load at the blade tip 211 which can be repeated for each of the similarly shaped blades 152.
Referring to
In other exemplary embodiments, the blade guide can include one or more surfaces cooperating with the blade 152 as it is moved into the working position. Referring to
The guide 700 can include an end surface 708 providing a stop for the blade 152 as the arm assembly 300 moves it towards the surface 12, producing a predetermined blade load for each blade as described above.
Referring to
The blade load can be increased while the blade 152 is in the working position by the motor 360 moving the arm assemblies downwards thereby moving the blade holder 202 in a direction towards the surface 12, increasing the deflection of the compliant blade member 210 which can also be referred to as increasing the interference of the blade 152. Increasing the blade load can meter a thinner layer of release agent 11 onto the surface during a metering operation, or clean more debris from the surface during a cleaning operation, or both. The blade load at tip 211 can be decreased while the blade 152 is in the working position, to meter a thicker layer of release agent and/or remove less debris from surface 12, by the actuator 360 moving the arm assemblies upwards thereby moving the blade holder 202 in a direction away the surface 12 while the blade tip 211 remains in contact with the surface.
Sensors can be used to monitor for streaks on output prints or on moving surface 12 and motor 360, controlled by controller 104, can provide incremental bi-directional changes in rotation to arm assemblies 300 moving the blade 152 towards or away from surface 12 to make small changes in the blade load to achieve a minimum blade load needed for preventing streaks during image forming, as described in further detail in the co-pending application U.S. application Ser. No. 12/201,140 filed Aug. 29, 2008, entitled “SYSTEM AND METHOD OF ADJUSTING BLADE LOADS FOR BLADES ENGAGING IMAGE FORMING MACHINE MOVING SURFACES”, the disclosure of which is hereby incorporated by reference in its entirety.
It is contemplated that two motor actuators 360, one for each arm assembly 300, can be used and controlled separately, if so desired. Using two motor actuators 360, the blade 152 can be skewed in the chute 120, such that the blade holder 210 is not parallel with respect to the surface 12, by moving the arm assemblies 300 such that each of the associated jaws are disposed a different distance from the surface. In this manner, it is possible to vary the blade interference, and thus the blade load, differently at each end of the blade 152.
At the end of the operational life of a blade 152, the used blade is withdrawn from operation by moving it from the working position back into the blade cassette for storage in the used blade section 167. Referring to
The arm assemblies 302 are moved upwards via actuator 360 as shown in
Referring now to
A main shaft 944 extends from a powered actuator, such as motor 936, to a pair of spaced apart sprockets 340 disposed above the unused blade storage section, each meshed with one of the racks 922 for moving the racks in a direction towards the loading/unloading aperture 170 as the motor 936 rotates. A second pair of sprockets 962 are disposed above the used blade storage section 167 and mesh with the racks 922 for moving the used blades from the loading/unloading aperture into the used blade storage section. The second sprockets 962 are disposed on an idler tube 956 mounted on the arm shaft 364. The idler tube 956 is coupled to the main shaft 944 for mutual rotation using a belt assembly 950 including a belt 960 connecting a sprocket 946 on the main shaft to a sprocket 952 on the idler shaft. In this manner, a single motor 936 can drive both racks 922 for moving the blades 152 from the unused blade storage section to the loading/unloading window and on to the used blade storage section.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5081505 | Ziegelmuller et al. | Jan 1992 | A |
| 5208639 | Thayer et al. | May 1993 | A |
| 5264904 | Audi et al. | Nov 1993 | A |
| 5385096 | Suzuki | Jan 1995 | A |
| 6311038 | Schlueter et al. | Oct 2001 | B1 |
| 7248813 | Burton | Jul 2007 | B2 |
| 20090110416 | Thayer et al. | Apr 2009 | A1 |
| 20090190975 | Thayer et al. | Jul 2009 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20100196068 A1 | Aug 2010 | US |
