Method and system for remote-sensing ink temperature and melt-on-demand control for a hot melt ink jet printer
First Claim
1. A method for regulating the temperature of a hot melt ink for a thermal ink jet printer which includes the steps of:
- a. providing a selected material adjacent to a source of hot melt ink and having a refractive index which varies in a known manner as a function of temperature,b. projecting light onto a surface of said selected material and thereby reflecting light therefrom at an intensity level which is proportional to the temperature level within said hot melt ink,c. sensing the intensity level of said reflected light and generating a temperature control signal in response thereto, andd. processing said temperature control signal to a heater element for said hot melt ink for regulating the temperature thereof.
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Accused Products
Abstract
A method and system for regulating the temperature of a hot melt ink wherein light reflected from a phase change material adjacent to the ink is detected, and a closed loop control signal proportional to the intensity of the reflected light is generated. The control signal is applied to a heater element for the ink and provides good temperature control thereof. In addition, the phase change material is used to generate an ink level indication signal which is also processed in a closed loop servo system in order to provide control over levels of the hot melt ink during operation of an ink jet printhead. In the embodiment of the present invention for controlling both ink temperature and ink levels within a pen body housing, there is provided a means and method for simultaneously sensing the liquid level and temperature at the solid/liquid interface within the pen body housing. This is done by simultaneously detecting the reflectivity of separate phase change material components located within or adjacent to the pen body housing and then processing closed loop detection signals which are optically coupled by way of control logic from the separate phase change material components to one or more heater elements located adjacent to the pen body housing. The present invention is also directed to a new and improved pen body construction which is uniquely suited for implementing the above novel method and system. This construction employs a flex circuit, an ink jet printhead and a multiple sensor assembly mounted adjacent to one wall of the pen body housing.
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Citations
20 Claims
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1. A method for regulating the temperature of a hot melt ink for a thermal ink jet printer which includes the steps of:
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a. providing a selected material adjacent to a source of hot melt ink and having a refractive index which varies in a known manner as a function of temperature, b. projecting light onto a surface of said selected material and thereby reflecting light therefrom at an intensity level which is proportional to the temperature level within said hot melt ink, c. sensing the intensity level of said reflected light and generating a temperature control signal in response thereto, and d. processing said temperature control signal to a heater element for said hot melt ink for regulating the temperature thereof.
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2. A system for regulating the temperature of a hot melt ink for a thermal ink jet printer which comprises:
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a. means providing a selected material adjacent to a source of hot melt ink and having a refractive index which varies in a known manner as a function of temperature, b. means for projecting light onto a surface of said selected material and thereby reflecting light therefrom at an intensity level which is proportional to the temperature level within said hot melt ink, c. means for sensing the intensity level of said reflected light and generating a temperature control signal in response thereto, and d. means connected between said sensing means and a heater element for processing said temperature control signal to said heater element for said hot melt ink for regulating the temperature thereof.
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3. A method for simultaneously sensing the liquid level and temperature within a pen body housing to control a melt rate of a solid ink contained therein, the pen body housing including a plurality of heater elements located adjacent to the pen body housing, and a plurality of phase change material components, each of said components having a reflectivity and each of said components housing, the method comprising the steps of:
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a. detecting the reflectivity of each of the phase change material components to obtain detection signals; and b. processing the detection signals from the components to control the heater elements and in turn control the melt rate of the solid ink.
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4. A system for simultaneously sensing the liquid level and temperature within a pen body housing comprising
a. a plurality of phase change material components, each of the components having a reflectivity, and each of the components being located within or adjacent to the pen body housing; -
b. a plurality of heater elements located adjacent to the pen body housing; c. a solid ink having a melt rate; d. means for detecting the reflectivity of each of the phase change material components to obtain separate detection signals; e. means connected to the detection means for processing the separate detection signals to control the heater elements and in turn control the melt rate of solid ink. - View Dependent Claims (5, 6)
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7. A system for simultaneously controlling the temperature and level of liquid ink at a liquid/solid interface within a pen body housing, including, in combination:
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a. first phase change sensor component and second phase change sensor component mounted within or adjacent to the pen body housing adjacent the liquid/solid interface, b. ink temperature detection means optically coupled to said first phase change component, c. ink level detection means optically coupled to said second phase change component, d. a plurality of heater elements mounted adjacent said pen body housing and adjacent to solid ink therein, and e. closed loop feedback control means connected between outputs of said ink temperature detection means and said ink level detection means and said heater elements for providing closed loop control signals to said heater elements in response to changes in reflectivity at said first phase change material component and the second phase change material component.
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8. An ink jet pen useful for dispensing hot melt ink including, in combination:
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a. an ink container casing; b. a plurality of heater elements adjacent to the ink container casing; c. a heater block located adjacent a bottom wall of said ink container casing and an insulating member separating the bottom wall from said heater block; d. sensor assembly means for measuring ink temperature and ink level of said hot melt ink, said sensor assembly means being affixed to said ink container casing, and having therein an ink temperature sensor and as an ink level sensor, both sensors operative in response ink within the ink container casing such that an optical property of the ink level sensor depends upon a level of said hot melt ink; and e. process control logic means connected between the sensor assembly means and heater elements for generating closed loop process control signals to the separate heater elements to thereby control the ink level and temperature of ink within the casing. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification