WO2019177592A1

WO2019177592A1 - Rollers with increased inertial mass

Info

Publication number: WO2019177592A1
Application number: PCT/US2018/022176
Authority: WO
Inventors: Donald J. Fasen
Original assignee: Hewlett Packard Development Co LP
Current assignee: Hewlett Packard Development Co LP
Priority date: 2018-03-13
Filing date: 2018-03-13
Publication date: 2019-09-19
Anticipated expiration: 2020-09-13

Abstract

In example implementations, a roller with increased inertial mass for a color printer is provided. The roller includes a driving motor, a drive shaft coupled to the motor and a cylindrical roller coupled to the drive shaft to move an intermediate transfer belt of a color printer. The cylindrical roller has an amount of mass added to an outer diameter of the cylindrical roller to provide a moment of inertia that is greater than 4.5 kilograms per meter squared (kg/m2).

Description

ROLLERS WITH INCREASED INERTIAL MASS

BACKGROUND

[0001] Printers can be used to print images onto media. Printers can print images with a variety of different materials. Some printers can print with ink jets, toner, and the like. Printers can be used to print black and white images and other printers can be used to print color images.

[0002] A printer may have a plurality of different subsystems that operate together to print the image. For example, the printer may have a digital front end to process and encode an image that is to be printed. The digital front end may then control the various subsystems to print the image, such as a paper transport path, a registration system, an imaging system, a stacker module, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] FIG. 1 illustrates an example color printer of the present disclosure;

[0004] FIG. 2 illustrates an example apparatus of the present disclosure;

[0005] FIG. illustrates the example apparatus of the present disclosure contacting a print media; and

[0006] FIG. 4 illustrates example comparison of a roller for an intermediate transfer belt of the present disclosure to a previous roller design.

DETAILED DESCRIPTION

[0007] Examples described herein provide rollers for an intermediate transfer belt (ITB) that have increased inertial mass. As discussed above, printers may have different subsystems that operate together to print an image. However, if there is an error in any one of the subsystems, the image may not print correctly onto the media.

[0008] In color laser printers, one subsystem may include an intermediate transfer belt (ITB). Color toner may be dispensed onto the ITB as the ITB moves in a process direction. Any disruptions to the velocity of the ITB can cause a color plane registration (CPR) error. The CPR error may be a misalignment of different colored toner dispensed onto the ITB.

[0009] In one example, heavy gauge media that contacts the ITB roller can disrupt the velocity of the ITB. For example, when a lead edge of the heavy gauge media initially contacts the ITB roller, the contact can cause a brief disruption of the velocity of the ITB. As result a top portion of the media can typically experience the most amount of CPR error.

[0010] The present disclosure improves the ITB roller by designing a roller with increased inertial mass. The roller of the present disclosure may have the same dimensions as existing rollers, but with more weight or mass distributed across a length of the roller. As a result, the roller of the present disclosure may improve the inertia of the roller to prevent the contact from heavy gauge media causing a disruption in the velocity of the ITB. In addition, by keeping the dimensions the same as existing rollers, the rollers of the current disclosure may be deployed without any changes to the ITB system or processing software.

[0011] FIG. 1 illustrates an example color printer 100 of the present disclosure. In one example, the color printer 100 may include a feeder 102, an imaging subsystem 104, and a stacker 106. It should be noted that the color printer 100 has been simplified for ease of explanation and may include additional components that are not shown. For example, the color printer 100 may include a transport path, a processor to process an image to be printed, a user interface to receive inputs and display outputs, and the like.

[0012] The feeder 102 may include print media 108. The print media 108 may be paper. The imaging subsystem 104 may be part of a printing system of the color printer 100 that prints a desired image or images onto the print media 108. The stacker 106 may receive the print media 108 after the color image is printed onto the print media 108.

[0013] In one example, the imaging subsystem 104 may include an intermediate transfer belt (ITB) 120. The ITB 120 may be a plastic belt. The ITB 120 may be used in color printers to transfer layers of colored ink toner 1 18 onto the print media 108 before the layers of colored ink toner 1 18 are cured onto the print media 108.

