Patent Application
20130188984
Embodiments are related to printing equipment, copy machines, Xerographic machines, Xerography, fans, and ducts.
Air is often blown into rooms, buildings, machines, and machine cavities to provide cooling. The airflow can introduce noise, such as acoustic noise, vibration, or uneven cooling. The noise usually goes unnoticed or is otherwise tolerated. However, there are situations wherein such noise results in problems that noticeably reduce the quality. One such situation is the airflow into certain models of printing machines, copy machines, and Xerographic equipment. Systems and methods for minimizing the impact of noise resulting from air flowing into copy machines are needed.
Aspects of the embodiments address limitations and flaws in the prior art by conditioning the airflow such that it does not noticeably impact printing and duplication processes.
In the interests of brevity, the term “printer” encompasses those machines used for printing and/or copying. Most printers are more sensitive to noise at some frequencies than at other frequencies. When noise is introduced into the system, particularly at those sensitive frequencies, print quality suffers. As with most machines, various printing operations occur at certain rates and thereby at certain frequencies. Noise at or near those frequencies or at multiples of those frequencies can result in noticeable “beat frequencies” that appear in the final product. For example, a 292 Hz banding problem has been observed in the output of a printer model. 292 Hz at first seems arbitrary, but the problem is very real when the printer or print quality is particularly sensitive to noise at that frequency.
On investigation, the noise source in the current example was found to be a centrifugal air blower spinning a 6 blade impeller at 2920 RPM. Each fan blade produces a slight pulse in the otherwise steady airflow such that the pulses occur at 292 Hz. The 292 Hz pulses were transmitted to a Xerographic chamber via the air supply hoses and ducts where they interacted with other printing operations to produce noticeable banding. Supply chain logistics indicated that changing the blower design was non trivial. Furthermore, a different blower would have introduced noise at other frequencies with possible problems that were yet to be diagnosed.
It is therefore an aspect of the embodiments to provide an acoustic cavity that conditions the airflow produced by the blower. Acoustic cavities can be designed to exhibit specific properties. In the current embodiments, the acoustic chamber is designed to dampen the pulses in the airflow at the frequency produced by the blower. The conditioned airflow then flows through a duct into a chamber of the printer to thereby produce printings that are not degraded by the airflow noise produced by the blower.
The accompanying figures, in which like reference numerals refer to identical or functionally similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the present invention and, together with the background of the invention, brief summary of the invention, and detailed description of the invention, serve to explain the principles of the present invention.
The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate embodiments and are not intended to limit the scope of the invention.
An acoustic cavity conditions the air flowing from a blower to reduce noise in the airflow. The air flowing directly out of the blower exhibits pulses produced by each impeller blade or fan blade. The airflow noise is thereby induced at certain frequencies. Printing operations inside a printer can also occur at specific frequencies. Introducing the airflow directly into certain areas of a printer can result in the noise frequencies and printing frequencies to combine and produce noticeable printing artifacts. An acoustic cavity tuned to dampen the airflow noise can condition the airflow and eradicate the printing artifacts.
The airflow 105 passes into an acoustic cavity 106 that filters out the pulses 104 to thereby produce a conditioned airflow 107 that is fed by a delivery duct 108 into an inner chamber 109 of a printer 101.
An acoustic cavity can be specifically designed to filter the pulses out of air flowing from a known blower design being operated at a known rate. The air flowing from the blower can be measured to determine its flow rate, pulse frequency, and pulse amplitude. Alternatively, the air flowing from the blower can be calculated or modeled. In many cases, the manufacturer can provide air flow data. The acoustic chamber and the air flowing through it can be modeled by a variety of modeling software packages using techniques such as computational fluid dynamics.
The conditioned airflow 107 from the muffler 201 can then pass to and through a delivery duct 108 and into a Xerographic chamber 208. The conditioned airflow 107 can cool the Xerographic chamber 208 and can speed the setting of toner 211 printed onto media 210 such as paper.
The conditioned airflow can then be ducted into the evaporation chamber 307 where it can provide cooling and can help set or dry ink 306 printed onto media 210.
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.
