Printing images or text on printable media in a printer includes various media processing activities, including pick-up, delivery to a print engine, printing, and conditioning of sheets of printable media. Conditioning may involve heating and pressing the sheets through or past a heated conveying component, such as a heated pressure roller (HPR), to remove liquid (for printers using liquid ink), to remove wrinkles or curvature, and/or to reform or flatten fibers in the sheets. Other examples of conditioners may include a resistive heating element and a heating lamp.
Features of the present disclosure are illustrated by way of example and not limited in the following figure(s), in which like numerals indicate like elements, in which:
For simplicity and illustrative purposes, the principles of the present disclosure are described by referring mainly to examples thereof. In the following description, numerous specific details are set forth in order to provide an understanding of the examples. It will be apparent, however, to one of ordinary skill in the art, that the examples may be practiced without limitation to these specific details. In some instances, well known methods and/or structures have not been described in detail so as not to unnecessarily obscure the description of the examples. Furthermore, the examples may be used together in various combinations.
Many printers, such as inkjet printers, may include a heated system that may, for example, help reduce media curl and ink smear, and may improve quality in printed output. Heated systems may include resistive heating elements, fusers, pressure rollers, calendaring rollers, etc. Heated systems may include a heat generating device that, when a media is to be conditioned may be supplied with a maximum amount of available power to quickly ramp up the temperature in the heated system to a target temperature. By supplying the maximum amount of available power during the ramp up period, the temperature may be increased to the target temperature in a minimized length of time. Following the ramp up period, the temperature in the heated system may be maintained at or near the target temperature for a duration of a print job, e.g., during a steady-state operation period using a maintenance control signal that may include zero power events interspersed with power application events.
Some heated systems may include various heating components, such as a heating lamp and a resistive heating element or multiple heating lamps and/or multiple resistive heating elements. A heating lamp may have a short thermal time constant, whereas a resistive heating element may have a high thermal-time constant or vice versa and the conditioning mechanisms they are heating may have longer or shorter time constants relative to each other. During the steady-state operation period, power may be applied to the heated system components in periods (or equivalently, cycles). Some or all of the periods may include both high-power events, when maximum cumulative power is applied to the various heating elements, and zero power events during which power is not applied to the heating components. The application of power to the heating components, e.g., heating lamps and the resistive heating elements, may be cycled with the zero power events to maintain the temperatures of conditioning mechanisms in the heated system within respective predefined temperature ranges. That is, continuous application of full power to the heating lamp and/or resistive heating elements during the steady-state power application cycle may cause temperatures in the heated system to be above respective predefined temperature ranges.
However, inclusion of both high power and zero power events during the power application cycles may cause an uneven or choppy delivery of power to the heating components. The uneven or choppy delivery of power may cause flicker, e.g., power-line flicker, to occur. Flicker may be defined as a visible change in brightness of lamps due to rapid fluctuations in the voltage of a power supply. For instance, a voltage drop may be generated over a source impedance of a grid by the changing load current of the heating lamps and/or the resistive heating elements. In a printer, the zero power events may cause flicker in lights that may share the same circuit path as the printer. In addition, or alternatively, the uneven or choppy delivery of the power to the heated system may negatively affect power line harmonics and conducted electro-magnetic compatibility (EMC) emissions.
Disclosed herein are apparatuses, heated systems, methods, and computer readable mediums that may control the application of power to minimize a warmup time of components in a heated system while smoothing the delivery of power to the components in the heated system, e.g., while reducing flicker caused by the application of power to the components. That is, a processor may select a sequencing and stacking group from a plurality of sequencing and stacking groups based on a requested power demand of heating components in a heated system. Each of the plurality of sequencing and stacking groups may include a sequencing and stacking arrangement that may be used to supply power to the components depending upon, for instance, a variance between a detected temperature and a preset temperature. The sequencing and stacking arrangements may be determined through testing and may be defined for each of the sequencing and stacking groups according to, for instance, arrangements that may result in a minimized amount of time used to reach a warmup temperature while smoothing the delivery of power to the components in the heated system. For instance, the arrangements may result in a reduced or minimized flicker caused by the application of power to the heated system components.