[0014] The imaging subsystem 104 may include a plurality of printheads 1 16 that dispense different colored ink toner (e.g., cyan, yellow, magenta, and black). The layers of colored ink toner 1 18 may be moved via the ITB 120 towards the print media 108. The ITB 120 may be moved via rotation of a roller 1 12 that is coupled to a motor 1 14.

[0015] The motor 1 14 may rotate the roller 1 12 with a desired angular velocity. The angular velocity may measure a speed of rotation of the roller 1 12 as shown by an arrow 150. The desired angular velocity may be a velocity that moves the ITB 120 such that the plurality of printheads 1 16 dispense a respective colored ink toner at precisely the right location on the ITB 120. The alignment of the different colored ink toner on the ITB 120 is known as color plane registration (CPR).

[0016] The colored ink toner may be dispensed onto the ITB 120 in an uncured form. In other words, the colored ink toner sits on the ITB 120 as a loose powder. When disruption of the desired angular velocity of the roller 1 12, and thereby disruption of the velocity of the ITB 120, occurs, the imaging subsystem 104 may suffer from CPR errors. Small disruptions to velocity of the ITB 120 may cause the colored ink toner to move on the ITB 120 or the plurality of printheads 1 16 to dispense the colored ink toner at wrong locations on the ITB 120. In other words, the layers of colored ink toner 1 18 may be misaligned, causing defects (e.g., offset colors) in the image that is printed on the print media 108.

[0017] As noted above, when the print media 108 is relatively heavy, the desired angular velocity of the roller 1 12 may be disrupted when a leading edge of the print media 108 contacts the roller 1 12 (e.g., the portion of the ITB 120 that is on the roller 1 12). However, the roller 1 12 of the present disclosure may be designed with additional mass (as discussed in further detail below) to maintain the desired angular velocity when print media contacts the portion of the ITB 120 that is on the roller 1 12. Maintaining the desired angular velocity may eliminate CPR errors.

[0018] In addition, the additional mass may be added such that the overall dimensions of the roller 1 12 may remain the same as previous roller designs.

As a result, the roller 1 12 may replace currently designed rollers in the color printer 100 without having to redesign the imaging subsystem 104. For example, the control of the plurality of printheads 1 16 and the ITB 120, the timing of dispensing the colored ink toner, and the like may all remain the same. Thus, the design of the roller 1 12 of the present disclosure may eliminate CPR errors, while minimizing the impact to the overall design of the color printer 100.

[0019] FIG. 2 illustrates an apparatus (e.g., the imaging subsystem 104) with the roller 1 12 of the present disclosure. In one example, the roller 1 12 may have cylindrical shape with an inner volume 210. A drive shaft 202 may be located in a center of the inner volume 210. It should be noted that FIG. 2 illustrates a cross section of the roller 1 12. Thus, the drive shaft 202 may be coupled to the roller 1 12 via an end cap or other similar type of mechanical coupling.

[0020] In one example, the drive shaft 202 may be coupled to the motor 1 14. The motor 1 14 may apply a force to the drive shaft 202 to rotate the drive shaft 202. The drive shaft 202 may then cause the roller 1 12 to rotate at a desired angular speed. The desired angular speed may be set to a speed that moves the ITB 120 to receive colored ink toner in proper alignment.

[0021] As noted above, the roller 1 12 of the present disclosure may include an additional mass 204. The additional mass 204 may be added to an inner portion 208 of an outer diameter 206 (e.g., the outer edge or surface) of the roller 1 12. In other words, the additional mass 204 may be added to fill a portion of the inner volume 210 of the roller 1 12. Said another way, the additional mass 204 may be added towards the center or towards the drive shaft 202 of the roller 1 12. As a result, the additional mass 204 may not change a diameter of the roller 1 12.

