Patent Application
20120189370
The presently disclosed embodiments generally relate to continuous feed printing environments, and more particularly, to media handling during printing processes.
A continuous feed (CF) printer prints on a band/roll of paper, which is separated into single sheets after printing. Many industries, such as banks, insurance companies, and print shops use CF printing systems for printing items such as forms and invoices. These systems generally provide high-speed prints with fewer registration errors.
A typical CF printing system transports significant amount of paper along its media path. The term “media path” refers to the route followed by media, such as paper, through an imaging-forming system. In the CF system, the media path includes equipment such as shafts, rollers, and diverting mechanisms, all used for transporting media through the system.
Along the media passage, media imaged with ink droplets passes through a radiant heater. As the media passes through the radiant heater, the heat causes the ink to further melt and flow, thereby fusing the ink to the media and forming an image. During the heating process, if the media comes in direct contact with the radiant heater or comes too close to the radiant heater, the media may ignite.
In addition, a fault may occur in the CF printers, causing the media to slow down while passing through the radiant heater. The slow speed may cause the media to catch fire in the event that it remains underneath the radiant heater for a prolonged time.
It would be highly desirable to protect the media from catching fire and resulting in any accident.
The present disclosure describes a system for protecting media in an image-forming device. The system includes a heating element for heating the media, and a media path adjacent to the heating element. The media is transported in the image-forming device along the media path. The system also includes a barrier assembly having one or more non-flammable restraint threads and a spring-tensioned positioner. The restraint threads are mounted between the heating element and the media path, and the spring-tensioned positioner assembly maintains the restraint thread in a fixed position.
The following detailed description is made with reference to the figures. Preferred embodiments are described to illustrate the disclosure, not to limit its scope, which is defined by the claims. Those of ordinary skill in the art will recognize a number of equivalent variations in the description that follows.
The present disclosure describes various embodiments of a system providing a guard for media in an image-forming device, such as a continuous feed printer. The media moves along a media path having equipment for transporting the continuous media. During transportation, a heating element heats the media along with the ink droplets deposited on the media for forming an image on the media.
For purposes of description, the present disclosure is discussed in relation to continuous feed printing systems; those skilled in the art, however, will appreciate that the subject matter disclosed may be applicable to any image-forming device that may face media damaging issues. The term “media” used in the present disclosure refers to continuously fed media of paper, plastic, or other suitable material.
The printhead assembly 104 discharges ink droplets directly onto the media 112 as the media 112 moves through the print zone 116. The printhead assembly 104 receives the ink from an ink supply assembly 117. Once the ink droplets are deposited, the media 112 moves through the media heating assembly 106. The media heating assembly 106 includes one or more heating elements 118 that radiate heat onto the media 112. The media 112 and the ink droplets on the media 112 absorb this radiation. The radiation further melts the ink droplets, making the ink flow and fuse to the media 112. The fused ink forms the desired image on the media 112. It will be evident to those skilled in the art that the media 112 is heated at a suitable color temperature known in the art.
The heated media 112 then passes through the fixing assembly 108 for permanently securing the desired image to the media 112. Specifically, the fixing assembly 108 flattens the heated ink droplets on the media 112 by applying pressure and heat, thereby permanently fixing the image on the media 112.
A barrier assembly 210 is mounted between the heating element 118 and the media 112 transported along the media path 114. The barrier assembly 210 includes one or more non-flammable restraints such as a restraint thread 212. The restraint thread 212 is mounted adjacent to the media path 114 near a leading edge and a trailing edge of the heating element 118 so that the restraint thread 212 remains at a fixed position. The leading edge refers to the edge from where the media 112 arrives underneath the heating element 118 from the media supply assembly 102 (
To maintain the restraint thread 212 in a fixed position, the barrier assembly 210 includes a spring-tensioned positioner assembly 214 perpendicular to the media path 114. In the present embodiment, the positioner assembly 214 includes a first positioner 216 and a second positioner 218. As shown, the first and the second positioners 216 and 218 are located near the leading and trailing edges of the heating element 118 respectively, perpendicular to the media path 114. The positioner assembly 214 holds the restraint thread 212 in a fixed position from both ends for preventing the restraint thread 212 to loosen. Specifically, the positioner assembly 214 engages the restraint thread 212 by clamping and supporting the thread 212 at a fixed position above and parallel to the web media 112, and applying tension to the thread 212. The diameter of the restraint thread 212 lies within a range of approximately 0.020 inches to 0.025 inches. The referenced diameter range is small enough to prevent the restraint thread 212 from casting a shadow on the media and enables uniform heating of the media 112.
In the operating position (
Apart from a single restraint thread 212, in an alternate embodiment, the barrier assembly 210 may include a number of restraint threads 212, arranged to form a mesh 300, illustrated in
Further, in the mesh 300, the distance between the restraint threads 212 lies within a range of approximately ¾ inch to 3 inches. This range is large enough to prevent any interference during the heating of the media 112, thereby enabling uniform heating of the media 112 by the heating element 118.
The restraint thread 212 is composed of at least one flame-resistant material. The flame-resistant material may be a fiberglass material, an inconel material, or a combination of the fiberglass and inconel materials. Any other suitable flame-resistant material known in the art may also be used for manufacturing the restraint thread 212.
In the present embodiment of the disclosure, the restraint thread 212 is composed of both fiberglass and inconel material. Specifically, the thread 212 is formed as a composite, with inconel embedded in fiberglass.
As known in the art, the fiberglass material is used for applications requiring intermediate capability up to 790° C. The fiberglass material thus provides a high thermal resistance. Inconel material adds strength to the restraint thread 212.
In addition, the inconel material is electrically conductive and forms a component of an electrical circuit in the image-forming device 100. Because the inconel material forms a part of the electrical circuit, a breakage in the restraint thread 212 breaks the circuit of the image-forming device 100, thereby resulting in a fault in the image-forming device 100.
On detection of a fault, the heating panels 208 retract to the non-operating position at a right angle (90 degrees) from the operating position. Specifically, the actuator 204 retracts the heating panels 208 to move the heating element 118 away from the media 112. This operation discontinues the function of the heating element 118 and prevents the thermal heating of the media 112. Accordingly, the non-operating position precludes the ignition of the media 112 even though the media 112 remains under the heating assembly 106 for a long time.
It should be noted that the description below does not set out specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, designs and materials known in the art should be employed. Those in the art are capable of choosing suitable manufacturing and design details.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be desirably 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.