According to examples, the processor may compare the requested power demand to thresholds and may select the sequencing and stacking group to be used in supplying power to the heated system components based on which of the thresholds the requested power demand exceeds and which of the thresholds the requested power demand falls below. In addition, the processor may control application of power to the heated system components according to the selected sequencing and stacking group.
According to examples, by reducing flicker caused by the application of power to the heated system components as disclosed herein, the heated system components may pass flicker testing requirements, e.g., may comply with international standards pertaining to flicker testing.
Throughout the present disclosure, the terms “a” and “an” are intended to denote one of a particular element or multiple ones of the particular element. As used herein, the term “includes” means includes but not limited to, the term “including” means including but not limited to. The term “based on” may mean based in part on.
Reference is first made to
Generally speaking, the apparatus 100 may be a computing apparatus, e.g., a personal computer, a laptop computer, a tablet computer, a smartphone, or the like. In these examples, the apparatus 100 may be separate from a heated system and may communicate instructions to the heated system over a direct or a network connection. In other examples, the apparatus 100 may be part of the heated system. In these examples, the apparatus 100 may be part of a control system of the heated system and may communicate instructions to components of the heated system, for instance, over a communication bus. Examples of the heated system are described in greater detail with respect to
As shown in
The processor 102 may fetch, decode, and execute the instructions 112 to determine a requested power demand for a first heating component and a second heating component. In some examples, the first heating component, which may be a heating lamp, and the second heating component, which may be resistive heating element, may be in a ramp up state in which the first heating component and the second heating component may be turned on after an idling period where the heating system is not in use and the heating system drops in temperature to a temperature within some percentage of, and in some examples, as low as, the ambient temperature. In another example, the heating system may be in a maintenance state in which the first heating component and the second heating component may operate to maintain a temperature of or within the heated system within a predefined temperature range.
When in the ramp up state, the first heating component and/or the second heating component may have a higher requested power demand than when in the maintenance state. That is, for instance, prior to or during portions of the ramp up state, the variance between the actual detected temperature in the heated system and a preset, e.g., setpoint, temperature may be relatively larger than the variance between the actual detected temperature and the preset temperature when the heated system is in the maintenance state. Thus, the processor 102 may determine the requested power demand based on the operating condition, e.g., a variance of a detected temperature and a preset temperature of the heated system.
The processor 102 may fetch, decode, and execute the instructions 114 to compare the requested power demand to a first threshold. In examples, the requested power demand may be based on the variance between a current detected temperature and a preset temperature, e.g., the processor 102 may function as a proportional controller. In an example, the first threshold may be based on the maximum power available in an alternating current (AC) source of the heated system. In an example, the maximum power available from an AC source may be determined as a product of the voltage and current supplied by the AC source as may be measured by a detector (not shown). In addition, or in other examples, the requested power demand may be based on a proportional, integral, derivative (PID) control, which may take into account the variance in the current detected temperature and the preset temperature, rate of temperature change is applied, cumulative temperature error, and/or the like. In these examples, the processor 102 may function as a PID controller.
The processor 102 may fetch, decode, and execute the instructions 116 to select a sequencing and stacking group of a plurality of sequencing and stacking groups for the first heating component and the second heating component corresponding to a result of the requested power demand being compared to the first threshold. In an example, the selected sequencing and stacking group may include a particular sequence of activating and deactivating the first heating component and the second heating component to both cause the first heating component and the second heating component to be warmed to a level that causes the heated system to have a certain temperature while smoothing power delivery, e.g., reducing flicker. Also, the selected sequencing and stacking group may include particular timings at which the first heating component and the second heating component are to be activated and/or deactivated. The particular timings may include concurrently activating and/or deactivating the first heating component and the second heating component. The selected sequencing and stacking group may further include the amount of power that is to respectively be supplied to the first heating component and the second heating component during the times at which the first heating component and the second heating component are activated. In addition, each of the plurality of sequencing and stacking groups may include particular sequencing and stacking arrangements.
For instance,
In the first sequencing and stacking group shown in graph 200 (
In the second sequencing and stacking group shown in graph 250 (
The particular sequencing and stacking arrangements included in the plurality of sequencing and stacking groups may be based upon sequencing and stacking arrangements that may result in a smoothing of power delivery, e.g., reduction of flicker, while maintaining detected temperatures within a desired temperature range. According to examples, the particular sequencing and stacking arrangements may be determined through testing of various threshold conditions, e.g., variance thresholds from intended temperatures or error levels. Thus, for instance, particular sequencing and stacking arrangements that may have resulted in a minimized warmup time for the first and second heating components while also smoothing power delivery, e.g., minimizing flicker, caused by the application of power to the first and second heating components for various threshold conditions and/or error levels may be determined through testing. The sequencing and stacking groups may be generated from the determined particular sequencing and stacking arrangements and may be stored with respect to various threshold conditions, e.g., in a lookup table. Generally speaking, the sequencing and stacking group shown in the graph 250 (
By way of example, there may be three temperature variance error levels, e.g., high, medium, and low. That is, when the difference between the actual detected temperature and the intended temperature exceeds a first threshold, the temperature variance level may be high, when the difference exceeds a second threshold and is below the first threshold, the temperature variance level may be medium, and when the difference is below the second threshold, the temperature variance level may be low. In addition, a different pulse width modulation (PWM) for supplying power to the first and second heating components may be assigned for each of the temperature variance levels. For instance, for the high temperature variance level, the PWM may be greater than 80%, for the medium temperature variance level, the PWM may be between 40% and 80%, and for the low temperature variance level, the PWM may be lower than 40%. In other examples, the processor 102 function as a PID controller as discussed herein.
The processor 102 may fetch, decode, and execute the instructions 118 to control application of power to the first heating component and the second heating component according to the selected sequencing and stacking group. The application of power according to the selected sequencing and stacking group may result in a smoothing of power delivery and may also result in a reduction in flicker caused by the application of the power to the first heating component and the second heating component.
Reference is now made to
The heated systems 300, 400 may each be a system in which an object, such as a sheet of media, may be heated. According to examples, the heated system may be part of a media printing system (not shown) in which the heated system may condition, e.g., apply heat, to media upon which a printing medium, e.g., ink, toner, or the like, has been applied. That is, for instance, the heated system may be positioned downstream of a print engine of the media printing system. In other examples, the heated system may be implemented to condition other types of objects, e.g., 3D printed objects, painted objects, or the like.
As shown in
In examples, the heating lamp 320 and the resistive heating element 318 may heat a sheet of media 402. For instance, the heated systems 300, 400 may include a first conveying component coupled to engage a second conveying component to receive, contact, heat, and convey the sheet of media 402. In this example, the first conveying component may be a heated belt 404 and the second conveying component may be a driven roller, which may be driven to rotate by a motor (not shown). Although not shown, the heat generating device 308 may include a second resistive heating element and a second heating lamp.
The heated system 400 may also include a media sensor 408 disposed along a media path 410, a platen 412, and a platen support structure 414 to support and guide the belt 404, and a chassis 416. In width, the belt 404, roller 406, platen 412 and the platen support structure 414 may extend “into the page” of
The heating lamp 320 may be a radiant heater, which may include a heating element 418. The heating lamp 320 may extend within the belt 404 to heat a heating zone 420 of the belt 404 by thermal radiation. The heating zone 420 may include the portions of the belt 404 that are in the field of view of the heating lamp 320 at any given moment in time. In various examples, the heated system 320 may include multiple heating lamps, which may be designed and arranged to heat different portions of the belt 404. During operation, the roller 406 may conductively be heated by contact with the belt 404, and a length or a piece of media 402, when present, may be heated by contact with the belt 404 and the roller 406. In some examples, the heating lamp 320 may be disposed outside of the belt 404. The heating element 320 may be a halogen-type lamp, but other types of lamps or other types of heating elements may be used to heat the belt 404 and/or the roller 406.