[0022] In one example, the additional mass 204 may be distributed evenly along a length“L” of the roller 1 12 and around a circumference of the roller 1 12. In other words, the roller 1 12 may have the same weight at any point along the length of the roller 1 12 and at any point around a circumference of the roller.

[0023] In one example, the amount of mass that is added may be enough mass to maintain an angular velocity of the roller 1 12 when the print media 108 contacts the roller 1 12. Said another way, the amount of mass that is added may be enough mass to increase a moment of inertia of the roller 1 12 to be greater than approximately 4.5 kilograms per meter squared (kg/m²).

[0024] In one example, the amount of mass that is added may be ten times a weight of the print media 108. For example, if the print media 108 has a mass of 13 grams per sheet, the additional mass 204 may have a mass of 130 grams. The 130 grams may be distributed evenly along the length of the roller 1 12 and around the circumference of the roller 1 12.

[0025] In one example, the additional mass 204 may be added by adding an additional amount of material to the roller 1 12. For example, the material may be a metal, a plastic, or a resin. In other words, the roller 1 12 may be fabricated from a plastic material and additional metal material may be added to the inner volume 210 of the plastic material.

[0026] In one example, the additional mass 204 may be added by filling the inner volume 210 of the roller 1 12. For example, the inner volume 210 may be filled with a plastic or resin. The plastic or resin can be in a fluidic form or small pellets to fill the inner volume 210.

[0027] FIG. 3 illustrates another apparatus (e.g., the imaging subsystem 104) with the roller 1 12. In one example, the apparatus may include the ITB 120 that receives layers of colored ink toner 1 18. The roller 1 12 (or cylindrical roller 1 12) may be coupled to the ITB 120. The motor 1 14 may be coupled to the roller 1 12. In one example, the roller 1 12 may include a drive shaft (e.g., the drive shaft 202 illustrated in FIG. 2) that is located inside of the roller 1 12 and coupled to the motor 1 14.

[0028] In one example, the motor 1 14 may move the ITB 120 via rotation of the roller 1 12. A print media 108 may be fed towards the ITB 120 to receive the layers of colored ink toner 1 18 to print a colored image onto the print media 108.

[0029] In one example, the roller 1 12 may have an additional mass 204 that is added to the roller 1 12. The additional mass 204 may increase a moment of inertia of the roller 1 12 such that the roller 1 12 may maintain a constant angular velocity when the ITB 120 contacts the print media 108.

[0030] The angular velocity may be a speed at which the roller 1 12 rotates as shown by an arrow 302. As discussed above, the angular velocity of the roller 1 12 may control an alignment of color planes of the layers of colored ink toner 1 18. The additional mass 204 may prevent the angular velocity of the roller 1 12 from changing or being affected by contact of the ITB 120 to the print media 108. As a result, the additional mass 204 on the roller 1 12 may help to eliminate CPR errors in the color printer 100.

[0031] In one example, the amount of mass that is added may be at least ten times a mass of the print media. The additional mass 204 may be distributed evenly across a length and circumference of the cylinder. Said another way, the shape of the additional mass 204 may be similar to the shape of the roller 1 12 (e.g., a cylindrical uniform mass). The additional mass 204 may be in the shape of a cylindrical uniform mass that has a same length and a diameter that fits inside of an inner volume of the roller 1 12.

[0032] FIG. 4 illustrates an example comparison of a roller 1 12 for an intermediate transfer belt 120 of the present controller to a previous roller design 412. The previous roller design 412 may have a drive shaft 402 inside of an inner volume 410. The previous roller design 412 may have a diameter 414 that is measured to an outer diameter 406.

[0033] The roller 1 12 of the present disclosure may be designed such that the roller 1 12 has the same diameter 414 as the previous roller design 412. As discussed above, the additional mass 204 may be added to an inner portion 208 of the outer diameter 206. In other words, the additional mass 204 may be added to add thickness in a direction towards the drive shaft 202. As a result, the diameter 414 of the roller 1 12 and the diameter 414 of the previous roller design 412 may be the same. [0034] Having the same diameter 414 may allow the roller 1 12 to be easily retrofitted into existing color printers without having to redesign the ITB 120, the control of the ITB 120 and the plurality of printheads 1 16, or the timing of the dispensing of the colored ink toner onto the moving ITB 120.

[0035] However, the design of the roller 1 12 with the additional mass 204 may increase the moment of inertia of the roller 1 12 to maintain an angular velocity of the roller 1 12 during contact with the print media 108 (e.g., directly or indirectly via the ITB 120 on the roller 1 12). For example, the amount of the additional mass 204 may be at least ten times a mass of the print media 108. The additional mass 204 may increase the mass of the roller 1 12 to increase the moment of inertia to approximately 4.5 kg/m² or more. In other words, the additional mass 204 may allow the roller 1 12 to have a moment of inertia that is greater than 4.5 kg/m².

[0036] As discussed above, maintaining the angular velocity of the roller 1 12 during contact with the print media 108 may eliminate CPR errors. Eliminating CPR errors may provide more accurately printed colored images on the print media 108 in the color printer 100.

[0037] It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. 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.

Claims

1. An apparatus, comprising:

a driving motor;

a drive shaft coupled to the motor; and

a cylindrical roller coupled to the drive shaft to move an intermediate transfer belt of a color printer, wherein the cylindrical roller has an amount of mass added to an outer diameter of the cylindrical roller to provide a moment of inertia that is greater than 4.5 kilograms per meter squared (kg/m²).

2. The apparatus of claim 1 , wherein the amount of mass added is at least ten times a mass of a print media that is used.

3. The apparatus of claim 1 , wherein the amount of mass added is distributed evenly across a length and a circumference of the cylindrical roller.

4. The apparatus of claim 1 , wherein the amount of mass is added by adding an additional amount of material used to fabricate the cylindrical roller.

5. The apparatus of claim 4, wherein the additional amount of material is added towards a center of the cylindrical roller.

6. The apparatus of claim 1 , wherein the amount of mass is added by filling an internal volume of the cylindrical roller with a material.

7. The apparatus of claim 6, wherein the material comprises a plastic or a resin.

8. An apparatus, comprising:

an intermediate transfer belt (ITB) to receive layers of ink toner;

a cylindrical roller coupled to the ITB; and

a motor coupled to the cylindrical roller to move the ITB via rotation of the cylindrical roller, wherein a print media contacts the ITB to receive the layers of ink toner and the cylindrical roller has an added amount of mass to maintain a constant angular velocity when the ITB contacts the print media.

9. The apparatus of claim 8 wherein the layers of ink toner comprises layers of different colored ink toner and the constant angular velocity controls an alignment of color planes of the layers of different colored ink toner.

10. The apparatus of claim 8, wherein added amount of mass comprises at least ten times a mass of the print media.

1 1. The apparatus of claim 8, wherein the added amount of mass is distributed evenly across a length and a circumference of the cylindrical roller.

12. The apparatus of claim 8, wherein the added amount of mass is added by adding a cylindrical uniform mass to an inner volume of the cylindrical roller.

13. A color printer, comprising:

a feeder to feed a print media;

an imaging subsystem to print a color image onto the print media, wherein the imaging subsystem, comprises:

an intermediate transfer belt (ITB) to receive layers of different colored ink toner;

a cylindrical roller coupled to the ITB; and

a motor coupled to the cylindrical roller to rotate the cylindrical roller at a desired angular velocity, wherein rotation of the cylindrical roller moves move the ITB towards the print media to transfer the different colored ink toner onto the print media, wherein the cylindrical roller maintains the desired angular velocity via an added amount of mass when contacting the ITB contacts the print media; and

a stacker to receive the print media after the color image is printed onto the print media.

14. The color printer of claim 13, wherein the added amount of mass provides a moment of inertia for the cylindrical roller that is greater 4.5 kilograms per meter squared (kg/m²).

15. The color printer of claim 13, the added amount of mass is evenly distributed across a length of an inner volume of the cylindrical roller.