The belt 404 and the roller 406 may contact and press against each other along a nip region 422 to receive and convey the media 402. The nip region 422 may extend along the shared width of the belt 404 and the roller 406. During operation, rotational movement of the roller 406 may drive the belt 404 to rotate by friction or by gearing, with or without media, in between the roller 406 and the belt 404. In addition, the temperature sensor 304 may monitor the temperature of the belt 404 to facilitate control by the processor 102 of the heating lamp 320. The temperature sensor 304 may be a non-contacting thermistor located outside and below the belt 404. Although a single temperature sensor 304 is depicted in
The resistive heating element 318 of the heat generating device 308 may generate heat that may be directed to the sheet of media 402 as the media 402 is fed to further condition the media 402. For instance, the resistive heating element 318 may include a resistive component that may become heated as a current is applied through the resistive component.
The apparatus 100 may control the heating lamp 320 and the resistive heating element 318 via the control mechanism 306 and may receive input from the temperature sensor 304. Particularly, for instance, the apparatus 100 may determine that the heated system 300, 400 is to be implemented to apply heat to an object, for instance, a sheet of media 402. The apparatus 100 may make this determination based on receipt of an instruction from a processor in a printing device, based on receipt of a signal from the media sensor 408, or the like.
Based on the determination, the apparatus 100 may initiate supply of power to the heating lamp 320 for a period of time and may initiate supply of power to the resistive heating element 318 as discussed in detail herein. The apparatus 100 may directly control the supply of power to the heating lamp(s) 320 and/or the resistive heating element(s) 318, e.g., without implementing the control mechanism 306. In addition, although the control mechanism 306 is depicted as being separate from the apparatus 100, in some examples, the control mechanism 306 may be integral with the apparatus 100. That is, for instance, the control mechanism 306 may be a feedback controller that the apparatus 100 may execute or implement. According to examples, the apparatus 100, and more particularly, the processor 102 may control application of power to the resistive heating element 318 and the heating lamp 320 according to a selected sequencing and stacking group as discussed herein to smooth power delivery during application of the power to the resistive heating element 318 and the heating lamp 320.
The non-transitory computer readable medium 110 may have stored thereon machine readable instructions 330-332 in addition to the instructions 112-118 that the processor 102 may execute. The processor 102 may fetch, decode, and execute the instructions 330 to generate a PWM signal to control the resistive heating element 318. The processor 102 may fetch, decode, and execute the instructions 332 to hold the PWM signal at a particular level until an actual resistive heating element 318 or heated apparatus (e.g., conditioning mechanism) is at or above a preset resistive heating element temperature.
Reference is now made to
As shown in
Various manners in which the processor 102 may operate are discussed in greater detail with respect to the methods 600 and 700 respectively depicted in
With reference first to
At block 604, the processor 102 may select a sequencing and stacking group of a plurality of sequencing and stacking groups for the first heating component and the second heating component corresponding to the requested power demand, each of the plurality of sequencing and stacking groups including a different sequencing and stacking arrangement for activation of the first heating component and the second heating component. As discussed herein, the processor 102 may select the sequencing and stacking group based upon whether a PWM value exceeds a first threshold, whether the PWM value falls below the first threshold but exceeds a second threshold, or whether the PWM value falls below the second threshold. Based on the PWM value exceeding the first threshold, as may occur during a ramp up phase of the heated system 300, 400, the processor 102 may select the sequencing and stacking group that may cause delivery of a predefined maximum power to the second heating component. However, based on the PWM value falling below the first threshold but exceeding a second threshold, as may occur during a maintenance phase of the heated system 300, 400, the processor 102 may select the sequencing and stacking group that may cause delivery of a predefined minimum power to the second heating component. As discussed above, the selected sequencing and stacking group may result in a smoothing of power delivery, which may also result in a reduction or minimization of flicker caused by the application of power to the first and second heating components.
At block 606, the processor 102 may control application of power according to the selected sequencing and stacking group to the first heating component and the second heating component to, for instance, minimize warmup time of the first and second heating components while smoothing power delivery, e.g., reducing flicker.
In an example, the processor 102 may determine the sequencing and stacking group based on the thermoelectrical coefficient of the first heating component and/or the thermoelectrical coefficient of the second heating component. For example, the heating lamp 320, during the ramp up phase, may call for or use less power when the internal resistance of the heating lamp 320 is low and more power as the internal resistance of the heating lamp 320 stabilizes.
In an example, the processor 102 may determine the sequencing and stacking group based on the first page out time. In an example, the processor 102 may determine the sequencing and stacking group based on the maximum power level of a power source available for the first heating component and the second heating component.
Turning now to
At block 704, the processor 102 may compare the requested power demand to a first threshold. As discussed herein, the first threshold may be based on a temperature variance between an actual detected temperature and a desired temperature or a PWM value from a PID controller. At block 706, the processor 102 may determine whether the requested power demand is greater than the first threshold. Based on a determination that the requested power demand is greater than the first threshold, at block 708, the processor 102 may select a first sequencing and stacking group of a plurality of sequencing and stacking groups. However, based on a determination that the requested power demand is less than the first threshold, at block 710, the processor 102 may determine whether the requested power demand is greater than a second threshold. Based on a determination that the requested power demand is greater than the second threshold, the processor 102 may select, at block 712, a second sequencing and stacking group of the plurality of sequencing and stacking groups.
However, based on the determination at block 710 that the requested power demand is less than the second threshold, at block 714, the processor 102 may select a third sequencing and stacking group of the plurality of sequencing and stacking groups. At block 716, the processor 102 may apply the selected one of the first, second, or third sequencing and stacking group.
Some or all of the operations set forth in the methods 600 and 700 may be included as utilities, programs, or subprograms, in any desired computer accessible medium. In addition, the methods 600 and 700 may be embodied by computer programs, which may exist in a variety of forms both active and inactive. For example, they may exist as machine readable instructions, including source code, object code, executable code or other formats. Any of the above may be embodied on a non-transitory computer readable storage medium.
Examples of non-transitory computer readable storage media include computer system RAM, ROM, EPROM, EEPROM, and magnetic or optical disks or tapes. It is, therefore, to be understood that any electronic device capable of executing the above-described functions may perform those functions enumerated above.
Turning now to
The non-transitory computer readable storage medium 800 may have stored thereon machine readable instructions 802-810 that a processor, e.g., the processor 102, may execute. The machine readable instructions 802 may cause the processor 102 to, receive a requested power demand for a heating lamp 320 (first heating component) and the resistive heating element 318 (second heating component). The machine readable instructions 804 may cause the processor 102 to compare the requested power demand to a first threshold. The machine readable instructions 806 may cause the processor 102 to, based on the requested power demand exceeding the first threshold, select a first sequencing and stacking group of a plurality of sequencing and stacking groups for the resistive heating element 318 and the heating lamp 320.
The machine readable instructions 808 may cause the processor 102 to, based on the requested power demand falling below the first threshold, select a second sequencing and stacking group of a plurality of sequencing and stacking groups for the resistive heating element 318 and the heating lamp 320. The machine readable instructions 810 may cause the processor 102 to control application of power to the resistive heating element 320 and the heating lamp 318 according to one of the first or the second selected sequencing and stacking group to smooth power delivery. In some examples, the non-transitory computer readable medium 800 may include additional instructions that may cause the processor 102 to generate a PWM signal to control the heating lamp 320 and the resistive heating element 318. For example, the processor 102 may generate a PWM signal to control the heating lamp 320 and the resistive heating element 318 according to the selected sequencing and stacking group.
Although described specifically throughout the entirety of the instant disclosure, representative examples of the present disclosure have utility over a wide range of applications, and the above discussion is not intended and should not be construed to be limiting but is offered as an illustrative discussion of aspects of the disclosure.
What has been described and illustrated herein is an example of the disclosure along with some of its variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Many variations are possible within the spirit and scope of the disclosure, which is intended to be defined by the following claims—and their equivalents—in which all terms are meant in their broadest reasonable sense unless otherwise indicated.
Filing Document | Filing Date | Country | Kind |
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PCT/US2018/049247 | 8/31/2018 | WO | 00 |